Fig. 2. Averaged normalised electromyographic (EMG) activity (A) and EMG envelope peaks (B) of leg muscles during walking and running at different normalised speeds. A speed of 100% corresponds to the gait transition speed (2.1±0.2ms-1). Swing-related muscles whose EMG activity was averaged over the swing phase (see A) include the tibialis anterior (TA), the long head of the biceps femoris (BFL) and the rectus femoris (RF). Support-related muscles whose EMG activity was averaged over the stance phase (see A) include the soleus (SO), the gastrocnemius medialis (GA), the vastus medialis (VA) and the gluteus maximus (GLM). An asterisk indicates a significant (P<0.05) difference in EMG activity between walking and running at the same speed. Normalised swing-related EMG activities in the TA, BFL and RF were typically lower during running than during walking at preferred running speeds (115, 130 and 145%), whereas support-related EMG activity in the ankle and knee extensors (SO, GA and VA) was typically lower during walking than during running at preferred walking speeds (55, 70 and 85%).
