Don Chaffin

Don B. Chaffin

Richard G. Snyder Distinguished University Professor Emeritus,
Industrial and Operations Engineering and Biomedical Engineering, College of Engineering

Director Emeritus, Human Motion Simulation Laboratory (HUMOSIM), 1998-2007

Director Emeritus, Center for Ergonomics (C4E), 1982-1997

The University of Michigan
Center for Ergonomics
1205 Beal, Room 1656 IOE Building
Ann Arbor, MI 48109-2117


Current interests and expertise

Computerized biomechanical models of the human musculoskeletal system now provide the means to evaluate the adverse effects and risks of heavy physical exertions. Such exertions are common in many jobs today, particularly in the Service Sector that employs over 68% of workers in the U.S. By using computerized simulations of human motions we are now able to predict many of the adverse musculoskeletal stresses during the design of future workplaces and vehicle interiors.

With the cost of musculoskeletal disorders exceeding $100 Billion annually, understanding the cause and prevention of these disorders is of National importance. The following are some of the research projects now being directed by Dr. Chaffin and his graduate students in this context:

  1. Refining and validating a biomechanical model of the shoulder muscles, ligaments and skeletal structures to predict injurious stresses and discomfort levels during static exertions.
  2. Development of models for studying dynamic exertions during reaching motions.
  3. Development of a whole-body strength prediction model that includes valid predictions of postures used during high exertion tasks.
  4. Development of an empirical description and kinematic models of normal body motions to be used in Computer Aided Designs of future workplaces and vehicles to accommodate various people when moving in these environments.

Other activities

Consultant to 25 different corporations, labor groups, and government agencies, including the Department of Labor, the Department of Health and Human Services, US Postal Service, Ford, United Auto Workers, General Motors, and Chrysler, on the increased costs and suffering associated with musculoskeletal disorders in industry. This work involves formal recommendations on the design of workplaces, equipment and tools, as well as presenting training programs for engineers and managers interested in the application of ergonomic principles to work design and evaluation.

Major Service Activities

  • Secretary General International Society for Biomechanics (1990-1991).
  • Founding Member and Past President (1987) American Society of Biomechanics.
  • US Dept. of Labor, National Advisory Council of Occupational Safety and Health Administration (1976-1980).
  • CDC-USPS-NIOSH Scientific Counselor (1988-1992).
  • UAW-GM Occupational Health and Safety National Advisory Committee (1994-2000).
  • NRC- Army Soldier Systems Panel(2002-06), Chair(2007-09)
  • NAE- Officer Nominating Committee (2005-06)
  • NAE- Vice Chair, Industrial, Operations and Manufacturing Section

    Industrial applications

    Workplace design, Physical work evaluation methods, Materials handling systems, Human motion simulation in CAD , Ergonomics in product and workcell design

    Key terms

    Occupational injuries, Materials handling, Industrial safety, Industrial trauma, Manual labor, Ergonomics, Industrial engineering, Musculoskeletal injury, Human factors engineering, Physiological responses, Conditioning, Fatigue, Man/machine systems, Occupational biomechanics, Work physiology, Personnel selection, Machine design, Occupational safety and health standards, Biomechanics, Torso muscle optimization, Digital Human Modeling and Simulation (DHM), Lifting, Biomechanical modeling

    I have been "Major Advisor" for the following Ph.D. Graduates:

