Flat Foot

Flat foot (also called pes planus or fallen arches) describes a medical condition in which the arch of the foot collapses, with the entire sole of the foot coming into complete or near-complete contact with the ground. In some individuals (an estimated 20–30% of the general population) the arch simply never develops in one foot (unilaterally) or both feet (bilaterally).

There is a functional relationship between the structure of the arch of the foot and the biomechanics of the lower leg. The arch provides an elastic, springy connection between the forefoot and the hindfoot. This association safeguards that a majority of the forces incurred during weight bearing of the foot can be dissipated before the force reaches the long bones of the leg and thigh.



flat foot, pes planus, falling arch, arch, foot pain, heel spur, back pain
Action of pronation causing a flat foot.


In pes planus, the head of the talus bone is displaced medially and distal from the navicular. As a result, the spring ligament and the tendon of the tibialis posterior muscle are stretched, so much so that the individual with pes planus loses the function of the medial longitudinal arch (MLA). If the MLA is absent or nonfunctional in both the seated and standing positions, the individuals has “rigid” flatfoot. If the MLA is present and function while the individual is sitting or standing up on their toes, but this arch disappear when a foot-flat stance, the individual has “supple” flatfoot. This latter condition can be correctable with well-fitting arch supports.

Three studies (see citations below in military section) of military recruits have shown no evidence of later increased injury, or foot problems, due to flat feet, in a population of people who reach military service age without prior foot problems. However, these studies cannot be used to judge possible future damage from this condition when diagnosed at younger ages. They also cannot be applied to persons whose flat feet are associated with foot symptoms, or certain symptoms in other parts of the body like leg, or back pain.

Flat Foot Treatment

Depending on the severity of the flat foot or feet and symptoms, there are many treatment options available.  Conservative treatments usually include Lowe Dye Strapping ( a taping technique) and arch supports (orthotics).  In some cases surgery is necessary,  the etiology of the flat foot deformity, will dictate the surgical procedure performed.

Much of the time orthotics are able to control the excessive pronation and related symtoms. Check out these Podiatrist Recommended Orthotics