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3D Static Strength Prediction Program Version 5.0.4 User`s Manual

1. eee 27 5 7 3 Body Segment Angle Dialog Box 3D Mode eee 28 5 7 4 Body Segment Angle Descriptions esee enne ener 29 5 7 4 1 Lower Leg Vertical Angle 2D and 3D Mode sss 29 5 7 4 2 Upper Leg Vertical Angles 2D and 3D Mode ss 29 5 7 4 3 Upper Arm Vertical Angles 2D and 3D Modes 30 5 7 4 4 Upper Arm Horizontal Angles 3D Mode Only 30 5 7 4 5 Forearm Vertical Angles 2D and 3D Modes esses 30 5 7 4 6 Forearm Horizontal Angles 3D Mode Only sees 31 5 7 4 7 Trunk Flexion Angle 2D and 3D Mode seen 31 5 7 4 8 Trunk Axial Rotation 3D Mode Only eere 32 5 7 4 9 Lateral Bending Angle 3D Mode Only eese 32 5 8 POSTURE PREDICTION 3D MODE ONLY eene 33 5 8 1 Introduction to the Inverse Kinematics Method of Posture Entry 33 5 9 2 Posture Prediction Dialog BOX do bt owe tended ute tavae MODUM IU 33 59 HOCKING MODE a O 34 5 10 UNDO REDO POSTURE CHANGE tado 35 SL HAND TOADS a e dede OE 35 5 11 1 Hand Force Vector Descriptions 2D Mode eene 35 5 11 2 Hand Load Entry 2D Mode ia 36 5 11 3 Hand Load Force Vector Descriptions 3D Mode oococonccccconcccnonccinoncconananinnnos 36 A
2. Univ of Michigan s 3DSSPP 5 0 0 Untitled File Task Input Display 3 Views Oblique View Reports About Front Top BE 3D Static Strength Prediction Program Version 5 0 LECTING CLOSE FROM THE CONTROL MENU OR CLICKING ON THE PRO GRAM WINDOW CLOSE BUTTON WILL RESULT IN EXITING THE CURRENT 3DSSPP SESSION A WARNING WILL APPEAR ONLY IF THE POSTURE OR TASK INPUTS HAVE BEEN MODIFIED SINCE THE LAST SAVE 3 2 ORTHOGONAL VIEW 3 VIEW WINDOWS The three orthogonal view posture entry windows display the posture being modeled in the top front and right side views Figure 3 2 The posture is displayed using stick figures so that joint angles are easily seen Each orthogonal view window has its own title bar which contains the direction of the view and has buttons on the right side for control ling the sizing of that window either convert to a button or enlarge to full screen for easier posture manipulation close is not allowed The joint angles of the hominoid can be directly manipulated by clicking any joint and dragging it to a new location New in 5 When the mouse cursor is over a selectable joint it will change from an arrow into a hand The name of the joint cur rently pointed to will be displayed in the status bar at the bottom of the main window Side Figure 3 2 Orthogonal View 3 View window Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Predicti
3. 1 3 BACKGROUND 3DSSPP is most useful in the analysis of the slow movements used in heavy materials han dling tasks since the biomechanical computations assume that the effects of acceleration and mo mentum are negligible Such tasks can be evaluated best by dividing the activity into a sequence of static postures and ana lyzing each individual posture To aid in posture entry an inverse kinematics algorithm was developed from research on the pre ferred postures of individuals manipulating loads with known hand positions This behavioral based algorithm is intended to provide a first approxima tion of the posture based on the specified hand posi tions and torques and forces on the hands and joints However the inverse kinematics algorithm may not yield a posture representative of the actual posture being modeled since the actual posture can be af fected by individual factors such as differences in body type postural preference and training as well as environmental factors such as the nature of the object being handled workplace obstructions trac Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 2 tion and the feet floor interface and worker apparel To minimize these effects only experienced work ers should be observed performing the tasks in ques tion Should additional posture modifications be necessary the program contains easy to use meth ods for altering the initial predi
4. Comment Page 55 value and a bar graph are shown The disc compres sion force predictions are compared with the Back Compression Design Limit BCDL 770 pounds or 3400 newtons and the Back Compression Upper Limit BCUL 1430 pounds or 6400 newtons as specified by NIOSH The back compression results should be inter preted with care Refer to Section 1 3 for technical details on the algorithms used to determine the disc compression forces and the following sections for the NIOSH guidelines used to establish the strength capability and disc compression limits Gender Male Percentile 50th Height 69 1 in Weight 176 4 lb m Percent of Population Capable Elbow Shoulder Torso Hip Knee Ankle Leg Loads Left 50 Right 50 Balance Acceptable Minimum Coef of Friction O 3DSSPP 5 0 0 Copyright 2005 The Regents of the University of Michigan ALL RIGHTS RESERVED Figure 9 3 Analysis summary report Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 56 9 2 2 1 BCDL and BCUL Limits The NIOSH Back Compression Limit notation has been revised to BCDL Back Compression De sign Limit and BCUL Back Compression Upper Limit as opposed to AL and MPL The limiting values are set forth in the Work Practices Guide for Manual Lifting NIOSH 1981 The BCDL guidelines are consistent with the biomechanical and psychophysical criteria
5. Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 10 you can skip to the next paragraph if you are al ready familiar with standard Windows program op eration New to Windows Note that the 3D or 2D in 2D mode button in the upper left hand cor ner is the Control Menu box when this button is clicked a menu appears which allows control over the location size and status of the entire program window The right hand buttons include minimize convert the program window to an entry on the windows status bar maximize alternate the program window be tween a full or partial screen display or close close the program window and quit the program The operation of the title bars of the five windows within the program window operate in similar fashion except that they control only their respective view not the entire program The main five windows 3 Views Oblique View and Status Window cannot be closed New to Windows Positioning the cursor over the program window borders will change the cursor to a different arrow shape If the left mouse button is then clicked and held the border can then be dragged to change the size of the window When adjusting the program window borders in this way two separate applications can be displayed e g 3DSSPP and a word processing program NEW TO WINDOWS PLEASE BE AWARE THAT DOUBLE CLICKING ON THE CONTROL MENU BUTTON SE
6. Joint angles see Body segment angles or Included joint angles Joint location report see Reports Joint moments report see Reports Knee Adjust by moving hips 12 Included angle see Posture Report L2 L3 LA L5 forces and moments 69 L4 L5 disc 3 L5 S1 disc see Disc compression force Definition 2 Forces and moments 69 Ligament strain see Ligament strain Location 66 Reported 58 Lateral bending see Body segment angles Length of barrier see Environment objects Barrier Ligament strain L5 S1 60 Lighting graphic display 52 Link lengths see Anthropometry Link weights see Anthropometry Locking mode 34 Lower arm angle see Body segment angles Lower leg angle see Body segment angles Lumbar rotated coordinate system 69 Lumbodorsal fascia 59 Maximum permissible limit MPL see NIOSH limits Mean strength 60 Menus pull down 10 Model type see Human figure Moments 67 New features 4 NIOSH limits Action limit AL 56 Disc compression guidelines 56 Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 80 Strength guidelines 56 Guidelines 56 Maximum permissible limit MPL 56 Oblique view 14 Menu see Menus Occupational Biomechanics 4 Opening files see File Open Orthogonal view see 3 View Output summary see Reports Analysis summary or see Windows Result status Pelvic rotation Adjustment 24 25 Reported 68 Percent capable see Strength pe
7. notation has been revised to the SDL Strength De sign Limit and SUL Strength Upper Limit as op posed to the AL Action Limit and MPL Maximum Permissible Limit The SDL designa tion is delimited by the green to yellow transition in the bar graphs and is set at 99 for men or 75 for women The SUL designation on the other hand is delimited by the yellow to red transition and is set at 25 for men or 1 for women The limiting values are set forth in the Work Practices Guide for Manual Lifting NIOSH 1981 The SDL guidelines are consistent with the bio mechanical and psychophysical criteria used to de velop the revised 1991 lifting equation Waters et al 1993 while the SUL are consistent with the cri teria used to develop the 1981 equation Because the 1991 version has moved from a three stage de cision matrix to a single lifting index in assessing the risk of low back pain these upper limits were not included as criteria for the 1991 version Fur ther discussion concerning the back compression design and upper limits as well as the basis for strength design and upper limits can be found in Occupational Biomechanics as mentioned previ ously 9 2 4 Leg Load and Balance The lower left corner of the screen reports the balance condition for the input posture The percentage load refers to the fraction of total weight body and load supported by that leg For example if the task involves a forward leaning pos
8. ture with the right foot forward then the right foot might be expected to bear a greater fraction of the overall load Conversely for a lateral bending left posture the upper torso weight and hand loads would be borne primarily by the left foot In addition to calculating the percent load on each foot the program calculates the center of pres sure COP of the forces applied to the supporting surfaces For standing these are the front and heel of the feet and for sitting these are the ischial tube rosities and back of the thighs or the feet Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 The center of pressure is compared to the Basis of Support and the Functional Stability Region not delimited on the graphic to determine if the bal ance condition is either ACCEPTABLE CRITI CAL or UNACCEPTABLE See Section 9 8 for definitions and the detailed balance reports 9 2 5 Required Coefficient of Ground Friction Horizontal forces at the L5 S1 vertebral disc are transmitted directly to ankle level since there is no horizontal external force entry at the lower extremi ties Therefore the ratio of horizontal forces at the L5 S1 level where upper extremity is assumed to be connected to the lower extremity to the sum of upper body weight lower body weight and vertical hand loads is the required coefficient of ground friction at the fee
9. L Internal Ob R Intemal Ob L External Ob R External Ob L Latis Dorsi R Latis Dorsi NN oo co OO oo mom Mom Armsin x In IES deo HE ie 33 16 3 46 14 46 14 Components Total 691 Shear lb Total 52 13 ae osterior hu EI ZO 28 21 Lateral 3DSSPP 5 0 0 Copyright 2005 The Regents of the University of Michigan ALL RIGHTS RESERVED Figure 9 5 3D Lowback Analysis Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 9 5 SAGITTAL PLANE LOWBACK ANALYSIS REPORT The sagittal plane low back analysis report Figure 9 6 displays low back data for the gender selected Positive muscle force values or segment weights indicate the downward direction of the forces acting on the vertebral disc Shear forces on the vertebral disc are due to the upper body weight posture and the horizontal hand forces When appropriate and known one standard deviation is displayed The L5 S1 disc compression force analysis is based on a model using the contraction forces from the Erector Spinae and Rectus Abdominus muscles Although this yields acceptable results for symmet ric lifts in the sagittal plane such results may un derestimate the disc compression force generated in asymmetric lifting Because asymmetric lifts re quire recruitment of additional torso muscles large asymmetric muscle acti
10. Strength capability see also Strength percent capable Strength percent capable 60 Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Analysis summary report 56 Concept 60 Limits see NIOSH limits Strength report see Reports Strength capabil ity Superimposed see Human figure Model types Supine see Hand orientation Support Selection 24 Feet 25 Seat type 25 Seated mode 25 Standing mode 25 Symmetry see Body segment angle Table see Environment objects Barrier Task Input menu see Menus Task input summary see Reports Task name task description 23 Thickness see Environment objects Barrier Tile now 43 Tiling 43 Title bars see Windows Top view see Windows 3 View Torso angles see Body segment angles or Posture report Transparent see Render Trunk angles see Body segment angles Type see Environment objects Barrier or Hand held objects Typefaces 6 Undo posture 35 Units English metric 24 Unlocking body segments see Locking mode Upper arm angles see Body segment angles Upper leg angle see Body segment angles Vectors force see Hand loads Vertical tilt see Camera Page 81 Wall see Environment objects Barrier Weight see Anthropometry Width see Environment objects Barrier or Hand held objects Zoom see Print preview Copyright 2005 The Regents of The University of Michigan ALL RIG
11. The val ues must be specified in the following order Left magnitude left vertical angle left horizon tal angle right magnitude right vertical angle and right horizontal angle HAN 15 5 20 85 222 15 80 5 14 7 EXPORT Command The EXPORT command initiates an analy sis and exports the results to the export file This command has no data items EXP Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Page 41 5 14 8 AUTOEXPORT Command The AUTOEXPORT command causes all subsequent ANT JOI and HAN commands to be followed by an analysis and exportation of result to the export file The data item is an integer digit representing the desired state of the command On is 1 and off is O AUT 1 5 14 9 Example Batch File 3DSSPPBATCHFILE COM COM DES 0 Sample Batch Suzy Anybody Nothing very meaningful AUTO ANT 1264 2 115 0 JOI 85 25 10 80 145 70 70 20 5 85 140 70 40 5 10 HAN 15 20 85 22 15 80 4 EXP COM COM COM Enable autoexport and do 5 differ ent hand loads AUT 1 DES 0 Loads A Suzy Anybody Hand loads case A HAN 15 2085 15 1580 4 DES 0 Loads B Suzy Anybody Hand loads case B HAN 20 20 85 20 15 80 DES 0 Loads C Suzy Anybody Hand loads case C HAN 25 20 85 25 15 80 DES 0 Loads D Suzy Anybody Hand loads case D HAN 30 20 85 30 15 80
12. and click Set Startup Task to Cur rent 4 7 RESET STARTUP TASK New in 5 Use this option to restore the startup task to the factory defaults the same startup pa rameters that come with a new install of 3DSSPP Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 4 8 PRINT ACTIVE WINDOW Five printing options are possible in 3DSSPP Print ing analysis screens and individual windows using the Print Active Window command printing a se ries of reports using the Print Reports command generating custom reports using the Copy to Clipboard commands and a word processing pro gram printing the Windows desktop or printing the 3DSSPP main program window The first option will be discussed here Instructions for printing a series of reports can be found in Section 9 15 Print ing by copying to the clipboard is found in Section 4 15 The final two printing options are found in Sections 4 11 and 4 12 In each case printing is handled through Windows which does not support printing more than one window at a time Please consult the Windows documentation for additional details on these options To print a specific view or report window 1 Make sure the item to be printed is in the cur rently active window the window with the highlighted status bar not the main program title bar This can also be verified by using File Print Preview Section
13. input data file must follow a specific format and JOINT ANSE don must include all of the information normally speci HANDLOADS HAN fied for an analysis The results of the analyses are output to an export file see Section 9 16 EXPORT EXP AUTOEXPORT AUT 5 14 2 COMMENT Command The COMMENT command is used to docu ment the batch file and can be used as often as desired in the batch file It is ignored by Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 40 3DSSPP An ordinary comment command might be entered as follows COM Anything you want to type to document your file 5 14 3 DESCRIPTION Command The DESCRIPTION command is used to set the analysis units and the three documenta tion fields which are normally entered under the Task Input Description menu dialog The first data item is an integer either O or 1 which sets the analysis units English is O and metric is 1 The remaining three data items are strings which must be enclosed in quotes They are the Task Name Analyst Name and the Analy sis Comment A typical description command line is as follows DES 0 Task Name Analyst Name Just some comments 5 14 4 ANTHROPOMETRY Command The ANTHROPOMETRY command is used to set the gender and anthropometry val ues for the subsequent analyses The first data item is an integer representing the gender Male is O and Female is 1 The second data item is an integer
14. markers on the orthogonal view windows The cur sor changes from the normal arrow to a pointing finger when the cursor is over a marker When the left mouse button is pressed and a marker is se lected the cursor changes to a set of cross hairs When the mouse button is released the cross hairs vanish and the joint is no longer selected Joints with hollow markers cannot be selected They may be directly movable as in the knees or they may be locked see section 5 9 Page 11 To move a joint select the marker as above and drag it to a new location The marker itself will not move but the cross hairs will Release the mouse button and the stick figure will update If the error checking algorithm decides that the joint position is not feasible from a biomechanical standpoint a pro gram message will be displayed The hand positions will not move unless the hand marker is specifically moved The inverse kinematics algorithm will automatically estimate the positions of the body segments between the joint selected and the hands such that the hands re main in the same position For example if the legs are altered then the positions of the torso and el bows are predicted If the torso is altered then only the position of the elbows are predicted and the po sition of the legs remain the same Note that the hand locations are measured with respect to the center of the feet in standing mode Thus if one foot is moved then the origin of
15. the Hand Loads dialog box Figure 5 28 2 Enter the load magnitudes for each hand the magnitudes can differ between hands 3 For each hand either enter the force vector angles according to the conventions de scribed previously or select one of the pre defined efforts as provided Each hand may have a different force vector Alternatively the force directions may be entered using direct manipulation see Section 3 2 1 4 Click OK when all parameters are entered correctly 5 12 ADVANCED HAND LOADS New to 5 In addition to the Hand Loads dialog SSPP now provides the Advanced Hand Loads dia log Figure 5 29 for component entry of hand loads To enter either a force or a torque for either hand just enter the component forces or component torques and SSPP will automatically compute the total torque or force Use Zero All to set all hand loads forces and moments to zero The coordinate system is defined with the X axis extending later ally with positive to the subjects right The positive Y axis extends forward and the positive Z axis ex tends vertically This forms a right had coordinate system and the forces and moments are defined ac cordingly 5 13 JOINT LOADS New to 5 The Task Input Joint Loads dialog box is used to enter loads at joints other than the hands Figure 5 30 Torques and forces can be applied to any joint Elbows Shoulders L5S1 Copyright 2005 The Regents of The Universit
16. this is the angle formed between 4170 the lower leg and the horizontal plane at the ankle For example in Figure 5 9 the lower leg forms a 30 degree angle with the horizontal plane Likewise a id PY straight legged standing posture would form an an gle of 90 degrees This convention holds for both the right and left lower leg Figure 5 10 Upper leg vertical angle 5 7 4 2 Upper Leg Vertical Angles 2D and 3D Mode This angle may also be called the knee vertical angle This is the angle between the upper leg and the positive horizontal vector Y extending forward from the knee For example in Figure 5 10 the up per leg forms a 170 degree angle with the positive Y vector A straight legged standing posture would form an angle of 90 degrees This convention holds for both the right and left upper legs Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 30 5 7 4 3 Upper Arm Vertical Angle 2D and 3D Mode This is the angle formed between the upper arm and a horizontal plane X Y at the shoulder When the upper arm is entirely in the horizontal plane the joint angle is O degrees If the upper arm is above the horizontal plane the angle is positive if the up per arm is below the angle is negative For both the right and left upper arm vertical angles the value increases as the arm moves up and away from the horizontal plane and decreases as it moves down and away Refer to Figure 5 11 for cl
