Fig. 3.

Muscle activity during walking at different slopes before and after injury. (A) Normalized electromyographic (EMG) activity recorded from the soleus (Sol) and tibialis anterior (TA) during downslope (Ds), level (Lv) and upslope (Us) treadmill locomotion in intact (N=8) and injured rats at 10 weeks following transection and surgical repair of the sciatic nerve (N=3). The Sol profiles are on the top (no fill) and the TA profiles are inverted (bottom) and shaded gray for clarity. The variance is illustrated as a corresponding gray tracing for both the Sol and TA (average + s.e.m.). (B) Selected components of normalized (as a percentage of the maximum activity recorded) Sol and TA EMG amplitudes were averaged and compared across slopes (Ds, inverted triangle; Lv, square; Us, triangle). Average overall EMG activity for the Sol was obtained during the portion of the step cycle indicated by the solid horizontal line and light gray shading in the top middle panel in A. These data are labeled Sol in B. The average Sol activity measured at the midpoint in the step cycle is labeled Sol (50%) and is indicated by the dotted line in A. Average overall EMG activity for the TA was obtained during the portion of the step cycle labeled TA with a double underline and shaded light gray in A.