FIGURE 1.

Composite traces of muscle force for a series of contractions in the medial gastrocnemius at a range of stimulation frequencies. Measured forces are shown in gray, and predicted forces are shown in black. The forces were modeled using differential model E, with v₀ estimated at 5 and 10 s⁻¹ (a) or 2.74 and 3.59 s⁻¹ (b) for the slow and fast-fibers, respectively, and with fast fibers comprising 75% of the muscle.