EMG PROFILES OF LOWER-EXTREMITY MUSCLES DURING CYCLING AT CONSTANT WORKLOAD AND CADENCE
EMG PROFILES OF LOWER-EXTREMITY MUSCLES DURING CYCLING AT CONSTANT WORKLOAD AND CADENCE
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DOI：
10.1016/1050-6411(92)90018-e
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发表时间：
1992-01-01
影响因子：
2.5
通讯作者：
GREGOR, RJ
中科院分区：
文献类型：
--
作者：
RYAN, MM;GREGOR, RJ
由于包括电极放置和实验设计在内的方法学差异，可以从文献中的可用数据得出关于骑行期间肌电图模式变异性的有限结论。本研究的目的是监测经验丰富的自行车手在恒定的工作量和节奏下的大量踩踏周期中十个下肢肌肉的肌电图信号。通过以 10% 的踩踏周期间隔计算变异系数 (CV) 来评估受试者之间的变异性。在一次试验中，受试者的肌电图模式非常一致。单关节髋关节和膝关节伸肌（臀大肌、股内侧肌和股外侧肌）的 CV 值最低（小于 30%）。这种低变异性似乎支持了它们作为发电机的作用。尽管实验条件相对相似，但腿筋肌肉的变异性普遍较高，出现了两种股二头肌模式。比较来自腘绳肌表面电极和细线电极的肌电图信号，以了解肌电图差异的可能原因。细线肌电图数据与使用表面电极获得的数据非常相似，表明串扰通常对腿筋信号的影响很小。胫骨前肌、腓肠肌和比目鱼肌表现出相当可重复的模式，所有研究的肌肉在踩踏周期的前 20% 中变异性最高。
Limited conclusions concerning the variability in EMG patterns during cycling can be made from available data in the literature because of methodological differences which include electrode placement and experimental design. The purpose of this study was to monitor EMG signals from ten lower extremity muscles over a large number of pedalling cycles in experienced cyclists at constant workload and cadence. Variability across subjects was evaluated by calculating the coefficient of variation (CV) at 10% intervals of the pedalling cycle. Within subject EMG patterns were very consistent within a single trial. The single-joint hip and knee extensors (gluteus maximus, vastus medialis, and vastus lateralis) had the lowest CV values (less than 30%). This low variability appears to support their role as power generators. Variability was generally higher in the hamstring muscles with two biceps femoris patterns emerging despite relatively similar experimental conditions. EMG signals from surface and fine wire electrodes for the hamstring muscles were compared for possible contribution to the discrepancies in the EMG profiles. Fine wire EMG data were quite similar to those obtained using surface electrodes, indicating that crosstalk had minimal effect, in general, on the hamstring signals. The tibialis anterior, gastrocnemius, and soleus muscles displayed fairly repeatable patterns, with variability highest in the first 20% of the pedalling cycle for all muscles studied.