Co-contraction of antagonist muscles: predictions and observations

A simple model representing the quasistatic behavior of skeletal muscle is presented in which the force produced by the muscle is a bilinear function of the muscle length and the neural activation of the muscle. Using two such muscles to represent the biceps and triceps, a biomechanical model of the elbow and forearm is developed. For maintenance of static posture of the elbow and forearm, this model predicts paradoxical patterns of muscular activation. An explanation of these counterintuitive patterns of muscular activation is presented and the competence of this model is assessed on the basis of preliminary experiments.<>