NHMRC Centre of Clinical Research Excellence in Spinal Pain, Injury and Health, School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, Australia.
Spine (Phila Pa 1976). 2010 Apr 1;35(7):818-24. doi: 10.1097/BRS.0b013e3181bc98f1.
Cross-sectional design.
To compare lumbar multifidus electromyographic activity (EMG) during predictable and unpredictable trunk loading between people with and without recurrent unilateral low back pain (LBP) during symptom remission.
Unpredictable loading is a common injury mechanism for LBP. Paraspinal muscle responses to trunk loading differ between people with and without a history of LBP, but whether the response differs between specific regions within the paraspinal muscles is unclear. Differences between deep (DM) and superficial fibers (SM) of multifidus have been implicated in other tasks. It is unknown whether DM and SM EMG differ between people in remission from recurrent LBP and healthy people during trunk loading.
DM and SM EMG was recorded bilaterally at L5 with intramuscular electrodes during predictable and unpredictable trunk loading and compared during 10 milliseconds epochs (250 milliseconds before to 150 milliseconds after loading) between sides, loading conditions, and groups.
DM EMG increased above baseline before and after predictable load onset, but returned to baseline at the time of impact. Both DM EMG bursts were less in the remission group and less on the non-painful side. Peak SM EMG amplitude on the previously painful side was earlier in the remission group than healthy participants. DM and SM EMG were less after unpredictable load onset in the remission group than healthy participants.
Despite symptom remission, DM EMG during predictable loading and DM and SM EMG during unpredictable loading were less in people with recurrent LBP than healthy participants.
横断面设计。
比较缓解期复发性单侧腰痛（LBP）患者和无腰痛史患者在可预测和不可预测的躯干负荷下腰椎多裂肌肌电图（EMG）活动。
不可预测的负荷是腰痛的常见损伤机制。腰痛患者和无腰痛史患者对躯干负荷的脊柱旁肌肉反应不同，但脊柱旁肌肉内特定区域的反应是否不同尚不清楚。多裂肌深部（DM）和浅层纤维（SM）的差异在其他任务中已被涉及。在缓解复发性 LBP 的人群和健康人群中，DM 和 SM EMG 在躯干负荷下是否存在差异尚不清楚。
采用肌内电极在 L5 双侧记录 DM 和 SM EMG，在可预测和不可预测的躯干负荷期间，在 10 毫秒时窗（负荷前 250 毫秒至负荷后 150 毫秒）内进行比较，并在两侧、负荷条件和组之间进行比较。
DM EMG 在可预测负荷开始前和开始后均高于基线，但在冲击时恢复到基线。缓解组的 DM 肌电爆发均较少，非疼痛侧较少。缓解组先前疼痛侧的 SM EMG 峰值振幅早于健康参与者。与健康参与者相比，缓解组在不可预测的负荷开始后 DM 和 SM EMG 较少。
尽管症状缓解，但在可预测的负荷下，缓解期复发性腰痛患者的 DM EMG 和不可预测的负荷下的 DM 和 SM EMG 均低于健康参与者。
