■这项研究的目的是确定整个月经周期中的全身性疲劳以及荷尔蒙变化如何影响步态过程中的躯干变异性和局部动态稳定性。
■一般疲劳是由跑步机上的增量测试引起的,月经周期分为三个阶段:卵泡,排卵,和黄体。二十六健康,未使用口服避孕药或其他月经周期正常的激素类药物的年轻志愿者(年龄18~28岁)参与了研究.他们以首选的速度在跑步机上走了4分钟,在增量测试之前,接下来是四组4分钟交替行走,也以首选的速度,和休息。根据躯干运动学数据,提取以下内容:沿步幅的标准偏差的平均值,作为变异性的度量,和最大Lyapunov指数,作为局部动态稳定性(LDS)的度量。
■增量测试后,变异性增加,LDS下降。然而,与以前的男性结果相比,女性倾向于更快地恢复到初始值。在卵泡期,荷尔蒙释放较少,志愿者在第一次休息间隔后不久LDS几乎完全恢复,这表明女性荷尔蒙会干扰疲劳恢复。然而,关于LDS,黄体期明显低于卵泡期。
■不服用口服避孕药的女性应该意识到,在剧烈活动后,她们在经前阶段容易出现步态不稳定性增加。
The purpose of this study was to identify how generalized fatigue along with hormonal changes throughout the menstrual cycle affects trunk variability and local dynamic stability during gait.
General fatigue was induced by an incremental test on a treadmill, and the menstrual cycle was divided into three phases: follicular, ovulatory, and luteal. Twenty-six healthy, young volunteers (aged 18 to 28 years) who did not use oral contraceptives or other hormonal drugs with a regular menstrual cycle participated in the study. They walked on the treadmill for 4 min at the preferred speed, before the incremental test, followed by four sets of 4 min alternating between walking, also at preferred speed, and resting. From trunk kinematic data, the following were extracted: the mean of the standard deviation along strides, as a measure of variability, and the maximum Lyapunov exponent, as a measure of local dynamic stability (LDS).
After the incremental test, variability increased, and LDS decreased. However, they showed a tendency to return to the initial value faster in women compared to previous results for men. In the follicular phase, which has less hormonal release, the volunteers had an almost complete recovery in LDS soon after the first rest interval, suggesting that female hormones can interfere with fatigue recovery. Nevertheless, concerning the LDS, it was significantly lower in the luteal phase than in the follicular phase.
Women that are not taking oral contraceptives should be aware that they are susceptible to increased gait instabilities in the pre-menstrual phase after strenuous activities.