    1969 LaVerne Hoag - Research Scientist (retired), Bell Laboratories
    1970 Kerry Kilpatrick - Professor, Indust. Eng. University of Florida
    1971 Michael Stern - Private Consultant
    1971 Marlan Thomas - Professor and past Chairman, Indust. Eng, Purdue University
    1972 Frederick Schanne - Vice President Operations, Ajilon Services, Inc.
    1973 Arun Garg - Professor, Indust. Eng. University of Wisconsin
    1973 Shashikant Kelkar - Professor, Production Eng., University of Bombay
    1973 Kyung Park - Research Scientist, Korean Inst. of Technology
    1973 Brian Quigley - Professor Emeritus, Sports Science, University Melbourne
    1974 Rodney Schutz - Research Scientist, AT&T Bell Laboratories, Whippany, NJ
    1976 Thomas Armstrong - Professor, Industrial Health and Industrial & Operations Eng, University of Michigan, Ann Arbor
    1979 Andy Freivalds - Associate Professor, Ind. End. Penn State Univ.
    1979 W. Monroe Keyserling - Professor, Industrial and Operations, University of Michigan, Ann Arbor
    1979 Myun Lee - Professor and past Chairman, Ind. Eng., Seoul Nat'l University
    1981 Steven Goldstein - Professor, vice-Provost, Orthopaedic Surgery, University of Michigan, Ann Arbor
    1982 Kwan Lee - Professor, Korea University, Seoul
    1982 Terry Stobbe - Professor, Indust. Eng., W. Virginia University.
    1983 Charles Anderson - President, Advanced Ergonomics, Inc., Dallas, Texas
    1985 Susan Evans - President, Susan Evans & Associates, Arlington, VA
    1986 Steven Wiker - Professor, WVU, President & CEO, ErgoTek, Inc., Morgantown, WV
    1986 Rob Radwin - Professor, Ind. Eng., Univ. of Wisconsin Madison
    1987 Don Bloswick - Professor, Ind. Eng./Mech. Eng., University of Utah
    1988 Mark Redfern - Chaired Professor,Biomedical Eng., University of Pittsburgh
    1989 Jeffrey Woldstad - Associate Professor, Ind. Eng., Texas Tech University
    1991 Richard Hughes - Associate Professor of Surgery, University of Michigan, Ann Arbor
    1992 Douglas Beck - Senior Useability Engineer, Hewlett-Packard, Colorado Springs, CO
    1992 Carter Kerk - Professor, South Dakota School of Mines & Technology, Rapid City, SD
    1993 Deborah Thompson - Plumb Ascension Consultants, L.L.C., Auburn Hills, MI
    1993 Marc Resnick - Professor, Florida International University, Miami
    1994 Maury Nussbaum - Associate Professor, Virginia Tech, Blacksburg, VA
    1994 Ulrich Raschke - Program Manager, Human Simulation Products, UGS-PLM Solutions, Ann Arbor, MI
    1997 Xudong Zhang - Associate Professor, Mechanical & Industrial Engineering, University of Illinois, Urbana-Champaign
    1998 Trina Buhr - Research Engineer, Medtronics, St. Paul, MN
    1998 Matt Reed - Associate Research Scientist, University of Michigan Transportation Research Institute, Ann Arbor
    2003 Woojin Park - Assistant Professor, Mechanical, Industrial and Nuclear Engineering, University of Cincinnati
    2004 Matthew Parkinson - Assistant Professor, Design Engineering, Penn State University & University College, PA
    2005 Clark Dickerson - Assistant Professor, University of Waterloo
    2006 Kevin Rider - Assistant Professor, University of West Virginia
    2007 David Wagner - Ozen Engineering
    2008 Suzanne Hoffman - Research Engineer, GM Technical Center

    Selected publications

    Chaffin, D.B. A Survey of Human Factors Courses in Engineering, HFES Educators Newsletter, March 2005.

    Torso Biomechanical Modeling

    Anderson, C., D. Chaffin and G. Herrin. A Study of Lumbosacral Orientation under Varied Static Loads. Spine, 11(5): 456-462, 1986.

    Chaffin, D.B. Biomechanical Modeling of the Low-Back During Load Lifting. Ergonomics, 31(5):685-697, 1988.

    Chaffin, D.B. and J. A. Ashton-Miller. Biomechanical Aspects of Low Back Pain in the Older Worker. J. Experimental Aging Research, 17(3):177-188, 1991.

    Nussbaum, M.A., D.B. Chaffin, R.E. Hughes and P.J. Moga. Simulation Analysis of a Comprehensive Torso Biomechanical Model. Proceedings of the XIIIth Inter. Congress on Biomechanics, Perth, Australia, 1991.

    Nussbaum, M.A., S.A. Lavender, R.E. Hughes, D.B. Chaffin and G.B.J. Andersson. Predicting Torso Muscle Activity During Asymmetric Loading: A Comparison of Three Optimization Models. Proceedings of the Amer. Soc. of Biomechanics, Tempe, Arizona, 1991.

    Lavender, S., Y. Tsuang, A. Hafezi, G. Andersson, D. Chaffin and R. Hughes. Coactivation of the Trunk Muscles during Asymmetric Loading of the Torso. Human Factors, 34(2):239-247, 1992.

    Nussbaum, M.A., S.A. Lavender, D.B. Chaffin and G.B.J. Andersson. Optimization-Based Torso Muscle Force Prediction: Asymmetric Loading in Two Flexed Postures. Proceedings of the North American Conference on Biomechanics, Chicago, 1992.

    Nussbaum, M.A., D.B. Chaffin, S.A. Lavender and C.J. Rechtien. Geometric Considerations in Optimization-Based Modeling of the Torso Musculature. Proceedings of the XIVth Inter. Congress on Biomechanics, Paris, France, 1993.

    Hughes, R.E., D.B. Chaffin, S.A. Lavender and G.B.J. Andersson. Evaluation of Muscle Force Prediction Models of the Lumbar Trunk Using Surface Electromyography. Journal of Orthopaedic Research, 12:689-698, 1994.

