Journal of Convergence for Information Technology (융합정보논문지)

Convergence Society for SMB (중소기업융합학회)
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A Comparative Study on the Characteristics of Friction with/without shoes by Analyzing Bio-signals during walking

보행 시 생체신호분석을 통한 신발 착용 유무에 따른 마찰 특성 비교

  • Oh, Seong-geun (Institute of Physical Education Science, Yong-in University) ;
  • Kim, Jin-Hyun (Department of Sports Rehabilitation, JeJu International University)
  • 오성근 (용인대학교 체육과학연구소) ;
  • 김진현 (제주국제대학교 스포츠재활학과)
  • Received : 2018.10.08
  • Accepted : 2018.12.20
  • Published : 2018.12.31
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Abstract

The utilized coefficient of friction (UCOF) as a ratio of the shear force to the normal force on the ground during walking is used to identify the point at which slip is likely to occur. Shoe walking will change the utilized coefficient of friction by shoe design such as sole thickness and hardness, heel shape, and outsole pattern. In this study, subjects are 21 adults (10 female, 11 male, age: $25.2{\pm}2.3yrs$, height: $165.6{\pm}7.2cm$), analysis variables were walking speed, GRF, when the UCOF is maximal, and Tangent of CoP-CoM angle, and correlation analysis with the utilized friction coefficient (UCOF). As a result, First, for the shod walking the time point which UCOF is maximum about heel strike was faster and the magnitude was larger than for barefoot walking. Second, the correlation between the tangent of CoP-CoM and UCOF of right foot was higher at the left heel striking point (UCOF2_h) which occurred in the post propulsion phase than at the right heel striking point (UCOF1_h). This suggests that the right foot UCOF is related to the braking phase of left foot( which is the propulsion phase of right foot) rather than the braking phase of right foot.

보행 시 지면에 대한 수직력에 대한 전단력의 비율, 즉 보행자가 사용한 마찰계수(UCOF)는 미끄러짐 발생 가능성 있는 시점을 식별하는데 사용된다. 신발보행은 신발창 두께와 경도, 뒤꿈치 모양, 밑창 문양 등의 신발 디자인이 사용마찰계수를 변화시킬 것이다. 본 연구에서는 보행 시 신발 착용 유무에 따른 사용마찰계수(UCOF) 차이를 분석하기 위해 성인남녀 21명(여자 10명, 남자 11명, 나이: $25.2{\pm}2.3yrs$, 키: $165.6{\pm}7.2cm$, 몸무게: $62.2{\pm}7.8kg$)을 대상으로 보행속도, 지면반력, 사용마찰계수(UCOF) 최대 시점, CoP-CoM-수직선 각도의 차이를 알아보고, 사용마찰계수(UCOF)와의 상관관계를 분석하였다. 그 결과, 첫째, 보행 시 신발 착용으로 인해 체중수용기(제동기)의 더 이른 시점에 사용마찰계수가 최대치에 도달하고, 또 그 크기도 증가한다. 둘째, CoP-CoM의 Tangent 값과 사용마찰계수(UCOF1)와의 상관관계는 오른발 제동 초기시점(UCOF1_h)보다 추진 후기에 발생하는 왼발(다음발) 착지시점(UCOF2_h)에서 더 높은 상관관계를 보여, 제동기 보다는 추진기(다음 발 제동기)와의 연관성을 시사한다.

Keywords

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Fig. 1. Asics G1 shoes

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Fig. 2. Illustration of horizontal and vertical GRF, the UCOF and tangent of CoM-CoP curves represented by the average curve for barefoot walking (black line) and shod walking(red bold line) over all participants. The blue arrows indicates the points at which UCOF is maximum.

Table 1. The elapsed times for barefoot and shod walking(unit: second).

JKOHBZ_2018_v8n6_59_t0001.png 이미지

Table 2. GRF, Tangent of CoM-CoP, Utilized coefficient of friction (UCOF) and walking speed with and without shoes for Right foot (GRF unit: Bodyweight %, speed unit : m/s).

JKOHBZ_2018_v8n6_59_t0002.png 이미지

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