{"title":"疲劳引起的肌电图活动变化在重复的竞速转弯后:一项初步研究。","authors":"Mickael Chollet, Pierre Samozino, Baptiste Morel, Maximilien Bowen, Alhammoud Marine, Frédérique Hintzy","doi":"10.1007/s00421-024-05691-0","DOIUrl":null,"url":null,"abstract":"<p><strong>Purpose: </strong>Alpine skiing races are physically demanding events characterized by numerous repeated near-maximal activations of the lower limb muscles. Although this type of task is known to induce neuromuscular fatigue, electromyographic activity (EMG) adaptations after repeated maximal-intensity skiing have not been previously investigated.</p><p><strong>Methods: </strong>Six skiers completed a 6-turns section with (FAT) and without performing 30 giant slalom (GS) turns (CONT). Isometric knee extensors maximal force (F<sub>max</sub>) was measured before and immediately after both conditions. On-snow EMG activity of VM, VL, RF, BF, SMST and GM muscles were compared between conditions for both the outside (OL) and inside (IL) legs using turn-averaged EMG amplitude (RMS<sub>OL</sub> and RMS<sub>IL</sub>) and EMG mean power frequency (MPF<sub>OL</sub> and MPF<sub>IL</sub>). EMG time-frequency maps were also computed and compared between conditions using statistical parametric mapping (SPM) analysis.</p><p><strong>Results: </strong>F<sub>max</sub> was significantly lower after FAT (-20.1%, p < 0.001), but did not change after CONT. RMS<sub>OL</sub> was lower in FAT for BF (-26.8%, p = 0.020). RMS<sub>IL</sub> was lower in FAT for VM (-24.7%, p = 0.036) and GM (-27.3%, p = 0.021). MPF<sub>OL</sub> was lower in FAT for VM (-8.2%, p = 0.028), VL (-11.3%, p = 0.025), RF (-13.1%, p = 0.007), SMST (-9.3%, p = 0.004) and GM (-7.4%, p = 0.034). MPF<sub>IL</sub> was lower in FAT for VM (-13.0%, p = 0.016) and RF (-11.1%, p = 0.034). SPM analysis indicated that the initiation phase of the turn was specifically affected.</p><p><strong>Conclusion: </strong>Thirty GS turns led to a substantial decrease in F<sub>max</sub> and altered motor command, as indicated by reduced EMG frequency content, specifically in the initiation phase of the turn. The present pilot data highlight the importance of characterizing neuromuscular fatigue in competitive GS skiing.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":""},"PeriodicalIF":2.8000,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Fatigue-induced changes in electromyographic activity after repeated racing turns: a pilot study.\",\"authors\":\"Mickael Chollet, Pierre Samozino, Baptiste Morel, Maximilien Bowen, Alhammoud Marine, Frédérique Hintzy\",\"doi\":\"10.1007/s00421-024-05691-0\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><strong>Purpose: </strong>Alpine skiing races are physically demanding events characterized by numerous repeated near-maximal activations of the lower limb muscles. Although this type of task is known to induce neuromuscular fatigue, electromyographic activity (EMG) adaptations after repeated maximal-intensity skiing have not been previously investigated.</p><p><strong>Methods: </strong>Six skiers completed a 6-turns section with (FAT) and without performing 30 giant slalom (GS) turns (CONT). Isometric knee extensors maximal force (F<sub>max</sub>) was measured before and immediately after both conditions. On-snow EMG activity of VM, VL, RF, BF, SMST and GM muscles were compared between conditions for both the outside (OL) and inside (IL) legs using turn-averaged EMG amplitude (RMS<sub>OL</sub> and RMS<sub>IL</sub>) and EMG mean power frequency (MPF<sub>OL</sub> and MPF<sub>IL</sub>). EMG time-frequency maps were also computed and compared between conditions using statistical parametric mapping (SPM) analysis.</p><p><strong>Results: </strong>F<sub>max</sub> was significantly lower after FAT (-20.1%, p < 0.001), but did not change after CONT. RMS<sub>OL</sub> was lower in FAT for BF (-26.8%, p = 0.020). RMS<sub>IL</sub> was lower in FAT for VM (-24.7%, p = 0.036) and GM (-27.3%, p = 0.021). MPF<sub>OL</sub> was lower in FAT for VM (-8.2%, p = 0.028), VL (-11.3%, p = 0.025), RF (-13.1%, p = 0.007), SMST (-9.3%, p = 0.004) and GM (-7.4%, p = 0.034). MPF<sub>IL</sub> was lower in FAT for VM (-13.0%, p = 0.016) and RF (-11.1%, p = 0.034). SPM analysis indicated that the initiation phase of the turn was specifically affected.