Fig. 3. Joint angles (broken lines) and normalized muscle lengths (solid lines, where 1.0 = length at rest), at 3.25 m s^-1 for the triceps (A) and for the two patterns of muscle strain observed in the vastus (B; referred to in Hoyt et al., 2005). Phases (denoted by vertical broken lines and numbers), based on kinematics, were the same as used in the analysis of the data obtained during level locomotion. Mean duration of EMG activity is indicated by shaded gray bars.