There are 20 muscles in the foot that give the foot its shape by holding the bones in position and expand and contract to impart movement. The main muscles of the foot are:
the anterior tibial, which enables the foot to move upward;
the posterior tibial, which supports the arch;
the peroneal tibial, which controls movement on the outside of the ankle;
the extensors, which help the ankle raise the toes to initiate the act of stepping forward; and
the flexors, which help stabilize the toes against the ground.
Smaller muscles enable the toes to lift and curl.
There are elastic tissues (tendons) in the foot that connect the muscles to the bones and joints. The largest and strongest tendon of the foot is the Achilles tendon, which extends from the calf muscle to the heel. Its strength and joint function facilitate running, jumping, walking up stairs, and raising the body onto the toes.
Ligaments hold the tendons in place and stabilize the joints. The longest of these, the plantar fascia, forms the arch on the sole of the foot from the heel to the toes. By stretching and contracting, it allows the arch to curve or flatten, providing balance and giving the foot strength to initiate the act of walking. Medial ligaments on the inside and lateral ligaments on outside of the foot provide stability and enable the foot to move up and down.
Skin, blood vessels, and nerves give the foot its shape and durability, provide cell regeneration and essential muscular nourishment, and control its varied movements.
