POSTER SESSION-ERGONOMICS THORACIC CRUSH INJURIES IN A TRACTOR WHERL ROLLOVRRz ESllMATION OF 3-D F‘OR.CRS Narayan Yoganandan, Y. King Liu,* John Winterbottom,* and Anthony Sances, Jr, Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI 53226 Department of Veterans Affairs Medical Center, Milwaukee, WI 53295 *Department of of Biomedical Engineering, University of Iowa, Iowa City, IA The objective of the present study was to determine the generalized dynamic force (and moment) histories which are primarily responsible for crush injuries to the human thorax during a tractor wheel rollover. A three-dimensional force and moment measuring load cell was used to collect dynamic data. A sandbag of approximately 22.7 kg simulating the human torso was placed on the load cell. Tractor wheel rollover tests were conducted at velocities ranging from 0 to 86 cm/s. Peak compressive forces ranged from 3,500 to 13,430 N. Off-axis (shear) forces were considerably smaller. Moments along the three directions and the off-axis forces developed after the development of the peak compressive force. This indicates that crushing injuries are primarily due to the principal (vertical) component-during in uiuo situations. ACKNOWLEDGEMENT: This research was supported in part by PHS CDC Grants R49CCR703640, R49CCR 502508, and the Department of Veterans AfTairs Medical Research Funds. AN APPLICATION OF THE BIOMECHANICAL SIMULATION OF HUMAN MOVEMENT TO THE EVALUATION OF DWELLING SPACE DESIGN Takashi Yokoi Industrial Products Research Inst., Tsukuba, Ibaraki 305, Japan. Biomechanical simulation of human movement was applied to the evaluation of cooking table height from the perspective of muscle stress. The eight-segment link model of the human body and musculoskeletal model of the lower limb were used in the simulation. The simulation includes linear optimization method for the estimation of individual muscle forces. The optimum cooking table height obtained through the present simulation was similar to those previously reported in the literature. It was confirmed the biomechanical simulation can be applied to the evaluation of dwelling spaces and equipment from the viewpoint of muscle stress. ASSESSMENT OF RISK FACTORS FOR CUMULATIVE TRAUMA DISORDERS (CTD) USING A VIDEO/COMPUTER GRAPHICS APPROACH R. Wells and A. Moore Department of Kinesiology, University of Waterloo Waterloo, Ontario, Canada, N2L 3Gl This paper describes an approach to assessing manual tasks for the potential of causing chronic musculoskeletal (cumulative trauma) disorders. The recent availability of affordable and portable video and computer systems as well as commercial instrumentation has allowed the marriage of these technologies to permit both quantitative and semi-quantitative monitoring and analysis of upper extremity work. Measures useful in quantifying risk factors are superimposed on the video image. Typical measures used are: 1) Shoulder muscle activation; 2) forearm muscle activation: 3) wrist angle and; 4) the coincidence of wrist flexion and forearm flexor muscle activation. Instrumentation combining a video image of the worker performing the task, together with superimposed quantitative information on risk factors, has been found very useful in obtaining semi-quantitative assessments in a many types of workplace. The system also provides storage and retrieval of machine readable quantitative data, synchronized to the video image, for further quantitative analyses. 681