DETERMINING INDIVIDUAL MUSCLE FORCES DURING MAXIMAL ACTIVITY - MODEL DEVELOPMENT, PARAMETER DETERMINATION, AND VALIDATION

This study focused on the development of a model to compute the individual muscle forces during loaded elbow flexion. The model consisted of a contractile component in series with an elastic component. The force produced by the contractile component was dependent on the length and velocity of contraction of the muscle fibres. An experimental procedure was developed, requiring a series of maximum isometric muscle actions at different joint angles, which permitted selected parameters for the muscle model to be determined experimentally. A simulation procedure incorporating the muscle model was used to estimate the muscle forces during a dumbbell curl (loaded elbow flexion). The model was validated by comparing muscle model estimated joint moment values with those estimated from inverse dynamics; the percentage root mean square difference between these two measures was 5.5 percent. The model was considered to be valid for the determination of the individual muscle forces during the studied maximal activity.