    Hughes, R.E. and D.B. Chaffin. The Effect of Strict Muscle Stress Limits on Abdominal Muscle Force Predictions for Combined Torsion and Extension Loadings. J. Biomechanics, 28(5):527-533, 1995.

    Chaffin, D.B. Postural Considerations in Lifting - Or Why Aren't My Arms Five Feet Long? in Occupational Musculoskeletal Disorders: Assessment, Treatment and Prevention, (Ed.) M. Nordin, G. Andersson and M. Pope Mosby Yearbook, Inc. 1995.

    Hughes, R.E., J.C. Bean and D.B. Chaffin. Evaluating the Effect of Co-contraction in Optimization Models-Technical J. Biomechanics, 28(7):875-878, 1995.

    Nussbaum, M.A. and D.B. Chaffin. Evaluation of Artificial Neural Network Modeling to Predict Torso Muscle Activity, Ergonomics, 39(12):1430-1444, 1996.

    Raschke, U. and D.B. Chaffin. Support for a Linear Length-Tension Relation of the Torso Extensor Muscles: An Investigation of the Length and Velocity EMG-Force Relationships. J. Biomechanics, 29:12):1597-1604, 1996.

    Raschke, U. and D.B. Chaffin. Trunk and Hip Muscle Recruitment in Response to External Anterior Lumbosacral Shear and Moment Loads. Clinical Biomechanics, 11(3):145-152, 1996.

    Raschke, U., B.J. Martin and D.B. Chaffin. Distributed Moment Histogram: A Neurophysiology Based Method of Agonist and Antagonist Trunk Muscle Activity Prediction. J. Biomechanics, 29(12):1587-1596, 1996.

    Nussbaum, M.A. and D.B. Chaffin. Pattern Classification Reveals Intersubject Group Differences in Lumbar Muscle Recruitment during Static Loading Activity. Clinical Biomechanics, 12(2):97-106, 1997.

    Nussbaum, M.A., B.J. Martin and D.B. Chaffin. A Neural Network Model for Simulation of Torso Muscle Coordination. J. Biomechanics, 30(3):251-258, 1997.

    Hughes, R.E. and D.B. Chaffin. Using Principal-Components Regression to Stabilize EMG-Muscle Force Parameter Estimates of Torso Muscles, IEEE Transactions on Biomedical Engineering, 44(7), 639-642, 1997.

    Nussbaum, M.A. and D.B. Chaffin. Lumbar Muscle Force Estimation using a Subject-Invariant 5-Parameter EMG-Based Model, Journal of Biomechanics, 31:667-672, 1998.

    Nussbaum, M.A., Chaffin, D.B. and Baker, G. Biomechanical Analysis of Materials Handling Manipulators in Short Distance Transfers of Moderate Mass Objects: Joint Strength, Spine Forces and Muscular Antagonism, Ergonomics, 42(12):1597-1618, 1999.

    Chaffin, D.B. Some Biomechanical Perspectives on Musculoskeletal Disorders: Workplace Causation and Prevention. Invited Plenary Talk: Ohio State University/NIOSH: State of the Art Research Symposium, May 21-23, 2003.

    Dickerson, C. and D.B. Chaffin. Dynamic Loading and Effort Perception During One-Handed Loaded Reaches. American Society of Biomechanics, 27th Annual Meeting, Toledo, Ohio, September 25-27, 2003.

    Chaffin, D.B. Primary Prevention of Low Back Pain through Application of Biomechanics in Manual Materials Handling Tasks, La Medicina del Lavoro (Italian), 2005.

    Human Strength and Fatigue Modeling

    Chaffin, D.B., A Computerized Biomechanical Model: Development and Use in Studying Gross Body Actions. J. Biomechanics, 2:429-441, 1969.

    Chaffin, D.B. and W.H. Baker. A Biomechanical Model for Analysis of Symmetric Sagittal Plane Lifting.AIIE Transactions, 2(1), 1970.

    Chaffin, D.B. Graphical Predictions of Human Strengths for Two-Handed IVA/EVA Tasks, Phase I Report. University of Michigan, Industrial Engineering Human Performance Laboratory, April 1971.

    Chaffin, D.B. Human Strength Simulations of Zero G One and Two Handed Activities, Phase 2 Report. University of Michigan, Industrial Engineering Human Performance Laboratory, April 1972.

    Martin, B.J. and D.B. Chaffin. Biomechanical Computerized Simulation of Human Strength in Sagittal Plane Activities. AIIE Transactions, 4(1), 1972.

