不同踩踏模式之疲勞介入對下肢動作的影響

Abstract

目的：疲勞現象對於不同踩踏模式，在足底壓力、肌電活化程度和下肢運動學參數的影響。材料與方法：15位健康男性 (年齡25.0±3.3歲、身高175.1±5.6公分、體重75.3±9.1公斤)。壓力鞋墊偵測負重運動與非負重運動疲勞前、後足底壓力和足底接觸面積。雙極肌電貼片黏貼於右側臀大肌、股直肌、股外側肌、股內側肌、股二頭肌、脛前肌和外側腓腸肌，擷取疲勞前、後踩踏時的肌電訊號，配戴心率帶和心率錶監測目標心跳率，並以伯格氏自覺用力指數量表評分疲勞前、後用力程度。以相依樣本t檢定呈現疲勞前、後心跳值和自覺用力指數，二因子重複量數變異數分析檢測疲勞前、後足底壓力、足底接觸面積、肌電訊號和下肢關節活動度，顯著水準值為α=.05，分析資料皆為右腳。結果：疲勞後，負重運動的前足壓力顯著上升，後足外側顯著下降，非負重運動後足外側顯著下降，負重運動足壓顯著大於非負重運動，前足接觸面積顯著小於非負重運動，中內側和後足顯著大於非負重運動。臀大肌活化程度顯著上升，脛前肌在非負重運動顯著下降，負重運動臀大肌活化較顯著。非負重運動髖關節和踝關節活動度分別上升和下降，兩者膝關節最小夾角疲勞後皆顯著下降。踝關節最大和最小夾角發生時間點在疲勞後延遲發。負重運動髖、膝、踝關節最大和最小夾角皆大於非負重運動，僅有踝關節活動度和最大夾角在疲勞後兩者之間沒有差異。結論：足壓分布往前足集中，負重運動對於臀大肌活化程度較顯著，脛前肌在非負重運動扮演傳遞踩踏力量重要的角色，膝關節活動度因為髖關節和踝關節活動度代償維持穩定，膝關節最小夾角和踝關節最大、最小夾角發生時間點在兩者皆受到疲勞顯著影響。Purpose: To investigate the influence of fatigue on biomechanics in weight-bearing and non-weight-bearing pedaling by measuring plantar pressure (PP), contact area (CA) electromyography (EMG), and lower limbs kinematics. Method: Fifteen male participants were recruited in this research (age: 25.0±3.3 years old, height: 175.1±5.6 cm, and weight: 75.3±9.1 kg). PP, CA, range of motion (ROM), maximal and minimal angle and angles happening time, and also heart rate (HR) and rate of perceived exertion (RPE) were measured before and after the exercise. The paired t test was used to evaluate HR and RPE before and after the exercise. The 2-way repeated ANOVA was used to evaluate PP, CA, ROM, lower limbs kinematics parameters before and after the exercise. The significant level was α=.05. Only right foot data were analyzed. Result: Forefoot PP increased and rearfoot PP decreased. Muscle activation of gluteus maximal (GM) increased, and tibialis anterior (TA) decreased during non-weight-bearing exercise. Knee flexion angle increased, delayed onset of ankle plantar flexion and dorsiflexion maximal angle. Hip and ankle ROM increased and decreased respectively during non-weight-bearing exercise. Conclusion: After the exhaustion, plantar pressure distribution towards forefoot. Muscle activation of GM increased and TA played an important role as a force transmitter in non-weight-bearing exercise. Knee ROM remained stable due to the compensation of hip and ankle joint. Delayed onset of ankle motion can be the key of exhaustion.