Analysis of foot shape deformation during walking and its application to designing insole

2006 Fiscal Year Final Research Report Summary

• Project/Area Number: 17570198
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Anthropology
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: KOUCHI Makiko National Institute of Advanced Industrial Science and Technology, Digital Human Research Center, Senior Researcher, デジタルヒューマン研究センター, 主任研究員 (80126052)
• Co-Investigator(Kenkyū-buntansha): 河内 まき子 独立行政法人産業技術総合研究所, デジタルヒューマン研究センター, 主任研究員 (80126052) ; MOCHIMARU Masaaki National Institute of Advanced Industrial Science and Technology, Digital Human Research Center, Deputy Director, デジタルヒューマン研究センター, 副センター長 (90358169) ; MOTOMURA Yoichi National Institute of Advanced Industrial Science and Technology, Digital Human Research Center, Senior Researcher, デジタルヒューマン研究センター, 主任研究員 (30358171)
• Project Period (FY): 2005 – 2006
• Keywords: Foot / 3D morphology / Plantar arch / Walking / Deformation / Comfort / Personal constructs interview / Insole

Research Abstract

The purpose of this study is to measure and quantitatively clarify the foot shape changes during walking in order to obtain grounds for designing the custom insole from individual foot shape. Insole can be used to improve the comfort by adjusting the differences between the shapes of the foot and last. For this purpose, a cat walk (BxLxH=100x800x100 [cm]) with a glass plate (35.5x40 [cm]) set in the middle was constructed. Four load cells were set under the glass plate, and the ground reaction force was measured (120 Hz). Video images of the sole were captured with a high frequency video camera (200 Hz) from below the glass plate. An in-house 4D shape measurement system consisting of 12 video cameras was set around the glass plate, and the shapes of four cross sections on the foot were measured (14 Hz). The right foot was measured for 45 subjects during walking and standing with weight distributed equally on both feet. Six measurements were measured from the sole video images, and the heights of the plantar arch and dorsal arch were measured from the instep cross-section data. Measurements at standing were compared with those at the first peak or the bottom of 2 peaks of the ground reaction force. It was found that compared to the measurement at standing, (1) the medial arch length increased but the lateral arch length does not during walking; (2) ground contact breadth at the ball and instep increased at the mid stance phase; (3) height of plantar arch does not decrease during the mid stance phase. The results suggest that the foot shape measured in the standing posture may be used as the basis for designing custom insole.