Arches of the foot

Arches of the foot
Skeleton of foot. Medial aspect.
Skeleton of foot. Lateral aspect.
Details
Latin	Arcus pedis
Dorlands /Elsevier	a_58/12150685
Anatomical terminology []

The arches of the foot, formed by the tarsal and metatarsal bones, strengthened by ligaments and tendons, allow the foot to support the weight of the body in the erect posture with the least weight.

They are categorized as longitudinal and transverse arches.

The longitudinal arches of the foot can be divided into medial and lateral arches.

The medial arch is higher than the lateral longitudinal arch. It is made up by the calcaneus, the talus, the navicular, the three cuneiforms (medial, intermediate, and lateral), and the first, second, and third metatarsals.

Its summit is at the superior articular surface of the talus, and its two extremities or piers, on which it rests in standing, are the tuberosity on the plantar surface of the calcaneus posteriorly and the heads of the first, second, and third metatarsal bones anteriorly. The chief characteristic of this arch is its elasticity, due to its height and to the number of small joints between its component parts.

Its weakest part (i.e., the part most liable to yield from overpressure) is the joint between the talus and navicular, but this portion is braced by the plantar calcaneonavicular ligament a.k.a. spring ligament, which is elastic and is thus able to quickly restore the arch to its original condition when the disturbing force is removed. The ligament is strengthened medially by blending with the deltoid ligament of the ankle joint, and is supported inferiorly by the tendon of the Tibialis posterior, which is spread out in a fanshaped insertion and prevents undue tension of the ligament or such an amount of stretching as would permanently elongate it.

The arch is further supported by the plantar aponeurosis, by the small muscles in the sole of the foot, by the tendons of the Tibialis anterior and posterior and Peronæus longus, and by the ligaments of all the articulations involved.