Abboud Jacques, Nougarou François, Pagé Isabelle, Cantin Vincent, Massicotte Daniel, Descarreaux Martin
Département d'Anatomie, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada.
Eur J Appl Physiol. 2014 Dec;114(12):2645-54. doi: 10.1007/s00421-014-2985-8. Epub 2014 Aug 31.
To identify and characterize trunk neuromuscular adaptations during muscle fatigue in patients with chronic low back pain (LBP) and healthy participants.
Forty-six patients with non-specific chronic LBP and 23 healthy controls were asked to perform a trunk muscles fatigue protocol. Surface electromyography was recorded using two adhesive matrix of 64 electrodes applied bilaterally over the erector spinae. Pain score, kinesiophobia and physical disability were analyzed through different questionnaires. To characterize motor variability, dispersion of muscular activity center of gravity was computed. Motor variability between groups was compared using repeated-measures analyses of variance.
Score of disability and kinesiophobia were significantly higher in patients with LBP. Results indicated a significant group effect characterized by an increased motor variability in the healthy group through the entire fatigue task on the left (p = 0.003) and right side (p = 0.048). Interestingly, increasing muscle fatigue led to increased motor variability in both groups (on both sides (p < 0.001) but with a greater increase in the healthy group.
Muscle recruitment is altered in patients with chronic LBP in the presence of muscle fatigue. Consequently, these patients exhibit changes in muscle recruitment pattern and intensity (lower levels of motor variability) during sustained isometric contraction that may be attributed to variation in the control of motor units within and between muscles. However, patients with LBP are able to increase their motor variability over time but with a lower increase compared to healthy participants.
识别并描述慢性下腰痛（LBP）患者和健康参与者在肌肉疲劳期间躯干神经肌肉的适应性变化。
46例非特异性慢性LBP患者和23名健康对照者被要求执行一项躯干肌肉疲劳方案。使用双侧竖脊肌上粘贴的两个64电极的粘性矩阵记录表面肌电图。通过不同问卷分析疼痛评分、恐动症和身体残疾情况。为了描述运动变异性，计算肌肉活动重心的离散度。使用重复测量方差分析比较组间运动变异性。
LBP患者的残疾和恐动症评分显著更高。结果表明存在显著的组间效应，其特征是在整个疲劳任务中，健康组左侧（p = 0.003）和右侧（p = 0.048）的运动变异性增加。有趣的是，肌肉疲劳加剧导致两组的运动变异性均增加（两侧均p < 0.001），但健康组增加幅度更大。
慢性LBP患者在肌肉疲劳时肌肉募集发生改变。因此，这些患者在持续等长收缩期间表现出肌肉募集模式和强度的变化（运动变异性水平较低），这可能归因于肌肉内和肌肉间运动单位控制的差异。然而，LBP患者能够随着时间增加其运动变异性，但与健康参与者相比增加幅度较小。