17. wheelchair above seat fio Defau t boy Cancel Figure 5 4 Support Selection dialog When seated mode is selected the user can choose whether or not to include front seat pan sup port and whether or not to include support from a back rest If the front seat pan support is selected then forces are applied to the back of the upper legs from the front edge of the seat pan The length of the seat pan is set by population factors which are a fraction of stature If the back rest is chosen then the height of the back rest can be adjusted to as low as 7 5 inches from the Seat Reference Point SRP 5 5 2 Feet Support New in 5 The user can specify which feet are supported If two feet are chosen then the pro gram will automatically determine the load in each foot Otherwise the full load is placed in the chosen foot The case of No foot support is only valid when the subject is seated 5 5 2 1 Foot Splay Angle New in 5 This is the angle between the foot direction heel to toe and the vector pointing directly forward of the subject A smaller degree angle will result in the feet being nearly parallel a larger angle will result in the feet being splayed out Suggested normal values are displayed Note that at this time the foot splay angle is only used to set the basis of support the feet and legs themselves are not rotated 5 5 3 Seating Parameters New in 5 Here the user can cha
18. 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 62 9 8 BALANCE REPORTS SEATED AND STANDING New to 5 The seated and standing balance re ports Figures 9 9 and 9 10 display the body sup port and balance details The stability condition as well as intermediate calculation values are listed and are most helpful in validating the balance cal culations To select the type of support seated or standing see the Support Selection dialog Balance Report Seated 3D Static Strength Prediction Program Version 5 0 9 8 1 Center of Pressure Calculation The Center of Pressure CP balance algorithm calculates the center of pressure and determines whether this location is within a stability region defined by the supporting surfaces The Center of Pressure algorithm calculates the whole body center of mass location from the bodyweights and centers of mass locations of each body part Then the hand locations and the vertical and horizontal hand forces are included along with the additional forces and moments added to the joints Finally the support reaction forces are estimated and the lower extrem ity joint forces and moments are re calculated to include these loads Residual moments are the mo ments calculated at the center of the pelvis that re main after the supporting forces are included They are error factors that indicated that the supporting forces are not perfectly balancing the body
19. 2D 3D Mode 24 3 View Menu commands see Menus Windows see Windows 3 View 3D low back see Disc compression force Abdominal force 2 3 59 About menu see Menus Action Limit see NIOSH limits Active window see Windows Adjusting posture Body segment angles see Body segment angles Direct manipulation 11 13 Analyses see Reports Analysis summary report see Reports Analyst name task description 23 Ankle Included angle 68 Anthropometry 25 Center of mass 62 Dialog box data entry 25 26 Gender 26 Height 26 Link lengths 61 Link weights 61 Percentiles 26 Report 61 Weight 26 Asymmetric lifting 58 Axial rotation see Body segment angles Azimuth see Environment objects B W see Human figure Back compression force see Disc compression force Back compression design limit see NIOSH limits Back compression upper limit see NIOSH limits Background see Color Balance 62 64 Center of Pressure 62 Barrier see Environment objects Body segment angles 27 33 Angle descriptions 29 33 Dialog box 27 28 Entering values 27 28 Forearm angles Horizontal 31 Vertical 30 Increment 28 Lower leg angle 29 Neutral 28 29 Reported see Reports Task input summary Symmetry 28 Trunk angles Axial rotation 32 Calculated torso 68 Direct manipulation 11 13 Flexion 31 Lateral bending 32 Upper arm angles Horizontal 30 Vertical 30 Upper leg vertical angle 29 Copyright 2005 The Regents of
20. 4 9 2 Choose File Print Active Window 4 9 PRINT PREVIEW Selecting File Print Preview opens the Windows Print Preview display Figure 4 2 Print Preview displays the contents of the currently active window as it would be printed were the File Print option selected The following options are relevant to 3DSSPP Print Prints the displayed window Zoom in Zoom out Three levels of magnifica tion are possible 25 50 and 100 2596 allows the entire page to be seen while 100 allows any text to be clearly read Zooming in increases the magnification while zooming out decreases the magnification Page 19 Close This option exits the Print Preview screen and returns to the prior view Aj Status Untitled Task Figure 4 2 File Print Preview display 4 10 PRINT SETUP Selecting File Print Setup displays a dialog box Figure 4 3 that allows the following items to be controlled Since many of the settings are printer specific not all may be available Refer to the Win dows documentation and the specific printer man ual for more information on these settings Printer For generating hard copies of the reports and individual postural views envi ronment or select another installed printer from the list by clicking on the right hand arrow and clicking on a printer name in the resulting list Orientation Referring to the printout and its orientation on the paper this setting should never have t
21. Input Posture Prediction indi cates the inverse kinematics method of posture entry is to be used It only functions in 3D Mode The basic concept behind inverse kinematics is that if the positions of the hands relative to the feet can be specified the positions of the other body joints and segments can be computed from algo rithms based upon behavioral data This means that in order to specify a posture all that needs to be done is for the analyst to enter the positions of the hands and the program will automatically predict the locations of the other body segments and joints This prediction is based on these hand locations the anthropometry of the worker and the load at the hands However because the inverse kinematics algorithm is based upon regression equations it yields the average posture a person would tend to take as a function of the hand locations and other task parameters Obviously because of behavioral Page 33 experiential and training differences between indi viduals not everyone will assume the same posture when the hands are at the same location However predicting a posture from known hand locations is always a good starting point for an analysis since the preferred posture generated by inverse kinemat ics algorithm is typically a reasonable posture for the sake of analysis Once the starting posture is specified the pos ture can be fine tuned through manipulating or moving individual b
22. Unpub lished MS Thesis Industrial Engineering Uni versity of Michigan Ann Arbor 1972 Chaffin D B Biomechanical Modeling for Simu lation of 3D Static Human Exertions Computer Applications in Ergonomics Occupational Safety and Health Elsevier Publishers B V 1992 Chaffin D B Andersson G B J and Martin B J Occupational Biomechanics 3rd edition John Wiley amp Sons New York 1999 Chaffin D B Redfern M S Erig M Goldstein S A Lumbar muscle size and locations from CT scans of 96 women of age 40 to 63 years Clinical Biomech 1990 5 1 9 16 Clarke H H Muscle Strength and Endurance in Man Prentice Hall Englewood Cliffs 1966 pp 39 51 Farfan H F Mechanical Disorders of the Low Back Lea and Febiger Philidelphia 1973 Holbein M A Chaffin D B Stability Limits In Extreme Postures Effects of Load Positioning Foot Placement and Strength Human Factors 1997 39 3 456 468 Kerk C J Chaffin D B Keyserling W M Sta bility as a constraint in sagittal plane human force exertion modeling Occupational Ergo nomics 1998 1 1 23 39 Kerk C J Chaffin D B Page G B Hughes R E A comprehensive biomechanical model us ing strength stability and COF constraints to predict hand force exertion capability under sag ittally symmetric static conditions IIE Transac tions 1994 26 3 57 67 Kishino et al Quantification of Lumbar Fun
23. a positive moment represents a counterclockwise moment This definition follows the right hand rule Company chuck Analyst Unknown Date 06 09 05 Task Untitled T ask Gender Male Percentile 50th Height 69 1 in Weight 176 4 Ib Comment Moments Due to Body Weight and External Applied Loads irr Ib Y Hand n a Elbow 1 n a Shoulder n a L 5 51 E 0 0 schial T uberasities Hip Knee Ankle Heel of Foot Front of Foot 3D55PP 5 0 0 Copyright 2005 The Regents of the University of Michigan ALL RIGHTS HESERVED Figure 9 13 Moments Report Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 68 9 12 POSTURE REPORT The posture report Figure 9 14 displays the limb and torso angles calculated by vector analysis on the input posture They are the included joint angles often used to describe postures Technically speak ing the included joint angles need to be corrected re computed by a vectorial screening of the posture editor in order to input the most accurate variables possible into the empirical strength prediction rou Posture 3D Static Strength Prediction Program Version 5 0 tines Since the population percent capable values are highly sensitive to variations in the mean strengths and standard deviations these corrected angles are used as independent variables in the em pirical strength equations to reduce the mean strength variabil
24. feet support has been selected in the Sup port Selection dialog The BOS region is depicted by the outer edge of the green band It will adjust according to the type of seat support selected The COP appears as a small yellow dot The small red dots show the location of the ischial tuberosities which are the lowest most bone surfaces of the pel vis The images of the pelvis and feet will change as the posture of the lower extremity is changed and the BOS boundary will automatically adjust Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Page 65 9 9 FORCES REPORT New to 5 The forces report Figure 9 11 lists the resultant forces produced by the loads and body weight in the direction of the main reference axes x y and z at each joint or surface The X axis Forces extends laterally from the origin with positive to the subject s right The Y axis extends from the origin to the front and the back of the body with positive being forward Lastly the Z axis extends vertically from the origin with positive upwards This defini tion follows the right hand rule Description Task Untitled T ask Comment Company chuck Analyst Unknown Date 06 09 05 Gender Male Percentile 50th Height 69 1 in Weight 176 4 Ib m Forces lb Due to Body Weight and External Applied Loads Left Hand Elbow Shoulde
25. in front of the hominoid from the feet center point Facing the hominoid from the front positive azimuth values move the barrier to the viewer s right the figure s left in a circular arc centered on the cylindrical coordinate system s vertical axis Negative azimuth values move the barrier around to the viewer s left The range of azimuth val ues is 180 to 180 degrees Elevation For both the wall and the table this input field asks for the dimension measured vertically from the origin to the barrier s top surface 8 2 4 Color Environment items can be displayed in any color including a separate color for the outline See Color section 8 4 1 8 3 CAMERA For viewing the figure the human graphic display uses a camera metaphor To understand the dimen sions that follow imagine viewing the figure through a camera Viewing position is changed by moving toward or away from the figure changing radius circling around the figure to the right or left changing rotation or circling up and over or down Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Oblique View Camera m Camera Location Focal Lenath 50 mm Distance 30 in Camera nale Vertical Tilt 20 Degrees Rotation 20 Degrees Display Offset Horizontal Offset o in Vertical Offset o in Default View Cancel Figure 8 4 Obl
26. may also run under Windows 98 ME and NT depending upon the ca pabilities of the computer The program has bees successfully tested to run under Vertual PC Version 7 for the Mac running Windows XP The program is available on a CD or can be downloaded from the website umichergo org 2 3 INSTALLING AND STARTING 3DSSPP 1 Insert media or download and find the in stallation file it will be named 3DSSPP_500_Setup exe or something very similar and double click its icon 2 Follow the on screen instructions Be sure to read the End User License Agreement 3 To begin working with 3DSSPP double click on the main program icon 3D or the filename 3DSSPP exe If the program has been added to the Start Menu or desktop then it can be started there as well Note If your computer is on a network your account may not have sufficient privileges to install new software If you experience difficulties with installation consult your network administrator Installation of 3DSSPP on a network not just a single workstation requires a special license 2 4 REGISTRATION New in 5 In order to use the full version of 3DSSPP the user must enter a registration code Figure 2 1 This should have been provided with your purchase of 3DSSPP To register simply en ter your company name and registration code in the spaces indicated If you choose not to enter a registration code Copyright 2005 The Regents of The University
27. of Strength Strength Capabilities m Description Company chuck Analyst Unknown Date 06 09 05 Task Untitled Task Gender Male Percentile 50th Height 69 1 in Weight 176 4 lb Comment m Capabilities Left Right Population Strength Muscle Mean SD Cap Population Strength Required Moment Muscle Mean SD Cap Moment in lb Effect firrlbj imb A irrlb Effect inb imlb A Elbow Flex Ext 86 FLEXN 528 130 100 85 FLEXN 568 140 100 Shoulder HumeralRot 33 635 144 100 33 683 155 100 RotnBk Fd 0 ESI 0 EE Abduc Adduc 211 617 152 99 211 ABDUCT 664 163 99 Required Torso Flex Ext 1689 3 32 1176 95 Lat Bending 0 Rotation 0 EXTEN 1963 788 EXTEN 1468 514 FLEXN 1228 406 Hip Flex E xt 825 1963 788 92 825 Knee Flex E xt 113 1468 514 99 113 Ankle Flex E xt 113 1228 406 33 113 3DSSPP 5 0 0 Copyright 2005 The Regents of the University of Michigan 4LL RIGHTS RESERVED Figure 9 7 Strength Capabilities Report Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 9 7 ANTHROPOMETRY REPORT The anthropometry report Figure 9 8 displays an thropometric data including the link lengths the center of gravity distances and the link weights The lower arm shown in the first row combines the hand and lower arm links Hence the hand weight 1s inc
28. representing the percentile for height and weight 95 is 0 50 is 1 and 5 is 2 If the percentile integer is 3 then the height and weight are set according the next two data items The third data item is the entry for Height and the last data item is the entry for Weight These are both floating point values If the percentile data item is not 3 then the third and last data items are not used in the analysis and should be entered as zeros ANT 0 2 65 5 150 2 3D Static Strength Prediction Program Version 5 0 5 14 5 JOINTANGLES Command The JOINTANGLES command is used to enter the posture segment angles as listed in the Segment Angles Menu Dialog for subsequent analyses All of the values are integers and the data items are input in the order of left side right side and trunk Specifically Forearm left horizontal forearm left V upper arm left horizontal upper arm left vertical upper leg left vertical lower leg left vertical forearm right horizontal forearm right vertical upper arm right horizontal upper arm right vertical upper leg right vertical lower leg right vertical trunk flexion trunk rotation and trunk bend ing JOI 85 25 10 80 145 70 70 20 5 85 140 70 40 5 10 5 14 6 HANDLOADS Command The HANDLOADS command is used to input the magnitude and direction of the loads on each hand for the subsequent analyses The magnitude data items are floating point values and the angle data items are integers
29. shoulder left hand left elbow left shoulder L5S1 right hip right knee right ankle left hip left knee and left ankle Force values include jnt forces followed by x y z forces for right elbow right shoulder left elbow left shoulder L5S1 right hip right knee right ankle left hip left knee left ankle Moment values include jnt mom followed by x y z moments for right elbow right shoulder left elbow left shoulder L5S1 right hip right knee right ankle left hip left knee and left ankle Low back values include low back L5 S1 disc compression L5 S1 disc compression std dev L5S1 sagittal shear L5S1 frontal lateral shear L4 L5 disc compression force LA LS disc anterio posterior shear and L4 L5 disc lateral shear Then include the re sultant force shear force X force Y force and Z force for each of the following r erector spi r rectus abdo r internal ob r Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Page 73 external ob r latis dorsi l erector spi 1 rectus abdo l internal ob 1 external ob and l latis dorsi Fatigue values include fatigue followed by Sin 251 and 501 values for left elbow flex ext left shoulder humeral rot left shoul der rotn bk fd left shoulder abduc adduc left hip flex ext left knee flex ext left ankle flex ext right elbow flex e
30. studies described and referenced in the same textbook in addition to other studies found in the scientific journals which offer strength data updates on experimental joint strength capabilities of industrial and civilian populations Results from this model demonstrate a strong correlation with average population static strengths r 0 8 1 4 NEW FEATURES OF VERSION 5 New in 5 Version 5 includes many enhance ments to the tools and data at the user s disposal If you are familiar with 3DSSPP you may want to look through the manual for sections beginning with the New in 5 header as you see at the be ginning of this paragraph 1 5 REMOTE OPERATION 3DSSPP may be operated remotely by another pro gram through a COM library interface This per mits value added software vendors to use the 3DSSPP biomechanical as an engine in their prod ucts Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 In this case 3DSSPP must still be licensed from the University of Michigan as either the full featured program or the 2D Mode only version In either case the program may be operated as a stand alone biomechanics or ergonomics analysis tool Value added vendors wishing to implement the 3DSSPP engine must purchase a special license from the University of Michigan COM library commands and header files will then be provided for either Visual Ba
31. used to develop the revised 1991 lifting equation Waters et al 1993 while the BCUL are consistent with the criteria used to develop the 1981 equation In the 3DSSPP the BCDL is delimited in the bar graphs by the green to yellow transition and the BCUL is delimited by the yellow to red transition Because the 1991 version of the Lifting Guide has moved from a three stage decision matrix to a single lifting index in assessing the risk of low back pain these upper limits were not included as criteria for the 1991 version Further discussion concerning the back compression design and upper limits as well as the basis for strength design and upper limits can be found in Occupational Biomechanics 9 2 3 Percent Capable The upper portion of the screen below the re port header is devoted to the strength capability of the selected gender at the major joints The dis played value for each joint is the lowest value ob tained from the strength capabilities calculated for the joint actions on the left and right side of the body The torso value is the smallest of axial rota tion strength lateral bending strength and flexion extension strength All of the strength capability percentages can be viewed in the Strength Capabili ties report described in Section 9 6 9 2 3 1 SDL and SUL Limits For percent capables percent of the population with sufficient strength the NIOSH Strength Limit 3D Static Strength Prediction Program Version 5 0
32. window Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 3 4 STATUS WINDOW This window is positioned in the lower right hand corner of the standard program window It lists miscellaneous input data and summary results see Figure 3 6 The Status Window also displays a graphical representation of the hominoid s Center of Pressure See Section 9 8 for information about balance and this graphic For information about other items in the Status Report see Section 9 2 Analysis Summary Report 3 5 REPORT WINDOWS Report windows are generated whenever a report option is selected from the Reports menu Changes in units anthropometry load or posture will auto matically be reflected in any open report windows L Status Untitled Task Gender Male Percentile 50th Anthropometry Hand Forces Ib Left 10 Right 10 Left Page 15 To close a report window easily simply press the Escape key while the report is the active window or use the standard close command on the win dow s title bar New in 5 A report can now be closed by pressing the Escape key when it is active has just been clicked New to Windows As with the view win dows mentioned above these windows also have their own respective title bars for controlling size Depending on the monitor and graphics hardware installed use of t
33. 17 New 18 Open 18 Save 18 Save as 18 Flesh see Render or Human figure Model type Floor see Environment objects Focal length see Camera Force at hands see Hand loads Forearm angles see Body segment angles Front view see Windows 3 View Frontal plane 69 Gender see Anthropometry Graphic human model see Human figure Hand forces see Hand loads Handheld object see Environment objects Hand loads Arrow display 45 Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Arrow colors 45 Dialog box 36 38 Descriptor 35 Force vectors 36 37 Magnitude 35 36 Reported see Reports Task input summary Vector components 37 Hand locations Direct manipulation 13 Measurement 33 34 Reported see Reports Analysis summary or Task input summary Status window 15 Hand orientation 33 Hand position see Hand locations Hand type see Human figure see Report header Height see Anthropometry Anthropometry stature 22 Environment 51 Report header 57 Hips Included angle see Posture Report Direct manipulation 12 Hominoid see Human figure Horizontal plane 29 69 Human figure 48 Color 48 Model figure types 48 Hand type 48 Lighting 52 Humeral rotation angle see Shoulder Importing files see File Import Included joint angles 68 Increment see Body segment angles Inverse kinematics 1 See Posture entry method Page 79
