The term fallen arch means that the arch in the foot has sunk. If it has sunk considerably, leaving the foot completely flat, this is known as flat feet. Treatment of a fallen arch or flat foot depends on the age of the patient and the just how severely the arch in the foot has sunk.

A normally formed foot arch distributes two thirds of the pressure of the body weight to the heels and one third to the ball of the foot. The inner side of the foot forms an arch which does not lie on the ground. If the arch of the foot sinks, then this causes a fallen arch, or flat foot if it is severe. Fallen arches often occur in combination with an inward bend of the foot (talpes valgus foot). This is known as a planovalgus foot. Acquired weakness of the foot muscles as well as the ligaments and tendons are often the cause of fallen arches or flat feet.  Malpositions of the leg such as X-legs can also lead to incorrect loading of the foot arch and thus the occurrence of fallen arches and flat feet as well. Besides these acquired forms, there is also a congenital form of flat feet which already occurs in early childhood. The congenital condition of flat feet should also not be confused with the commonly observed planovalgus foot. A planovalgus foot can occur as normal manifestation in childhood as a result of an incompletely developed skeleton. Usually this form of planovalgus foot recedes without treatment and the foot arch is fully-formed in puberty at the latest. In rare cases, a flat foot can also occur from this.

In childhood and adolescence, a talpes valgus foot or fallen arch does not usually not cause any symptoms. Pain can occur later in the foot, in particular when the patient has flat feet. Knee pain, muscle tension in the lower leg or back pain can result from malposition of the foot arch.

A fallen arch, talpes valgus foot or flat foot is normally already recognisable by examining the fees and inspecting the arch of the foot. The pressure distribution on the foot can be exactly determined with a special examination of the foot imprint (podography).

Treatment of a fallen arch or flat foot depends on the age of the patient, its severity and the individual symptoms. Conservative treatment with inserts and physiotherapeutic exercises is started primarily in childhood/young adulthood as well as in the case of only mildly flat feet in adulthood.

Surgical treatment with surgical correction is only for cases where conservative treatment is insufficient or the symptoms are very serious.

Centres 7