Fig. 6. Proximal muscle strain (bold lines) and EMG patterns (thin lines) recorded in vivo during level (red traces) versus incline (blue traces) locomotion for muscles of various animals (gait indicated in parentheses on right). Example patterns show increased shortening of the horse triceps and vastus (Wickler et al., 2005), the rat biceps (Gillis and Biewener, 2002) and wallaby biceps femoris (McGowan et al., 2007), as well as reduced net lengthening of the wallaby vastus, when moving on an incline. Stance duration is shown by the light red (level) and light blue (incline) shading. All muscles are displayed with the same fascicle strain and temporal scales. For fascicle strain traces, the tick on the scale bar indicates zero strain.