34. 3D Static Strength Prediction Program Version 5 0 4 User s Manual The University of Michigan Center for Ergonomics August 2005 3D Static Strength Prediction Program Version 5 0 4 User s Manual The University of Michigan Center for Ergonomics QUESTIONS Questions regarding computer hardware and operating systems should be addressed by the analyst s com puter support personnel Questions regarding this software may be addressed to The University of Michigan Office of Technology Transfer University of Michigan Wolverine Tower Suite 2071 3003 South State Street Ann Arbor MI 48109 1280 Tel 734 936 0435 Fax 734 936 1330 email um software umich edu umichergo org Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page ii 3D Static Strength Prediction Program Version 5 COPYRIGHT AND DISCLAIMER The program contained on the original distribution disk is the sole property of The Regents of The University of Michigan NO part of the program or this manual may be reproduced or distributed in any form or by any means without the prior written permission of The Regents of The University of Michigan with the exception that you may transfer copies of the original program to a hard disk to run or to another disk for backup purposes only THE PROGRAM ON THE ORIGINAL DISTRIBUTION DISK IS PROVIDED AS IS WITH OUT WARRANTY OF ANY KIND EITHER EXPRESS OR IMPLIED INCLUDING WAR RANTIES O
35. 5 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 48 graphics display and has no bearing on the biome chanical analyses provided the task parameters are correctly entered The selection of model type and rendering has a considerable effect on the time required to generate the figure displayed on the screen especially in sys tems with slower CPU s and clock speeds In gen eral improved graphics realism will noticeably in crease the time required for the program to accu rately display and analyze a given posture Oblique View Human Figure Model Type C None C Wireframe Flesh Hand Type Open Cupped C Fist DK Figure Color Enable Shoes Apply Clothing Color Cancel Figure 8 2 Oblique View Human Figure dia log box 8 1 HUMAN FIGURE Selecting Oblique View Human Figure displays a dialog box Figure 8 2 which allows the user to select the following display options relevant to the human figure 3D Static Strength Prediction Program Version 5 0 8 1 1 Model Type Four different models of the human figure are provided The default is to display the wire frame figure The Stick Skeleton and Flesh are the same as were discussed in the 3 Views Menu Chapter None This option prevents the hominoid from being displayed in the oblique view window Wireframe This model provides a partially transparent wireframe model of the homi noid This model render
36. 8 4T URESH IST AR PUP ASK tii poenis o qos 18 48 JRINTACTIVE WINDOW sisi isos 19 49 PRINT PREVIEW aiii nia ita 19 4 10 PRINTS UU tao ao des 19 4 11 PRINT APPLICATION 2 ad 20 4 127 PRINT DESKTOP tati dsd 20 413 COPY APPHICATION isdem QU URS ULP OI AE RA UA 20 Z4 COPY DESKTOP 21 4 15 PRINTING THROUGH THE WINDOWS CLIPBOARD 21 416 IS QU ec PC 21 Chapter 5 TASK INPUT MENU COMMANDS siii 23 5 1 DESCRIPTION aaa 23 52 SBEMETRIC A ENGLISH UNITS ti 24 ic am Yd WA BS Gas MODE a e cen cad e dd 24 9 4 GRA MMT Yi ad 24 5 0 SUPPORT SELECTION unitat 24 5 5 1 Standing or Seated Support Selection ooococnnccccnnocccooncccnonnnononnnononcnonnnccnonnccnnns 24 Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5cm Page vii A Feet Support oae abe asthma sepu eT nT 25 9 2 2h be BOWS ay PC SG oa eee Loo atcitetess os es 25 5 5 3 Seang Parameters o osten imer gecko eae doregt blind e dul tefta hepatis erences 25 3 00 ANTHROPOME TR Y coisa sca sae oues ena abunde eeu 25 SN GU Population tL 26 6 141 Open Population EHE a apiid eed In ae EAE ondas 26 5 6 1 2 Select Default Population 1 5 Irae reete eet eoe eret eiii 26 041 3 Edit POPULAR enreda cidad areas 26 3 7 BODY SEGMENT ANGLES sil a 27 5 7 1 An Introduction to Body Segment Angles Method of Posture Entry 27 5 7 2 Body Segment Angle Dialog Box 2D Mode
37. B Chaffin D B and Reed M P Center of pressure excursion capability in per formance of seated lateral reaching tasks Sub mitted for publication in Clinical Biomechanics Reid J G Costigan P A and Comrie W Pre diction of trunk muscle areas and moment arms by use of anthropometric measures Spine 1987 12 273 5 Rohmert W Problems of determination of rest allowances Part 2 Determining rest allowances in different human tasks Applied Ergonomics 1973 4 158 162 3D Static Strength Prediction Program Version 5 0 Shanne T A A Three Dimensional Hand Force Capability Model for the Seated Operator Un published Ph D Thesis Industrial Engineering University of Michigan Ann Arbor 1972 Smith and Mayer Quantification of Lumbar Func tion Part 1 Spine 1985 10 8 757 764 Stobbe T The Development of a Practical Strength Testing Program for Industry Unpub lished Ph D Thesis Industrial Engineer ing University of Michigan Ann Arbor 1980 Tracy et al The geometry of the muscles of the lumbar spine determined by magnetic resonance imaging Spine 1989 14 186 93 Waters T R Putz Anderson V Garg A and Fine L J Revised NIOSH Equation for the Design and Evaluation of Manual Lifting Tasks Ergonomics 1993 36 7 749 776 Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Page 77 Index
38. C Table 8 1 4 Enable Shoes This selection applies shoes to the oblique display of the human model It makes no difference to the calculations or results 8 1 5 Clothing Color Selecting this button allows the user to change the color of the hominoid s apparel Page 49 8 2 ENVIRONMENT Selecting Oblique View Environment displays a dialog box Figure 8 3 which allows the user to select the following display options relevant to en vironment objects This feature is provided to aid the analyst in matching postures to photographs or video images However physical interaction be tween the environment items and the human figure is not calculated nor are analysis results affected by the presence or absence of environment objects 8 2 1 Floor This object has fixed dimensions and is automati cally positioned beneath the figure s feet Click on the box to insert or remove the floor from display 8 2 2 Handheld Object Be aware that 3DSSPP always positions the hand held object between the hands with the hands cen tered on the sides of the object if the task being modeled involves an asymmetrically held object the modeled image will not match the actual task The inclusion of the hand held object on the graph ics display has no bearing on the biomechanical analyses and is only included for realistic appear ance Type Four object options are available none cube cylinder or sphere The object is automatically p
39. D Static Strength Prediction Program Version 5 0 3 2 2 5 Trunk Lateral Bending Trunk lateral bending corresponds to side to side bending of the trunk Positioning is best ac complished with squat stoop postures via the top view or with erect postures via the front view Se lect and move the marker which is midway between the two shoulder joints 3 2 2 6 Right and Left Elbows The elbow positions that can be entered are constrained by the positions of the shoulders and of the hands Figure 3 4 The elbow must always be the correct distance from both the shoulder and the hand Thus there is a limit to the positions that can be assumed by the elbow For example when hold ing one hand in a given location i e grabbing a door knob and holding the body still the elbow can be moved around somewhat The positions that can be reached by the elbow with the hand and shoulder fixed are the ones that can be selected Since a point selected may not always be a valid elbow location the program will attempt to find the valid elbow position nearest to the location that has been clicked Shoulder Position Hand Position fixed fixed O Upper Aim Length Forearm Length fixed fixed Elbow movable Figure 3 4 Constraints on elbow position Page 13 3 2 2 7 Hand Positions If the locations of the hands in three dimen sional space are known then the best method for specifying the hand locations is to choose Task Input Postur
40. DES 0 Loads E Suzy Anybody Hand loads case E HAN 35 20 85 35 15 80 COM COM COM Do 3 different postures with metric output COM DES 1 Posture A Suzy Anybody Posture case A JOI 60 10 10 75 135 60 70 20 5 80 145 75 45 5 0 DES 1 Posture B Suzy Anybody Posture case C JOI 80 20 15 80 140 70 75 25 10 85 150 80 40 15 10 DES 1 Posture C Suzy Anybody Posture case C JOI 90 25 20 85 145 80 80 30 15 90 155 85 35 25 15 COM COM Do the 3 different percentiles for female with English output COM Note For values of percentile not equal to 3 the height and weight COM data entries are ignored and may be anything readable here set to 0 COM DES 0 Anthro A Suzy Anybody Female 5th ANT1200 DES 0 Anthro B Suzy Anybody Female 50th ANT1100 DES 0 Anthro C Suzy Anybody Female 95th ANT1000 Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 42 3D Static Strength Prediction Program Version 5 0 Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Page 43 Chapter 6 DISPLAY MENU COMMANDS The Display Menu Figure 6 1 contains the dialog boxes for controlling the program display window Automatic tiling of the default five window ar rangement can be enabled or disabled or the pro gram can be tiled on command In addi
41. Description Company chuck Analyst Unknown Date 06 08 05 Task Untitled Task Gender Male Percentile 50th Height 69 1 in Weight 176 4 lb Comment r Center of Pressure in Forward to Backward Right to Left Base of Support at Seat in Front Boundary Left Boundary Right Boundary r Residual Pelvic Moments in lb x m 170 6 0 0 0 0 Maximum Balance Moments Stability in Balance Acceptable Left Right af x IT 1133 0 Seat Front 287 5 Ball of Foot 4177 2 411 2 0 0 685 3 0 0 685 3 0 0 X iM Z 1199 0 411 2 287 5 685 3 0 0 4177 2 685 3 0 0 3DSSPP 5 0 0 Copyright 2005 The Regents of the University of Michigan ALL RIGHTS RESERVED Figure 9 9 Balance Report Seated Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 9 8 2 Stability Regions For balance to be obtained the COP must be contained within a stability region defined by the supporting surfaces Two stability regions are de termined and considered The Basis of Support BOS is a region defined by the size and location of the supporting surfaces For example in standin the feet can only support a posture if the Center of Pressure is within the BOS otherwise the person Balance Report Standing Page 63 will fall over However it has been show
42. F MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE The entire risk as to the performance of the program and interpretation of the output from the pro gram is with the user The University of Michigan assumes no responsibility or liability of any kind for errors in the program errors in the output from the program or for any consequential or inciden tal damages that may arise from use of the program All display screens used by the program are copyrighted by the University of Michigan No screen or part thereof may be used in any publication or promotion without the express written consent of The Regents of The University of Michigan U S GOVERNMENT RESTRICTED RIGHTS The PROGRAM and documentation are provided with restricted rights Use duplication or disclosure by the Government is subject to restrictions as set forth in subdivisions c 1 ii of the Rights in Technical Data and Computer Software clause at 252 227 7013 Contractor Manufacturer is The University of Michigan Ann Arbor Michigan 48109 Copyright 2005 The Regents of The University of Michigan Windows NT Windows 2000 Windows ME and Windows XP are registered trademarks of the Microsoft Corporation Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5cm Page iii End User License Agreement PROGRAM 3D Static Strength Prediction Program TM Software IMPORTANT READ CAREFULLY This Agreemen
43. HTS RESERVED
44. LL Horizontal Angle iecit ii o tata tuu tos mide t atv Quot ins 36 5 11 3 2 Vertical Angle ete a reet ua esa e Uo Eee EPOR na UN e PR TRES 37 5 11 4 Hand Load Entry 3D Mode iae een eee ote tb epa doradas dass ases eua eren ice adan 37 512 ADVANCED HAND LOADS asii eei nt oid et deri deep 37 Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page viii 3D Static Strength Prediction Program Version 5 513 JOINT TOADS oii e E od oi 37 S 1331 Zero do os des ES 38 913 2 7860 AN ain ra Ua led Van pedit crn A a anos 39 Dale RUN BA TCA F E e ar ai 39 Al Bateh File Formatore snis eo ne 39 SA4 1 1 FirstLine A ae a IM aE oE uds 39 5 14 1 2 Command Structure arica rios ies 39 914 2 COMMENT Command sentaron 39 5 14 3 DESCRIPTION Command eitis eere teo eene tas ehe eoe HEUS ena Ta oe ER doe 40 5 14 4 ANTHROPOMETRY Commaand esses enne 40 5 14 5 JOINTANGLES Command ierat einen en leere eae te desired 40 5314 6 HANDEORNDS COMMON dde idis 40 5 14 7T EXPORT Command tes 40 5 14 83 AUTOEXPORT Comida e nn egt a utin ai hans 41 14 90 Example Bate ln PAIe e eed aite e inea E 41 Chapter 6 DISPLAY MENU COMMANDS 1 doecinatisub rare eno ee obe Ipae ta ease ttd ode aiii ds 43 6 1 AUTO ias dia 43 6 2 TILENO Nata pa 43 6 3 STATUS BAR votan nai 43 Chapter 7 3 VIEWS MENU COMMANDS essen eene nennen enne cannnnnnccon cnica nennnes 45 7 1 SHOW FORCES caida 45 JT gt COLORS cita
45. TS RESERVED Page 60 9 6 STRENGTH CAPABILITIES RE PORT 3D Static Strength Prediction Program Version 5 0 The Population Strength Means depend upon the gender and posture They are not stratified by height or weight anthropometry because the corre lation is weak Also there is currently insufficient The strength capabilities report Figure 9 7 outputs data to stratify the strength means by age the results of the strength model The Percent Capable is the percentage of the population with the strength capability to generate a moment larger than the resultant moment It is cal culated as a function of the resultant moment mean strength and standard deviation of the mean strength using a normal distribution as follows The Required Moments torque produced by the load and body weight for each joint are calcu lated using a biomechanical model based on a static linkage algorithm and are dependant upon the an thropometry posture and hand load The Population Mean Strengths and their stan dard deviations are computed from empirical mean strength equations The equations are based on ex perimental strength studies by Stobbe 1980 Shanne 1972 Burgraaff 1972 Clarke 1966 Smith and Mayer 1985 Mayer et al 1985 Ki shino et al 1985 Kumar Chaffin and Redfern 1985 and many others Percent Capable D Z Q n f exp Cx 2 dx where Z 2 Required Moment at joint Mean Strength Std Dev
46. TWARE REQUIREMENTS 5 5 esee iter eee ia 7 23 INSTALLING AND STARTING 3D SSPP src ati 7 24 REGISTRATION sind aa 7 23 STARTUP SCREEN Ss sd 8 2 67 DEMO MODE coins 8 2T GBMODDEG up pede i o E d E 8 Chapter 3 SCREEN AREAS rosadas ias 9 3 1 PROGRAM WINDOW ous na 9 32 ORTHOGONAL VIEW 3 VIEW WINDOWS cc ceeesceecceseceeceeeeeeeneeeeees 10 2 2 1 Direct MantpulatiGl i5 ois nase oct acs ay yates ores a deme tees tans scies etus d nere 11 3 2 2 Preferred Order and Techniques of Joint Manipulation 11 3 2 2 Rightand Left NA A E seu I2 A E A outta eee endear eames 12 Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page vi 3D Static Strength Prediction Program Version 5 29 29 CO gn A O eas Sn ees drea e 12 3 2 2 4 Trunk Ds Han qt lustabap laeta ite tens 12 32 2 5 Trunk Lateral Bend dd eiae 13 3 22 6 Riphtand Lett EIBOWSz c eei ea tS ERR 13 OUS Hand Posto NN AT CLE d 13 3 2 2 8 Modeling Whole Body Postures eene 13 33 OBLIQUE VIEW WINDOW 5 e ctsreceteee ada 14 Sp STATUS WINDOW spin 15 35 REPORT WINDOWS unio alas 15 Chapter 4 FILE MENU COMMANDS rnit teinte rere ir 17 4 1 FILE MANAGEMENT DIALOG BOXES essere nnne 17 qu RO 18 43 COREN iin aa TE Opes thot daa E A chit alte ance tt 18 Be SAVE ate ia eae ns eae 18 LEES O A S 18 4 6 SET STARTUP TASK TO CURRENT 4 s eeeeeeeeeeerener entretenir 1
47. The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Page 53 Chapter 9 REPORTS MENU COMMANDS The Reports Menu Figure 9 1 contains the many analysis options available in 3DSSPP A task input summary report is also available which lists all of the input data entered by the user Two additional options include commands for printing reports and exporting output data to a file When a report is selected the report data is dis played in a new window over the posture entry win dows which may be manipulated as any other win dow For example its contents can be printed through File Print Active Window or be copied to the clipboard or the window can be re sized Changes in units anthropometry load or pos ture will automatically be reflected in any open re port windows Remember that although running additional reports may appear to close an existing report window by hiding the previous report win dow no existing report windows are closed by this action To close individual report windows use the control menu on the report window s title bar Each report contains a header block with basic information about the analyzed task Included are the company analyst date task name gender per centile anthropometry height weight and task comment For all report screens the output can be Univ of Michigan s 3DSSPP 5 0 0 Untitled File Task Input Display 3 Vie
48. The University of Michigan ALL RIGHTS RESERVED Page 78 Camera 50 51 Distance 50 Focal length 50 Rotation 51 Vertical tilt 50 Center for Ergonomics 1 Center of gravity see Balance Center of mass see Anthropometry Clipboard see Printing Using Window s clipboard Coefficient of ground friction 57 Color Background 51 Environment 48 Human figure 48 Comments task description 23 Compression force see Disc compression force Coordinate system 66 Coronal plane 69 Cube see Environment object Handheld object Cylinder see Environment object Handheld object Description task description 23 Direct manipulation see Posture entry methods Disc compression force Analysis summary report 55 3D low back report 58 L4 L5 disc 3 4 58 L5 S1 disc 2 3 59 70 L5 S1 report 59 NIOSH guidelines 58 Sagittal plane low back 59 Optimization algorithm 3 58 Display menu see Menus Distance see Camera or Environment objects Bar rier Elbow 13 Included angle see Posture Report Elevation see Environment objects Barrier Environment objects 48 50 3D Static Strength Prediction Program Version 5 0 Barrier 49 50 Color 50 Floor 49 Handheld object 49 Erector spinae muscle 2 59 Error reporting 5 Exit 21 Export output summary 71 72 File format 72 Feet 11 24 25 Center of feet 66 Ground friction 57 Load on feet 57 Shoes 48 Splay angle 25 Support 25 File Menu see Menus Name
49. Yiew Reports Mew Ctrl N Open Ctri O Save Ctrl 5 Save As Set Startup Task to Current Reset Startup Task Print Active Window Ctrl P Print Preview Print Setup Print Application Print Desktop Ctrl F Ctrl D Copy Application Copy Desktop Exit Figure 4 1 File Menu 4 1 FILE MANAGEMENT DIALOG BOXES 11 New to Windows When any of the file man agement dialog boxes are opened for the first time in any 3DSSPP session the files displayed are lo cated in the working directory Refer to the Win dows User s Manual for instructions on changing the working directory for a program item if task files are to be stored in a directory separate from the program s executable file Once a file is saved or opened in a directory other than the working direc tory the directory used last becomes the default directory for the remainder of the session New to Windows If the file name desired is already displayed double click it Use the follow ing controls to display file names in other drives or directories File name This is the input field where the file to be opened or saved is chosen either by typing its name in the edit field or clicking on its name in the list above the edit field Look In This section displays the working di rectory To change to a different directory or drive click the down arrow Files of type This control regulates the files dis played by
50. after the abdominal force effect and joint forces in three di mensions over the tilted L4 L5 disc torso muscle moment arms lateral and anterior posterior and muscle areas are the inputs to the three dimensional torso muscle force optimization routine The rou tine outputs the resultant muscle contraction forces at the L4 L5 level and the disc compression force as the vector sum of muscle ten muscles contractile forces abdominal force upper body weight above L4 L5 level and the hand loads Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 4 L Erector Spi 3D Static Strength Prediction Program Version 5 0 Y Figure 1 3 Low back forces and moments Depiction of torso muscle areas and orientation with respect to the L4 L5 disc is shown in Figure 1 3 The initials L and R before the muscle la bels represent the Left in the X quadrant and Right in the X quadrant sides of torso The vec tor sum of Anterior Posterior Shear Force and Lat eral Shear Forces represents the Total Shear Force 1 3 3 Static Strength Model A technical discussion of the static strength model used in the program is provided in Chapter 6 of Occupational Biomechanics 3rd Edition by Chaffin Andersson and Martin 1999 published by J Wiley amp Sons Inc 605 Third Ave New York NY 10158 Worker strengths used for the predic tion model have been compiled from a collection of strength
