School of Kinesiology and Nutritional Science, California State University, Los Angeles, CA, 90032, USA.
Eur J Appl Physiol. 2018 May;118(5):927-936. doi: 10.1007/s00421-018-3810-6. Epub 2018 Feb 16.
To determine the effects of an acute bout of unilateral static stretching on handgrip strength of both the stretched and non-stretched limb. It was reasoned that if the non-stretched limb experienced a decrease in force output, further evidence for a neural mechanism to explain a post-stretch force reduction would be obtained as no mechanical adaptation would have occurred.
Thirty participants performed maximum voluntary unilateral handgrip contractions of both limbs before and after stretching the finger flexors of the strength-dominant side only. Each trial was assessed for peak force, muscle activity (iEMG), and rate of force generation.
Following the stretching bout, peak force and iEMG decreased by 4.4% (p = 0.001) and 6.4% (p = 0.000) respectively in the stretched limb only. However, rate of force generation was significantly impaired in both the stretched (- 17.3%; p = 0.000) and non-stretched limbs (- 10.8%; p = 0.003) 1 min post-stretch, and remained similarly depressed for both limbs 15 min later.
Acute stretching negatively impacts rate of force generation more than peak force. Moreover, a reduced rate of force generation from the non-stretched limb indicates the presence of a cross-over inhibitory effect through the nervous system, which provides additional evidence for a neural mechanism.
确定单次急性单侧静态伸展对伸展侧和未伸展侧握力的影响。如果未伸展侧的力量输出减少，则可以获得进一步的神经机制证据，以解释伸展后的力量减少，因为不会发生机械适应。
30 名参与者在伸展优势侧的手指屈肌之前和之后进行了双侧最大自主单侧握力收缩。每次试验均评估峰值力、肌肉活动（iEMG）和力量产生速度。
伸展后，伸展侧的峰值力和 iEMG 分别下降了 4.4%（p=0.001）和 6.4%（p=0.000）。然而，伸展和未伸展侧的力量产生速度在伸展后 1 分钟时均显著受损（伸展侧为-17.3%；p=0.000，未伸展侧为-10.8%；p=0.003），15 分钟后仍保持相似的抑制。
急性伸展对力量产生速度的负面影响大于峰值力。此外，未伸展侧的力量产生速度降低表明通过神经系统存在交叉抑制效应，这为神经机制提供了额外的证据。
