Figure 13.12 The subtalar axes of motion. (A) Medial view. (B) Superior view. (C) Neutral position of the subtalar joint. (D) Pronation at the subtalar joint. (E) Supination at the subtalar joint.
transverse tarsal joint is the talonavicular joint, where a twisting in inversion and eversion occurs as the midfoot moves relative to the rearfoot. The talonavicular joint consists of the convex head of the talus and the concave surface of the navicular bone.
The calcaneocuboid joint forms the lateral compo- nent of the transverse tarsal joint and is formed by the anterior surface of the calcaneus and the cuboid. There is less motion at this wedge-type joint compared with the talonavicular joint.
Capsule and Ligaments
The spring ligament, also called the calcaneonavicular ligament, supports the talonavicular joint through its attachment to the sustentaculum talus of the calcaneus and the plantar surface of the navicular bone. The liga- ment supports the plantar and medial surfaces of the talonavicular joint. The joint capsule of the talonavicu- lar joint is reinforced by fi bers of the deltoid ligament, the talonavicular ligament, and the spring ligament. The