51. arification Be aware that the horizontal plane is fixed in orienta tion and does not rotate with the trunk This allows the upper arm angles to be measured independent of the overall posture Figure 5 11 Upper arm vertical angles 5 7 4 4 Upper Arm Horizontal Angles SD Mode Only In contrast to the legs the shoulder joint in 3DSSPP is capable of three degrees of freedom which makes the upper arm capable of rotation about the vertical Z axis The upper arm horizon tal angle measures this rotation and is the angle formed by the upper arm with the X axis when viewing the figure from overhead i e when the 3D Static Strength Prediction Program Version 5 0 upper arm is projected onto the X Y plane at the shoulder see Figure 5 12 When the upper arm lies along the X axis with the arm pointing away from the body the angle is O degrees If the upper arm is forward of the X axis toward the positive Y axis then the angle is positive if the upper arm is behind the X axis toward the minus Y axis the angle is negative This convention holds for both the right and left upper arm horizontal angles Note that the upper arm horizontal angle does not have meaning when the upper arm is perfectly vertical it has no projection onto the X Y plane other than a point and need not be entered in this case Figure 5 12 Upper arm horizontal angles 5 7 4 5 Forearm Vertical Angles 2D and 3D Mode This angle is interpreted in a
52. as a range of 0 to 180 degrees If the vector is directed behind a vertical plane at the hand the angle has a range of 0 to 180 degrees For both hand vectors 0 lies along the positive X axis Refer to Figures 5 25 and 5 26 for clarification Note that the horizontal angle does not have meaning when the force direction is perfectly verti cal it has no projection on to the X Y plane other than a point and need not be entered in this case FORCE LEFT HAND Y FORCE Figure 5 25 Positive horizontal hand force vec tor angles Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Y Y Figure 5 26 Negative hand force vector hori zontal angles 5 11 3 2 Vertical Angle Assuming the hand force vector tail is in the grip center of the hand the angle between the vec tor and the horizontal X Y plane is the hand force vertical angle If the vector is directed above the horizontal plane the angle has a range of O to 90 degrees Should the vector be directed below the horizontal plane the angle ranges from 0 to 90 de grees Refer to Figures 5 22 5 23 and 5 27 for ad ditional clarification Figure 5 27 Vertical hand force vector angles with right horizontal angle of 0 and left hori zontal angle of 180 Page 37 5 11 4 Hand Load Entry 3D Mode To enter the hand loads in 3D Mode 1 Choose Task Input Hand Loads to display
53. cted posture to more closely represent the posture observed in the work place 1 3 4 L5 S1 Forces and Moments The Lumbar Disc Compression Force at L5 S1 level is calculated as the sum of Erector Spinae Rectus Abdominus either one active per posture abdominal force upper body weight above L5 S1 level and hand load Figure 1 1 Furthermore forces acting upon the L5 S1 disc are resolved to compute the shear components in the Anterior Posterior and Lateral directions The vector sum of 3D Static Strength Prediction Program Version 5 0 these two shear forces is called the Resultant Shear Force on the L5 S1 disc In addition to the Resul tant Shear Force the disc may be subjected to fur ther stress due to those loading and postural condi tions which create torsion about the longitudinal axis of the L5 S1 disc often called the Moment about the L5 S1 disc normal Uneven hand loads and or rotation of the torso from side to side during the task can easily generate an axial rotation mo ment about the L5 S1 disc normal or the torsion on L5 S1 depicted by Figure 1 2 For a typical lifting task the low back Erector Spinae muscle produces a contractile force acting at the muscle moment arm distance this varies be tween male and female for the moment equilib rium at L5 S1 level Abdominal force acting at the abdominal moment arm distance which also varies between males and females as well as between population perc
54. ction Part 4 Spine 1985 10 10 921 927 Kumar S Moment arms of spinal musculature de termined from CT scans Clinical Biomech 1988 3 137 44 Kumar S Chaffin D B and Redfern M Iso metric and Isokinetic Back and Arm Lifting Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 76 Strengths Device and Measurement J Biome chanics 1988 21 1 35 44 Mayer et al Quantification of Lumbar Function Part 2 and Part 3 Spine 1985 10 8 765 772 and 10 10 912 920 McGill S M and Norman R W Partitioning of the L4 L5 dynamic moment into disc ligamen tous and muscular components during lifting Spine 1986 11 666 78 McGill S M and Norman R W Effects of an anatomically detailed erector spinae model of L4 L5 disc compression and shear J Biomech 1987 20 591 600 McGill S M Patt N Norman R W Measure ment of the trunk musculature of active males using CT scan radiography implications for force and moment generating capacity about the LA L5 joint J Biomech 1988 21 329 41 National Institute for Occupational Safety and Health Work Practices Guide for Manual Lift ing Technical Report No 81 122 U S Dept of Health and Human Services NIOSH Cincin nati Ohio 1981 Nemeth G and Ohlsen H Moment arm lengths of trunk muscles to the lumbosacral joint obtained in vivo with computed tomography Spine 1986 11 158 60 Parkinson M
55. da dai 45 Chapter 8 OBLIQUE VIEW MENU COMMANDS sese 47 8 1 HUMAN FIGURE nano eod eto Ri eade Ai 48 S ub Model Typene etu mee ci dua e 48 Golo A A toad estt Med hdi ad t mele Sante M fd hats 48 O MEINE LVDS eas ie cima aye ane tua cid dt est ne en 48 Sb A S PE P UA 49 A AS A o bles aes tutatet i isis edu m AS 49 8 2 ENVIRONMENE urls 49 368 EIE FIOO atn E 49 8 2 2 Handheld Obituario alan 49 Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5cm Page ix 8 29 Bamer n eane a 50 AEN Cl a o EE 50 3 CAMERA Teie et Mus pott nad psgh o Shean dae ahaa a uM C dad 50 Bd BAC RG ROC IND s setae de di ead uat iu 52 omae etc pU Ir 22 S43 Load NOW Images sexos IN I aito I EMINUS UR MN EI HN eU IUE 52 Bd A E E 52 Chapter 9 REPORTS MENU COMMANDS sessesseeeeeeeeenennee teen neenr enne teen nn nennen 53 9 1 TASK INPUT SUMMARY REPORT citan 54 9 2 ANALYSIS SUMMARY rut o 54 EI Hand OTC moe D I 54 9 2 2 Disc Comptesston POLCe cincta seeds octo ios 55 92 240 BCDL and BCUL Limit Plast too al 56 9 73 O SI ad tus 56 9 2 3 1 SDL and SUL Limit Flags AS 56 924 Les Eoadand Balane iiO 56 9 2 5 Required Coefficient of Ground Friction eee 57 95 FATIGUE REPORT siii aa 57 9 4 3D LOW BACK ANALYSIS REPORT eene rennen 58 9 5 SAGITTAL PLANE LOW BACK ANALYSIS REPORT 59 9 5 1 E
56. e central axis points up vertically and the angle refer ence line projects straight ahead from the figure The reason for the odd measurement center is that the human graphic drawing origin is at the center of the hips This is to be improved in the future Type Three barrier options are available none wall and table Only one barrier can be dis played at a time and the default is no barrier The wall type is oriented vertically and al ways faces the figure The table type is ori ented horizontally with its inner edge always facing the figure Length This field specifies the barrier s left to right horizontal dimension This dimension appears the same and is measured the same for either the wall or the table barrier types Width This field allow the user to specify the barrier s vertical dimension as a wall or its horizontal front to back dimension as a table 3D Static Strength Prediction Program Version 5 0 Thickness This field allows the user to specify thickness of the barrier Distance This input field specifies the radial distance of the barrier from the hominoid s central vertical axis For both the wall and the table this dimension is measured hori zontally from the vertical axis of the cylindri cal coordinate system to the barrier s center see above Azimuth This input field specifies in degrees the angular position of the barrier s center with respect to a reference line projecting straight out
57. e crosshair and arrowhead position The color may also be defined using the input fields When the desired color is attained click on Add to Custom Colors to update the Custom Color list in the pri mary dialog box 8 4 Load New Image Click on Browse to load a digital image file and set it as the background for the oblique window The 3D Static Strength Prediction Program Version 5 0 Windows file input dialog will appear Select an image file and click Open Currently supported file types include gif ico and jpeg The digital image will appear in the background of the oblique win dow The Graphic Human Model will be visible on top of the image Choose either Center or Stretch to adjust the view of the image Finally select the Use Image box to enable the image to be displayed 8 5 LIGHT The light dialog Figure 8 6 controls the shading of the hominoid Automatic shading can be selected by checking the Use fixed 3 point lighting scheme button The light intensity can then be chosen for the desired effect Single Point Lighting Light position with respect to subject Front Back Left Right Front Left C Center Center Top Bottom Top C Center C Back Bottom Right Checking this box will nullify the choices made above Use fixed 3 point lighting scheme m Light Intensity I 60 Reset Lighting to Default RN Figure 8 6 Oblique View Light dialog box Copyright 2005
58. e Prediction to use the posture pre diction dialog box However sometimes the hand locations are not known In this case the user may want to specify the hand locations by selecting the hands and dragging to the desired location in an appropriate orthogonal view The other hand will remain in the same location but the rest of the body will be predicted Therefore the hand positions should be set before altering the rest of the body Both hands can be moved at the same time by hold ing down the CTRL key while selecting either hand 3 2 2 8 Modeling Whole Body Pos tures In order to model postures most efficiently when using the inverse kinematics method the joint positions must be specified in the order specified above As mentioned earlier the general procedure is first obtain a starting posture by specifying the position of the hands in the posture prediction win dow and then fine tune or adjust the posture by manipulating joints beginning with the legs and then proceeding upward towards the hands Remember that when manipulating joints other than the hands the hands will remain in the same posi tion and that the inverse kinematics algorithm will always estimate the positions of body segments which are between the joint altered and the hands Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 14 3 3 OBLIQUE VIEW WINDOW The oblique view window is the lower left hand view window F
59. e load projected onto the X Y and Z axes and also as the resultant magnitude 1 A positive X component indicates a task re quiring a sideways push to the left while a negative X component indicates a task re quiring a sideways push to the right 2 If the task involves pulling towards the body the Y component will be positive if the task Limb Angles Deg Trunk Angles Deg Fore Arm 45 Upper Arm 60 Upper Leg Lower Leg 390 Flexion Rotation Bending Hands Neutral Left Right Horz Vert Lat Location in 15 8 24 2 7 0 Horz Deg Vert Deg Maaflb Force 90 90 10 0 Horz Vert Lat 15 8 24 2 7 0 Horz Deg Vert Deg Maaflb 90 90 10 0 3DSSPP 5 0 0 Copyright 2005 The Regents of the University of Michigan ALL RIGHTS RESERVED Figure 9 2 Task input summary report Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 involves forward pushing the Y component will be negative 3 If the task involves lifting the Z component of the hand forces will be negative a posi tive Z component indicates a task using a downward push 9 2 2 Disk Compression Force The 3D low back compression force at L4 L5 is displayed below the hand forces Both a numeric Analysis Summary Description Company chuck Analyst Unknown Date 06 09 05 Task Untitled Task
60. ees Increment 3D Static Strength Prediction Program Version 5 0 FIN ot wesw wo Ok serm poe Apply Backward Combined Hands Exertion Cancel up Figure 5 24 Task Input Hand Loads dialog box for 2D mode 5 11 2 Hand Load Entry 2D Mode To enter the hand loads in 2D Mode 1 Choose Task Input Hand Loads to display the Hand Loads dialog box Figure 5 24 2 Enter the combined load magnitude for both hands This value will be split equally be tween the hands 3 Enter the force vector vertical angle accord ing to the convention described previously If the vector points backward select the Back ward button such that the box is checked 4 Click OK when the parameters are entered correctly 5 11 3 Hand Load Force Vector De scriptions 3D Mode The hand force vector angle convention used in the 3D Mode is different than in the 2D Mode Separate force magnitudes and directions are en tered for each hand The angle convention is the same for both hands 5 11 3 1 Horizontal Angle Illustrating the hand load force as a vector with its tail in the grip center of the hand and its arrow pointing in the direction of the force the hand load horizontal angle is the angle between the X axis and the force vector when viewing the figure from over head i e when the force vector is projected onto the X Y plane If the vector is directed forward of a vertical plane at the hand the angle h
61. en the posture is satisfactory click OK to close the dialog box 5 7 3 Body Segment Angle Dialog Box 3D Mode Choosing Task Input Body Segment Angles indicates that the body segment angle method for posture entry is to be used and displays the Body Segment Angle entry dialog box Figure 5 8 To use the body segment angle method for pos ture entry 1 Choose Task Input Body Segment Angles to display the Body Segment Angle dialog box Figure 5 8 2 Enter the angles according to the conventions Body Segment Angles m Limb 4nales Forearm Upper Arm Upper Leg Lower Leg 3D Static Strength Prediction Program Version 5 0 described below for 3D Mode angles To enter a value in a specific field click on the field or use the TAB key to move from field to field The field sequence using the TAB key is to move through the left side first then the right side and finally the trunk angles If the posture is symmetric enter the angles for the right side and click on the SYMME TRY button This time saving feature copies the values from the right side into the respec tive left side spaces however the left side values can still be changed or entered indi vidually if desired Note that this feature only copies the right side values to the left side not vice versa A body segment angle can also be altered using the INCREMENT buttons Click on the angle value then click on the increment value desi
62. entiles also is balancing the mo ment equilibrium on the Erector Spinae muscle side of the equation i e helping to reduce the required Erector Spinae muscle force According to the Abdominal Pressure Force Low Back Muscle Force Disk Compression Force Hand Load Figure 1 1 Simplistic diagram of low back forces for lifting Sagittal Model Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Page 3 Torsion About the L5 S1 Normal Vertebrae X Right Side Frontal Plane Shear Force Y Anterior Posterior Dir Sagittal Plane Shear Force On L5 S1 Disc Resultant Vector Sum of X and Y Shear Force On L5 S1 Figure 1 2 Shear forces and torsion on a vertebral disc model s algorithm for a press down task however the anterior rectus abdominus muscle would pro duce a contractile force to maintain L5 S1 moment equilibrium acting at the muscle moment arm dis tance which also varies between males and females as well as between population percentiles As documented so far the L5 S1 compression algo rithm is based on Erector Spinae muscle contrac tion Rectus Abdominus muscle contraction either one active at any given time the Abdominal Pres sure affected by posture and the resultant moment and forces at L5 S1 joint Erector Spinae Rectus Abdominus and Ab dominal Force computation for L5 S1 moment equi libriu
63. es of 3DSSPP that 2D users will be unable to use 2D users can operate the 3DSSPP in demo mode see section 2 6 Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Page 9 Chapter 3 SCREEN AREAS 3 1 PROGRAM WINDOW The program window Figure 3 1 contains the 3DSSPP application with its view windows dia logs and report windows At the top of the main program window is the main program title bar which contains the program title the name of the postural data file currently in use and standard Univ of Michigan s 3DSSPP 5 0 0 Untitled File Task Input Display 3 Views Oblique View Reports About Be Front Windows control buttons for the entire program If the task file has been modified from its last saved state an asterisk will appear in the title bar after the filename Note The remaining part of section 3 1 is for users unfamiliar with Windows program operation Whenever you see the text New to Windows IP Untitled Task ae Status Untitled Task m Anthropometry 5 r Hand Forces lb Hand Locations in Gender Male Percentile 50th Left 10 Right 10 Left Ht in 69 1 We lb 176 4 Horizontal 32 7 Vertical Lateral m 3D Low back Compression lb L4 L5 751 r Strength Percent Capable c X n o Shoulder Balance Acceptable Figure 3 1 3DSSPP main program window
64. gment from the L5 S1 disc to the center of the shoulders The rotation should be measured as the left shoulder location relative to the X axis As shown in Figure 5 16 if the left shoulder is rotated behind the X axis the angle is positive As shown in Figure 5 17 if the left shoulder is rotated in front of the X axis the angle is negative In other words Y Figure 5 16 Positive axial rotation 3D Static Strength Prediction Program Version 5 0 Y Figure 5 17 Negative axial rotation for counter clockwise rotation the angle is positive and vice versa The range of motion for this angle is limited to 90 degrees 5 7 4 9 Lateral Bending Angle 3D Mode Only This is the angle formed between the trunk axis and the Z Y plane If the torso is bent towards the positive X axis the angle is positive If the torso is bent toward the negative X axis the angle is nega tive Referring to Figures 5 18 and 5 19 note that this convention holds whether the torso is bent or erect The range of motion for lateral bending is limited to 40 degrees Figure 5 18 Lateral bending angle with stooped torso Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 X Y PLANE Figure 5 19 Lateral bending angle with erect torso 5 8 POSTURE PREDICTION 3D MODE ONLY 5 8 4 Introduction to the Inverse Kine matics Method of Posture Entry Choosing Task
65. gment of the body which can be locked is the trunk The de fault is that no segments are locked The joint mark ers change to hollow circles which cannot be se lected for direct manipulation To lock body segments 1 Choose Task Input Locking Mode to dis play the Locking Mode dialog box Figure 5 21 2 Select the body segments to be locked none legs only legs and trunk or arms and trunk 3 Click OK Locking Mode Ed No Locking Lock Legs Lock Legs and Trunk C Lock Arms and Trunk Cancel Figure 5 21 Task Input Locking Mode dia log box Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 5 10 UNDO REDO POSTURE CHANGE New to 5 The Undo Posture Change command returns the posture to the previous posture after a change in the joint angles Redo Posture Change will redo the changes made to posture New to 5 The user can now undo any number of posture changes In previous versions only a single change could be undone Similarly Redo can be used to redo any number of changes to the joint angles Undo and Redo work for all pos ture changes whether made by direct manipulation posture prediction or directly through the Body Segment Angles dialog Changes made by moving to 2D mode or by loading a new file cannot be undone New to 5 We have designed this new func tionality to aid yo
66. he full screen display button may be necessary to view an entire report on the screen As an alternative the report windows have scroll bars on the right side and bottom to scan the con tents within the window The window borders may also be dragged to re size the window Refer to Windows Help for more details on window sizing arranging and button functions See Chapter 9 for a description of each report m Hand Locations in Right Ht fin 63 1 wt lb 176 4 Horizontal 158 158 Vertical 24 2 24 2 Lateral 7 0 7 0 m 3D Low back Compression Ib L4 L5 631 m Strength Percent Capable Elbow Shoulder Torso Hip Knee Ankle 100 33 35 32 33 Balance Acceptable 33 Coef of Friction O J 3DSSPP 5 0 0 Copyright 2005 The Regents of the University of M ichigan ALL RIGHTS RESERVED Figure 3 6 Results Status window Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 16 3D Static Strength Prediction Program Version 5 0 Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Page 17 Chapter 4 FILE MENU COMMANDS The File Menu Figure 4 1 contains the file man agement and printing options for 3DSSPP Addi tional file management functions are available through Windows Univ of Michigan s 3DSSPP 5 0 0 Untitled ES Task Input Display 3 Views Oblique
67. hrough the Task Input Posture Prediction dialog box 3DSSPP then predicts a possible posture based on inverse kinematics and a posture preference al gorithm For either method the user may adjust the pos ture further using the direct manipulation method by selecting a joint segment and indicating a new joint position by dragging to the location Or if de sired the direct manipulation may be used initially to explore various joint positions without using ei ther of the other posture entry methods 5 1 DESCRIPTION Selecting Task Input Description allows the user to specify the name and other information relative to the task being analyzed and include additional comments about the task The name and part of the comment field appear in the analysis report headers The following inputs are available Figure 5 2 Task name This field allows input of the task name Analyst name This field defaults to the User Name used when starting 3DSSPP Comments This field allows additional com ments relevant to the task such as environ mental conditions to be appended to the task record Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 24 Task Description Task Name Untitled T ask Analyst Name Unknown Comments Cancel Figure 5 2 Task Input Description dialog 5 2 SET METRIC ENGLISH UNITS This command toggles the units used for data entry and analysis results betwee
