DEVELOPMENT AND EVALUATION OF A MUSCULOSKELETAL MODEL OF THE ELBOW JOINT COMPLEX

This paper describes the development and evaluation of a musculoskelet al model that represents human elbow flexion-extension and forearm pro nation-supination. The length, velocity, and moment arm for each of th e eight musculotendon actuators were based on skeletal anatomy and joi nt position. Musculotendon parameters were determined for each actuato r and verified by comparing analytical moment-angle curves with experi mental joint torque data. The parameters and skeletal geometry were al so utilized in the musculoskeletal model for the analysis of ballistic (rapid-directed) elbow joint complex movements. The key objective was to develop a computational model, guided by parameterized optimal con trol, to investigate the relationship among patterns of muscle excitat ion, individual muscle forces, and to determine the effects of forearm and elbow position on the recruitment of individual muscles during a variety of ballistic movements. The model was partially verified using experimental kinematic, torque, and electromyographic data from volun teer subjects performing both isometric and ballistic elbow joint comp lex movements. This verification lends credibility to the time-varying muscle force predictions and the recruitment of muscles that contribu te to both elbow flexion-extension and forearm pronation-supination.