Which components constitute open-chain pronation of the subtalar joint?

Which components constitute open-chain pronation of the subtalar joint?

• A. Dorsiflexion, Eversion, Abduction
• B. Dorsiflexion, Inversion, Adduction
• C. Plantarflexion, Eversion, Abduction
• D. Plantarflexion, Inversion, Adduction

Answer: (A)

Open-chain pronation at the subtalar joint is a tri-plane, non-weightbearing movement. It consists of dorsiflexion at the ankle, eversion of the calcaneus, and abduction of the forefoot. These motions occur together when the foot moves freely under the leg, allowing the medial arch to lower and the foot to adapt to uneven surfaces. The other groupings pair plantarflexion with either inversion or adduction, which align with the opposite motion pattern (supination), not pronation in the open-chain sense.

Open-chain pronation at the subtalar joint is a tri-plane, non-weightbearing movement. It consists of dorsiflexion at the ankle, eversion of the calcaneus, and abduction of the forefoot. These motions occur together when the foot moves freely under the leg, allowing the medial arch to lower and the foot to adapt to uneven surfaces. The other groupings pair plantarflexion with either inversion or adduction, which align with the opposite motion pattern (supination), not pronation in the open-chain sense.