Modified pressure distribution patterns in walking following reduction of plantar sensation.

The aim of the present study was to investigate the influence of reduced plantar sensation on pressure distribution patterns during gait of 40 healthy subjects (25.3+/-3.3 yr, 70.8+/-10.6 kg and 176.5+/-7.8 cm) with no history of sensory disorders. Plantar sensation in the subjects was reduced by using an ice immersion approach, and reduced sensitivity was tested with Semmes-Weinstein monofilaments. All subjects performed six trials of barefoot walking over a pressure distribution platform under normal as well as iced conditions. Plantar cutaneous sensation was significantly reduced after the cooling procedure (p<0.0001). Pressure distribution analysis showed substantially modified plantar pressure distribution patterns during the roll-over process (ROP) under iced conditions. Analysis of peak pressures revealed significant reductions under the toes and under the heel (p<0.001). The contact time and the relative impulse for the whole foot did not change significantly between the two conditions. For the different areas, a significant load shift from the heel and toes towards the central and lateral forefoot and the lateral midfoot was observed. The results indicate the strong influence of reduced afferent information of the sole of the foot on the ROP in walking.