Fig. 1. Representation of the time course of stimulation for the experimental stretches. Here, 0% length refers to the length at which active maximal isometric force was obtained (average sarcomere length about 2.1 µm; Lutz and Rome, 1994). The fibres were activated at an initial length for 1 s (sufficient for the force to reach the maximal isometric force at that length), then stretched 10% of fibre length to the final length in 0.25 s (40% s^–1). The fibre was then held at this final length for another 4.75 s (sufficient time for steady-state isometric force to be established; Edman et al., 1982).