68. ich the file was last saved If the task parameters have never been saved choosing File Save opens the same dialog box used by File Save As 4 5 SAVE AS Choosing File Save As will allow the current task settings to be saved under a new file name To do so 3D Static Strength Prediction Program Version 5 0 1 Choose File Save As Figure 4 1 2 Enter the desired file name using the meth ods listed above in Section 4 1 3 If the file name already exists a dialog box appears asking if the existing file is to be re placed with the new file Choose the appro priate response If NO the previous dialog box is reopened to allow a new file name to be entered If YES the existing file is over written 4 6 SET STARTUP TASK TO CUR RENT New in 5 New to 3DSSPP 5 is the ability to save a set of input and view parameters as the Startup Task Selecting this option will cause 3DSSPP to save all current parameters including joint angles colors window positions reports open hand loads etc in a startup task file This file will be opened automatically whenever 3DSSPP loads Use this option to create a default workspace with commonly used parameters New in 5 For example if the you wish to always work with a different colored background or to position the workspace windows a certain way every time you start a new task just create a new task file change the background color or reposition the windows
69. igure 3 5 and by default displays a shaded flesh human graphic figure The title bar displays the task title as entered under the Task Input Description menu New in 5 Right clicking inside the oblique view window will bring up a context menu of com monly used commands New in 5 The oblique view of the homi noid can be manipulated from the Oblique View menu see Chapter 8 by using the context menu see previous paragraph or manually with the fol lowing commands note click alone always re fers to left clicking e Click Drag Move hominoid 5D Untitled Task 3D Static Strength Prediction Program Version 5 0 e Right Click Drag Rotate hominoid Ctrl left click Drag can also be used e Shift Click Drag Left Right Zoom in out e Shift Click Drag Up Down Move camera forward or backward Alternatively rotate the mouse wheel to achieve the same effect New to Windows The title bar also in cludes buttons for controlling its size similar to the orthogonal view windows In addition its borders may also be dragged to re size the window Posi tioning the cursor over the program or view win dow borders will change the cursor to a different arrow shape If the left mouse button is then clicked and held the border can then be dragged to change the size of the window Refer to Windows Help for more details on window sizing arranging and but ton functions Figure 3 5 Oblique View
70. in Hand Positions Modify Population Factors OK Cancel Figure 5 5 Task Input Anthropometry dialog 3D Static Strength Prediction Program Version 5 0 5 6 1 Population The Population command can be used to select an alternate set of anthropometry values including Stature body weight link lengths link weights link centers of gravity and strength The default values are for a US industrial population as deter mined by the University of Michigan Center For Ergonomics The population dialog is shown in Figure 5 6 Male Factors Open Population File Reset To Default Edit Population Factors Figure 5 6 Task Input Anthropometry Population 5 6 1 1 Open Population File The Open Population File command is used to select a population file using the Windows open file dialog The anthropometric values contained in the file are used in place of the program default values 5 6 1 2 Reset to Default Population The Reset to Default Population command reinstates the program default anthropometric val ues 5 6 1 3 Edit Population The Edit Population command is used to create new population files A password is required to use this command and it is not recommended for normal program users Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 5 7 BODY SEGMENT ANGLES 5 7 1 An Introduction to the Body Segment Angles Method of Po
71. ing down on the object Rotation This field specifies the angle from a Apply Iv Use Image Select Color Cancel Figure 8 5 Oblique View Background selection dialog box Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 52 vertical plane separating the left and right halves of the object from which it is being observed Ranging from 180 to 180 degrees O degrees is looking di rectly at the front of the figure while 90 degrees is looking at the figure s left side observer s right side New to 5 The camera view can be ad justed using the mouse by clicking and dragging in the oblique view window See Section 3 3 8 4 BACKGROUND Selecting Oblique View Background allows the user to set the background of the oblique view win dow for the task being analyzed to either a solid color or a digital image Figure 8 5 8 4 1 Color Click on Select Color to select a solid color back ground for the oblique window The Windows col ors dialog will appear For basic colors click on the color desired and click OK For custom colors either click on a defined color and click OK or click on Define Custom Colors to open the custom color screen In the left box move the crosshairs around to the color desired In the right box move the little arrowhead at the far right up and down to select the shade of the color The Color Solid box will display the current color as defined by th
72. ique View Camera dialog box and under the figure change in vertical tilt As this movement occurs the camera remains di rected on the figure s hips and always upright e g does not roll In addition the figure can be made to appear larger or smaller by increas ing or decreasing the camera s focal length similar to using a zoom lens Although different combinations of and radial distance from the figure will produce the same apparent size the figure will appear bloated and distorted for short focal lengths and flattened for long focal lengths just like an actual camera 3DSSPP provides the camera metaphor for more exact matching of hominoid postures to photographs or video Selecting Oblique View Camera displays a dialog box Figure 8 4 which allows the user to select the following model viewing options Oblique View Background C Center Stretch Focal Length This field specifies the camera s focal length High focal length values magnify and flatten the image low values make the image smaller and distorted Distance This field specifies the radial distance of the camera s film plane to the center of the fig ure s hips Vertical Tilt This field specifies the vertical angle of the camera in degrees Vertical tilt is a measure of the angle from the horizontal plane at which the object is being observed Ranging from 89 to 89 0 is at waist level looking at the object and 89 is directly overhead look
73. istent with its mission of education and research desires to grant a license to use the PROGRAM subject to the terms and conditions set forth below The parties therefore agree as follows L LICENSE MICHIGAN hereby grants to LICENSEE a non exclusive non transferable right to install and use the PRO GRAM on one CPU at a time in executable form only and subject to the terms and conditions of this Agree ment If the PROGRAM is being installed and used on behalf of an educational entity then LICENSEE shall have the right to install and use multiple copies of the PROGRAM for academic training or educational pur poses Il LIMITATION OF LICENSE AND RESTRICTIONS A LICENSEE shall not use print copy translate reverse engineer decompile disassemble modify create de rivative works of or publicly display the PROGRAM in whole or in part unless expressly authorized by this Agreement B LICENSEE agrees that it shall use the PROGRAM only for LICENSEE S sole and exclusive use and shall not disclose sell license or otherwise distribute the PROGRAM to any third party without the prior written consent of MICHIGAN LICENSEE shall not assign this Agreement and any attempt by LICENSEE to as sign it shall be void from the beginning LICENSEE agrees to secure and protect the PROGRAM and any copies in a manner consistent with the maintenance of MICHIGANSS rights in the PROGRAM and to take appropriate action by instruction or agreement with its emplo
74. ity Note that the torso and pelvic angles combine to form the entered trunk flexion angle and that a lateral trunk rotation will induce a torso rotation if the trunk is also flexed m Description Company chuck Analyst Unknown Date 06 09 05 Task Untitled Task Comment Gender Male Percentile 50th Height 69 1 in Weight 176 4 lb m Calculated Limb Angles Elbow Included Shoulder Vertical Shoulder Horizontal Humeral Rotation Hip Included Knee Included Ankle Included Calculated Torso Angles Torso Flexion Extension Torso Axial Rotation Torso Lateral Bending Pelvic Rotation 3DSSPP 5 0 0 Copyright 2005 The Regents of the University of Michigan ALL RIGHTS RESERVED Figure 9 14 Posture Report Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 9 13 SPINAL FORCES AND MOMENTS REPORT Page 69 upon posture The Euler Matrix approach is imple mented for the translation described projection on to the disc surface For the spinal forces and moments report Figure 9 15 the resultant moments and forces at the spinal segments are displayed First these are presented with respect to the main x y and z global coordi nate system defining the Coronal top down Sagit tal side view and Horizontal front view planes second these are presented with respect to the lum bar rotation coordi
75. ity of Michigan ALL RIGHTS RESERVED Page 58 9 4 3DLOWBACK ANALYSIS REPORT The predicted disc compression force shown in the analysis summary screen are detailed in 3D Low back Analysis Figure 9 5 The report lists the L4 L5 disc compression force and can be compared to the NIOSH BCDL of 3400 Newtons or 770 pounds and BCUL of 6400 Newtons or 1430 pounds See Appendix III for details on the NIOSH guidelines 3D Lowback Analysis m Description 3D Static Strength Prediction Program Version 5 0 The 3D Lowback Analysis linear programming optimization algorithm calculates the L4 L5 disc rotated moments and forces and optimizes the resul tant disc compression force on the disc as a result of a three dimensional analysis of the contractile forces expected from ten major muscles in the lum ber region upper body weight above the disc and the hand forces Refer to Section 1 3 2 for a dia gram of the torso cross section at the L5 L4 lumbar level depicting the ten muscles taken into account in this three dimensional back compression algo rithm and additional technical details on the algo rithm Company chuck Analyst Unknown Date 06 09 05 Task Untitled Task Comment Gender Male Percentile 50th Height 69 1 in Weight 176 4 Ib Muscles p L4 L5 Diss Muscle Forces lb Shear x Result L Erector Spi 277 R Erector Spi 270 L Rectus 4bdo R Rectus Abdo
76. lays the unit vectors for the directions of the strength moments in the main reference global Strength Direction Vectors 3D Static Strength Prediction Program Version 5 0 coordinate system The X axis extends laterally from the origin with positive to the subjects right The Y axis extends from the origin to the front and the back of the body with positive being forward Lastly the Z axis extends vertically from the origin with positive upwards m Description Company chuck Analyst Unknown Date 06 09 05 Task Untitled Task Comment Gender Male Percentile 50th Height 69 1 in Weight 176 4 lb Moment Direction Vectors r Elbow Flex Ext Shoulder Rot n Bk Fd Abduc Adduc Humeral Rot L551 Flex Ext Lat l Bending Rotation Hip Flex Ext Knee Flex Ext Ankle Flex Ext 3DSSPP 5 0 0 Copyright 2005 The Regents of the University of Michigan 4LL RIGHTS RESERVED Figure 9 16 Strength Direction Vectors Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 9 15 PRINT REPORTS COMMAND A series of reports can be printed using the Reports Print Reports command Figure 9 17 The re ports will print in the order they are listed Use File Print Setup to change printers or printer options 1 Choose Reports Print Reports 2 Click on the check boxes to select the reports to be printed 3 Pres
77. luded in the link weight The center of gravity distance for the elbow is similarly adjusted As noted by the citation the L5 to shoulder link in cludes the head and neck weight but not the head and neck length the length displayed is that of the Anthropometry m Description Page 61 L5 S1 to the center between the shoulders The Hip to L5 link represents the pelvic bone and surround ing muscles to the L5 S1 disc Finally the center of gravity distances are measured from the end of the link which is internally closest to the feet the proxi mal end for the upper extremity and the distal end for the lower extremity Near the end of the report is the name of the population used for the analysis as set in the An thropometry dialog Section 5 6 Company chuck Analyst Unknown Date 06 08 05 Task Untitled Task Gender Male Percentile 50th Height 69 1 in W eight 176 4 lb Comment Link Lenath in Lower Arm and Hand VES Upper Arm 13 0 Shoulder to Shoulder 14 1 L5 to Shoulder Center 15 0 L5 To Shoulder Head and Neck n a L5 and Above n a Hip to L5 3 8 Hip to Hip 7 0 Upper Leg 17 8 Lower Leg 15 8 Foot 10 5 Diaphragm Moment Arm 5 9 Population Production 5 0 0 CG to Proximal End Distance in 5 8 4 1 6 8 n a n a W eiaht Ib 3DSSPP 5 0 0 Copyright 2005 The Regents of the University of Michigan ALL RIGHTS RESERVED Figure 9 8 Anthropometry Report Copyright
78. m Version 5 0 Hand Location Left Right Horizontal 1 2 11 Vertical 11 5 11 Lateral Apply Unda Cancel Figure 5 20 Task Input Posture Prediction dialog box 3 Enter the hand locations referenced to a point on the ground between the ankles by using the TAB key to move from field to field or clicking on the desired fields Horizontal refers to the distance from the above point in the forward backward direc tion where forward distances are positive and backward distances are negative Vertical refers to the distance from the floor where positive values are above the floor and negative values are below the floor Lateral refers to the side to side distance from the center of the body where positive values are to the right and negative values are to the left 4 Click OK after the parameters are entered to predict posture and exit the dialog box 5 9 LOCKING MODE One way to enhance the inverse kinematics method is by using segment locking This feature allows certain body segments of the modeled posture to be locked preventing the inverse kinematics algo rithm from changing the joint angles of those seg ments For example if the legs are in the desired posture while using direct manipulation the legs should be locked before manipulating the hand po sitions If the legs are not locked the legs will be re predicted and the joint angles changed by the inverse kinematics algorithm A second se
79. m are based on the moment arm length data with standard deviation as compiled from studies by McGill Patt and Norman 1988 Reid Costigan amp Comrie 1987 Nemeth and Ohlsen 1986 and Chaffin Redfern Erig and Goldstein 1989 1 3 2 3D Compression and Torso Mus cle Force Optimization at L4 L5 Torso muscle moment arms and muscle orienta tion data for the LA L5 level have been studied more extensively than at any other lumbar level Hence the three dimensional back compression optimiza tion is computed at LA L5 lumbar level L4 L5 level torso muscle five on the left side and five on the right side areas moment arms and contractile force direction data were utilized from studies by McGill Patt and Norman 1988 Reid Costigan amp Comrie 1987 Nemeth and Ohlsen 1986 Chaf fin Redfern Erg amp Goldstein 1989 Kumar 1988 Tracy et al 1989 and McGill and Norman 1986 Torso muscle tensile forces are computed using the double optimization technique of Bean Chaffin and Shultz 1988 First an upper bound on muscle intensity the ratio of muscle force to physiological cross sectional area is found by minimizing the maximum muscle intensity such that the moment equilibrium conditions are satisfied and second the muscle forces satisfying the moment conditions and muscle intensity bounds which minimize the muscu lar contribution to spinal compression force are de termined L4 L5 joint resultant moments
80. manipulated as desired by the analyst The orthogonal view windows consist of three views top view horizontal plane front view frontal plane and right side view sagittal plane When a new task file is opened the default layout locates the top view in the top left window the front view in the top center window and the side view in the top right window The figures rep resenting the posture being modeled are drawn to scale according to the selected anthropometry and include force direction arrows originating from the hand locations force vectors which are perpendicu lar to the plane of the screen are not drawn These are the only windows in which direct manipulation can be used to adjust the modeled posture in addition direct manipulation can only be used when the figures are displayed as stick fig ures Univ of Michigan s 3DSSPP 5 0 0 Untitled File Task Input Display RATES v Show Forces B E pi uada c NN im Colors Oblique View Reports Top Figure 7 1 3 Views menu in 3DSSPP 7 1 SHOW FORCES Selecting 3 Views Show Forces allows the user to toggle the display of joint and hand forces in the orthogonal view windows 7 2 COLORS Selecting 3 Views Colors brings up a dialog box Figure 7 2 that allows the user to change the color of any element in the orthogonal view windows To change any color simply click the correspond ing button and use the color selection dialog box to choose a new c
81. mple report layout as printed through the Windows clipboard and a word processor Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Page 23 Chapter 5 TASK INPUT MENU COMMANDS The Task Input Menu Figure 5 1 contains the dia log boxes for specifying a description of the analy sis task the main program controls and the three major inputs required to use 3DSSPP the worker anthropometry posture and hand loads for the task to be analyzed There are three methods by which postures can be entered into 3DSSPP the body segment angle method the posture prediction method and the di rect manipulation method The body segment angle method requires the analyst to specify the appropri ate 15 angles for the body through the Task Input Body Segment Angle dialog box The posture pre diction method requires the user to define the loca Univ of Michigan s 3DSSPP 5 0 0 Untitled Display 3 Views Oblique View Reports Description Set Metric Units Set 2D Mode Gravity Support Selection Ctri A Anthropometry Body Segment Angles Ctrl B Posture Prediction Locking Mode Undo Posture Change Ctrl L Ctrl 2 Redo Posture Change Ctrl Hand Loads Ctrl H Advanced Hand Loads Joint Loads Ctrl J Run Batch File Figure 5 1 Task Input menu in 3DSSPP tion of the hands in three dimensional space t
82. n that peo ple do not normally let the Center of Pressure get close to the edge of the BOS supposedly as a safety factor Therefore a Functional Stability Region FSR has been defined and experimentally deter mined within which people tend to keep the Center of Pressure Between the perimeter of these two regions is a critical region of balance where a per son may feel insecure m Description Comment Company chuck Analyst Unknown Date 06 09 05 Task Untitled Task Gender Male Percentile 50th Height 69 1 in Weight 176 4 Ib Right Front Right Middle Right Back Left Front Left Middle Left Back 4 5 8 5 6 6 4 1 3 1 3 4 5 8 5 6 6 4 1 3 1 3 Center of Pressure Calculations r Boundary Coordinates x y in gt r Distance to Boundaries in Dist to Front 3 6 Dist to Back 0 8 Dist to Right 35 Dist to Left 35 m Center of Pressure Coordinates in Forward to Backward 3 1 Right to Left 0 m Leg Loads Left 50 Right 50 Stability Balance Acceptable Residual Support Moments in lb A i 120 7 0 0 Maximum Balance Moments Left i Right A Ball 1884 7 Heel 177 9 Y 685 3 685 3 Z A M 0 0 1884 7 685 3 0 0 0 0 177 9 585 3 0 0 3DSSPP 5 0 0 Copyright 2005 The Regents of the University of Michigan ALL RIGHTS RESERVED Co
83. n the Metric and English systems The current units are switched to the units specified in the displayed command The default is English units Any open windows will be updated immediately 5 3 SET 2D 3D MODE This command toggles between the 2D and 3D en try mode The 3D 2D program icon at the top left corner of the program windows changes to indicate the current mode 2D mode limits the input to a sagittal plane symmetric posture with symmetric hand forces The entry dialog boxes are simplified and posture prediction is disabled The posture can only be entered and changed by body segment an gle entry A version of 3DSSPP may be purchased which prohibits the operation of the 3D Mode In this case the 3D Mode can only be run in demo mode Pos ture prediction and other features are disabled 3D Static Strength Prediction Program Version 5 0 5 4 GRAVITY New in 5 This menu item will open a dialog box that allows the user to alter the gravity factor that 3DSSPP uses in its calculations Figure 5 3 Several suggested alternative gravity values are provided Note that changing the gravity value will not affect external forces on the body only the force caused by the weight of the body s links Acceleration of Gravity 32 185 fus Earth Gravity Y Apply Cancel Figure 5 3 Task Input Gravity dialog 5 5 SUPPORT SELECTION New in 5 This command opens the Support Selection dialog which controls standi
