Tsur A, Glass I, Solzi P
Rehabilitation Unit, Western Galilee Hospital, Nahariya, 22100, Israel.
Disabil Rehabil. 2002 Sep 10;24(13):647-53. doi: 10.1080/09638280210125805.
The purpose of the study was to determine whether mechanical nerve root compression could indirectly contribute to early muscle fatigue because of impaired activation.
The patients' two legs and the control group's dominant leg were subjected to exhausting foot dorsiflexion against 2 kg weight. Electrophysiological parameters were measured under three conditions: before, upon completion of, and five minutes after the exhausting effort (i.e. causing unbearable fatigue). The study was performed in a warm room (24 degrees C), in the EMG laboratory of a rehabilitation centre using standard equipment. Eighteen patients participated in the study (12 males and six females, mean age 47.8 +/- 12.0 years). They suffered from lumbar radiculopathy and unilateral complaints at the L4, L5 innervation territory. There were 22 matched controls (18 males and 4 females, mean age 44.4 +/- 9.9 years) that were healthy subjects. The patients' two legs and the dominant leg of the control participants were tested. The peroneal nerve was stimulated supra-maximally, behind the fibular head. Recording the activity of the anterior tibial muscle served to calculate F-wave latency, the conduction velocity of the nerve and muscle complex (NMCV), the compound muscle action potential (CMAP) amplitude and the exhaustion time.
Following the exhausting fatigue, the symptomatic, asymptomatic, and control legs exhibited a significant decrease in NMCV and reduced CMAP amplitude (p < 0.05). In each condition (rest, effort, recovery), the patients' two leg types exhibited similar NMCV (symptomatic vs asymptomatic), yet each of these two types was significantly slower than the controls' NMCV. A significant prolongation of F-wave latency after an exhausting effort was found in the symptomatic legs.
Our results suggest that a continuous exhausting effort impairs F-wave latency and NMCV, presumably by decreasing the proportion of fast conducting nerve fibres. Peroneal nerve root compression can contribute to early fatigue of the respective muscles.
本研究旨在确定机械性神经根压迫是否会因激活受损而间接导致早期肌肉疲劳。
让患者的双腿以及对照组的优势腿对抗2千克重量进行疲劳性足背屈。在三种情况下测量电生理参数：疲劳努力前、疲劳努力完成时以及疲劳努力后五分钟（即导致无法忍受的疲劳时）。研究在温暖的房间（24摄氏度）中，于康复中心的肌电图实验室使用标准设备进行。18名患者参与了研究（12名男性和6名女性，平均年龄47.8±12.0岁）。他们患有腰椎神经根病，且在L4、L5神经支配区域有单侧症状。有22名匹配的对照组（18名男性和4名女性，平均年龄44.4±9.9岁），均为健康受试者。对患者的双腿以及对照参与者的优势腿进行测试。在腓骨头后方超最大程度刺激腓总神经。记录胫前肌的活动以计算F波潜伏期、神经肌肉复合体传导速度（NMCV）、复合肌肉动作电位（CMAP）幅度和疲劳时间。
在疲劳性疲劳后，有症状的腿、无症状的腿和对照腿的NMCV均显著降低，CMAP幅度减小（p<0.05）。在每种情况（休息、努力、恢复）下，患者的两种腿型表现出相似的NMCV（有症状的腿与无症状的腿），但这两种腿型中的每一种都明显慢于对照组的NMCV。在有症状的腿中发现疲劳努力后F波潜伏期显著延长。
我们的结果表明，持续的疲劳努力会损害F波潜伏期和NMCV，可能是通过降低快速传导神经纤维的比例。腓总神经根压迫会导致相应肌肉的早期疲劳。
