Which ligament is referred to as the spring ligament due to supporting the foot's arch and is stretched in flat foot?

Which ligament is referred to as the spring ligament due to supporting the foot's arch and is stretched in flat foot?

• A. Spring (plantar calcaneonavicular)
• B. Deltoid ligament
• C. Long plantar ligament
• D. Plantar fascia

Answer: (A)

The key idea is a ligament that acts like a spring to keep the medial longitudinal arch of the foot elevated. This ligament runs from the sustentaculum tali of the calcaneus to the navicular bone, supporting the head of the talus as the arch bears weight. When the foot flattens (flat foot), this ligament is stretched and can’t hold the talar head up, contributing to loss of the arch. The other structures—deltoid ligament (medial ankle stabilizer), long plantar ligament (helps support the lateral arch but isn’t the spring), and plantar fascia (a deep plantar aponeurosis that supports the arch broadly)—do not carry the specific “spring” role.

The key idea is a ligament that acts like a spring to keep the medial longitudinal arch of the foot elevated. This ligament runs from the sustentaculum tali of the calcaneus to the navicular bone, supporting the head of the talus as the arch bears weight. When the foot flattens (flat foot), this ligament is stretched and can’t hold the talar head up, contributing to loss of the arch. The other structures—deltoid ligament (medial ankle stabilizer), long plantar ligament (helps support the lateral arch but isn’t the spring), and plantar fascia (a deep plantar aponeurosis that supports the arch broadly)—do not carry the specific “spring” role.