84. n understanding the de scriptions and instructions found in this manual Orthogonal 3 View views The three posture entry windows displaying the posture being modeled in top right side and front views Oblique view The window displaying a figure in the posture modeled from a user defined orientation In new files this is the lower left hand window Vertical Tilt Referring to the camera metaphor of the oblique view this is a measure of the angle from the horizontal plane at which the object is being observed Ranging from 89 to 89 degrees O degrees is at waist level looking at the object and 89 degrees is di rectly overhead looking down on the object Rotation Also referring to the camera metaphor of the oblique view this is a measure of the angle from a vertical plane separating the left and right halves of the object at which it is being observed Ranging from 180 to 180 degrees 0 degrees is looking directly at the front of the figure while 90 degrees is look ing at the figure s left side Focal length Also referring to the camera meta phor of the oblique view this simulates the effect of the camera focal length on the im age for better posture matching with photo graphs Long focal lengths magnify and flat ten images while short focal lengths shrink and distort images Distance Referring to the camera metaphor of the oblique view this is the distance from which the figure is observed Input field The
85. nate system as defined by trans lating the moments and forces at the segmental level onto the disc surface which rotates dependent Furthermore as related to the postural input LA L5 disc rotation is considerably less than L2 L3 disc rotation the L4 L5 disc 1s located lower within the torso The empirical relations between the disc rotation three dimensional and the worker s maxi mum flexion extension lateral bend and the torso axial rotation have been derived from published experimental x ray studies Spinal Forces and Moments Description Company chuck Analyst Unknown Date 06 09 05 Task Untitled Task Gender Male Percentile 50th Height 69 1 in Weight 176 4 lb Comment Global Forces Ib Y Z WM 0 0 96 4 0 0 n a n a n a 0 0 0 0 n a 0 0 Moments in lb L2 L3 L3 L4 L4 L5 L5 81 Rotated n a Moments in lb Forces Ib x Y Z x Y Z 0 0 0 0 0 0 0 0 0 0 0 0 0 0 n a 7 1 26 0 59 1 n a 96 4 96 7 96 9 n a 0 4 22 8 45 1 n a L2 L3 L3 L4 L4 L5 ESE 0 0 0 0 0 0 n a 3DSSPP 5 0 0 Copyright 2005 The Regents of the University of Michigan ALL RIGHTS RESERVED Figure 9 15 Spinal Forces and Moments Report Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 70 9 14 STRENGTH DIRECTION VECTORS REPORT The strength direction vectors report Figure 9 16 disp
86. ng and seated support parameters Figure 5 4 5 5 1 Standing or Seated Support Se lection New in 5 Use this box to convert between a standing analysis and a seated analysis In a standing analysis the program automatically esti mates support forces for the feet in order to balance the bodyweight and other forces on the body In a seated analysis the program can estimate support forces including forces supporting the ischial tube rosities of the pelvis the back of the upper legs be hind the knees the back of the torso and the feet New in 5 In addition when in seated mode the center of the measurement coordinate system is at the Seat Reference Point SRP The SRP is automatically calculated from the intersec tion of the trunk and upper leg angles and is dis placed perpendicular to the body segments by popu lation factors which are fractions of stature Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Support Selection Feet Support Both feet supported C Left foot supported Left fis C Right foot supported C No foot s Ippor Foot Splay Angle degrees Right fi 5 15 sitting standing 3 Frontiseat pan 7 5 walking 3 5 striding Support Selection Standing C Seated Seat Back rest center height m Seating Parameters Additional Pelvic Tilt degrees fo D standing 15 sitting 25
87. nge the pelvic tilt The program estimates the pelvic tilt assuming a standing posture Additional tilt as when seated can be added Suggested normal values are displayed 5 6 ANTHROPOMETRY Selecting Task Input Anthropometry opens the Anthropometry dialog box Figure 5 5 To change the anthropometry being analyzed 1 Choose Task Input Anthropometry Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 26 2 Click on the desired gender male is the de fault gender 3 Select the method to be used to select the anthropometry either 95th 50th 5th popula tion or data entry to input a specific height and weight The default is the 50th percen tile 4 If the method to be used is data entry move the cursor to the input fields and enter the height and weight If one of the percentiles is selected then the input fields contain the selected percentile height and weight 5 Click Apply to update the view windows and keep the anthropometry dialog box displayed or click OK to update the view windows and close the anthropometry dialog box Extreme anthropometries are not accommo dated by the model The data entry values accept able for height are 50 76 inches 127 193 cm and for weight are 100 244 pounds 45 4 110 kg Anthropometry Male gmmeee C Female Height and Weight goth Apply e 50th C Sth C Data Entry Height 69 3 in Weight 173 8 Ib Mainta
88. ntial or incidental damages the above exclusions may not apply to LICENSEE In no event however will MICHIGAN be liable to LICENSEE under any theory of recovery in an amount in excess of the license royalty paid by LICENSEE under this Agreement B LICENSEE agrees that MICHIGAN has no obligation to provide to LICENSEE any maintenance support or update services Should MICHIGAN provide any revised versions of the PROGRAM to LICENSEE LICEN SEE agrees that this license agreement shall apply to such revised versions C MICHIGAN does not warrant endorse or certify any individual or organization as a trainer for the PRO GRAM or any special strength testing data input or other equipment to be used with the PROGRAM D Ifthe physical media provided hereunder contains any defects upon receipt by LICENSEE LICENSEE shall have thirty 30 days in which to return said defective media and MICHIGAN shall provide a replacement free of charge V WARRANTY OF LICENSEE LICENSEE warrants and represents that it will carefully review the User s Manual and that it is aware of the necessity for training in the field of ergonomics and the underlying biomechanical model of the PROGRAM and of the necessity for having an expert in the field of ergonomics review and interpret data provided in or by the PROGRAM including the User s Manual LICENSEE further warrants and represents that it either has such training or will incorporate the services of individuals with s
89. nting method the Windows Clipboard is used as a translator between 3DSSPP and another Windows application typically a word processor After the 3DSSPP views are arranged tiled in the desired format the program window is copied to the clipboard by choosing File Copy Application or File Copy Desktop Next the operation is switched to the other Windows application and the Clipboard contents are pasted into the working area Since the pasted 3DSSPP layout is treated as a graphic image it can be manipulated within the other application as necessary to create a custom report Please note that only one display can be cop 1ed to the Clipboard at one time For example to copy the five views into a Win dows based word processing program Figure 4 4 1 Arrange the windows as desired by clicking and dragging the borders to shrink each win dow and then by clicking and dragging on the title bars 2 Choose File Copy Application 3 Switch to the word processing application if not already running load the word process ing application with an appropriate docu ment 4 Position the cursor in the word processor at the desired location and paste the Clipboard Page 21 contents into the document To copy reports as in Figure 4 4 to the word processor 1 Select the desired report 2 Maximize the report window to full screen using the button in the window title bar 3 Choose File Copy Application 4 Switch to
90. o be changed in 3DSSPP The default is portrait page is taller than it is wide when the output is viewed upright Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 20 Paper Size This option allows the use of non standard size paper the default is standard letter size 8 1 2 x 11 Paper Source This option refers to the paper handling capability of the printer upper and lower tray bin feeders for single sheets of paper tractor settings for continuous feed or manual feeds for one sheet at a time Properties These are options specific to the printer selected generally regarding printing quality Refer to the printer manual or click on the HELP button if available for details Network This button allows you to connect to a printer on your local network 4 11 PRINT APPLICATION Selecting File Print Application prints the 3DSSPP main program window i e Figure 3 1 as displayed at the time of selection Printing begins without any further user input relying instead on the default print settings The process may be inter rupted by clicking on CANCEL in the print status box that appears onscreen Print Setup Printer Name Status Ready Type Adobe PDF Converter Where My Documents Comment Creates Adobe PDF Paper Size Letter x Automatically Select Y Source Network 3D Static Strength Prediction Program Version 5 0 4 12 PRINT DESKTOP Selec
91. ody joints or segments Thus in most cases the general procedure employed when using the inverse kinematics method will be to first specify a starting posture by setting the locations of the hands and then adjusting the posture by ma nipulating other joints of the body No matter how much the rest of the body is manipulated the hands will remain in the same position 5 8 2 Posture Prediction Dialog Box The posture prediction dialog box Figure 5 20 is used in 3D entry mode to specify the positions of the hands relative to a point on the floor between the ankles Note that the hand orientation helps the computer decide upon elbow elevation When the palm is prone palm down the elbow tends to be high in the air The elbow is lower when the hand is semi prone and is very low when the palm is supine palm upward A good rule of thumb is that if there is any doubt about the hand orientation choose semi prone If the palm is not completely pointing down or completely pointing up the best choice is semi prone To use posture prediction 1 Choose Task Input Posture Prediction 2 Select the hand orientation that best describes the worker Supine palms up Semi prone palms facing each other Prone palms down Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 34 Posture Prediction Hand Orientation in C Pronated Neutral Supinated 3D Static Strength Prediction Progra
92. of Michigan ALL RIGHTS RESERVED Page 8 3D Static Strength Prediction Program Version 5 0 The University of Michigan s 3DSSPP Registration Company Name Registration Number HHHHH HHHHH initially you can still choose to experience 3DSSPP in Demo Mode To enter a registration number after running the program for the first time simply choose registra tion under the About menu A correct registration code will only need to be entered once When a major revision of 3DSSPP is released however a new code may be required 2 5 STARTUP SCREENS Before the data entry windows appear three pre liminary screens of general information are dis played which should be read carefully if the pro gram is being used for the first time After each screen is read either press ENTER or click on the OK button to continue After the final information screen the program will load 2 6 DEMO MODE New in 5 Users without a proper registration code can run 3DSSPP in Demo Mode In Demo Mode all functionality of 3DSSPP can be accessed but the Anthropometry of the hominoid will be locked at 5th Percentile Male and calculations should not be used as indicative of the general population mo Demo Mode Figure 2 1 3DSSPP Registration dialog box 2 7 2D MODE HHHHH HHHHH If you have purchased a 2D version of the program your registration code will indicate this as it con tains the string 2D There are some featur
93. of Michigan s 3D Static Strength Prediction Program Es 3DSSPP is based on over 30 years of research at the Center for Ergonomics regarding the biomechanical and static strength ca pabilities of the employee in relation to the physical demands of the work environment This manual provides the user of the 3D Static Strength Predic tion Program with an instructional reference for properly applying 3DSSPP to aid in the evaluation of the physical demands of a prescribed job Fur thermore 3DSSPP can aid the analyst in evaluating proposed workplace designs and redesigns prior to the actual construction or reconstruction of the workplace or task Used both as a job design evaluation tool and for instructional purposes the program is applicable to worker motions in three dimensional space 1 4 PURPOSE OF MANUAL The purpose of this manual is to provide the analyst with 1 A description of the hardware and software necessary to run the program 2 An explanation of the task parameters pro gram options and the information obtainable from the program 3 Instructions on how to apply the program and interpret the results 1 2 CAUTION 3DSSPP should not be used as the sole determinant of worker strength performance or job designs based on that performance Other criteria and professional judgment are required to properly design safe and productive jobs Be sure to read the End User Li cense Agreement at the beginning of this manual
94. olor Orthogonal View Colors Li EE r Figure Colors Figure Cole Background Force Color Floor Colors i Fill Outline Cancel Figure 7 2 3 Views Colors dialog box Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 46 3D Static Strength Prediction Program Version 5 0 Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Page 47 Chapter 8 OBLIQUE VIEW MENU COMMANDS The Oblique View Menu Figure 8 1 contains the dialog boxes for controlling the display attributes of the oblique view window While the orthogonal views are useful for viewing vertical and horizontal angles for data entry they do not offer an accurate means of comparing the final posture to photo graphs or video of the actual worker performing the task 3DSSPP provides this user defined oblique view utilizing a Graphic Human Model This view simplifies the process of comparing the modeled posture to photographs and aids in more realisti cally representing proposed changes to task pos tures In the oblique view window the human figure representing the modeled posture may be viewed from any distance and view angle Additionally a camera focal length can be simulated which changes the perspective in the scene This is very useful when comparing the modeled posture to pho tographs taken with diffe
95. on Program Version 5 0 New in 5 Clicking the right mouse button right clicking inside one of the 3 View windows will bring up a context menu of commonly used commands The windows within a program are sometimes referred to as tiles and the act of arranging the win dows is called tiling The tiling of the three or thogonal view window and the other two windows is controlled under the Display menu To automati cally fit all five main windows inside the primary program window just press Ctrl T or select Dis play Tile Now See Chapters 6 and 7 for addi tional comments and more details on display op tions New to Windows As with the program window the borders of the orthogonal view win dows may be dragged to re size the window Posi tioning the cursor over the program or view win dow borders will change the cursor to a different arrow shape If the left mouse button is then clicked and held the border can then be dragged to change the size of the window When adjusting the view window borders in this way all five windows can be shrunk to remain in view when the program win dow is shrunk or to allow the display of an addi tional window or dialog box Refer to Windows Help for more details on window sizing arranging and button functions 3 2 4 Direct Manipulation To manipulate the posture through the Orthogo nal View windows select the joint to be manipu lated by clicking on one of the round solid joint
96. onsistent terms are deemed rejected by MICHIGAN D Unless otherwise exempt therefrom LICENSEE agrees that it will be responsible for any sales use or excise taxes imposed by any governmental unit in this transaction except income taxes E LICENSEE acknowledges that the PROGRAM is of United States origin Licensee agrees to comply with all applicable international and national laws that apply to the PROGRAM including the United States Export Administration Regulations as well as end user end use and destination restrictions issued by the United States Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5cm Page v TABLE OF CONTENTS Copyright and Disclaimer aran ita ii DE E DH RU VASE 11 End User License ADEMAS ae 111 Casper INTRODUCTION OS I LE PURPOSE OE MANTA deis 1 L2 CAUTION CM DE 1 A A enitn utut atiende A 1 LIT L S 1 Forces and Moments A ee ee 2 1 3 2 3D Compression and Torso Muscle Force Optimization at L4 L5 3 1 3 3 Static Strength Model ui aras 4 1 4 NEW FEATURES OF VERSION soldada asia 4 1 5 REMOTE OPERATION acit esr iet e aed e i DSi RU edge 4 L6 ERROR REPORTING it Qe ID E ED ta RO UNO EIE 3 1 7 SPECIAL DEFINITIONS averia 5 LS SPECIAL TYPEFACES ni e Stas o 6 Chapter 2 GETTING STARTED 00 e A e oq E ies ences pads 7 21 HARDWAREREQUIREMENTS eeeeetieeteesisecos trenes ener ea sees e tin enda aee iuda 7 22 SOF
97. ositioned at the midpoint of the hands and scaled to fill the space between the hands The default is no object Height With this field the vertical dimen sion of the handheld object is specified in inches or centimeters depending on the units currently selected The vertical dimension is measured from the bottom to top of the ob ject at its largest cross section Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 50 Depth With this field the horizontal forward backward dimension of the hand held object can be specified in inches or cen timeters depending on the units currently selected The horizontal dimension is meas ured from the front of the object farthest side from the figure to its back closest side to the figure along a line that lies in the global horizontal plane and is perpendicular to the line connecting the hand centers In the three dimensional display typically appears as the depth of the object when the figure is viewed from the side 8 2 3 Barrier A barrier represents either a wall or a table as a thin plate of user defined thickness A wall and a table cannot be displayed simultaneously The barrier may be repositioned if it appears to be in contact with the humanoid The Distance Elev and Azimuth input fields refer to a cylindrical coordi nate system with the origin over the center of the feet at the height of the hips when standing Th
98. ppend C Tab tea Figure 9 18 Reports Export Summary dia log box C verwrite Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 72 3D Static Strength Prediction Program Version 5 0 4 The Export Summary Options dialog box appears Select the type of output the type of delimiter and file mode desired 5 Press ENTER or click OK 6 When the file has been written a dialog box appears stating Summary successfully ex ported 9 16 1 Export Output File Format All selected output values for each analysis are ex ported on one line as text values The following values are always exported at the beginning of the line Analyst company units task name gender height and weight Immediately thereafter follow the selected blocks of data values Each block be gins with the block abbreviation text string value The abbreviations and block values are as fol lows Hand forces hand forces body segment angles seg ang summary results summary strength str cap posture angles post ang joint locations nt loc joint moments nt mom and low back low back The data values included in each block are listed as follows Hand forces include hand forces right force magnitude r force vert angle r force horiz angle left force magnitude l force vert an gle and 1 force horiz angle Body segment angles include seg ang r forearm ve
99. pyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Figure 9 10 Balance Report Standing Page 64 9 8 3 Balance Condition The calculation values listed in the balance re ports include the Basis of Support coordinates X to the right and Y forward with respect to the human form graphic the Center of Pressure coordinates and the distances from the Center of Pressure to the front back right and left boundary The stability condition output is either ACCEPTABLE CRITI CAL or UNACCEPTABLE ACCEPTABLE CP BALANCE The Center of Pressure location is within the FSR and the posture is stable CRITICAL CP BALANCE The Center of Pres sure location is outside the FSR and yet within the BOS The posture is stable but the person will not feel secure UNACCEPTABLE CP BALANCE The Center of Pressure is outside the BOS and posture cannot be maintained 3D Static Strength Prediction Program Version 5 0 9 8 4 Center of Pressure Graphic The balance reports include a graphical depic tion of the COP BOS boundary and the supporting surfaces The output is also included in the Status Window of the main screen For the standing case the graphic shows the feet and the green BOS region The COP appears as a small yellow dot The images of the feet will change as the posture of the lower extremity is changed and the BOS will automatically adjust For the seated case the graphic shows the pelvis and feet if
