Arches of the foot. The arrangement of bones in the foot,supported by associated ligaments and action of associated muscles,gives the sole of the foot and arched or curved shape. The curve running from the heel to toe is called the longitudinal arch,and the curve running across the foot is called the transverse arch.
In the normal longitudinal arch,only the calcaneus and the distal ends of the metatarsals should touch the ground,the bone between lifted clear. This gives a conventional footprint shape. If however,the concavity of the sole is lost because of sagging ligaments or tendons,the arch sinks and much more of the sole of the foot is in contact with the ground: this is called flat foot. Because the arches of the foot are important in distributing the weight of the body evenly whilst upright,whether stationary or moving,the flat foot loses the springiness of normal foot structure and leads to sore feet when standing,walking or running for long periods. As there are movable joints between all the bones of the foot,very strong muscles and ligaments are necessary to maintain the strength,resilience and stability of the foot during walking,running and jumping.
posterior tibialis muscle. This is the most important muscular support of the longitudinal arch. It acts as a sling or suspension apparatus of the arch.
short muscles of the foot. This group of muscles is mainly concerned with the maintenance of the longitudinal and transverse arches. They make up the fleshly part of the sole of the foot.