    Foust, D.R., D.B. Chaffin, R.G. Snyder and J.K. Baum. Cervical Range of Motion and Dynamic Response and Strength of Cervical Muscle. SAE Transactions, 4(82), SAE Paper No. 730975, Reprinted November 1974 and 1973.

    Chaffin, D.B., Manual Materials Handling and Low-back Pain, in Occupational Medicine, C. Zenz (ed.), Year Book Medical Publishers, Chicago, 1975.

    Chaffin, D.B. On the Validity of Biomechanical Models of the Low-back for Weight Lifting Anlaysis. ASME Proc., 75-WA-B10-1, Amer. Soc. Mech. Eng., New York, 1975.

    Garg, A. and D. Chaffin. A Biomechanical Computerized Simulation of Human Strength. AIIE Transactions, 7(1), March 1975.

    Owings, C.L., D.B. Chaffin, R.G. Snyder and R.H. Norcutt. Strength Characteristics of U.S. Children for Product Safety Design. University of Michigan Report 011903-F, October 1975.

    Garg, A., D.B. Chaffin, and A. Freivalds. Biomechanical Stresses from Manual Load Lifting: A Static v. Dynamic Evaluation, AIIE Transactions, 14(4), 1982.

    Freivalds, A., D.B. Chaffin and A. Grag. A Dynamic Biomechanical Evaluation of Lifting Maximum Acceptable Loads. J. Biomechanics, 17(4), 1984.

    Anderson, C.K. and D.B. Chaffin. A Biomechanical Evaluation of Five Lifting Techniques, Applied Ergonomics, 17(1), 1986.

    Chaffin, D.B., A. Freivalds and S.M. Evans. On the Validity of an Isometric Biomechanical Model of Worker Strengths. IIE Transactions, 19(3):280-288, 1987.

    Andres, R.O. and D.B. Chaffin. Validation of a Biodynamic Model of Pushing and Pulling.J. Biomechanics, 24(11):1033-1045, 1991.

    Chaffin, D.B. and M. Erig. Three-Dimensional Biomechanical Static Strength Prediction Model Sensitivity to Postural and Anthropometric Inaccuracies. IIE
    22(3):215-227, 1991.

    Chaffin, D.B. Ergonomics, in McGraw-Hill Yearbook of Science & Technology, McGraw-Hill, Inc., New York, p. 130-133, 1992.

    Erdil, Dickerson and Chaffin. Biomechanics of Manual Materials Handling and Low Back Pain, in Occupational Medicine, (Zenz ed.) Mosby, 1994.

    Chaffin, D.B. Ergonomic Basis for Job-Related Strength Testing, in Disability Evaluation, eds. S.L. Demeter, G.B.J. Andersson, G.M. Smith - lst edition American Medical Association, Mosby, St. Louis, MO, Chapter 17, pp. 159-167, 1996.

    Ulin, S.S., C.L. Patellos, D.B. Chaffin, S.B. Blitz, C.A. Emerick, F. Lundy and L.A. Misher. Biomechanical Analysis of Methods used for Transferring Totally Dependent Patients, Spinal Cord Injury Nursing, 14(1): 19-27, 1997.

    Chaffin, D.B., B.S. Stump, M.A. Nussbaum, and G. Baker. Low-back Stresses when Learning to Use Materials Handling Device. Ergonomics, 42(1):94-1210, 1999.

    Chaffin, D.B. Static Biomechanical Modeling in Manual Lifting, in The Occupational Biomechanics Handbook (Karwowski and Marras eds.) CRC Press LLC, Ch., 52, pp. 933-944, 1999.

    Chaffin, D.B. Ergonomic Basis for Job-related Strength Testing. To appear in Disability Evaluation, 2nd edition, Eds S.L. Demeter and G.B.J. Andersson, 2002

    Dickerson, C., B.J. Martin, D.B. Chaffin. The Relationship Between Shoulder Torque and the Perception of Muscular Effort in Loaded Reaches. Ergonomics, 49(11):1036-1051, 2006.

    Dickerson, C., B.J. Martin, D.B. Chaffin. Predictors of Perceived Effort in the Shoulder During Load Transfer Tasks. Ergonomics, 50(7):1004-1016, 2007.

    Hoffman, M.P. Reed, D.B. Chaffin. The Relationship between Hand Force Direction and Posture during Two-Handed Pushing Tasks. Proceedings of the Human Factors and Ergonomics Society Annual Meeting, 2007.

    Seo, T.J. Armstrong, J.A. Ashton-Miller, D.B. Chaffin. The Effect of Torque Direction and Cylindrical Handle Diameter on the Coupling between the Hand and a Cylindrical Handle. Journal of Biomechanics, 40:3236-3243, 2007.

