Which ligament limits eversion of the subtalar joint?

Which ligament limits eversion of the subtalar joint?

• A. Interosseous talocalcaneal ligament
• B. Deltoid ligament
• C. Calcaneofibular ligament
• D. Posterior talofibular ligament

Answer: (A)

The subtalar joint relies on ligaments that bind the talus to the calcaneus to control side-to-side motion. The interosseous talocalcaneal ligament, located inside the sinus tarsi between the talus and calcaneus, is the primary restraint to motion at this joint, including eversion. It tensions as the calcaneus tilts outward, preventing excessive eversion of the subtalar joint.

The other ligaments mentioned play different roles: the deltoid ligament is a medial stabilizer of the ankle (talocrural joint) and primarily resists eversion there, not subtalar motion. The calcaneofibular and posterior talofibular ligaments are lateral stabilizers that mostly limit inversion rather than eversion of the subtalar joint.