The calcaneofibular ligament is attached above to the malleolar fossa on the posteromedial side of the lateral malleolus and passes posteroinferiorly to attach below to a tubercle on the lateral surface of the calcaneus.
The numerous synovial joints between the individual tarsal bones mainly invert, evert, supinate, and pronate the foot:
Inversion and eversion is turning the whole sole of the foot inward and outward, respectively.
Pronation is rotating the front of the foot laterally relative to the back of the foot, and supination is the reverse movement.
Pronation and supination allow the foot to maintain normal contact with the ground when in different stances or when standing on irregular surfaces.
The major joints at which movements occur include the subtalar, talocalcaneonavicular, and calcaneocuboid joints (Fig. 6.105). The talocalcaneonavicular and calcaneocuboid joints together form what is often referred to as the transverse tarsal joint.
Intertarsal joints between the cuneiforms and between the cuneiforms and the navicular allow only limited movement.
The joint between the cuboid and navicular is normally fibrous.
The subtalar joint is between: the large posterior calcaneal facet on the inferior surface of the talus, and the corresponding posterior talar facet on the superior surface of the calcaneus.
The articular cavity is enclosed by synovial membrane, which is covered by a fibrous membrane.
The subtalar joint allows gliding and rotation, which are involved in inversion and eversion of the foot. Lateral, medial, posterior, and interosseous talocalcaneal ligaments stabilize the joint. The interosseous talocalcaneal ligament lies in the tarsal sinus (Fig. 6.106).
The talocalcaneonavicular joint is a complex joint in which the head of the talus articulates with the calcaneus and plantar calcaneonavicular ligament (spring ligament) below and the navicular in front (Fig. 6.107A).
The talocalcaneonavicular joint allows gliding and rotation movements, which together with similar movements of the subtalar joint are involved with inversion and eversion of the foot. It also participates in pronation and supination.
The parts of the talocalcaneonavicular joint between the talus and calcaneus are: the anterior and middle calcaneal facets on the inferior surface of the talar head, and the corresponding anterior and middle talar facets on the superior surface and sustentaculum tali, respectively, of the calcaneus (Fig. 6.107B).
The part of the joint between the talus and the plantar calcaneonavicular ligament (spring ligament) is between the ligament and the medial facet on the inferior surface of the talar head.
The joint between the navicular and talus is the largest part of the talocalcaneonavicular joint and is between the ovoid anterior end of the talar head and the corresponding concave posterior surface of the navicular.
The capsule of the talocalcaneonavicular joint, which is a synovial joint, is reinforced: posteriorly by the interosseous talocalcaneal ligament, superiorly by the talonavicular ligament, which passes between the neck of the talus and adjacent regions of the navicular, and inferiorly by the plantar calcaneonavicular ligament (spring ligament) (Fig. 6.107C,D).
The lateral part of the talocalcaneonavicular joint is reinforced by the calcaneonavicular part of the bifurcate ligament, which is a Y-shaped ligament superior to the joint. The base of the bifurcate ligament is attached to the anterior aspect of the superior surface of the calcaneus and its arms are attached to: the dorsomedial surface of the cuboid (calcaneocuboid ligament), and the dorsolateral part of the navicular (calcaneonavicular ligament).