    Seo, T.J. Armstrong, D.B. Chaffin, J.A. Ashton-Miller. Inward Torque and High-Friction Handles Can Reduce Required Muscle Efforts for Torque Generation. Human Factors, 50(1):37-48, 2008.

    Seo, T.J. Armstrong, D.B. Chaffin, J.A. Ashton-Miller. The Effect of Handle Friction and Inward or Outward Torque on Maximum Axial Push Force. Human Factors, 50(2):227-236, 2008.

    Human Exertion Software Development and Use

    Park, K.S. and D.B. Chaffin. Prediction of Load Lifting Limits for Manual Materials Handling. Professional Safety, 20(5), May 1975.

    Garg, A. and D.B. Chaffin. A Biomechanical Computerized Simulation of Human Strength. AIIE Transactions, 7(1):1-5, 1975.

    Langolf, G., D. Chaffin and J. Foulke. An Investigation of Fitts' Law Over a Wide Range of Movement Amplitudes. Journal of Motor Behavior, 8(2), June 1976.

    Chaffin, D.B., G.D. Herrin, W.M. Keyserling and A. Garg. A Method for Evaluating the Biomechanical Stresses Resulting from Manual Materials Handling Jobs. AIHAJ, 38(6), 1977.

    Garg, A., D. Chaffin and G. Herrin. Prediction of Metabolic Rates for Manual Materials Handling Jobs. AIHA Journal, 39:661-674 August 1978.

    Garg, A., D. Chaffin and A. Freivalds. Biomechanical Stresses from Manual Load Lifting -- A Static and Dynamic Evaluation. IIE Transactions, 14(4):272-281, 1982.

    Chaffin, D.B., R.O. Andres and A. Garg. Volitional Postures during Maximal Push/Pull Exertions in the Sagittal Plane. Human Factors, 25(5):541-550, 1983.

    Evans, S.M., D. Chaffin, and J. Foulke. A Methodology for Integrating Ergonomics Information in Workspace Design., Proceedings of the 1984 International Conference on Occupational Ergonomics.

    Freivalds, A., D. Chaffin, A. Garg and K. Lee. A Dynamic Biomechanical Evaluation of Lifting Maximum Acceptable Loads. J. Biomechanics, 17(4):251-262, 1984.

    Chaffin, D. Computerized Models for Occupational Biomechanics. Scandinavian J. of Occupational Health and Safety and Biomechanics X, (B. Johnson Ed.), Human Kinetics, Champaign, IL 1986.

    Evans, S. and D. Chaffin. Using Interactive Visual Displays to Present Ergonomics Information in Workspace Design. Trends in Ergonomics/Human Factors III, W. Karwowski (Editor), Elsevier Science Publishers: (North-Holland), 1986.

    Kumar, S., D.B. Chaffin and Mark Redfern. Isometric and Isokinetic Back and Arm Lifting Strengths: Device and Measurement. J. Biomechanics, 21(1):35-44, 1988.

    Lee, K.S., D.B. Chaffin, G.D. Herrin, and A.M. Waikar. Effects of Handle Height on Lower Back Loading in Cart Pushing and Pulling. J. Applied Ergonomics, 22(2):117-123, 1991.

    Chaffin, D.B. Biomechanical Modeling for Simulation of 3D Static Human Exertions, in Computer Applications in Ergonomics, Occupational Safety and Health, ed. M. Mattila and W. Karwowski, Elsevier Science Publishers, N.Y., 1992.

    Thompson, D.D., D.B. Chaffin, R.E. Hughes and O. Evans. The Relationship of Isometric Strength to Peak Dynamic Hand Forces During Submaximal Weight Lifting. Int. J. of Ind. Ergonomics, 9:15-23, 1992.

    Woldstad, J.C. and D.B. Chaffin. Dynamic Push and Pull Forces While Using a Manual Material Handling Assist Device. IIE Transactions, 26(3):77-88, 1994.

    Chaffin, D.B. Development of Computerized Human Static Strength Simulation Model for Job Design, Human Factors and Ergonomics in Manufacturing, 7(4):305-322, 1997

    Chaffin, D.B. Biomechanical Aspects of Workplace Design, in Handbook of Human Factors and Ergonomics, ed. G. Salvendy, John Wiley & Sons, Inc., Ch. 23, pp. 772-789, 1997.

    Kerk, C.J., D.B. Chaffin and W.M. Keyserling. Stability as a Constraint in Sagittal Plane Human Force Exertion Modeling, Occupational Ergonomics, 1(1):23-39, 1998.

    Feyen, R., Y. Liu, D. Chaffin, G. Jimmerson and B. Joseph. New Software Tools Improve Workplace Design, Ergonomics in Design, April, pp. 24-30, 1999.

