Figure 6.

Activation-induced changes in proportion of sarcomeres with lengths that fall onto the ascending limb, plateau region, and descending limb of the theoretical force-length (FL) curve at short (A) and long (B) muscle lengths. A theoretical FL curve of the mouse TA (Walker and Schrodt, 1974; Herzog et al., 1992; Gokhin et al., 2014) adapted from Gordon et al. (1966) is shown in (C). For the relaxed-short muscle, 44% of the sarcomeres were located on the plateau region of the force-length relationship. For the relaxed-long muscle, 9% of the sarcomeres were located on the plateau region. In the active muscle, 14 and 27% of the sarcomeres were located on the plateau region for the short and long muscle length, respectively.