Fast stretching of single skeletal muscle fibers abolishes residual force enhancement

Abstract

It has been shown that the steady-state isometric force of a muscle after active stretching is greater than the steady-state force for a purely isometric contraction at the same length and activation level. This property of skeletal muscle has been called residual force enhancement (rFE) (Abbott & Aubert, 1952). Despite half a century of study, the mechanisms underlying rFE remain unknown. It has been shown that when myofibrils were actively stretched while cross-bridges were not allowed to cycle, rFE was substantially reduced, suggesting that cross-bridge cycling is necessary to induce rFE (Leonard & Herzog, 2010; Powers et al., 2014).