摘要
目的采用经典落球试验研究范式和sEMG信号分析方法,研究急性运动性腰部肌肉疲劳和主观心理预期对腰部多裂肌前馈控制的影响。方法选取10名18～26岁健康男性被试,采用双因素(预期因素2×疲劳因素2)实验设计,分别于"间歇性腰部肌肉等长疲劳负荷试验"前后完成落球试验,采集被试肱二头肌和L5～S1腰部多裂肌sEMG信号,计算sEMG信号距离落球刺激的起始时间和平均反应强度,观察急性腰部肌肉疲劳和主观心理预期对被检肌肉快速反应时间和反应强度的影响。结果本研究所采用的疲劳负荷试验造成被试腰部多裂肌MPF平均下降18%;主观心理预期能够明显加快腰部多裂肌快速反应时间;疲劳具有加快腰部多裂肌快速反应时间的趋势,但无明显统计学意义;主观心理预期能够明显降低腰部多裂肌反应强度,而疲劳对腰部多裂肌快速反应强度均无明显影响。结论主观心理预期能够明显加快腰部多裂肌的快速反应时间,从而为腰部稳定性提供代偿性保护;急性运动性肌肉疲劳不能改变腰部多裂肌的快速反应时间和快速反应强度,证明中枢神经系统对腰椎稳定肌活动的前馈控制具有较好的稳定性。
Objective： To investigate the effects of psychological expectation and local muscle fatigue on the feed-forward motor control of lumbar multifidus by means of combination of Ball-hitting Test and surface electromyography signal analysis.Method： 10 healthy male volunteers aged 18-26 participated in this study.A double factor experiment was designed in which subjects performed Ball-hitting Test both before and after finishing intermittent loading tests evoking isometric contraction of MF to fatigue.The sEMG signals of biceps brachii and lumbar multifidus（L5～S1） were sampled.The onset of the sEMG signals to the ball-hitting stimulation and average response intensity were calculated.The latency and the amplitude were surveyed of the acute muscle fatigue and subjective psychological expectation on targeted muscles.Results：（1） The MPF of lumbar MF declined 18%.（2）Psychological expectation accelerated the onset of lumbar MF significantly.（3）There was a tendency that the response of lumbar MF to Ball-hitting Test became faster under the circumstance of fatigue,though not significantly.（4）Psychological expectation could reduce the average amplitude of lumbar MF while fatigue couldn’t.Conclusion： Psychological expectation can shorten the latency of lumber MF which provides compensatory protection to lumbar stability.Acute muscle fatigue doesn’t change the reaction time and intensity of lumber MF,demonstrating that the feed-forward control of CNS over the activity of lumber postural muscles is stable.
出处
《人类工效学》
2013年第2期14-18,共5页
Chinese Journal of Ergonomics
关键词
腰部多裂肌
前馈控制
心理预期
肌肉疲劳
落球实验
肌电图
lumbar multifidus
feed-forward motor control
psychological expectation
muscle fatigue
ball hitting test（BHT） sEMG
