Ischemia causes muscle fatigue
Ischemia causes muscle fatigue
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DOI：
10.1016/s0736-0266(00)90019-6
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发表时间：
2001-05-01
影响因子：
2.8
通讯作者：
Rempel, DM
中科院分区：
文献类型：
--
作者：
Murthy, G;Hargens, AR;Rempel, DM
这项研究的目的是确定缺血是否会降低腕伸肌(ECR)的氧合。会导致肌肉力量产生的减少。在8名受试者中，用近红外光谱仪(NIRS)无创、连续地测量右侧ECR的肌肉氧合(TO2)，同时通过经皮电刺激(1 Hz，0.1ms)诱发肌肉抽动。连续记录基础血压、肌肉氧合和抽动力，然后将上臂止血带扩张到5个不同的压力水平之一：20、40、60 mm Hg(随机顺序)、舒张压(69+/-9.8 mm Hg)和收缩压(106+/-12.8 mm Hg)。每个压力水平维持3-5分钟，然后是一个足以使测量回到基线的恢复期。对于每个止血带压力水平，平均TO2从静息基线(100%TO2)下降到99+/-1.2%(扫描电子显微镜)、96+/-1.9%、93+/-2.8%、90+/-2.5%和86+/-2.7%。平均抽动力从静息基础(100%用力)下降到99+/-0.7%(扫描电子显微镜)，96+/-2.7%。93+/-3.1%、88+/-3.2%和86+/-2.6%。止血带压缩60 mm Hg及以上时的肌肉氧合和抽动力显著低于基线值(P<；0.05)。肌痉挛力量减少与肌肉氧合减少呈剂量依赖关系(r=0.78。P<；0.001)。虽然这种相关性不能证明因果关系，但结果表明，缺血导致肌肉氧合降低7%或更多，会导致前臂伸肌的肌力产生减少。因此，脑缺血与TO？会导致肌肉疲劳。(C)2001年骨科研究会。爱思唯尔科学有限公司出版。版权所有。
The purpose of this investigation was to determine whether ischemia, which reduces oxygenation in the extensor carpi radialis (ECR) muscle. causes a reduction in muscle force production. In eight subjects, muscle oxygenation (TO2) of the right ECR was measured noninvasively and continuously using near infrared spectroscopy (NIRS) while muscle twitch force was elicited by transcutaneous electrical stimulation (1 Hz, 0.1 ms). Baseline measurements of blued volume, muscle oxygenation and twitch force were recorded continuously, then a tourniquet on the upper arm was inflated to one of five different pressure levels: 20, 40, 60 mm Hg (randomized order) and diastolic (69 +/- 9.8 mm Hg) and systolic (106 +/- 12.8 mm Hg) blood pressures. Each pressure level was maintained for 3-5 min, and was followed by a recovery period sufficient to allow measurements to return to baseline. For each respective tourniquet pressure level, mean TO2 decreased from resting baseline (100% TO2) to 99 +/- 1.2%(SEM), 96 +/- 1.9%, 93 +/- 2.8%, 90 +/- 2.5%, and 86 +/- 2.7%. and mean twitch force decreased from resting baseline (100% force) to 99 +/- 0.7% (SEM), 96 +/- 2.7%. 93 +/- 3.1%, 88 +/- 3.2%, and 86 +/- 2.6%. Muscle oxygenation and twitch force at 60 mm Hg tourniquet compression and above were significantly lower (P < 0.05) than baseline value. Reduced twitch force was correlated in a dose-dependent manner with reduced muscle oxygenation (r = 0.78. P < 0.001). Although the correlation does not prove causation, the results indicate that ischemia leading to a 7% or greater reduction in muscle oxygenation causes decreased muscle force production in the forearm extensor muscle. Thus, ischemia associated with a modest decline in TO? causes muscle fatigue. (C) 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.