Perception of great change of the center of heel pressure according to backward leaning

Abstract

  The following three problems were examined: 1) Is there a great change of heel pressure distribution according to backward leaning? 2) Can this change be perceived accurately? 3) What is the relationship between the standing position at great change of heel pressure distribution and the skeletal structure of the foot? Twelve subjects with a mean age of 32.0 years (SD=12.3) participated in the study. The change of heel pressure distribution according to backward leaning was evaluated by simultaneously measuring the movement of the center of foot pressure and that of the center of heel pressure. The position of the lateral process of calcaneus and the highest point of the trochlear surface of body of talus were analyzed using an X-ray photograph. A great change in heel pressure distribution according to backward leaning was observed at 3.8 cm (SD=0.5), and the perceived position was 3.5 cm (SD=0.6). These two positions were significant different and also showed a significant correlation (r=0.91). The standing position at great change of heel pressure distribution correlated significantly with the position of the lateral process of calcaneus (r=0.86), and also with the position of the highest point of the trochlear surface of body of talus (r=0.71). We conclude that there is a great change of heel pressure distribution according to backward leaning, that this change is perceived accurately, and that there is a closely relationship between the standing position at great change of heel pressure distribution and the form of the foot.