Walking strategy in diabetic patients with peripheral neuropathy

OBJECTIVE - Diabetic neuropathic patients show a peculiar loading pattern of the foot, which led us to hypothesize that a substantial modification exists in their deambulatory strategy. The aim of the present study was to support this hypothesis by quantifying the changes of the loading patterns and by monitoring the excursion of center of pressure (COP) during gait. RESEARCH DESIGN AND METHODS - A total of 21 healthy volunteers (C) and 61 diabetic patients were evaluated: 27 diabetic subjects without neuropathy (D), 19 with neuropathy (DN), and 15 with previous neuropathic ulcer (DPU). A piezo-dynamometric platform was used to record the foot-to-floor interaction by measuring loading time and the instantaneous COP position during the stance phase of gait. RESULTS - Loading time was significantly longer in neuropathic patients than in control subjects (DPU: 816.8 +/- 150 ms; DN: 828.6 +/- 152 ms; D: 766.5 +/- 89.9 ms; C: 723.7 +/- 65.7 ms; P < 0.05). COP excursion along the medio-lateral axis of the foot clearly decreased from C to DPIJ groups (C: 6.41 +/- 0.1 cm; D: 4.88 +/- 0.2 cm; DN: 4.57 +/- 0.1 cm; DPU: 3.36 +/- 0.1 cm; P < 0.05) as well as COP excursion along the longitudinal axis for the DPU group only (C: 26.6 +/- 1 cm; D: 26.9 +/- 1 cm; DN: 27.2 +/- 1 cm; DPU: 24.2 +/- 1 cm; P < 0.05). COP integrals were significantly reduced for all pathological classes (DPU: 14.2 +/- 8 cm(2); DN: 25.8 +/- 6 cm(2); D: 27.7 +/- 3 cm(2); C: 38.6 +/- 6 cm(2); p < 0.05). CONCLUSIONS - The accurate quantification of loading patterns and of COP excursions and integrals highlights changes of foot-to-floor interaction in diabetic neuropathic patients. The decreased medio-lateral and longitudinal COP excursions and corresponding changes of loading times and patterns support our hypothesis that a change in the walking strategy of diabetic patients with peripheral neuropathy does occur.