Journal of Korean Foot and Ankle Society (대한족부족관절학회지)

Korean Foot & Ankle Society (대한족부족관절학회)
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Assessment of Validity and Reliability of Plantar Pressure in Smart Insole

스마트 인솔의 족저압 측정 결과에 대한 타당도 및 신뢰도 평가

  • Kang, Ho Won (Department of Orthopedic Surgery, Ewha Womans University Mokdong Hospital) ;
  • An, Yae Lynn (Department of Orthopedic Surgery, Seoul National University College of Medicine) ;
  • Kim, Dae-Yoo (Department of Orthopedic Surgery, Busan Paik Hospital) ;
  • Lee, Dong-Oh (Department of Orthopedic Surgery, SNU Seoul Hospital) ;
  • Park, Gil Young (Department of Orthopedic Surgery, Seoul National University Hospital) ;
  • Lee, Dong Yeon (Department of Orthopedic Surgery, Seoul National University College of Medicine)
  • Received : 2022.04.11
  • Accepted : 2022.08.17
  • Published : 2022.09.15
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Abstract

Purpose: Smart insoles are wearable devices that are inserted into shoes. Smart insoles with built-in pressure and acceleration sensors can measure the plantar pressure, stride length, and walking speed. This study evaluated the validity and reliability of the plantar pressure measurements of smart insoles during walking on flat ground. Materials and Methods: Twenty one subjects were included in this study. After wearing smart insoles, I-SOL® (Gilon, Seongnam, Korea), the subjects walked a 10 m corridor six times at a rate of 100 steps/min, and the middle three steps, free from direction changes, were chosen for data analysis. The same protocol was repeated after wearing Pedar-X (Novel Corporation, Munich, Germany), an insoletype plantar pressure measurement equipment with proven validity. The average maximum pressure (Ppeak, kPa) and the time at which Ppeak appeared (Ptime, %stride) were calculated for each device. The validity of smart insoles was evaluated by using the interclass correlation coefficient (ICC) of Ppeak and Ptime between the two instruments, and Cronbach's alpha was obtained from the Ppeak values to evaluate the reliability. Results: The ICC of Ppeak was 0.651 (good) in the hallux, 0.744 (good) in the medial forefoot, 0.839 (excellent) in the lateral forefoot, and 0.854 (excellent) in the hindfoot. The ICC of Ptime showed 0.868 (excellent) in the hallux, 0.892 (excellent) in the medial forefoot, 0.721 (good) in the lateral forefoot, and 0.832 (excellent) in the hindfoot. All ICC values showed good or excellent results. The Cronbach's alpha of Ppeak measured in the smart insoles was 0.990 in the hallux, 0.961 in the medial forefoot, 0.973 in the lateral forefoot, and 0.995 in the hindfoot; all indicated excellent reliability in all areas. Conclusion: The plantar pressure measurements of smart insoles during walking on a flat ground showed validity compared to Pedar-X, and high reliability after repeated measurements.

Keywords

Acknowledgement

This work was supported by the Korea Medical Device Development Fund grant funded by the Korea government (the Ministry of Science and ICT, the Ministry of Trade, Industry, and Energy, the Ministry of Health & Welfare, the Ministry of Food and Drug Safety) (Project Number: 1711138420, KMDF_PR_20200901_0193).

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