INFLUENCE OF FOOTWEAR ON WEIGHT-ACCEPTANCE PLANTAR PRESSURE DISTRIBUTION DURING WALKING

Abstract

The purpose of this study was to evaluate plantar pressures during the initial portion of the support phase of walking for different footwear conditions. Five healthy males volunteered as subjects. Plantar pressure was determined using a TEKSCAN in-shoe pressure measurement system. A thin sensor insole with 1,260 force sensors each 26 mm2 in area was attached to the bottom of an athletic shoe insole. Forces were sampled at 100 Hz while the subjects walked on just the insole and specially constructed shoes with hard and soft polyurethane midsoles. Data were collected for five trials of a right footfall during a 10 m walk for each condition. Simultaneous in-shoe and force plate measurements were collected and a method was developed to calibrate the raw values using the force platform. Custom written software was used to calculate plantar pressure during the first 30% of stance in three areas centered about the center of pressure. Area I was defined as the area inside a 20.4 x 20.4 mm square, area 2 as the area inside a 40.8 x 40.8 mm square exclusive of area I, and area 3 as the area inside a 61.2 x 102 mm rectangle exclusive of area 2. The greatest maximum and average pressures wefe observed during walking on just the insole. For this condition, pressures were great near the center of pressure and dropped off sharply away from the center of pressure. During walking in shoes, pressures were lower and more evenly distributed over the plantar surface of the foot. Slightly greater pressures were observed for the hard versus the soft shoes. The results of this study indicate that compared to just an insole, soft and hard shoes reduce and more evenly distribute pressure over the plantar surface of the foot during the weight-acceptance phase of walking.