Dynamic and Static Ability of Balance and Postural Control in Japanese Obese Children

The purpose of this study was to examine dynamic and static ability of balance and postural control in obese female children and healthy male adults. Obese female children (n=5, age 9.0±2.1yrs) and healthy male adults (n=5, age 25.2±9.5yrs) participated in this study. The subjects were instructed to perform walking, running and counter-movement jump separately on the force platform. The measurements of kinematic data during each movement were collected by using the VICON 460 motion analysis system. The center of pressure (COP) displacement of the ground reaction force was recorded at a frequency of 20 Hz. While the subjects were taking stationary standing position with opened eyes or closed eyes on the force platform for 30 seconds, and the total length of COP displacements was calculated. Body composition was measured by bio-impedance method. There was a significant difference between obese female children and healthy male adults in BMI (27.8±2.7 vs. 22.3±3.9, p<0.05) and %fat (43.9±5.7 vs. 17.1±7.3%, p<0.01). Mean inversion-eversion angle of the hip joint during the walking (13.0±3.4 vs. 47.1±25.1 deg., p<0.05) and anterior-posterior length of COP (34.2±5.7 vs. 46.8±6.3 mm, p<0.01) were significantly larger in the obese subjects than in the normal subjects. These results indicate a high risk of fall into the obese children during exercise. From the present results, we reconfirmed that obese female children had significantly poorer composite dynamic and static balance test scores than the healthy male adults. The present study suggested a high risk of fall into the obese children during the exercises.