Figure 4. Effect of loading and unloading.

In each row, a basic pattern is plotted versus normalized gait cycle (as in Figs 2 and 3), and scaled in amplitude for the indicated muscles and loading conditions (see legend). For each condition, all muscles within a module received the same activation timing and waveform, but the magnitude was allowed to vary. Both timing and magnitude were allowed to vary between conditions. GMAX, gluteus maximus; GMED, gluteus medius; VAS, 3-components vastus (medialis, lateralis, intermedius); RF, rectus femoris; HAM, hamstrings; BFsh, short head of biceps femoris; MGAS, medial gastrocnemius; SOL, soleus; TA, tibialis anterior. Modified from McGowan et al. (2010) with permission from Elsevier.