Cannavan Dale, Coleman David R, Blazevich Anthony J
Physical Education and Exercise Science, College of Arts and Sciences, Seattle Pacific University, 3307 3rd Avenue West, Seattle, WA 98119, USA.
Clin Biomech (Bristol). 2012 Mar;27(3):306-12. doi: 10.1016/j.clinbiomech.2011.10.003. Epub 2011 Nov 1.
The effects of an acute bout of moderate-duration static stretching on plantar flexor force production, series compliance of the muscle-tendon unit, and levels of neuromuscular activation were examined.
Eighteen active individuals (9 men and 9 women) performed four 45-s static plantar flexor stretches and a time-matched control of no stretch (where subjects remained seated in the dynamometer for 4 min with no stretch being performed). Measures of peak isometric moment, rate of force development, neuromuscular activation (interpolated twitch technique and electromyography), twitch force characteristics, passive moment during stretch, and tendon elongation during maximal voluntary contractions were taken before and after the stretching.
Despite a significant stress-relaxation response during stretch (9.3%, P<0.01) there were no significant differences in peak isometric moment (P=0.35; effect size 0.13), rate of force development (P=0.93; effect size 0.01), neuromuscular activation (interpolated twitch: P=0.86; electromyography: P=0.09; effect size 0.02), or tendon elongation (P=0.61; effect size 0.07) after stretching. Twitch characteristics were also unchanged after stretching, although there was a reduction in the rate of twitch torque relaxation (RR(t); P<0.01).
The acute bout of moderate-duration static stretching did not impair the force generating capacity of the plantar flexors or negatively affect muscle-tendon mechanical properties. Static stretching may not always have detrimental consequences for force production. Thus, clinicians may be able to apply moderate-duration stretches to patients without risk of reducing muscular performance.
研究了一次急性中等时长静态拉伸对跖屈肌力量产生、肌腱单位的串联顺应性以及神经肌肉激活水平的影响。
18名活跃个体（9名男性和9名女性）进行了四次45秒的静态跖屈肌拉伸，并进行了时长匹配的无拉伸对照（受试者坐在测力计上4分钟，不进行拉伸）。在拉伸前后测量了等长峰值力矩、力量发展速率、神经肌肉激活（内插单收缩技术和肌电图）、单收缩力量特征、拉伸过程中的被动力矩以及最大自主收缩时的肌腱伸长。
尽管在拉伸过程中出现了显著的应力松弛反应（9.3%，P<0.01），但拉伸后等长峰值力矩（P=0.35；效应量0.13）、力量发展速率（P=0.93；效应量0.01）、神经肌肉激活（内插单收缩：P=0.86；肌电图：P=0.09；效应量0.02）或肌腱伸长（P=0.61；效应量0.07）均无显著差异。拉伸后单收缩特征也未改变，尽管单收缩扭矩松弛速率（RR(t)）有所降低（P<0.01）。
一次急性中等时长静态拉伸并未损害跖屈肌的力量产生能力，也未对肌腱力学性能产生负面影响。静态拉伸可能并不总是对力量产生有不利影响。因此，临床医生或许能够对患者进行中等时长的拉伸，而不会有降低肌肉性能的风险。
