Plantar pressure differences between obese and non-obese adults: A biomechanical analysis

OBJECTIVE: To investigate plantar pressure differences between obese and no n-obese adults during standing and walking protocols using a pressure distr ibution platform. SUBJECTS: Thirty-five males (age 42.4 +/- 10.8 y; 67 - 179 kg) and 35 femal es (age 40.0 +/- 12.6 y; 46 - 150 kg) divided into obese (body mass index ( BMI) 38.75 +/- 5.97kg/m(2)) and non-obese (BMI 24.28 +/- 3.00 kg/m(2)) sub- groups, respectively. MEASUREMENTS: Data collection was performed with a capacitive pressure dist ribution platform with a resolution of 2 sensors/cm(2) (Emed F01, Novel Gmb H, Munchen). The measurement protocol included half and full body weight st anding on the left, right and both feet, respectively, and walking across t he platform, striking with the right foot. Pressures were evaluated for eig ht anatomical sites under the feet. RESULTS: For both men and women, the mean pressure values of the obese were higher under all anatomical landmarks during half body weight standing. Si gnificant increases in pressure were found under the heel, mid-foot and met atarsal heads II and IV for men and [I] and IV for women. Foot width during standing was also significantly increased in obese subjects. For walking, significantly higher peak pressures were also found in both obese males and females. CONCLUSION: Compared to a non-obese group, obese subjects showed increased forefoot width and higher plantar pressures during standing and walking. Th e greatest effect of body weight on higher peak pressures in the obese was found under the longitudinal arch of the foot and under the metatarsal head s. The higher pressures for obese women compared to obese men during static weight bearing (standing) may be the result of reduced strength of the lig aments of the foot.