Spinal alignment and the center of pressure while standing in children aged 6–12 years

Abstract

Poor posture (thoracic hyperkyphosis) in children is reportedly caused by changes in their living environment. A previous study (conducted 30 years ago) reported that the position of the center of pressure (COP) in a child with an upright posture was approximately 40% from the heel. The present study aimed to determine the position and characteristics of the COP while standing in children aged 6–12 years. This study enrolled 83 elementary school students. A Win-Pod (Medicapteurs) platform was used to measure the COP. The COP position was expressed as a percentage from the heel as a relative ratio with a foot length of 100%. Spinal Mouse® was used to measure thoracic kyphosis, lumbar lordosis, sacral anteversion, and trunk inclination angles in the standing position. The COP position was 30.3±8.9% from the heel. We found positive correlations between the COP position, height, and weight. Further, the COP position was significantly more anterior in 28 upper elementary grade children (35.1 ± 9.2%) than in 25 middle (29.5 ± 8.6%) and 30 lower grade children (26.5 ± 6.7%). Regarding sex differences, the COP position was significantly more anterior in 46 boys (32.3 ± 9.8%) than in 37 girls (27.9 ± 6.9%). There was a weak positive correlation between the COP position and trunk inclination angle (r=0.251, p<0.05). Thus, we found that the COP position in modern children aged 6–12 years while standing was 30.3 ± 8.9% from the heel, indicating a shift toward the heel (backward) compared to that reported in previous studies.