100. r ESS Forward Seat Edge Ischial Tuberosity Backrest Hip 0 0 0 0 Knee 0 0 0 0 Ankle 0 0 0 0 Heel of Foot 0 0 0 0 Front of Foot 0 0 0 0 65 8 0 0 0 0 65 8 88 2 0 0 0 0 88 2 nn 0 0 0 0 95 7 79 0 0 0 0 0 79 0 19 2 0 0 0 0 19 2 3DSSPP 5 0 0 Copyright 2005 The Regents of the University of Michigan ALL RIGHTS RESERVED Figure 9 11 Forces Report Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 66 9 10 LOCATIONS REPORT The locations report Figure 9 12 lists the calcu lated locations of each joint hand and supporting surface The locations x y z are listed in the hand reference coordinate system For standing cases the origin 0 O 0 of this coordinate system is at the center of the feet Center of the ankles pro jected downward to the floor support of the lowest foot For seated cases the origin 0 0 0 of this coordinate system is at the Seat Reference Point Locations 3D Static Strength Prediction Program Version 5 0 SRP The SRP is automatically calculated from the intersection of the trunk and upper leg angles and is displaced perpendicular to the body segments by population factors which are fraction of stature The X axis extends laterally from the origin with positive to the subjects right The positive Y axis extends forward from the origin and the positive Z axis extends vertically from the origin with positive upwards Thi
101. r both the right and left forearm horizontal angles Note that the lower arm horizontal angle does not have meaning when the lower arm is perfectly vertical it has no projection onto the X Y plane other than a point and need not be entered in this case Page 31 Figure 5 14 Forearm horizontal angles 5 7 4 7 Trunk Flexion Angle 2D and 3D Mode This is the angle between the projection of the trunk axis the center of the hips to the center of the shoulders onto the Z Y plane and the positive Y axis Figure 5 15 When standing straight the trunk angle is 90 degrees If the trunk is level with the horizontal plane ground the angle is 0 If the trunk is flexed below the horizontal plane the angle is negative The range of motion for this angle should be such that the angle between the trunk and the upper legs is between 40 and 100 degrees Note that within the biomechanical model the trunk is formed by the pelvis and the torso links which are each assigned separate angles based on the entered trunk flexion angle according to an al gorithm derived from empirical data The two links are visible in the human graphics in the display view windows Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 32 Figure 5 15 Trunk flexion angle 5 7 4 8 Trunk Axial Rotation 3D Mode Only The trunk axial rotation is defined as the rota tion of the torso about the axis formed by the line se
102. rcent capable Percentiles see Anthropometry Population strength 61 Posture report see Reports Posture entry methods Body segment angle 27 Direct manipulation 11 Posture prediction 33 Preferred order 11 Inverse kinematics 33 Undo 35 see also Body segment angles Posture prediction see Posture entry methods Printer 19 Printing Active window 19 Application 20 Desktop 20 Preview 19 Reports 19 53 Setup 19 Using Window s clipboard 21 Prone see Hand orientation Pushing pulling tasks 35 38 3D Static Strength Prediction Program Version 5 0 Quitting program 21 Rectus abdominus muscle 2 58 59 Reports 15 53 Header information 58 Printing 19 Printing multiple reports 71 Units 24 see also Exporting output summary Resultant load moment 67 Rotation see Camera Sagittal plane 69 Low back report 59 Saving data see Files Seat see Support Selection Segment locking see Locking mode Semiprone see Hand orientation Shaded see Render Shear forces 2 4 58 59 Shoulder 27 Included angles see Posture Report Location see Location Report Side view see Windows 3 View Skeleton see Human figure Model type Slips and falls see Coefficient of ground friction Software errors 5 Sphere see Environment objects Handheld object Stick figure see Human figure Model types Strength Data base 60 Design limit 56 Direction vectors 70 Model 4 Limits see NIOSH limits Reported see Reports
103. re entry 1 Choose Task Input Body Segment Angle to display the Body Segment Angle dialog box Figure 5 7 2 Enter the angles according to the conventions described below for 2D Mode angles To enter a value in a specific field click on the field or use the TAB key to move from field to field 3 A body segment angle can also be altered using the INCREMENT buttons Click on the angle value then click on the increment value desired 1 5 10 15 20 25 finally click on the to increase the value in steps of the increment selected or click on the to decrease the value The posture will re draw automatically to provide feedback as to the effect of the incremental posture change Note that the body segment angle changed is the angle highlighted in the section prior to using this feature 4 When all the angles have been entered or a check of the posture is desired click on RE DRAW to update the view windows This e 10 Si Be Em Pen pesa Neutral Stand Cancel Figure 5 7 Task Input Body Segment Angles dialog box for 2D Mode Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 28 keeps the body segment angle dialog box displayed should additional changes be nec essary 5 An UNDO button can be selected to revert to the previous posture 6 A NEUTRAL SIT STAND button can be used to set the limb and trunk angles for a sitting or standing neutral posture 7 Wh
104. red 1 5 10 15 20 25 finally click on the to increase the value in steps of the increment selected or click on the to decrease the value The posture will re draw automatically to provide feedback as to the effect of the incremental posture change Note that the body segment angle changed is the angle highlighted in the Limb Angles or Trunk Angles section prior to using this feature When all the angles have been entered or a check of the posture is desired click on RE m Trunk Angles Flexion 48 Axial Rotation fo Lateral Bending fo Neutral Stand Increment Figure 5 8 Task Input Joint Angle dialog box for 3D Mode Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Page 29 DRAW to update the view windows This keeps the body segment angle dialog box displayed should additional changes be nec essary 6 An UNDO button can be selected to revert to the previous posture 7 A NEUTRAL SIT STAND button can be used to set the limb and trunk angles for a sitting or standing neutral posture 8 When the posture is satisfactory click OK to 30 close the dialog box X 2 03 Sgey wogmentAngie Desepp Figure 5 9 Lower leg vertical angle tions 5 7 4 1 Lower Leg Vertical Angle 2D and 3D Mode This angle may also be called the ankle angle from horizontal With the horizontal plane defined as the X Y plane
105. rent focal length lenses since different focal lengths can produce vastly dif ferent perspective distortions These can be matched by setting the focal length to match the camera in the Oblique View Camera dialog box When taking posture photographs for later use with 3DSSPP remember to note the camera focal length The oblique view window can also enhance posture evaluation and realism if environment ob jects are used 3DSSPP provides four different kinds of objects that can be placed in the figure s immediate environment a hand held object cube sphere or cylinder a barrier vertical wall or hori zontal table a seat and a floor These can be dis played in any combination along with the human figure The barrier can be user defined for length and width as well as positioned using a cylindrical coordinate system centered on the human figure 3DSSPP automatically sizes and positions the seat and floor and fits the handheld object to the space between the figure s hands Be aware that 3DSSPP always centers the hands on the sides of the hand held object if the task being modeled involves an asymmetrically held object the modeled image will not match the actual task This is a function of the Univ of Michigan s 3DSSPP 5 0 0 Untitled File Task Input Display 3 Views Mess Reports About Human Figure Environment Top Camera Background Light Figure 8 1 Oblique View menu in 3DSSPP Copyright 200
106. rt angle r forearm horiz angle r upper arm vert angle r upper arm horiz angle r upper leg angle r lower leg angle l forearm vert angle l forearm horiz angle l upper arm vert angle l upper arm horiz angle l upper leg angle 1 lower leg angle torso lat bend angle torso flex angle and torso ax rotat angle Summary values include summary L5 S1 disc compression LA L5 disc compression the six strength capables from the summary analysis report coef of friction load on left foot 96 and balance condition Strength capable values include str cap right elbow flex ext right shoulder humeral rot fwd bkwd rot and adduc abduc left elbow flex ext left shoulder humeral rot fwd bkwd rot and adduc abduc torso flexion ext lat bend and axial rot right hip flex ext right knee flex ext right ankle flex ext left hip flex ext left knee flex ext and left ankle flex ext Posture angle values include post ang r el bow included r upper arm vert r upper arm horiz r humeral rot r hip included r knee included r ankle included 1 elbow in cluded 1 upper arm vert 1 upper arm horiz l humeral rot l hip included l knee in cluded l ankle included pelvic rotation torso flexion torso axial rotation and torso lateral bending Location values include jnt loc followed by x y z locations for right hand right elbow right
107. s ture Entry When using this method for entering postures 3DSSPP can model virtually any posture if the user enters the appropriate fifteen joint angles described below In 2D entry mode only five angles must be set The feet are always assumed to be on solid ground even if placed at different heights i e standing on one leg can only be analyzed by enter ing a posture which balances the body over the sin gle leg Care has been taken to make body segment an gle entry as consistent as possible Nonetheless the extra degrees of freedom at the trunk arms and hand force vectors require special attention for proper entry Depending on what is being de scribed the reference planes for some of these an gles differ The program will in certain cases disal low an input if its error checking algorithm decides that the input exceeds a joint s range of motion The angle definitions are given below Note that the horizontal angles do not have meaning when the arms are perfectly vertical and need not be entered in this case 2D Body Segment Angles m Increment Fore Arm Upper Arm Upper Leg Lower Leg Trunk Flexion LS Page 27 5 7 2 Body Segment Angle Dialog Box 2D Mode Choosing Task Input Body Segment Angles indicates that the body segment angle method for posture entry is to be used and displays the Body Segment Angle entry dialog box Figure 5 7 To use the body segment angle method for pos tu
108. s ENTER or click OK Note the Select All and Select None buttons These select all or no reports for printing and can speed the selection of desired combinations of re ports Print Reports m Select All Open Reports None Task Input Summary Analysis Summary Fatigue Lowback Analysis 3D Lowback Analysis Sagittal Plane Strength Capabilities Anthropometry balance Seated Balance Standing Forces Locations Moments Posture Spinal Forces and Moments LS NN E M M NEN M E UU E M NEM I Strength Direction Vectors coca Figure 9 17 Reports Print Reports dialog Page 71 9 16 EXPORT OUTPUT SUMMARY Through Reports Export Output Summary se lected data generated by 3DSSPP can be saved as an external tab or comma delimited text file for import and further analysis in spreadsheet or other applications software Figure 9 18 Other than this data no reports can be exported text files To export the summary data to a text file 1 Choose Reports Export Output Summary 2 The dialog box is opened with the default file name of summary txt Enter the file name and extension desired 3 Press ENTER or click OK Export Summary Options Select any combination of output v Hand Forces v Body Segment Angles v SummaryResults v Strength Capabilities Iv Posture Angles V Joint Locations Iv Joint Forces V Joint Moments V Low Back m Delimiter File Mode Comma A
109. s are to be pressed at the same time the keys to be pressed will appear in bold faced text with a plus sign between them The first key should be held while the second key is pressed For example if in structed to hold ALT and press PrtSc print screen the instruction will appear as fol lows press ALT PrtSe If a specific menu sequence is to be followed the sequence will appear in italicized bold faced text with a pipe symbol between each item For example to access the units selection dialog the instruction to choose the Task Input menu and select the Units item would appear as Task Input Units Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Page 7 Chapter 2 GETTING STARTED 2 1 HARDWARE REQUIREMENTS Due to the complexity of the interactions between 3DSSPP and the Windows environment as well as the computations that are performed by the posture prediction inverse kinematics human modeling graphics and 3D back optimization routines the minimum hardware configuration recommended to run the program consists of the following IBM PC or compatible with a Pentium processor running at 1 GHz or greater 128 MB RAM 20 MB of available hard disk space VGA monitor and graphics card 256 colors or better 2 2 SOFTWARE REQUIREMENTS A Microsoft Windows 2000 or XP operating system is required to run 3DSSPP It
110. s faster and allows the user to see elements of the environment which are obscured by the hominoid Flesh This model provides a fleshed out figure which is useful for comparisons to photo graphs or in any situation where a more real istic representation is needed e g viewing interference and or proximity with objects in the human figure s environment On slow machines this figure utilizes a compromise between display accuracy and speed 8 1 2 Figure Color The figure s skin can be changed to any color The current skin color is displayed in the color box to change the color click Figure Color and select a new color using the provided dialog box 8 1 3 Hand Type Not Implemented The hand grip displayed with the figure can be open cupped or in a fist The default is open hands and can only be changed in the oblique view This option is for viewing purposes only and does not factor into the program s calculations Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Environment m Misc Objects Floor Visible Handheld Object 7 Type a E None Height E 2 in C Box Depth 12 in C Cylinder C Sphere Outline Barrier Type None Length 40 in Width 20 in Thickness 2 in C Wall Distance 20 in Azimuth fo Deg Elevation o in Apply Cancel Figure 8 3 Oblique View Environ ment dialog box
111. s forms a right had coordinate system Description Task Untitled T ask Comment Company chuck Analyst Unknown Date 06 09 05 Gender Male Percentile 50th Height 69 1 in Weight 176 4 Ib Locations in Y Hand 7 0 0 Elbow 7 0 0 Shoulder 0 0 L5 51 00 0 1 Ischial Tuberosities Forward Seat Hip 3 5 0 0 Knee 3 5 0 0 Ankle 35 0 0 Heel of Foot 3 5 2 0 Front of Foot 3 5 8 5 E 234 293 43 2 43 2 56 1 56 1 40 1 36 3 39 0 0 36 3 18 5 35 0 0 18 5 oe 35 0 0 2 0 0 0 2 0 0 0 0 0 a5 8 5 0 0 3DSSPP 5 0 0 Copyright 2005 The Regents of the University of Michigan 4LL RIGHTS RESERVED Figure 9 12 Locations Report Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 9 11 MOMENTS REPORT The moments report Figure 9 13 lists the resultant moments produced by the loads and body weight about the main reference axes x y and z at each joint and support surface The X axis extends later ally from the origin with positive to the subject s right The Y axis extends from the origin to the Moments Description Page 67 front and the back of the body with positive being forward Lastly the Z axis extends vertically from the origin with positive upwards A negative moment value indicates a clockwise moment about the given joint axis
112. section of the screen highlighted or underlined by the cursor Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 6 3D Static Strength Prediction Program Version 5 0 Model output All of the output with respect to one set of task parameters Only part of the output is displayed on the screen at any one time Posture The different angles about the joints of the body describing the orientation of the body in space Reactive load Reaction force or moments pro vided by the body s musculoskeletal system to the resultant load Record One set of task parameters Resultant load The load in force or moments acting upon the body Task parameters Data describing the task in cluding the force magnitude and direction anthropometry and postural angles 1 8 SPECIAL TYPEFACES The format described below is used throughout the manual to indicate if or when information should be entered or a key pressed to describe messages that appear on the screen and outline examples used within the manual 1 If instructed to type information the infor mation will appear in capital letters For ex ample if a task description is to be typed the instruction will appear as follows type CART PUSHING TASK 2 If one key is to be pressed the key to be pressed will appear in bold faced text For example if the TAB key is to be pressed the instruction will appear as follows press TAB 3 If two key
113. sic or Visual C software de velopment University of Michigan Software Technology Management Office Wolverine Tower Room 2071 3003 South State Street Ann Arbor MI 48109 1280 Tel 734 936 0435 Fax 734 936 1330 1 6 ERROR REPORTING Considerable effort has been made to eliminate software errors bugs from this version of the 3DSSPP software prior to release If however a software error occurs at any time during 3DSSPP operations Windows will display an error message and request to close the applica tion Should this occur please note the posture be ing analyzed any other programs currently running and the type of computer system being used Then please copy the message in its entirety close the application and contact the Center for Ergonomics at the University of Michigan By providing the above information when problems occur the Center is aided greatly in its efforts to develop useful software of the highest quality The University of Michigan The Center For Ergonomics 1205 Beal IOE Building Ann Arbor MI 48109 2117 SSPPSupport umich edu Phone 734 763 2243 Fax 734 764 3451 Page 5 1 7 SPECIAL DEFINITIONS This manual assumes the user is familiar with basic Windows terminology such as icons clipboard dia log boxes click drag and re sizing windows If this is not the case please refer to the Windows Help for additional details In addition the follow ing definitions will aid i
114. similar fashion as the upper arm vertical angle Section 5 7 4 3 and is the angle formed between the lower arm and the horizontal plane intersecting the elbow Again the horizontal plane is assumed to be the X Y plane When the hand is level with the elbow the joint angle is O degrees If the hand is above the elbow the forearm vertical angle is positive if below the angle is negative For both the right and left fore arm vertical angles the value of the angle increases as the hand moves upward and decreases as the hand moves downward as indicated by Figure 5 13 Be aware that in this convention the origin of the horizontal plane is located at the elbow and is independent of upper arm angles and overall body posture Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Figure 5 13 Forearm vertical angles 5 7 4 6 Forearm Horizontal Angles 3D Mode Only While looking down onto the figure such that the lower arm is projected onto the X Y plane at the elbow the angle formed between the lower arm and the X axis constitutes the forearm horizontal angle Figure 5 14 When the forearm is aligned with the X axis and the hands are pointing away from the body the angle is O degrees When the forearm is located in front of the X axis the angle is positive If the forearm crosses behind the X axis then the angle is negative This convention holds fo
115. specifying the file extensions By default this is set to display all 3DSSPP task files these files end with tsk The other option available is to click on the arrow to the right and choose All Files to display all files in the current directory New to Windows The DOS wildcard char acters and can be used in any part of the File Name edit field to limit the files displayed For ex ample TXT lists all files with the extension txt Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 18 4 2 NEW To start a new analysis choose File New 3DSSPP resets all task parameters to their default values and changes the file name in the title bars to UNTITLED If a file is in use currently a dialog box appears asking 1f the current file should be saved if the file is not saved any changes to that file since its last save are lost Choose NO to con tinue or YES to invoke the File Save As dialog box and save changes see Section 4 5 4 3 OPEN To work with previously defined task parameters posture loads etc saved in version 4 3 1 or later of 3DSSPP 1 Choose File Open Figure 4 1 2 Select the desired file using the methods listed above in Section 4 1 3 3DSSPP will then restore the program to all the task settings in force at the time when the file was last saved 4 4 SAVE Choosing File Save will save the current task set tings to the file name under wh
116. stimated L5 S1 Ligament Strain cicicescssisscacisscesesaseccaseetodencteaeacccseneavedeanend 59 9 6 STRENGTH CAPABILITIES REPORT e eeeeeeeeeeeeeeen rennen 60 9 7 ANIHROPOMETRY REPORT nescio pite e i reri eene tese 61 9 8 BALANCE REPORTS SEATED AND STANDINQ eere 62 9 8 1 Center or Pressure C alculattoniscc usse aveo E pe ue Neg 62 9 82 Stability RESTOS A A dde ae A tu A duc dn qu ip dicun ud 63 ds Balance Conditl ns uc etie Up dica 64 93 4 Center or Pressure Graphic arseen E EE E 64 OO SBORCES REPORT a Du e R aci 65 9 107 COCA TONS REPORT O a 66 AL MOMENTS REPOR Ti e e dun nce lameness 67 9 12 POSTURE REPORT sn as 68 9 13 SPINAL FORCES AND MOMENTS REPORT eene 69 9 14 STRENGTH DIRECTION VECTORS REPORT eene 70 Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page x 3D Static Strength Prediction Program Version 5 9 15 PRINT REPORT COMMAND o ocococononononononononononononononononononononononononononononononenenonoss 71 9 16 EXPORT OUTPUT SUMMARY ococonononononononononononononononononononononononononocononononononess 71 9T6 T Exp rt O tp t File POrmial 2 ii aed tee 72 References canina nati e E D Dia 75 Inde arias ias tas TI Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Page 1 Chapter 1 INTRODUCTION The University
