Physiological consideration of muscle force distribution

An analytical model for the determination of muscle forces under isometric loading conditions has been developed. The muscle length-tension as a function of the muscle architecture was developed and included in the model. The upper bound for each of the muscle forces was calculated from the muscle stress, physiological cross-sectional area, normalized muscle force (both active and passive), and the muscle activation level. The muscle force distribution under a given loading condition was achieved by minimizing the activation level of the muscles. Applications of the model for the analyses of muscle force involving multiple joints or a single joint with multiple degrees of freedom were also discussed.