Definition
A hollow foot (medically: Pes cavus, Pes excavatus) is a malposition of the foot. It can be congenital or acquired in the course of life. Depending on the degree of the malposition, the hollow foot can be recognized as such from the outside.
A change in the longitudinal arch of the foot results in an increased curvature of the foot towards the upper side, which creates a hollow space on the underside of the foot. This is due to a dysbalance of the muscles of the foot and lower leg. A hollow foot is noticed, depending on the time of its occurrence, by the symptoms caused or by the parents of the affected child. The diagnosis of a hollow foot can be made by a doctor after a physical examination and an x-ray of the affected foot. The most common other foot malpositions are the splayfoot, flat foot, and pigeon-toed foot.
Causes of a hollow foot
The congenital hollow foot is relatively frequent among the different forms of the hollow foot and occurs familiarily more frequently. The causes of the congenital form have not yet been fully clarified. A hollow foot can also occur in the course of life.
The underlying cause can be of neurological, orthopedic or neuromuscular origin. Often, however, no cause can be found, in which case we speak of a so-called idiopathic hollow foot. A hollow foot, which occurs in the course of life, is caused by a dysbalance in the muscles of the foot and lower leg, which leads to a pathological change in the longitudinal arch of the foot on the underside of the foot.
In general, both nerves and muscles and their interaction can be disturbed. There are a number of diseases that are known to cause a hollow foot in patients. Examples are neural muscular atrophy – the most common neuromuscular cause of hollow feet – or the so-called Friedrich’s ataxia, which is one of the neurological causes. In this disease, destruction of parts of the central nervous system leads to the development of a hollow foot. Muscle injuries caused by accidents can also cause a hollow foot.
