The spring ligament passes from the anterior and medial margins of the sustentaculum tali forward to the inferior and inferomedial aspect of the navicular. As mentioned, its superior surface articulates with the underside of the head of the talus. This ligament maintains apposition of the medial aspects of the forefoot and hindfoot and in so doing helps to maintain the normal arched configuration of the foot. Laxity of the ligament allows a medial separation between the calcaneus and forefoot, with the forefoot assuming an abducted position with respect to the hindfoot. At the same time, the foot is allowed to“untwist,” which effectively lowers the normal arch of the foot, and the talar head is allowed to move medially and inferiorly. Further discussion of the twisted configuration and arching of the foot is included in the section on biomechanics.