Mechanical properties of a single equivalent muscle producing forearm supination

Muscles involved in forearm supination in man were analyzed in terms of a two component muscle model. The properties of the contractile component and series elastic component were determined by a series of dynamic contractions at four levels of perceived exerted effort. Generally characteristics were found to be highly non-linear, however at submaximal effort levels mechanical relationships contained long linear segments. This was interpreted as an attempt to make muscle behaviour more linear and thus more predictable. The outlined method is not limited to forearm supination, and allows description not only of muscle properties, but also of strategies employed in the use of muscles. When determined muscle characteristics were used in a validated muscle model, accurate prediction of contractions for individual subjects was possible.