Excessive pronation of the foot may create an imbalance over time, potentially leading to injuries of the lower limbs. It is important to understand what causes overpronation and how to prevent or correct this issue. The purpose of this study was to examine effects of body mass on foot pronation. Subjects were examined according to BMI, sex, age, shoe size and amount of regular running activity. Each participant completed a Sit-to-Stand Navicular Drop Test (SSNDT) to measure individual foot pronation. It was concluded that using the SSNDT is a reliable way to measure foot pronation. No correlation was observed between BMI and degree of pronation, suggesting that obesity is not a predictor of poor walking mechanics and many factors must be considered during assessment of overpronator subjects.