The Problem

All toddlers have flat feet because of a low angle of calcaneal inclination, by five to six years this angle has increased, and in most cases, a medial longitudinal arch becomes apparent. Inclination of the calcaneus is vital to the foot, as if there is a reduced or negative calcaneal inclination the plantar aponeurosis will be lengthened, the windlass mechanism will not occur, and the foot will not achieve supination at the propulsive phase of gait. The most significant feature of paediatric pes planovalgus (pathological flat foot) is medial bulging in the area of the talo-navicular joint. The medial longitudinal arch is usually low, but not always completely absent. A collapse of the mid-tarsal joint indicates that the calcaneus has been forced to rotate postero-laterally under the talus. The talus will assume a more medial and vertical position as the sustentaculum tali loses its supporting position beneath the neck of the talus. These changes render the foot ineffectual at withstanding the forces of ground reaction, which are highest at the propulsive phase of gait.

The Concept

Early treatment is vital, for if a child continues to walk on this foot type, the condition rapidly becomes irretrievable. Control of the child’s foot needs to be achieved quickly and comfortably by utilising a triplanar wedge directed against the talo-navicular bulge and medial arch, which will increase the calcaneal inclination angle. As the calcaneus is dorsiflexed it will also adduct, restoring talo-calcaneal congruency. Restoring alignment in this way helps to maintain the stability of the foot. Support of the foot also controls the internal leg rotation associated with sub-talar joint pronation and thereby reduces other symptoms such as knee pain (e.g. Osgood-Sclatters disease). Prevention of the collapse of the medial arch will reduce the strain on supportive ligaments and other soft tissues, thereby allowing the patient to enjoy running and walking whilst remaining symptom free.