Just before toe-off, the foot pronates again to prepare for the swing phase where dorsiflexion is necessary for clearance of the toes. It is during the initial supination that the foot elongates and stretches the plantar fascia, most severly along the medial band and at its insertional point on the medial calcaneal tubercle. Such excessive stress results in a hypertrophic connective tissue response that progresses from fibrocartilage to osseous spur formation 17 . Most hyperkeratotic lesions are a secondary response to altered biomechanics and associated osseous adaptations. Lesions on the dorsum of digits and beneath the metatarsal heads are the most common.
Interdigital lesions are also common.
The altered dynamic pull of tendons and muscles in the foot secondary to biomechanical abnormalities or systemic diseases like diabetes and its intrinsic muscle denervation, predisposes the patient to digital contractures. Frictional forces between the inner shoegear and contracted digit causes hyperkeratotic formations that become quite painful. These lesions are most frequently located on the dorsal surfaces of the joints and may ulcerate if neglected. Periodic paring of the clavi symptomatically relieves the pain and accomodative padding is used to reduce direct pressure. Frequently surgical intervention is requested to alleviate symptoms.