    Chaffin, D.B. Biomechanical Models in High Exertion Manual Jobs, in Occupational Ergonomics Work Related Musculoskeletal Disorders of the Upper Limb and Back, eds:. Violante, F., Armstrong, T, Kilbom, A., Chapter 13, 157-177, 2000.

    Park, W., Chaffin D.B. Modifying Motions to Meet New Constraints, Proceedings of 15th Triennial Congress of the International Ergonomics Association, 2000.

    Park, W., Chaffin, D.B., Martin, B. A Motion Modification Algorithm for Memory-based Human Motion Simulation, Proceedings of Human Factors and Ergonomics Society 46th Annual Meeting, 2002.

    Chaffin, D.B., Woolley, C., Dickerson, C., Parkinson, M. Modeling of Object Movement Capability in the Spinal Cord Injured Population, International Journal of Industrial Ergonomics, 33(3):229-236, 2004.

    Chaffin, D.B. Improving Digital Human Modeling for Proactive Ergonomics in Design, Ergonomics, 48(5): 478-491, 2005.

    Dickerson, C., D.B. Chaffin, R.E. Huges. A Mathematical Musculoskeletal Shoulder Model for Proactive Ergonomic Analysis. Computer Methods in Biomechanics and Biomedical Engineering, 10(6):389-400, 2007.

    Human Posture and Motion Modeling

    Park, K. and D. Chaffin. Biomechanical Evaluation of Two Methods of Manual Load Lifting, AIIE Transactions, 6(2), June 1974.

    Armstrong, T.J., D.B. Chaffin and J.A. Foulke. A Methodology for Documenting Hand Positions and Forces During Manual Work. Journal of Biomechanics, 12:131-133, 1979.

    Garg, A., D. Sharma, D. Chaffin and J.M. Schmidler. Biomechanical Stresses as Related to Motion Trajectory of Lifting. Human Factors, 25(5):527-540, 1983.

    Anderson, C. and D. Chaffin. A Biomechanical Evaluation of Five Lifting Techniques. Applied Ergonomics, 17(1):2-8, 1986.

    Chaffin, D., L. Gallay, C. Woolley and S. Kuciemba. An Evaluation of the Effect of Worker Training on Lifting Postures. International Journal of Industrial Ergonomics, 1:127-136, 1986.

    Gilad, I., M. Redfern, D.B. Chaffin and S.N. Byun. Angular Displacement of Torso During Lifting: A System Comparison of Two Measuring Methods. Human Movement Science, 8:547-569, 1989.

    Wiker, S.F., D.B. Chaffin and G.D. Langolf. Shoulder Posture and Localized Muscle Fatigue and Discomfort. Ergonomics, 32(2):211-237, 1989.

    Wiker, S.F., G.D. Langolf and D.B. Chaffin. Arm Posture and Human Movement Capability. Human Factors, 31(4):421-441, 1989.

    Beck, D.J. and D.B. Chaffin. An Evaluation of Inverse Kinematics Models for Posture Prediction, CAES, Finland 1992.

    Chaffin, D.B. and G.B. Page. Postural Effects on Biomechanical and Psychophysical Weight-lifting Limits. Ergonomics, 37(4):663-676, 1994.

    Nussbaum, M.A., X. Zhang., D.B. Chaffin, B.S. Stump and U. Raschke. A Reduced Surface Marker Set for Upper Limb Kinematics: Heuristics and Optimization. Proceedings of the 20th Annual Meeting of American Society of Biomechanics, Atlanta, GA, 1996.

    Resnick, M.L. and D.B. Chaffin. Kinematics, Kinetics, and Psychophysical Perceptions in Symmetric and Twisting Pushing and Pulling Tasks Human Factors, 38(1):114-129, 1996.

    Zhang, X. and D.B. Chaffin. Task Effects on Three-Dimensional Dynamic Postures during Seated Reaching Movements: An Analysis Method and Illustration. Proceedings of the 40th Human Factors and Ergonomics Society Annual Meeting Philadelphia, PA, 1996. (Winner of the Industrial Ergonomics Best Student Paper Award.)

    Zhang, X., D.B. Chaffin and Q. Shen. Effects of Target Location on Torso Kinematics during Seated Discrete Reaching Movements in Three Dimensions. Proceedings of the 20th Annual Meeting of American Society of Biomechanics, Atlanta, GA, 1996.

    Zhang, X., M.A. Nussbaum, and D.B. Chaffin. Calibrating Instantaneous Helical Axes to Identify the Elbow and Shoulder Joint Centers for Movement Studies. Proceedings of the 20th Annual Meeting of American Society of Biomechanics. Atlanta, GA, 1996.

