History dependence of skeletal muscle force production: implications for movement control.

In this study, we review existing evidence on the history dependence of skeletal muscle force production. Specifically, we investigate the steady-state forces following shortening or stretching of an activated skeletal muscle preparation and compare these forces to the corresponding steady-state forces obtained for purely isometric contractions at identical lengths. Force depression following shortening and force enhancement following stretch can reach values of almost 50% of the corresponding isometric reference force, and thus might affect movement control. We also show novel results on history-dependent effects for voluntary contractions in human skeletal muscles, thereby emphasizing that voluntary force production is affected by the contractile history of the target muscles. These results lead to the conclusion that history-dependent force production should be considered in models of movement control and voluntary force production.