Which ligament is the primary restraint to inversion of the subtalar joint?

Which ligament is the primary restraint to inversion of the subtalar joint?

• A. Deltoid ligament
• B. Interosseous talocalcaneal ligament
• C. Cervical ligament
• D. Spring ligament

Answer: (C)

Inversion of the subtalar joint is limited by the ligaments that span between the talus and calcaneus. The cervical ligament sits at the posterior aspect of the subtalar joint and tightens as the heel inverts, acting as the main restraint to that motion. Its orientation specifically counters the inward tilt of the calcaneus relative to the talus, making it the primary stabilizer against inversion. The interosseous talocalcaneal ligament provides additional deep stabilization but isn’t the main limiter, while the deltoid and spring ligaments contribute more to medial support and arch maintenance, respectively.