The plantar aponeurosis, also known as the plantar fascia, is a strong layer of white fibrous tissue situated beneath the skin on the sole of the foot. Towards the front of the foot, at the mid-metatarsal level, it divides into five sections, each extending into a toe and straddling the flexor tendons. Laterally it is divided into three sections: the medial, the lateral, and the central. The central portion, being the most important structurally and functionally, is attached at its origin to the medial calcaneus. The medial portion overlies the muscles to the hallux (big toe) and the lateral portion overlies muscles to the little toe. During walking, the plantar aponeurosis functions mainly during "heel rise" to "toe off." It stabilises the arch of the foot and flexing of the first metatarsal, enabling the first metatarsal to carry the majority of the body weight. It also provides shock absorption when the foot hits the ground. Inflammation or injury of the plantar aponeurosis is common in athletes and will cause foot pain and, if left untreated, may result in further leg injuries. The condition is treated with rest, analgesics, or in extreme cases, extracorporeal shock wave therapy.
Written and medically reviewed by the Healthline Editorial Team
In Depth: Plantar aponeurosis