Impact of body weight on shifting of foot pressure among adult subjects.

Purpose: The aim of the study was to compare the distribution of foot plantar pressure between normal and obese adult subjects during walking.

Methods: Sixty male and female adult volunteers (aged 20-40) were recruited into the study. They were equally divided into 30 normal subjects (BMI = 18.5-22.9 kg/cm²) into group I and 30 obese subjects (BMI ≥ 25.0 kg/cm²) into group II, according to their BMI.

Results: There were statistically significant differences between normal and obese subjects in foot length, width, and pressure distribution in the hindfoot, midfoot, forefoot, and toes. There was a statistically significant increase in the plantar pressure of all measured areas in obese persons in comparison with the normal subjects. In addition, all measures of foot pressure showed statistically significant differences between the same sex of both groups, while the obese subjects of both genders have higher foot pressure in all measured areas. High positive correlations were detected between BMI, peak pressure, foot contact, and foot width in both groups, but there was a weak positive correlation between normal BMI and foot contact area.

Conclusion: The distribution of plantar foot pressure is different in adult obese subjects than in normal adult subjects during walking activity. The obese persons have larger foot length, width, higher peak pressure, and contact area. This study can help physical therapists to understand the differences of foot pressure between normal and obese subjects, and consequently, to detect any expected foot abnormalities accompanied by obesity.