Pattern of abnormal tangential forces in the diabetic neuropathic foot

Objectives. The role of tangential stress in neuropathic foot ulceration is yet unknown. The aim of this study was to investigate the tangential forces developed during gait by the whole foot and by selected subareas of it, namely the heel, the metatarsals and the hallux. Methods. 61 diabetic patients have been evaluated: 27 without neuropathy, 19 with neuropathy and 15 with previous neuropathic ulcer. The patients were compared with 21 healthy volunteers. A piezo-dynamometric platform was used to measure the three components of the ground reaction force under the total foot and the selected subareas. Results. A significant reduction was observed for the forward peak and the backward peak of the anteroposterior ground reaction force component measured under the whole foot. Patients with previous neuropathic ulcer showed a significant increase of the mediolateral stress under the metatarsals. Conclusions. Tangential stress is altered in diabetic neuropathic patients; the increased mediolateral component suggests that tangential stress could have a role in the high risk of recurrence observed in patients with previous ulceration.