Falla Deborah, Gizzi Leonardo, Tschapek Marika, Erlenwein Joachim, Petzke Frank
Pain Clinic, Center for Anesthesiology, Emergency and Intensive Care Medicine, University Hospital Göttingen, Göttingen, Germany Department of Neurorehabilitation Engineering, Bernstein Focus Neurotechnology (BFNT) Göttingen, Bernstein Center for Computational Neuroscience, University Medical Center Göttingen, Georg-August University, Göttingen, Germany.
Pain. 2014 May;155(5):944-953. doi: 10.1016/j.pain.2014.01.027. Epub 2014 Feb 3.
This study investigated change in the distribution of lumbar erector spinae muscle activity and pressure pain sensitivity across the low back in individuals with low back pain (LBP) and healthy controls. Surface electromyographic (EMG) signals were recorded from multiple locations over the lumbar erector spinae muscle with a 13×5 grid of electrodes from 19 people with chronic nonspecific LBP and 17 control subjects as they performed a repetitive lifting task. The EMG root mean square (RMS) was computed for each location of the grid to form a map of the EMG amplitude distribution. Pressure pain thresholds (PPT) were recorded before and after the lifting task over a similar area of the back. For the control subjects, the EMG RMS progressively increased more in the caudal region of the lumbar erector spinae during the repetitive task, resulting in a shift in the distribution of muscle activity. In contrast, the distribution of muscle activity remained unaltered in the LBP group despite an overall increase in EMG amplitude. PPT was lower in the LBP group after completion of the repetitive task compared to baseline (average across all locations: pre: 268.0±165.9 kPa; post: 242.0±166.7 kPa), whereas no change in PPT over time was observed for the control group (320.1±162.1 kPa; post: 322.0±179.5 kPa). The results demonstrate that LBP alters the normal adaptation of lumbar erector spinae muscle activity to exercise, which occurs in the presence of exercise-induced hyperalgesia. Reduced variability of muscle activity may have important implications for the provocation and recurrence of LBP due to repetitive tasks.
本研究调查了腰痛（LBP）患者和健康对照者腰椎竖脊肌活动分布及下背部压痛敏感性的变化。对19名慢性非特异性LBP患者和17名对照者在进行重复性提举任务时，使用13×5的电极网格从腰椎竖脊肌的多个位置记录表面肌电图（EMG）信号。计算网格每个位置的EMG均方根（RMS），以形成EMG振幅分布图。在提举任务前后，在背部类似区域记录压痛阈值（PPT）。对于对照者，在重复性任务期间，腰椎竖脊肌尾侧区域的EMG RMS逐渐增加得更多，导致肌肉活动分布发生变化。相比之下，尽管EMG振幅总体增加，但LBP组的肌肉活动分布保持不变。与基线相比，LBP组在完成重复性任务后的PPT较低（所有位置的平均值：术前：268.0±165.9 kPa；术后：242.0±166.7 kPa），而对照组未观察到PPT随时间的变化（320.1±162.1 kPa；术后：322.0±179.5 kPa）。结果表明，LBP改变了腰椎竖脊肌活动对运动的正常适应性，这种适应性改变发生在运动诱发的痛觉过敏的情况下。肌肉活动变异性降低可能对重复性任务导致的LBP激发和复发具有重要影响。
