Figure 9.

Sum extensor (A) and flexor (B) moment arm (MA – in metres) and torque (Nm) at different abduction angles around the ankle. Ankle is dorsiflexed as joint angle increases. T refers to torque; M to moment arm. AbZero refers to ankle abducted at 0°, Ab10 at 10°, Ab20 at 20°. Black arrows depict ranges of joint angles used for bipedal walking, quadrupedalism and climbing (Isler, 2005; Watson et al. 2009). In climbing, the ankle is abducted up to 10° and can be dorsiflexed by as much as 119° (DeSilva, 2008). Dotted black arrow used for climbing as only maximum dorsiflexion angle is known, unlike in bipedal walking where the exact range is known.