Pronation of the foot is its function by which its arch lowers or dips towards the ground while the patient bears weight on his feet, so that the foot can absorb the shock that comes with its impact with the ground. The navicular bone drops and normally all feet pronate as this mechanism is essential for smooth movement of the body. However, when this arch lowers by an excessive measure or degree, the foot is said to be over pronating or pronating excessively. This is dangerous and causes a the joints of the lower limb to go out of alignment and bear more stress due to poor biomechanics. Over pronation of the foot can cause pain in the arch, ankle, shin, knee, thigh, lower back and also the neck. Corrective shoe inserts in the form of insoles are an absolute must for patients who experience over pronation.

Over pronation is the most common cause of plantar fasciitis, heel spur, shin splints, heel pain, medial knee pain and corns and calluses on the great toe and the first metatarsal head. It can cause strain on the big toe and second toe. It can also cause instability in the foot.