Fig. 1. Mean myoelectric intensity spectra for the plantaris (A), soleus (B) and medial gastrocnemius (C) muscle during three locomotor conditions (N=6 for each muscle). Data are shown as mean (black line) and s.e.m. (grey lines), with the division between stance and swing phase denoted by the broken, grey vertical line; 0% stride duration represents initial ground contact. Partitioning of the stride is represented in D, including data from the plantaris muscle (10° 40 cm s^–1). The division between stance and swing phase is shown by the broken, thick, vertical grey line.