Fig. 2. Mean values of normalized peak muscle force and normalized root mean squares of electromyographic activity (EMG) of MG and SOL for all seven experimental animals. (A) Normalized peak MG force, (B) normalized MG EMG, (C) normalized SOL force, (D) normalized SOL EMG. All values are normalized relative to the mean value obtained at 0.4-0.6 m s^-1 level treadmill walking for cats 1-5 and 7, and the mean value of level walking for cat 6. ^*P<0.05; ^**P<0.01; the numbers of steps for each condition are given in Table 1.