Department of Neurorehabilitation, Graduate School of Health Sciences, Kio University, Koryo-cho, Nara, Japan.
Miura Internal Medicine Michiko Pediatrics Clinic, Marugame-shi, Kagawa, Japan.
PLoS One. 2020 Dec 17;15(12):e0244111. doi: 10.1371/journal.pone.0244111. eCollection 2020.
In patients with chronic low back pain (CLBP), reduced lumbar flexion-relaxation and reduced variability of muscle activity distribution are reported as abnormal muscle activity. It is not known how abnormal muscle activity and pain-related factors are related to CLBP-based disability. Here, we performed an association rule analysis to investigated how CLBP disability, muscle activity, and pain-related factors in CLBP patients are related.
Surface electromyographic signals were recorded from over the bilateral lumbar erector spinae muscle with four-channel electrodes from 24 CLBP patients while they performed a trunk flexion re-extension task. We calculated the average value of muscle activities of all channels and then calculated the flexion relaxation ratio (FRR) and the spatial variability of muscle activities. We also assessed the pain-related factors and CLBP disability by a questionnaire method. A clustering association rules analysis was performed to determine the relationships among pain-related factors, the FRR, and the variability of muscle activity distribution.
The association rules of severe CLBP disability were divisible into five classes, including 'low FRR-related rules.' The rules of the mild CLBP disability were divisible into four classes, including 'high FRR-related rules' and 'high muscle variability-related rules.' When we combined pain-related factors with the FRR and muscle variability, the relationship between abnormal FRR/muscle variability and CLBP disability became stronger.
Our findings thus highlight the importance of focusing on not only the patients' pain-related factors but also the abnormal motor control associated with CLBP, which causes CLBP disability.
在慢性下背痛（CLBP）患者中，报告的异常肌肉活动包括腰椎屈伸松弛减少和肌肉活动分布的可变性降低。目前尚不清楚异常肌肉活动和与疼痛相关的因素与基于 CLBP 的残疾有何关系。在这里，我们进行了关联规则分析，以研究 CLBP 患者的 CLBP 残疾、肌肉活动和与疼痛相关的因素之间的关系。
我们使用四通道电极从 24 名 CLBP 患者的双侧腰竖脊肌上记录表面肌电图信号，同时进行躯干前屈-后伸任务。我们计算了所有通道的肌肉活动平均值，然后计算了屈伸比（FRR）和肌肉活动分布的空间可变性。我们还通过问卷调查方法评估了与疼痛相关的因素和 CLBP 残疾。采用聚类关联规则分析来确定与疼痛相关因素、FRR 和肌肉活动分布的可变性之间的关系。
严重 CLBP 残疾的关联规则可分为五类，包括“低 FRR 相关规则”。轻度 CLBP 残疾的规则可分为四类，包括“高 FRR 相关规则”和“高肌肉可变性相关规则”。当我们将与疼痛相关的因素与 FRR 和肌肉可变性结合起来时，异常 FRR/肌肉可变性与 CLBP 残疾之间的关系变得更强。
因此，我们的研究结果强调了不仅要关注患者与疼痛相关的因素，还要关注与 CLBP 相关的异常运动控制，这是导致 CLBP 残疾的原因。
