Qualitative method of analysis of long-term motion characteristics using the insole

Abstract

In this research, we conducted an image analysis from the imprint in shoe insoles. This measurement method is thought to be meaningful because it does not prevent the subject’s natural motion and allows for the capture of a long-term imprint. The subjects were 10 university student (badminton players). Images of insoles ( Dominant Leg group : DL, No-Dominant Leg group : NDL ) were obtained using a camera. The luminance value ( LV ) for each insole was converted to a normalized luminance ( NLV ) value with the minimum value of the insole set to "0" and the maximum value set to "100". NLV was used to calculate the mean for all items with in pixel coordinates and produce a mean luminance value ( MLV ). MLV was divided into 6 regions ( each group ). When a significant difference was recognized, Tukey's multiple comparison test was performed. The occupancy ratio was calculated. The results showed a strong imprint at the big toe, ball of the foot, and calcaneal region. The imprint in the arch of the foot was extremely weak. The imprint of toes other than the big toe in NDL tended to be weak. The center of gravity had the same wave form as the center of pressure. MLV by region showed significant differences mainly between the big toe, fore-foot, and calcaneal region. The occupancy ratio showed significant differences in dominance in the fore-foot, metatarsal medial part, and metatarsal lateral part.