Foot posture, range of motion and plantar pressure characteristics in obese and non-obese individuals.

Obesity is a world-wide health problem and is strongly associated with musculoskeletal disorders of the lower limb. The aim of this study was to evaluate plantar loading patterns in obese and non-obese individuals, while accounting for the contribution of foot structure, range of motion and walking speed. Sixty-eight participants (mean±SD age, 52.6±8.0 years), including 47 females (69%), underwent assessments of body mass index, foot pain and foot structure. Plantar pressures were also obtained, using a floor-mounted resistive sensor mat system. Multiple regression analysis was used to determine which variables were most strongly associated with plantar loading patterns. Obese individuals exhibited flatter feet, reduced inversion-eversion range of motion, and higher peak plantar pressures when walking. After accounting for foot structure and walking speed, bodyweight was found to be significantly associated with elevated loading of the foot, particularly the forefoot and midfoot. These findings suggest that obesity increases the stresses applied to the foot directly, via increased bodyweight, and indirectly, via alterations to foot structure, which may partly explain the link between obesity and the development of foot pain. Clinicians dealing with foot problems should consider the effect of increased bodyweight on plantar loading in obese patients.