Figure 3.

Variation in the measured muscle–tendon lengths at which fascicles fall slack (A and D), fascicle slack lengths (B and E) and a two-dimensional measure of pennation (C and F)

A–C are histograms of data from muscle fascicles in 10 subjects (142 fascicles for A and B, and 159 fascicles for C). Measurements that were repeated at each site have not been included in A–C. D–F show pairs of repeated measurements made on 22 fascicles (D and E) or 23 fascicles (F) from 5 subjects. Shading differentiates the 5 subjects’ data (S1, S2, … S5). Vertical lines connect the pair of measurements made at a single site in one subject.