    Zhang, X., D.B. Chaffin, and D. Thompson. The Development of Dynamic Simulation Models of Seated Reaching Motions while Driving. to appear in SAE Transactions (presented at SAE Congress, February 1997).

    Liu, Y., X. Zhang, and D. Chaffin. Perception And Visualization of Human Posture Information For Computer Aided Ergonomic Analysis. Ergonomics 40(8):818-833, 1997.

    Zhang, X. and D.B. Chaffin. Task Effects on Three-Dimensional Dynamic Postures during Seated Reaching Movements: An Investigative Scheme and Illustration. Human Factors, 39(4):659-671, 1997.

    Holbein, M.A. and D.B. Chaffin. Stability Limits in Extreme Postures: Effects of Load Positioining, Foot Placement, and Strength. Human Factors, 39(3):456-468, 1997.

    Zhang, X., A.O. Kuo and D.B. Chaffin. Optimization-Based Differential Kinematic Modeling Exhibits a Velocity-Control Strategy for Dynamic Posture Determination in Seated Reaching Movements, Journal of Biomechanics, 31:1035-1042, 1998.

    Feyen, R., Liu, Y., Chaffin, D., Jimmerson, G., and Joseph, B. New Software Tools Improve Workplace Design, Ergonomics in Design, April, pp. 24-30, 1999.

    Faraway, J.J., X. Zhang and D.B. Chaffin. Rectifying Postures Reconstructed from Joint Angles to Meet Constraints (Technical Note), Journal of Biomechanics, 32:733-736, 1999.

    Zhang, X. and Chaffin, D. The Effects of Speed Variation on Joint Kinematics during Multisegment Reaching Movements, Human Movement Science, 18:741-757, 1999.

    Faraway, J.J., Zhang, X., and Chaffin, D.B. Rectifying Postures Reconstructed from Joint Angles to Meet Constraints (Technical Note), Journal of Biomechanics, 32:733-736, 1999.

    Park, W., Woolley, C.B., Foulke, J., Chaffin, D.B., Raschke and Zhang. Integration of Electromagnetic and Optical Motion Tracking Devices for Capturing Human Motion Data. SAE Technical Paper 991911, 1999.

    Nussbaum, M. and Chaffin, D. Effects of Pacing when Using Materials Handling Manipulators, Human Factors, 41(2):214-225, 1999.

    Zhang, X., Nussbaum, M.A. and Chaffin, D.B. Back Lift versus Leg Lift: An Index and Visualization of Dynamic Lifting Strategies, Technical note. Journal of Biomechanics, 33:777-782, 2000.

    Zhang, X. and Chaffin, D. A Three-dimensional Dynamic Posture Prediction Model for Simulating In-vehicle Seated Reaching Movements: Development and Validation, Ergonomics, 43(9):1314-1330, 2000.

    Feyen, R., Liu, Y., Chaffin, D., Jimmerson, G., and Joseph, B. Computer-aided ergonomics: a case study of incorporating ergonomics analyses into workplace design, Applied Ergonomics, 31:291-300, 2000.

    Chaffin, D.B., Faraway, J., Zhang, X. and Woolley, C. Stature, Age, and Gender Effects on Reach Motion Postures Human Factors 42(3):408-420, 2000.

    Park, Chaffin, Martin. Development of a Robust Dynamics Motion Modification Method. Proceedings of SAE Digital Human Modeling Conference, 2000.

    Park, Chaffin, Martin. Development of an Angle-time-based Dynamic Motion Modification Method. SAE Technical Paper Series 2000-01-2176, 2000.

    Park, W., D.B. Chaffin, and B.J. Martin. Modifying Motions for Avoiding Obstacles. SAE Transactions110(6): 2250-2256, 2002.

    Chaffin, D.B. On Simulating Human Reach Motions for Ergonomics Analyses, Human Factors and Ergonomics in Manufacturing, Vol. 12(3) 1-13, 2002.

    Park, W., Chaffin, D., Martin, D. Toward Memory Based Human Motion Simulation: Development and Validation of a Motion Modification Algorithm. IEEE Transactions on Systems, Man and Cybernetics, 34(3):376-386, 2004.

    Kim, K.H., Martin, B.J., Chaffin, D.B. Modelling of Shoulder and Torso perception of Effort in Manual Transfer Tasks. Ergonomics 47(9):927-944, 2004.

    Park, Chaffin, Martin, Faraway. A Computer Algorithm for Representing Spatial-Temporal Structure of Human Motion and Motion Generalization. Journal of Biomechanics, 38(11): 2321-2329, 2005.

