不同自行車褲對舒適度與肌肉活化與氧飽和度之影響

Abstract

背景：自行車運動長時間維持軀幹屈曲的姿勢，常導致脊柱及核心肌群間活化之不平衡，導致脊柱受力改變而增加腰椎負荷，進而造成下背疼痛 (Low Back Pain, LBP)。自行車褲透過於肢段加壓，能夠提供支撐身體組織的功能，藉此減少肌肉為了抵銷運動過程中的晃動而產生的額外活化，進而達到延緩肌肉疲勞的效果。然而，自行車褲對於軀幹肌肉活化與氧飽和度以及LBP的影響仍尚未被研究證實。目的：本研究欲探討藉由肌貼提供下背支撐之背帶式自行車褲對股四頭肌與腰部豎脊肌之肌電活化程度、肌肉氧飽和度、自覺痠痛程度與運動自覺程度之影響。方法：參與者為12位男性業餘自行車手 (年齡，22 ± 3歲；身高，174 ± 2公分；體重，69 ± 6公斤；最大有氧輸出功率，243 ± 31瓦)，隨機交叉次序穿著平口式自行車褲 (SRT)、背帶式自行車褲 (BIB) 及背帶式自行車褲加上下背部肌貼支撐 (KT)。在首次實驗中，受試者於自行車訓練台上執行遞增負荷腳踏車測驗以決定其最大有氧輸出功率 (peak aerobic power output, POmax)；在後續三次實驗中，以60% POmax進行45分鐘固定負荷自行車騎乘，並分別於開始騎乘後第0、15、30及45分鐘，測量股外側肌與腰部豎脊肌之肌電活化程度、肌肉氧飽和度、自覺痠痛程度 (Visual Analog Scale, VAS) 以及運動自覺強度 (Borg’s rating of perceived exertion, RPE)。以二因子重複量數變異數分析分析不同自行車褲與騎乘時間對股外側肌與腰部豎脊肌之肌肉活化程度、肌肉氧飽和度、VAS以及RPE之影響。結果：不同自行車褲對股外側肌及腰部豎脊肌之肌肉活化程度、肌肉氧飽和度、VAS以及RPE沒有顯著影響。結論：背帶式自行車褲加上下背部肌貼支撐在45分鐘固定負荷自行車騎乘無益於減少肌肉活化及增加肌肉氧飽和度，故無法提供降低下背疼痛之效果。Introduction: Spinal and core muscle activation imbalances in a prolonged flexed posture associated with cycling may lead to maladaptive spinal kinematics and increased spinal stresses contributing to low back pain (LBP). Bicycle compression garment could attenuate activation of the muscle during cycling, and this muscle activation decrease may be beneficial in terms of muscle savings and postpone the onset of muscle fatigue for cyclists. Purpose: The purpose of this study is to examine whether the bicycle compression garment which provides trunk supporting could help trunk stabilization to reduce LBP and attenuate muscle fatigue during 45-minute of cycling. Methods: Twelve male amateur cyclists were recruited [age, 22 ± 3 years; height, 174 ± 2 cm; body mass, 69 ± 6 kg; peak aerobic power output, 243 ± 31 W] in this study, and were required to complete a peak aerobic power output (POmax) trial, and three randomized crossover 45-minute constant-load trials. During the first trial, participants performed the incremental cycling test on a cycling trainer in order to determine the individual POmax of each participant. During the following trials, participants cycled for 45 minutes at their 60% POmax wearing three different bicycle compression garments: cycling shorts (SRT), bib shorts (BIB), and low back-supporting bib shorts (KT). The DELSYS surface electromyography system was used to measure the muscle activation of vastus lateralis and lumbar erector spinae at initial cycling (first min), 15th, 30th, and ending cycling (last min). Near-infrared spectroscopy (NIRS) was used for measuring tissue oxygen saturation of vastus lateralis and lumbar erector spinae, including oxyhemoglobin (O2Hb), deoxyhemoglobin (HHb), total hemoglobin (tHb) and tissue saturation index (TSI), were continuously monitored throughout all trials. The Visual Analog Scale (VAS) was used for evaluating the rating of lower-back and lower-limb muscle soreness. The Borg’s Rating of Perceived Exertion (RPE) was used for measuring the status during cycling test. The obtained data were statistically processed by two-way repeated-measures ANOVA analysis. Results: The muscle activation, oxygen saturation, VAS and RPE showed no difference between cycling shorts. Conclusion: Low back-supporting bib shorts (KT) worn during 45-minute constant-load cycling did not improve comfort level and muscle activation and oxygen saturation.