장승완(Seungwan Jang) ; 이현영(Hyun Young Lee) ; 이경은(Gyeongeun Lee) ; 김훈(Hoon Kim) ; 김영(Young Kim) ; 민세동(Se Dong Min)
Alternative shoes (Crocsⓡ, C) are shoes often used in Daily life for comfort and fashion purposes. However, alternative shoes do not support the back of the foot, reducing athletic ability, and lowering the height of the foot can cause loss of balance and fall if caught by an obstacle. Therefore, in this study, we compared alternative shoes and sneakers (S) to determine the difference in foot height when passing an obstacle, and implemented an IMU sensor in the form of an accessory that can be conveniently used in alternative shoes. The implemented sensors were compared and evaluated through motion capture. in this study, a gait track with a mixture of curves and straight lines was created to simulate situations that may occur in real daily life, and obstacles of 1 cm, 10 cm, 20 cm, and 26 cm were used. Through this, obstacle gait was performed according to the height of the obstacle and the type of shoe. Comparison of obstacle heights according to shoe type was analyzed using an independent samples t-test. As a result of the analysis, it was found to be 1 cm (C = 9.63 ± 2.06 cm, S = 10.94 ± 2.03 cm, t = -2.115, p < 0.05) and 26 cm (C = 41.3 ± 3.71 cm, S = 43.04 ± 3.92 cm, t = -2.075, p < 0.05) indicated a statistically significant difference. This confirmed that the alternative shoes lifted the foot lower than the sneakers at the obstacle. This indicates that alternative shoes do not support the back of the foot, which tends to lower the height of the foot when passing obstacles. A comparative evaluation of motion capture and IMU sensors was performed using Bland-Altman plots and Pearson Correlation. As a result of comparative evaluation, alternative shoes were found to have a positive correlation with r values of 0.543*, 0.434**, and 0.464** at 1 cm, 10 cm, and 26 cm, excluding 20 cm. However, sneakers show no correlation for all obstacles. This suggests that the IMU sensor can be used by attaching it to an alternative shoe and measuring foot height. In the case of sneakers, it was discovered that the reflective marker attached to the tongue area was affected by the movement of the instep and ankle and curved gait, causing the foot to move when leaving the ground and passing an obstacle. To compensate for this phenomenon, additional research is needed in which reflective markers are attached to areas that are not affected by instep and ankle movements and curved gait. Additionally, the noise removal function due to the impact of the IMU sensor and the drift error filtering function due to integration must be improved.