The Skeletal System: The Appendicular Skeleton - Chapter questions - Problem 15F

Each foot has three arches- two longitudinal and one transverse arch-- really a lateral and a medial aspect of a longitudinal arch, and a transverse arch. The medial longitudinal arch starts in the calcaneus, rises to the talus, passes through the navicular, and ends anteriorly in the cuneiforms and the metatarsals. The lateral component of the longitudinal arch also starts in the calcaneus. It then rises to the cuboid ( highest point), descends to the ball of the foot at the heads of the lateral metatarsals. The transverse arch trends between the medial and lateral aspects of the foot. It is formed by the navicular, three cuneiforms, and the bases of the five metacarpals The bones which form the arches are held in their arcuate positions by ligaments and tendons. The collagen and elastic tissues of the binding structure enable the arches to deform( flatten), when weight is applied to them, and to recoil and resume their original shapes when the weight is lifted. The elasticity or flexibility of the arches enable them to perform the following functions: 1. Support the weight of the body 2. Distribute the body's weight over soft and hard tissues 3. Increase leverage of muscles of walking 4. Store energy