1st and 2nd plantar layers of the foot (English)

The medial, lateral and central plantar muscles can be alternatively classified according to four muscular layers. The first (left) and second (right) layers can be identified in this image. The first layer is composed of three muscles: the abductor hallucis (medial), flexor digitorum brevis (central) and abductor digiti minimi (lateral). All three extend distally from the calcaneal tuberosity to the toes and contribute to the maintenance of the concavity of the foot. The second layer of plantar muscles consist of the quadratus plantae muscle and four lumbrical muscles, both of which belong to the central muscle group of the foot. Tendons of the flexor hallucis longus and flexor digitorum longus muscles run within the same plane as these muscles. The quadratus plantae muscle arises by a medial and lateral head from the calcaneus and inserts onto the lateral aspect of the tendon of the flexor digitorum longus muscle as it passes through this region. The four lumbrical muscles arise from the tendons of the flexor digitorum longus muscle at their angles of separation, and insert onto the medial aspect of the extensor expansions of toes 2-5.