Conchola Eric C, Thiele Ryan M, Palmer Ty B, Smith Doug B, Thompson Brennan J
Department of Wellness, Oklahoma State University, Stillwater, Oklahoma, USA.
Applied Musculoskeletal and Human Physiology Laboratory, Department of Health and Human Performance, Oklahoma State University, Stillwater, Oklahoma, USA.
Muscle Nerve. 2015 Nov;52(5):844-51. doi: 10.1002/mus.24598. Epub 2015 Sep 3.
We examined the effects of neuromuscular fatigue on volitional electromechanical delay (EMD) of leg extensors and flexors between genders.
Twenty-one men and 20 women performed 2 maximal voluntary contractions (MVCs), followed by intermittent isometric contractions of leg extensors and flexors using a 0.6 duty cycle (6-s contraction, 4-s relaxation) at 50% of MVC until volitional fatigue was achieved. MVCs were again performed at 0, 7, 15, and 30 min post-fatigue.
EMD was greater compared with baseline at all post-fatigue time phases for the leg flexors (P = 0.001-0.007), while EMD was greater at Post0, Post15 and Post30 (P = 0.001-0.023) for the leg extensors. EMD was also greater for leg extensors compared with leg flexors only at Post0.
No differential gender-related fatigue effects on EMD were shown. There were different fatigue-induced responses between leg extensors and flexors, with leg extensors exhibiting higher EMD immediately post-fatigue.
我们研究了神经肌肉疲劳对不同性别的腿部伸肌和屈肌随意肌电延迟（EMD）的影响。
21名男性和20名女性进行了2次最大自主收缩（MVC），随后以MVC的50%进行腿部伸肌和屈肌的间歇性等长收缩，占空比为0.6（收缩6秒，放松4秒），直至达到随意性疲劳。在疲劳后0、7、15和30分钟再次进行MVC。
腿部屈肌在所有疲劳后时间阶段的EMD均高于基线（P = 0.001 - 0.007），而腿部伸肌在Post0、Post15和Post30时EMD更高（P = 0.001 - 0.023）。仅在Post0时，腿部伸肌的EMD也高于腿部屈肌。
未显示出与性别相关的EMD疲劳差异效应。腿部伸肌和屈肌之间存在不同的疲劳诱导反应，腿部伸肌在疲劳后立即表现出更高的EMD。
