Fig. 2.
TIP model calculations with stance leg length (L) against θL. The blue lines are average data for backward running (BR) and the red lines for forward running (FR), with the thicker parts for the deceleration phase and the thinner parts for the push-off phase. FRPO and BRPO are push-off in FR and BR respectively, and the arrows indicate the walking directions. The stars indicate where Mk(max) occurred. In both FR and BR the leg shortened during the deceleration phase and extended during the push-off phase. The stars are very close together for FR and BR; the peak knee moment therefore occurred at similar body orientations for both running styles. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)