Figure 2.

Force–velocity relations for fast (a) and slow (b) muscle, calculated from simulation-I. Simulations are shown for maximal (solid lines), and 20% activation (dashed lines), and for muscle mass of 1.05 g (circles) and 16.33 kg (squares). achieved at 0.01F₀ with no external load (c) and the strain-rate achieved at 0.15F₀ with an added external load of 0.6M (d) are shown for a range from maximal (solid lines) through to 20% activation (shortest dashes). Note the similar strain-rates for fast and slow muscles at 20 and 30% activation (open circles), respectively, representing data from Holt et al. [12]. Fast muscle is shown in blue and slow muscle in red for (a–d). The initial lengths required to achieve at L₀ are shown as a function of muscle mass and activation for the fast (e) and slow (f) muscle for simulation-II.