| 研究実績の概要 |
Medial longitudinal arch (MLA) play spring-like action far braking and accelerating in normai gait.Previous study showed high-arched feet as rigid and low-arched feet as hypermobile. However arch deformation due to growth and development have not been clarified. The purpose of this study was to clarify medial longitudinal arch deformation during gait in elementary school girls.
Ground reaction force (GRF), MLA angle and height of 45 female elementary school girls (first-grade 21, sixth-grade 24) at preferred speed were investigated with a highspeed camera (240fps) and an Emed q-100 pedography platform (100Hz). We placed markers on the medial aspect of the first metatarsal head, the navicular tuberosity, and the medial aspect of the posterior calcaneus. MLA angle was calculated as the angle between the first metatarsal head, the navicular tuberosity and the medial calcaneus in the local sagittal plane.
Stance time was first-grade 0.55±0.03sec, sixth grade 0.58±0.05sec. Most GRF occurred at the beginning and end of stance phase. MLA height decreased from heel contact and increased after heel rise to its maximum, on the other hand MLA angle increased from heel contact and decreased after heel rise to its maximum at toe-off. No difference was observed between both groups. Large deformation in MLA was observed around 75% stance phase, where maximum GRF in forefoot was indicated. This tendency was similar in both first and sixth grade elementary school girls.
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