의족 블레이드 구조를 적용한 워킹화가 장시간 파워워킹 시 생체역학적 변인에 미치는 영향 = Effects of Walking Shoes Featuring a Prosthetic Blade Structure on Lower Limb Biomechanics During Prolonged Power Walking

다국어 초록 (Multilingual Abstract)

Objective: This study aimed to examine the effects of structural differences in walking shoes on lower limb biomechanics during prolonged power walking.
Method: Ten healthy adult males (age: 25.0 ± 3.7 yrs; height: 172.6 ± 3.4 cm; weight: 71.1 ± 10.9 kg; body mass index (BMI): 23.8 ± 3.4) completed 30 min of treadmill power walking at 1.9 m/s under two footwear conditions: Shoe A (control) and Shoe B (modified with an elastic rearfoot blade structure). Data were collected at 0, 15, and 30 minutes. Motion was tracked using an 8-camera infrared system and an instrumented treadmill, while surface electromyography (EMG) was recorded from the tibialis anterior and gastrocnemius medialis. Key variables included gait parameters, ankle joint kinematics and kinetics, ground reaction force, and muscle fatigue. A two-way repeated measures analysis of variance (ANOVA) (α = .05) was used for statistical analysis.
Results: At 30 minutes, Shoe B demonstrated improved gait efficiency, with significantly longer step length, longer contact time and reduced cadence compared to Shoe A. The impact peak force was higher in Shoe B at all time points, but the loading rate showed no between-shoe difference. For both shoes, negative ankle power, vertical loading rate, peak braking force and peak propulsion force increased over time. Contrary to typical fatigue indicators, EMG analysis showed that muscle activation root mean square (RMS) decreased over time, while the median frequency (MDF) of the gastrocnemius increased.
Conclusion: After 30 minutes of power walking, the blade-equipped Shoe B showed superior gait efficiency compared to the standard Shoe A. Although Shoe B produced a higher impact peak force, the equivalent loading rate between the shoes suggests the blade structure effectively mitigated shock by prolonging the impact time. While some biomechanical variables indicated the onset of fatigue over time, the EMG results did not show clear muscle fatigue. Therefore, the 30-minute exercise protocol was likely insufficient to cause clear muscle fatigue in the healthy young participants.