Windlass mechanism

At heel strike, the plantar fascia is slack to allow the foot to accommodate uneven surfaces. As the heel lifts and forefoot dorsiflexes toward toe-off, the distal plantar fascia “winds” up and around the first MTP joint pulling the plantar fascia taut, shortening the distance between the heel and forefoot, raising the arch– creating a stiffer lever for propulsion. (10)