Gender Differences and Relationships between Physical Parameters on Evaluating the Center of Foot Pressure in Static Standing Posture

This study investigated gender differences in various parameters when evaluating the center of foot pressure (CFP) during static standing posture based on the relationships between physical parameters characteristics. The subjects were 100 healthy young males and females. The measurement of CFP was carried out 3 times with a 1 minute rest, and the mean of trials 2 and 3 was used for the analysis. The measurement device was an Animas's stabilometer G5500. Data sampling frequency was 20 Hz. Sixty parameters with higher trial-to-trial reliability were selected from the following 7 domains: distance, center average, distribution of amplitude, area, velocity, power spectrum, and body sway vector.The parameters evaluating the amount of body sway tended to be greater in males than in females. The parameters showing a significant gender difference also showed strong relationship with body linearity (BL). A significant relationship of parameters and physical characteristics was found in body linearity (BL) and body width (BW) in males, and body girth (BG) and body fat (BF) in females. However, it is inferred that the influence of physical characteristics on parameters depends on the size of physical characteristics rather than the factor of a gender difference, and that the influence of body size sway was found when the physique was beyond a fixed value. The influence of physical characteristics tends to show in sway in the X-axis direction, and it was considered that the size of the support base or the characteristics of the foot and the knee joints, which easily move in a front-back direction, related to the sway. Even in the evaluation of parameters with the same body-sway characteristics, a gender difference was found and the relationships with the physical characteristics were not always the same.