</p><p><strong>Conclusion: </strong>Thirty GS turns led to a substantial decrease in F<sub>max</sub> and altered motor command, as indicated by reduced EMG frequency content, specifically in the initiation phase of the turn. The present pilot data highlight the importance of characterizing neuromuscular fatigue in competitive GS skiing.</p>\",\"PeriodicalId\":12005,\"journal\":{\"name\":\"European Journal of Applied Physiology\",\"volume\":\" \",\"pages\":\"\"},\"PeriodicalIF\":2.8000,\"publicationDate\":\"2024-12-21\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"European Journal of Applied Physiology\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://doi.org/10.1007/s00421-024-05691-0\",\"RegionNum\":3,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"PHYSIOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"European Journal of Applied Physiology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1007/s00421-024-05691-0","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSIOLOGY","Score":null,"Total":0}
引用次数: 0
摘要
目的:高山滑雪比赛是一项体力要求很高的运动,其特点是下肢肌肉多次重复的接近最大的激活。虽然这种类型的任务已知会引起神经肌肉疲劳,但在重复的最大强度滑雪后肌电图活动(EMG)适应性尚未被研究过。方法:6名滑雪者完成了6个转弯(FAT),而没有进行30个大回转(GS)转弯(CONT)。在两种条件之前和之后立即测量等长膝关节伸肌最大力(Fmax)。利用旋转平均肌电信号振幅(RMSOL和RMSIL)和平均工频(MPFOL和MPFIL),比较了外腿(OL)和内腿(IL)条件下VM、VL、RF、BF、SMST和GM肌肉的雪上肌电信号活动。使用统计参数映射(SPM)分析计算并比较不同条件下的肌电时频图。结果:FAT后Fmax显著降低(-20.1%),p OL显著降低(-26.8%,p = 0.020)。RMSIL在VM (-24.7%, p = 0.036)和GM (-27.3%, p = 0.021)中的FAT较低。VM MPFOL是低脂肪(-8.2%,p = 0.028),六世(-11.3%,p = 0.025),射频(-13.1%,p = 0.007), SMST (-9.3%, p = 0.004)和通用汽车(-7.4%,p = 0.034)。MPFIL降低VM (-13.0%, p = 0.016)和RF (-11.1%, p = 0.034)的FAT。SPM分析表明,弯的起始阶段受到特别的影响。结论:30个GS圈导致Fmax显著降低,运动指令改变,这可以从EMG频率含量的降低中看出,特别是在旋转开始阶段。目前的试验数据强调了在竞技GS滑雪中表征神经肌肉疲劳的重要性。
Fatigue-induced changes in electromyographic activity after repeated racing turns: a pilot study.
Purpose: Alpine skiing races are physically demanding events characterized by numerous repeated near-maximal activations of the lower limb muscles. Although this type of task is known to induce neuromuscular fatigue, electromyographic activity (EMG) adaptations after repeated maximal-intensity skiing have not been previously investigated.
Methods: Six skiers completed a 6-turns section with (FAT) and without performing 30 giant slalom (GS) turns (CONT). Isometric knee extensors maximal force (Fmax) was measured before and immediately after both conditions. On-snow EMG activity of VM, VL, RF, BF, SMST and GM muscles were compared between conditions for both the outside (OL) and inside (IL) legs using turn-averaged EMG amplitude (RMSOL and RMSIL) and EMG mean power frequency (MPFOL and MPFIL). EMG time-frequency maps were also computed and compared between conditions using statistical parametric mapping (SPM) analysis.
Results: Fmax was significantly lower after FAT (-20.1%, p < 0.001), but did not change after CONT. RMSOL was lower in FAT for BF (-26.8%, p = 0.020). RMSIL was lower in FAT for VM (-24.7%, p = 0.036) and GM (-27.3%, p = 0.021). MPFOL was lower in FAT for VM (-8.2%, p = 0.028), VL (-11.3%, p = 0.025), RF (-13.1%, p = 0.007), SMST (-9.3%, p = 0.004) and GM (-7.4%, p = 0.034). MPFIL was lower in FAT for VM (-13.0%, p = 0.016) and RF (-11.1%, p = 0.034). SPM analysis indicated that the initiation phase of the turn was specifically affected.
Conclusion: Thirty GS turns led to a substantial decrease in Fmax and altered motor command, as indicated by reduced EMG frequency content, specifically in the initiation phase of the turn. The present pilot data highlight the importance of characterizing neuromuscular fatigue in competitive GS skiing.
期刊介绍:
The European Journal of Applied Physiology (EJAP) aims to promote mechanistic advances in human integrative and translational physiology. Physiology is viewed broadly, having overlapping context with related disciplines such as biomechanics, biochemistry, endocrinology, ergonomics, immunology, motor control, and nutrition. EJAP welcomes studies dealing with physical exercise, training and performance. Studies addressing physiological mechanisms are preferred over descriptive studies. Papers dealing with animal models or pathophysiological conditions are not excluded from consideration, but must be clearly relevant to human physiology.