    Park, Martin, Choe, Chaffin, Reed. Representing and Identifying Alternative Movement Techniques for Goal-directed Manual Tasks. Journal of Biomechanics, 38(3):519-527, 2005

    Wagner, D.W., M.P. Reed, Chaffin, D.B. Predicting Foot Positions for Manual Materials Handling Tasks, SAE, Digital Human Modeling for Design and Engineering Symposium, Univ. of Iowa, June 2005.

    Raschke, U., Schutte, D.B. Chaffin. Simulating Humans: Ergonomic Analysis in Digital Environments. The Handbook of Industrial Engineering (3rd Edition), 2006.

    Parkinson, M.B., Chaffin, D.B., M.P. Reed. Center of Pressure Excursion Capability in Performance of Seated-Lateral Reaching Tasks, Clinical Biomechanics, 21(1): 26-32, 2006.

    Chaffin, D.B. Human Motion Simulation for Vehicle and Workplace Design. Human Factors and Ergonomics in Manufacturing, 17(5):475-484, 2007.

    Hoffman, M.P. Reed, D.B. Chaffin. Predicting Force-Exertion Postures from Task Variables. Proceedings of SAE Digital Human Modeling for Design and Engineering Conference, 2007.

    Holbein-Jenny, M.A., M. Redfern, Gottesman, D.B. Chaffin. Kinematics of Heelstrike During Walking and Carrying: Implications for Slip Resistance Testing. Ergonomics, 50(3):352-363, 2007.

    Park, W., Chaffin, D.B., Martin, B.J., Yoon, J.  Memory-Based Human Motion Simulation for Computer-Aided Ergonomic Design.  IEEE Transactions on Systems, Man, and Cybernetics, 38(3): 513-527, 2008.

    Anthropometric Modeling

    Armstrong, T.J., D.B. Chaffin and J.A. Foulke. A Method for Measuring Shapes of Anatomical Surfaces. Technical Note-Journal of Biomechanics, 12:397-399, 1979.

    Chaffin, D. Fundamentals of Anthropometry and Biomechanical Job Evaluations. In Handbook of Industrial Engineering, edited by G. Salvendy, John Wiley & Sons, Inc. 1982.

    Nussbaum, M.A., D.B. Chaffin and C.J. Rechtien. Muscle Lines-of-Action Affect Predicted Forces in Optimization-Based Spine Muscle Modeling. J. Biomechanics, 28(4):401-409, 1995.

    Nussbaum, M.A. and D.B. Chaffin. Development and Evaluation of a Scalable and Deformable Geometric Model of the Human Torso. Clinical Biomechanics, 11(1):25-34, 1996.

    Chaffin, D., C. Woolley, T. Buhr and L. Verbrugge. Age Effects in Biomechanical Modeling of Static Lifting Strengths," ed. W. A. Rogers, chapter in Designing for an Aging Population: Ten Years of Human Factors/Ergonomics Research, Human Factors and Ergonomics Society, Santa Monica, CA , 1997.

    Recent Books

    Pope, M.H., J. Frymoyer, G.B.J. Andersson and D.B. Chaffin. Occupational Low Back Pain Assessment, Treatment and Prevention, Mosby-Year Book, Inc., St. Louis 1991.

    Chaffin, D.B.. Digital Human Modeling for Vehicle and Workplace Design, SAE Bookstore, Warrendale, PA 2001.

    Chaffin, D.B., G.B.J. Andersson and B.J. Martin.Occupational Biomechanics (4th Edition) J. Wiley & Sons, New York, NY 2006.

    Delleman N, Haslegrave C, Chaffin D. (Eds.) Working Postures & Movements - Tools for Evaluation and Engineering , Taylor and Francis, 2004.


    Recent sponsored activity

    Biomechanical Analysis of the Lower Back During Twisting, (Rush-Presbyterian-St. Luke's Medical Center), 04/01/93 - 03/31/96;
    Seated Operator Motion Simulation, (Chrysler Corporation), 01/01/95 - 12/31/97;
    Materials Handling Devices (MHDs): Ergonomics Technology Specification and Design, (Ford Motor Company), 01/01/96 - 12/31/96.


    Previous positions

    Director, Center for Occupational Health and Safety Engineering, University of Michigan, 1982-1998;
    Chair, Industrial and Operations Engineering, University of Michigan, 1977-1981;
    Assistant Professor, Physical Medicine, University of Kansas, 1967-1968;
    Project Engineer, Bendix, 1964-1965;
    Quality Control Engineer and Foreman, General Motors, 1962-1964.
    Director, Center for Ergonomics, 1981 - 1997



    English, French

    University of Michigan - - - - - - College of Engineering- - - - - -IOE Department