117. t Useful in analyzing pushing and Fatigue Page 57 pulling tasks for risk of falls due to slippage this is the coefficient of static friction between the floor and the shoe soles required to prevent slippage given this specific combination of posture and load 9 3 FATIGUE REPORT New in 5 The Fatigue Report Figure 9 4 dis plays the calculated percent of maximum voluntary contraction MVC of the required effort at each joint Percentages are calculated for three popula tion strength capabilities 5 25 and 50 percentile corresponding to very weak weak and average strength workers These values can be used with frequency and duration information to estimate lo calized muscular fatigue See Rohmert 1973 and other more recent work m Description Company chuck Analyst Unknown Date 06 09 05 Task Untitled Task Gender Male Percentile 50th Height 69 1 in Weight 176 4 Ib Comment Left Required Percent MVC Population Strength 5 25 Percentile Elbow Flex Ext 20 Shoulder Humeral Rot B Rot n Bk Fd 0 Abduc Adduc 41 Flex Ext Lat l Bending Torso Rotation Hip Flex Ext Knee Flex Ext Ankle Flex E xt 50 16 5 0 34 45 0 0 42 8 3 Right Required Percent MVC 5 25 50 25 18 15 8 6 5 0 0 0 32 3DSSPP 5 0 0 Copyright 2005 The Regents of the University of Michigan 4LL RIGHTS RESERYED Figure 9 4 Fatigue report Copyright 2005 The Regents of The Univers
118. t is a legal agreement between LICENSEE and The Regents of The University of Michigan a constitutional corporation of the State of Michigan MICHIGAN The term LICENSEE shall mean the person installing the PROGRAM defined below in Paragraph 1 if it is solely for per sonal use by that person on the personal equipment of that person Alternatively if the PROGRAM is being installed on equipment for use by another legal entity such as a corporation limited liability company or partnership then the person installing the PROGRAM by proceeding with the installation certifies that he or she has authority to bind that legal entity to this Agreement and that legal entity shall be considered to be the LICENSEE By installing copying downloading accessing or otherwise using the PROGRAM you and LICENSEE agree to be bound by the terms of this Agreement If you or LICENSEE if a separate legal entity do not agree with the terms of this Agreement do not install access or use the PROGRAM instead you should return it to the University of Michigan for a full refund BACKGROUND 1 The University of Michigan through its Center for Ergonomics has developed a proprietary computer program and related documentation known as the 3D Static Strength Prediction Program for use by trained individuals as a job physical stress analysis model in the field of ergonomics hereinafter referred to as PROGRAM and 2 LICENSEE desires to obtain and MICHIGAN cons
119. tal plane space When moving the ankle the position of the knee will be calculated to accommodate the posi tions of the ankle and hips The position of the floor on the screen is always the same Therefore if one foot is lifted off the ground and then the other is lifted the body will drop to the floor Both feet are always assumed to be supported even when posi tioned at different levels For one foot support see Support Selection Section 5 5 Note again that the hand locations are measured with respect to the center of the feet in standing mode Thus if one foot is moved then the origin of the measurement is moved and the numerical loca tion of the hands will change however the hands will remain in the same relative location with re spect to the stationary foot 3 2 2 2 Hips Since the knees cannot be moved or manipu lated the most straightforward manner for bending or straightening the legs is by adjusting the hip po sition The left and the right hip can only be moved in tandem when the hips are selected the right and 3D Static Strength Prediction Program Version 5 0 left hip are selected simultaneously As was true for the ankles the position of the hips can only be altered in two dimensional sagittal plane space and is easiest to manipulate in the side view To increase the bend in the legs adjust the hips downward conversely to straighten the legs move the hips upward 3 2 2 3 Trunk Flexion Trunk fle
120. the measurement is moved and the numerical hand locations will change but the relative location of the hands to the stationary foot will be maintained 3 2 2 Preferred Order and Techniques of Joint Manipulation When attempting to position any joint or body segment using the inverse kinematics method keep in mind that the algorithm always attempts to pro duce a reasonable positioning of the body segments not being manipulated based on the current fixed position of the hands The manipulation of the torso particularly in lateral bending or axial rotation is especially sensitive to this program tendency With out going into a detailed explanation of the inverse kinematics algorithm users should be aware that there must be a moderate amount of bending at the elbows before one attempts to move the torso in either lateral bending or axial rotation A few at tempts at moving the torso with and without elbow bending should confirm the necessity of having some bend at the elbows The preferred order of entry is given in Figure 3 3 with descriptions for each joint Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 12 Trunk La Arms Legs Figure 3 3 The sequence in which joint angles are determined using posture prediction 3 2 2 1 Right and Left Ankles The ankle positions can be entered most easily in the side view since in 3DSSPP the legs and feet can only move in two dimensional sagit
121. the word processing application if not already running load word processing application with an appropriate document 5 Position the cursor in the word processor at the desired location and paste the Clipboard contents into the document Once the desired 3DSSPP data is pasted into the word processor comments or a report body can be added and the entire report package printed at one time through the word processing application 4 16 EXIT New to Windows Selecting File Exit will end the program If the current task parameters have been changed since the last save a dialog box will appear asking if changes to the file should be saved Choose the appropriate response if YES the file is saved if the task parameters have never been saved the File Save As dialog box will appear if NO the program terminates and the recent changes to the file are lost and if CANCEL the program continues running with the file currently opened Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 22 3D Static Strength Prediction Program Version 5 0 Eak Window Help Adobe PDF Acrobat Comments e Document1 Microsoft Word Untitled Task Untitled Task Gender Male Percentile 50th Ht in 69 3 Wt Ib 173 8 Population Production 4 4 1 Hand Locations in left This figure is now a Word document Tm Ln 2 Col 28 REC TRK ExT love EY o H v g Sec 1 1n At 5 17 Figure 4 4 Sa
122. ting File Print Desktop prints the contents of the screen at the time of selection This is similar to the DOS print screen PrtSc key and immedi ately starts the printing process using the default print settings The process may be interrupted by clicking on CANCEL in the print status box that appears onscreen 4 13 COPY APPLICATION Selecting this menu option will copy a picture of the 3DSSPP program window to the Windows clip board Once copied the picture can be pasted into drawing and publishing applications 11 New to 5 This effect can also be achieved by pressing Alt PrintScreen if the main window is highlighted Alt PrintScreen will copy to the clipboard whatever window is active This is useful for copying individual 3DSSPP windows or reports This functionality is standard in Windows Adobe PDF v Properties Drientation Portrait C Landscape Cancel Figure 4 3 File Print Setup dialog box Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 4 14 COPY DESKTOP Selecting this menu option will copy a picture of the entire screen including visible programs other than 3DSSPP to the Windows clipboard Once copied the picture can be pasted into drawing and publishing applications This effect can also be achieved by pressing the PrintScreen key 4 15 PRINTING THROUGH THE WIN DOWS CLIPBOARD In this pri
123. tion the mes sage bar can be displayed or hidden 6 1 AUTO TILE If the Auto Tile command is checked then the stan dard 3 over 2 arrangement of the view windows will be reset when ever the program window is sized If an alternative arrangement of the view windows is desired then the Auto Tile feature should be disabled To enable or disable simply click on the command 6 2 TILE NOW If the Tile Now command is selected the view win dow tiling will be reset to the standard 3 over 2 ar rangement 6 3 STATUS BAR This command controls the appearance of the mes sage bar The message bar displays various help and error messages It is displayed if the command is checked and hidden if it is not checked To check or uncheck simply click on the command Univ of Michigan s 3DSSPP 5 0 0 Untitled File Task Input BEES w Auto Tile Tile Now w Status Bar Ctrl T 3 Views Oblique View Reports About EHE Figure 6 1 Display menu in 3DSSPP Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 44 3D Static Strength Prediction Program Version 5 0 Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Page 45 Chapter 7 3 VIEWS MENU COMMANDS The 3 Views Menu Figure 7 1 contains the dialog boxes for controlling the display attributes of the three orthogonal view windows These windows may be rearranged and
124. u in making adjustments to the hominoid s posture It should be most useful when making minute manipulations of the hominoid s posture to achieve the desired position 5 11 HAND LOADS Please note that in this program hand force re fers to the force being applied TO the hand not the force applied by the hand A verbal description of the action of each hand in response to the force exerted on it is displayed to confirm the correct en try 5 11 1 Hand Load Force Vector De scriptions 2D Mode The hand force vector angle convention used in the 2D Mode is different than in the 3D Mode The notation includes a vertical angle value and a back wards indicator Illustrating the hand load force as a vector with its tail in the grip center of the hand and its arrow pointing in the direction of the force the hand load Page 35 vertical angle is the angle between the positive Y axis and the force vector See Figures 5 22 and 5 23 The force vector may point forward or back ward with respect to the subject UPWARD DOWNWARD FORCE Figure 5 22 Vertical hand force vector angles with a horizontal angle of 90 Upward Force Y X Y Plane Downward Force Figure 5 23 Vertical hand force vector angles with a horizontal angle of 90 Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 36 2D Combined Hand Forces m Combined Applied Load Magnitude a lb Vertical 30 Degr
125. uch training in any use or interpretation of data provided in or by the PROGRAM VI TERMINATION If LICENSEE at any time fails to abide by the terms of this Agreement MICHIGAN shall have the right to imme diately terminate the license granted herein require the return or destruction of all copies of the PROGRAM from LICENSEE and certification in writing as to such return or destruction and pursue any other legal or equitable remedies available VII MISCELLANEOUS A This Agreement shall be construed in accordance with the laws of the State of Michigan Should LICEN SEE for any reason bring a claim demand or other action against MICHIGAN its agents or employees arising out of this Agreement or the PROGRAM licensed herein LICENSEE agrees to bring said claim only in the Michigan Court of Claims B THIS AGREEMENT REPRESENTS THE COMPLETE AND EXCLUSIVE STATEMENT OF THE AGREEMENT BETWEEN MICHIGAN AND LICENSEE AND SUPERSEDES ALL PRIOR AGREE MENTS PROPOSALS REPRESENTATIONS AND OTHER COMMUNICATIONS VERBAL OR WRIT TEN BETWEEN THEM WITH RESPECT TO USE OF THE PROGRAM THIS AGREEMENT MAY BE MODIFIED ONLY WITH THE MUTUAL WRITTEN APPROVAL OF AUTHORIZED REPRESEN TATIVES OF THE PARTIES C The terms and conditions of this Agreement shall prevail notwithstanding any different conflicting or addi tional terms or conditions which may appear in any purchase order or other document submitted by LICEN SEE LICENSEE agrees that such additional or inc
126. ue on the currently selected joint Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED mum 3D Static Strength Prediction Program Version 5 0 Page 39 External Applied Forces and Moments 5 14 1 Batch File Format Joint Forces Ib 0 M Companent Cancel 5 14 1 1 First Line of File Y Component The first line of all batch files must be Z Component 3DSSPPBATCHFILE Moments inv lb X Component Zero Current Y Component 5 14 1 2 Command Structure Z Component Zero All All lines must have one and only one com Figure 5 30 Task Input Joint Loads dialog mand The command must begin with a com mand name upper case only and must end with the terminating character No charac 5 13 2 Zero All ters should follow the terminating character Blanks are used to delimit all commands data New to 5 This button will clear the forces and items and the terminating character At least torques on every joint even those not currently one blank must be used additional blanks for shown This button will not affect hand loads visual organization are acceptable The legal commands and their abbrevia tions are as follows 5 14 RUN BATCH FILE COMMENT COM The Run Batch File feature enables automatic DESCRIPTION DES analysis of tasks specified in a data file It is useful when many biomechanical analyses are to be per ANTHROPOMETRY ANT formed on data derived from another program The
127. vities and loads may be cre Sagittal Plane Lowback Analysis Page 59 ated about the spine In these cases the use of the 3D Low back Analysis is recommended For fur ther details on the L5 S1 model refer to Section 1 3 1 9 5 1 Estimated L5 S1 Ligament Strain At the bottom of the report the estimated L5 S1 ligament strain for the gender selected is displayed This represents the strain in the lumbodorsal fascia which is attached between the L5 and S1 vertebrae and plays a major role in resisting forward flexion Since the observed elastic limit for the lumbodorsal fascia is 3096 estimated L5 S1 ligament strain val ues which exceed 30 may indicate risk for injury See Anderson et al 1985 Anderson 1983 Bazer gui et al 1978 and Farfan 1973 Description Company chuck Analyst Unknown Date 06 09 05 Task Untitled Task Comment Compression Force at L5 51 Total Compression Ib Components Erector Spinae Rectus Abdominus Abdominal Hand Loads Upper Body Weight Gender Male Percentile 50th Height 69 1 in Weight 176 4 lb m Shear Force at L5 51 Total Shear lb Components Sagittal Plane Frontal Plane Estimated Ligament Strain 2 3DSSPP 5 0 0 Copyright 2005 The Regents of the University of Michigan ALL RIGHTS RESERVED Figure 9 6 Sagittal Plane Lowback Analysis Copyright 2005 The Regents of The University of Michigan ALL RIGH
128. ws Oblique View MiS Task Input Summary Analysis Summary Fatigue Lowback Analysis 3D Lowback Analysis Sagittal Plane Strength Capabilities Anthropometry Balance Seated Balance Standing Forces Locations Moments Posture Spinal Forces and Moments Strength Direction Vectors Print Reports Export Output Summary Figure 9 1 Reports menu in 3DSSPP Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 54 toggled between English or Metric units by choos ing Task Input Metric or Task Input English see also Section 5 2 The windows do not have to be closed to change the units 9 1 TASK INPUT SUMMARY REPORT The Task Input Summary Figure 9 2 displays a summary of the data entered under the Task Input menu items including the 1 Joint angles 2 Hand locations 3 Hand force magnitude and direction and 4 Additional joint forces Task Input Summary Description Company chuck Analyst Unknown Date 06 09 05 Task Untitled Task Gender Male Percentile 50th Height 69 1 in Weight 176 4 Ib Comment 3D Static Strength Prediction Program Version 5 0 9 2 ANALYSIS SUMMARY REPORT The analysis summary report Figure 9 3 displays five areas of information Hand Forces Lowback Disc Compression Percent Capable Balance and Coefficient of Friction 9 2 1 Hand Forces The forces on the hand are listed as the vector components of th
129. xion corresponds to the forward bending of the trunk The center of rotation is the hip The side view gives the best perspective on trunk flexion The graphic marker associated with trunk flexion is located at the base of the head Note that within the biomechanical model the trunk is formed by the pelvis and the torso links which are each assigned separate angles based on the entered trunk flexion angle according to an algorithm derived from empirical data The two links are visible in the human graphics in the dis play view windows 3 2 2 4 Trunk Axial Rotation Trunk axial rotation corresponds to the rota tion of the trunk about the axis of the spine To change the rotation value select and move the solid marker at the shoulder Axial rotation is the most difficult of the joint angles to enter At times the computer may have difficulty in interpreting the cursor position Therefore it may be neces sary to click in several locations to see how the computer interprets the cursor position For this angle trying the different view windows may be helpful if altering axial rotation in one of the views does not appear to work well however in general the top view tends to be more favorable for erect postures whereas the front view tends to be easier to manipulate with stoop postures It may be useful to utilize the Undo program fea ture Section 5 10 Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3
130. xt right shoulder humeral rot right shoulder rot n bk fd right shoulder abduc adduc right hip flex ext right knee flex ext right ankle flex ext torso flex ext torso lat bending torso rotation Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page 74 3D Static Strength Prediction Program Version 5 0 Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED 3D Static Strength Prediction Program Version 5 0 Page 75 REFERENCES Anderson C K Chaffin D B Herrin G D and Matthews L S A Biomechanical Model of the Lumbosacral Joint During Lifting Activities J Biomechanics Vol 18 No 8 pp 571 584 1985 Anderson C K A Biomechanical Model of the Lumbosacral Joint for Lifting Activities Ph D Thesis Department of Industrial and Operations Engineering The University of Michigan 1983 Bazergui A Lamy CX and Farfan H F Mechanical Properties of the Lumbodorsal Fas cia Paper no IA 08 Proceedings of the 1978 Society for Experimental Stress Analysis Meet ing Wichita KS 1978 Bean J C Chaffin D B Schultz A B Biome chanical model calculation of muscle contrac tion forces A doublelinear programming method J Biomech 1988 21 59 66 Beck D J An Evaluation of Inverse Kinematics Models for Posture Prediction CAES 92 Tam pere Finland 1992 Burgraaff J D An Isometric Biomechanical Model for Sagittal Plane Leg Extension
131. y of Michigan ALL RIGHTS RESERVED Page 38 Hand Loads m Left Applied Load 3D Static Strength Prediction Program Version 5 0 Magnitude 10 lb Right Applied Load Magnitude 10 Ib m Angle Degrees Vertical 90 Horizontal 90 Angle Degrees Vertical 90 Horizontal 90 m Increment UN Be DS ERIS mu m Left Effort Description By Angle Entry C Lift C Push Forward Exert Left C PushDown Pull Back C Exert Right Right Effort Description By Angle Entry C Lift C Push Forward Exert Left C PushDown Pul Back C Exert Right ww Figure 5 28 Task Input Hand Loads dialog box for 3D mode Advanced Hand Load Entry m Left Hand Force lb X n s Z 0 0 Total 10 Total Torque irrlb Right Hand X ro 0 Cancel Force lb Torque irrlb Figure 5 29 Task Input Advanced Hand Loads dialog box Hips Knees Ankles Use this functionality to simulate situations like leaning against a table force on the hips or carrying a backpack force on the shoulders and L5S1 New to 5 Joint forces are by default displayed in the orthogonal view windows To turn off the display of these joints uncheck the 3 Views Show Forces menu option 5 13 1 Zero Current New to 5 This button will zero the force and torq
132. yees who are permitted access to the PRO GRAM in order to satisfy LICENSEE S obligations under this Agreement LICENSEE is authorized to copy the PROGRAM for backup purposes only III TITLE AND OWNERSHIP A Noownership rights of MICHIGAN in the PROGRAM are conferred upon LICENSEE by this Agreement B LICENSEE acknowledges MICHIGAN S proprietary rights in the PROGRAM and agrees to reproduce all copyright notices supplied by MICHIGAN on all copies of the PROGRAM and on all PROGRAM outputs and copies of PROGRAM outputs IV DISCLAIMER OF WARRANTY AND LIMITATION OF LIABILITY A THE PROGRAM IS PROVIDED AS IS WITHOUT WARRANTY OF ANY KIND EITHER EXPRESS OR IMPLIED INCLUDING WITHOUT LIMITATION THE IMPLIED WARRANTIES OF MERCHANT ABILITY AND FITNESS FOR A PARTICULAR PURPOSE MICHIGAN DOES NOT WARRANT Copyright 2005 The Regents of The University of Michigan ALL RIGHTS RESERVED Page iv 3D Static Strength Prediction Program Version 5 THAT THE FUNCTIONS CONTAINED IN THE PROGRAM WILL MEET LICENSEE S REQUIRE MENTS OR THAT OPERATION WILL BE UNINTERRUPTED OR ERROR FREE MICHIGAN shall not be liable for special indirect incidental or consequential damages with respect to any claim on account of or arising from this Agreement or use of the PROGRAM even if MICHIGAN has been or is hereafter advised of the possibility of such damages Because some states do not allow certain exclusions or limitations on im plied warranties or of liability for conseque

3D Static Strength Prediction Program Version 5.0.4 User`s Manual

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