Effects of Low-Level Laser Therapy on Biceps Braquialis Muscle Fatigue in Young Women
Effects of Low-Level Laser Therapy on Biceps Braquialis Muscle Fatigue in Young Women
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DOI：
10.1089/pho.2012.3388
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发表时间：
2013-12-01
影响因子：
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通讯作者：
Muniz Renno, Ana Claudia
中科院分区：
文献类型：
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作者：
Higashi, Renan Hideki;Toma, Renata Luri;Muniz Renno, Ana Claudia
目的：探讨低强度激光治疗(LLLT)对20例年轻女性肱二头肌疲劳的影响。背景资料：精疲力竭的体力活动会导致肌肉疲劳，从而降低肌肉力量，并可能导致运动控制障碍和肌肉疼痛。为了加速肌肉疲劳的恢复，人们对几种生化和生物物理资源进行了研究。其中，LLLT是重点研究的对象。方法：20名受试者被随机分成一组激光治疗组和一组安慰剂组，在两次交叉设计实验过程中，第二次治疗在第一次治疗后7天内进行。在第一阶段，受试者接受了二头肌表面肌电(SEMG)数据的收集，然后对同一肌肉进行积极的或安慰剂的LLLT，然后是另一组二头肌的EMG样本。在实验过程中采集了五次血样。第二届会议的程序与第一届会议相同，但LLLT除外，后者与第一届会议相反。疲劳方案包括60秒的肘关节屈伸运动，最大重复次数的75%。以血乳酸、肌电疲劳、疲劳过程中肘关节屈伸重复次数为指标评价激光治疗的效果(波长808 nm，输出功率100 mW，功率密度35.7W/cm(2)，每点70s，8点7J/点)。结果：肌电疲劳和血乳酸值组间差异无统计学意义。平均肘屈伸次数安慰剂组为22.6+/-7.58，主动LLLT组为25.1+/-9.89，但差异无统计学意义(p=0.342)。结论：LLLT在延缓年轻女性样本中的肌肉疲劳方面效果有限，尽管在主动激光组观察到有较低的二头肌肌电疲劳的趋势。在肌肉收缩次数和乳酸浓度方面没有发现组间差异。
Objective: This study aims to investigate the effects of low-level laser therapy (LLLT) on biceps brachi muscular fatigue in 20 young females. Background data: Exhausting physical activity leads to muscular fatigue, which could decrease muscular strength, and may cause impairment in motor control and muscle pain. Several biochemical and biophysical resources have been studied in an attempt to accelerate the recovery of muscle fatigue. Among these, LLLT is emphasized. Methods: Twenty subjects were randomized in one laser group and one placebo group in two sessions of a crossover design experimental procedure; the second session taking place within 7 days of the first. In the first session, subjects underwent a collection of surface electromyographic (SEMG) data of the biceps brachii muscle, followed by active or placebo LLLT at the same muscle, followed then by another EMG sample of biceps brachii. Blood samples were collected five times during the experimental procedure. Second session procedures were identical to the first, with exception of LLLT, which was the opposite of the first session. The fatigue protocol consisted of 60sec of elbow flexion-extension movement performed with 75% of one maximum repetition. Blood lactate, EMG fatigue, and the number of elbow flexion-extension repetitions during the fatigue protocol were used to evaluate the effects of laser therapy (808nm wavelength, 100mW output power, power density of 35.7 W/cm(2), 70sec each point and 7J/point on eight points). Results: No statistical differences were found for eletromyographic fatigue and blood lactate values between groups. Mean numbers of elbow flexion-extension repetitions were 22.6 +/- 7.58 after placebo, and 25.1 +/- 9.89 after active LLLT group, but these differences were not statistically significant (p=0.342). Conclusions: LLLT had limited effects on delaying muscle fatigue in a young female sample, although a tendency was observed in the active laser group toward showing lower electromyography fatigue of biceps brachii muscle. No intergroup differences were found in the number of muscle contractions and lactate concentration.