“The peroneus longus tendon wraps around the cuboid (and the brevis attaches to the base of the 1st metatarsal) on its way to insert onto the base of the 1st metatarsal. When it contracts, it dorsiflexes and everts the cuboid, which, along with the soleus (which plantar flexes and inverts the subtalar joint) allows dorsiflexion of 4th and 5th metatarsals and “locks” the lateral column.  Without this mechanism, there is no locking. Without locking, there is no supination. Without supination, there is little rigidity and inefficient propulsion. ”

Citation: https://thegaitguys.tumblr.com/post/31983175442/supination-anyone-the-importance-of-the