The spring ligament (plantar calcaneonavicular ligament) is the primary static stabilizer for which part of the foot arch, and its rupture is the key pathology in adult acquired flatfoot?

• A Medial longitudinal arch; supports the head of the talus ✓
• B Lateral longitudinal arch; supports the cuboid
• C Transverse (metatarsal) arch; supports the second metatarsal base
• D Subtalar joint; maintains subtalar alignment

Explanation

The spring ligament (plantar calcaneonavicular) bridges the sustentaculum tali of the calcaneus to the navicular and directly cradles the head of the talus — the keystone of the medial longitudinal arch. It acts as a static sling preventing talar head plantar flexion and medial deviation. Its degeneration (often combined with tibialis posterior tendon dysfunction) is the initiating step in adult acquired flatfoot (pes planus). The lateral longitudinal arch is stabilized by the long and short plantar ligaments. The transverse arch is maintained by the peroneus longus tendon crossing the sole and the ligaments of Lisfranc's joint.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.