The effect of arch height and body mass on plantar pressure

High plantar foot pressure is one of the important risk factors for diabeti c foot ulceration. Several factors have been associated with increased foot pressures; however, the effect of arch height and body mass on plantar pre ssure is not entirely clear from the available literature. Therefore, the a im of this study was to investigate the effect of the arch index (a measure of arch height) and body mass on plantar pressure in a group of 34 non-dia betic and diabetic subjects. Arch height was measured as the arch index-a r atio of midfoot to whole foot ground contact area. Foot pressures were meas ured during barefoot walking. The arch index was not Found to be significan tly associated to peak pressure or pressure time integral at any region of the foot. However, there was a non-significant trend towards higher plantar pressure at the medial side of feet in subjects with low arches. In additi on, subjects with low-arched feet had significantly higher body mass indexe s (BMI) compared to subjects with high-arched feet (28.6 +/- 4.8 vs 24.3 +/ - 3.3 kg/m2, p < 0.05), and BMI was associated to arch index (r = 0.36, p < 0.05). Body mass was significantly associated with peak pressure and press ure time integral at several regions of the foot (0.33 < r < 0.47, p < 0.05 ). To conclude, both body mass and arch index (arch height) contribute to i ncreased foot pressures. The effect of arch height on foot pressures can po ssibly be explained by the effect of BMI on the arch of the foot during wei ght bearing.