Centre of Precision Rehabilitation for Spinal Pain (CPR Spine), School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UNITED KINGDOM.
Med Sci Sports Exerc. 2024 Feb 1;56(2):193-208. doi: 10.1249/MSS.0000000000003314. Epub 2023 Oct 11.
We quantified the relationship between high-density surface electromyographic (HDsEMG) oscillations (in both time and frequency domains) and torque steadiness during submaximal concentric/eccentric trunk extension/flexion contractions, in individuals with and without chronic low back pain (CLBP).
Comparisons were made between regional differences in HDsEMG amplitude and HDsEMG-torque cross-correlation and coherence of the thoracolumbar erector spinae (ES), rectus abdominis (RA), and external oblique (EO) muscles between the two groups. HDsEMG signals were recorded from the thoracolumbar ES with two 64-electrode grids and from the RA and EO muscles with a single 64-electrode grid placed over each muscle. Torque signals were recorded with an isokinetic dynamometer. Coherence (δ band (0-5 Hz)) and cross-correlation analyses were used to examine the relationship between HDsEMG and torque signals. For this purpose, we used principal component analysis to reduce data dimensionality and improve HDsEMG-based torque estimation.
We found that people with CLBP had poorer control during both concentric and eccentric trunk flexion and extension. Specifically, during trunk extension, they exhibited a higher HDsEMG-torque coherence in more cranial regions of the thoracolumbar ES and a higher HDsEMG cross-correlation compared with asymptomatic controls. During trunk flexion movements, they demonstrated higher HDsEMG amplitude of the abdominal muscles, with the center of activation being more cranial and a higher contribution of this musculature to the resultant torque (particularly the EO muscle).
Our findings underscore the importance of evaluating torque steadiness in individuals with CLBP. Future research should consider the value of torque steadiness training and HDsEMG-based biofeedback for modifying trunk muscle recruitment strategies and improving torque steadiness performance in individuals with CLBP.
我们量化了高密度表面肌电图（HDsEMG）振荡（在时域和频域中）与患有和不患有慢性下背痛（CLBP）的个体在进行次最大向心性/离心性躯干伸展/屈曲收缩期间的扭矩稳定性之间的关系。
我们比较了两组之间的区域差异，包括胸腰椎竖脊肌（ES）、腹直肌（RA）和外斜肌（EO）的 HDsEMG 幅度和 HDsEMG-扭矩交叉相关和相干性。使用两个 64 电极网格记录胸腰椎 ES 的 HDsEMG 信号，使用单个 64 电极网格记录 RA 和 EO 肌肉的 HDsEMG 信号。扭矩信号使用等速测力计记录。使用相干性（δ 波段（0-5 Hz））和交叉相关分析来检查 HDsEMG 和扭矩信号之间的关系。为此，我们使用主成分分析来降低数据维度并提高基于 HDsEMG 的扭矩估计。
我们发现，患有 CLBP 的人在进行向心性和离心性躯干屈曲和伸展时控制能力较差。具体来说，在进行躯干伸展时，他们在胸腰椎 ES 的更颅侧区域表现出更高的 HDsEMG-扭矩相干性，并且与无症状对照组相比，HDsEMG 交叉相关更高。在进行躯干屈曲运动时，他们表现出更高的腹部肌肉 HDsEMG 幅度，激活的中心更颅侧，并且该肌肉对产生的扭矩的贡献更高（特别是 EO 肌肉）。
我们的研究结果强调了评估患有 CLBP 的个体扭矩稳定性的重要性。未来的研究应考虑使用扭矩稳定性训练和基于 HDsEMG 的生物反馈来改变躯干肌肉募集策略，并提高患有 CLBP 的个体的扭矩稳定性性能。
