Kirking Meghan, Berrios Barillas Reivian, Nelson Philip Andrew, Hunter Sandra Kay, Hyngstrom Allison
Department of Physical Therapy, Marquette University, Milwaukee, WI 53201, USA.
Department of Occupational Therapy, Concordia University, Mequon, WI 53097, USA.
Brain Sci. 2017 Jan 12;7(1):8. doi: 10.3390/brainsci7010008.
Despite the implications of optimizing strength training post-stroke, little is known about the differences in fatigability between men and women with chronic stroke. The purpose of this study was to determine the sex differences in knee extensor muscle fatigability and potential mechanisms in individuals with stroke.
Eighteen participants (10 men, eight women) with chronic stroke (≥6 months) and 23 (12 men, 11 women) nonstroke controls participated in the study. Participants performed an intermittent isometric contraction task (6 s contraction, 3 s rest) at 30% of maximal voluntary contraction (MVC) torque until failure to maintain the target torque. Electromyography was used to determine muscle activation and contractile properties were assessed with electrical stimulation of the quadriceps muscles.
Individuals with stroke had a briefer task duration (greater fatigability) than nonstroke individuals (24.1 ± 17 min vs. 34.9 ± 16 min). Men were more fatigable than women for both nonstroke controls and individuals with stroke (17.9 ± 9 min vs. 41.6 ± 15 min). Individuals with stroke had less fatigue-related changes in muscle contractile properties and women with stroke differed in their muscle activation strategy during the fatiguing contractions.
Men and women fatigue differently post-stroke and this may be due to the way they neurally activate muscle groups.
尽管优化中风后力量训练具有重要意义，但对于慢性中风男性和女性之间疲劳性的差异却知之甚少。本研究的目的是确定中风患者膝伸肌疲劳性的性别差异及其潜在机制。
18名慢性中风（≥6个月）参与者（10名男性，8名女性）和23名非中风对照者（12名男性，11名女性）参与了本研究。参与者以最大自主收缩（MVC）扭矩的30%进行间歇性等长收缩任务（收缩6秒，休息3秒），直至无法维持目标扭矩。使用肌电图确定肌肉激活情况，并通过股四头肌电刺激评估收缩特性。
中风患者的任务持续时间比非中风患者短（疲劳性更高）（24.1±17分钟 vs. 34.9±16分钟）。对于非中风对照者和中风患者，男性比女性更容易疲劳（17.9±9分钟 vs. 41.6±15分钟）。中风患者肌肉收缩特性的疲劳相关变化较小，中风女性在疲劳收缩期间的肌肉激活策略有所不同。
中风后男性和女性的疲劳方式不同，这可能是由于他们神经激活肌肉群的方式不同。
