Department of Chirotherapy, General Hospital of the Air Force, Beijing, China.
Pain Management Centre, Department of Anaesthesiology, Singapore General Hospital, Singapore.
J Chin Med Assoc. 2019 Jan;82(1):35-39. doi: 10.1097/JCMA.0000000000000004.
Patients with chronic nonspecific low-back pain (CNSLBP) lack the flexion-relaxation phenomenon in full-trunk bending. This can be quantified by surface electromyography (SEMG) measurement of lumbar erector muscle. The study objective is to explore the clinical utility of the SEMG flexion-extension ratio (FER) in distinguishing patients with CNSLBP from painfree persons.
This was a comparative cross-sectional study. We adopted a balanced study design by recruiting 130 participants each for the CNSLBP and control arms. Each participant underwent dynamic SEMG measurement in full-trunk bending, which consisted of standing, flexion, relaxation, and extension. The FER ratio was the ratio of the maximum SEMG in flexion to the maximum SEMG during extension. Receiver-operating characteristic (ROC) analysis was conducted to identify optimal values of the FER and associated sensitivity, specificity, and diagnostic accuracy.
The CNSLBP group and control group were generally comparable in terms of demographics and clinical profile. The CNSLBP group had higher SEMG amplitudes during flexion but lower SEMG during extension. The mean (SD) FER of the CNSLBP group was 0.90 (0.26), which was almost double that of controls 0.47 (0.14). The ROC curve identified an optimal FER cutoff of ≥ 0.692, for which sensitivity and specificity were 76.15% (95%confidence interval [CI], 68.14-82.66) and 98.46% (95%CI, 94.56-99.58). The diagnostic accuracy was 92.1% (95%CI, 88.70-95.54).
The FER derived by lumbar muscle SEMG is able to distinguish patients with CNSLBP from pain-free people with excellent accuracy. This provides good evidence that a customized FER can be used in various clinical scenarios.
慢性非特异性下腰痛（CNSLBP）患者在全脊柱弯曲时缺乏屈伸放松现象。这可以通过腰椎竖脊肌表面肌电图（SEMG）测量来量化。本研究旨在探讨 SEMG 屈伸比（FER）在鉴别 CNSLBP 患者与无痛人群中的临床应用价值。
这是一项对比性的横断面研究。我们通过招募 CNSLBP 组和对照组各 130 名参与者，采用平衡研究设计。每位参与者都接受了全脊柱弯曲时的动态 SEMG 测量，包括站立、弯曲、放松和伸展。FER 比值是弯曲时最大 SEMG 与伸展时最大 SEMG 的比值。进行了受试者工作特征（ROC）分析，以确定 FER 的最佳值及其相关的灵敏度、特异性和诊断准确性。
CNSLBP 组和对照组在人口统计学和临床特征方面总体相似。CNSLBP 组在弯曲时的 SEMG 幅度较高，但在伸展时的 SEMG 幅度较低。CNSLBP 组的平均（标准差）FER 为 0.90（0.26），几乎是对照组 0.47（0.14）的两倍。ROC 曲线确定了最佳 FER 截断值≥0.692，此时的灵敏度和特异性分别为 76.15%（95%置信区间[CI]，68.14-82.66）和 98.46%（95%CI，94.56-99.58）。诊断准确性为 92.1%（95%CI，88.70-95.54）。
腰椎肌肉 SEMG 得出的 FER 能够准确地区分 CNSLBP 患者和无痛人群。这为使用定制的 FER 在各种临床情况下提供了很好的证据。
