Pronation of the foot with many overuse injuries in running including medial tibial stress syndrome, or shin splints, and knee pain Hintermann states, “Individuals with injuries typically have pronation movement that is about two to four degrees greater than that of those with no injuries.” He adds however, that between 40% and 50% of runners who overpronate do not have overuse injuries. This suggests that although pronation may have an effect on certain injuries, it is not the only factor influencing their development. The design principles of foot orthoses are founded on knowledge of the functional anatomy of the foot. Pronation of the foot
Flexor retinaculum of foot abductor hallucis muscle. Enumerated from the medial side, the four canals which it forms transmit the tendons of the tibialis posterior and flexor digitorum longus muscles; the posterior tibial artery and tibial nerve, which run through a broad space beneath the ligament; and lastly, in a canal formed partly by the talus, the tendon of the flexor hallucis longus. The entrapment of the tibial nerve beneath the laciniate ligament causes tarsal tunnel syndrome, characterized by pain, numbness and tingling of the medial plantar surface of the foot. The situation is aggravated by standing and walking, and often worse at night.