Fig 5. Windlass mechanism.
a) the plantar fascia connects the calcaneus and the proximal metatarsophalangeal joint; b) when the proximal metatarsophalangeal joint is dorsiflexed, the fascia is tightened and the medial longitudinal arch raises; c) in HH, the proximal metatarsophalangeal joints are passively dorsiflexed. This position may cause Windlass mechanism which leads to more tension in the forefoot when wearing HH.