以下肢肌電訊號探討踏車運動座墊位置

Abstract

目的：探討健身車不同垂直高度與水平前後位置及不同座椅後傾角度下座墊位置對下肢肌群的影響。方法：實驗徵召20名健康大專生參與實驗（平均年齡24.15 ± 2.13歲、身高170 ± 8.58公分、平均體重62.16 ± 2.13公斤)。在實驗第一部分以受試者90%、95%、100%三種腿長做高度，配合五種水平位置共做15種不同座位之踩踏測試，第二部分固定受試者95%腿長做為高度以五種不同座椅後傾角度做測試，分別記錄下肢肌電訊號及踩踏舒適度問卷。結果：不同高度與前後座墊位置下，股直肌隨座位高度增加，而肌肉徵召量遞減;股二頭肌與內腓腸肌則隨座位向前，而徵召量遞減。在固定腿長之不同座椅後傾角度下，隨角度增加，脛前肌徵召量增加，而內腓腸肌則遞減。問卷發現，座墊位置向前、座椅後傾角度增加，會增加肩部的不舒適程度。結論：當座位水平向前調整時，下肢肌肉整體有較低的徵召趨勢。當座椅傾角減少時，下肢肌肉總量有較高的徵召趨勢。由於無法單純透過下肢肌電訊號判斷舒適程度，因此可透過問卷輔助。Purpose: The purpose of this study was to investigate the Electromyography (EMG) on lower extremity in different cycling seat positions based on different seat tube angles (STA). Methods: Twenty healthy college students (age 24.15 ± 2.13 yrs; height 170 ± 8.58 cm; weight 62.16 ± 2.13 kg) were recruited in this study. Fifteen different cycling seat positions including 3 different heights (90%, 95%, 100% of leg length) and 5 different forward/backward position were investigated. Result: 1. The activation of the Rectus femoris decreased accompanied by increasing seat height; the activation of the Biceps femoris and the Medial Gastrocnemius decreased accompanied by forward seat position. 2. The activation of Tibialis Anterior increased accompanied by the STA increased, but the Medial Gastrocnemius decreased under the same seat height of 95% leg length. According to the questionnaire to our participants, they felt discomfort when the seat was forward and the STA increased. Conclusions: The activation of power extremity was lower when the seat moved forward. Besides, the activation of lower extremity was higher when the STA deceased.