Abstract

Purpose

The goal of this study was to assess differences in low back stabilization and underlying mechanisms between patients with low back pain (LBP) and healthy controls. It has been hypothesized that inadequate trunk stabilization could contribute to LBP through high tissue strains and/or impingement. Evidence to support this is inconsistent, and not all methods that have been used to study trunk stabilization are equally suitable. We have recently developed a method to assess intrinsic and reflexive contributions to trunk stabilization, which aims to circumvent the limitations of previous studies.

Methods

Forty-nine participants suffering from chronic LBP and a control group of fifty healthy subjects participated in this study. Trunk stabilization was measured using force-controlled perturbations directly applied to the trunk. The actuator displacement and contact force between the actuator and subject were measured as well as electromyography (EMG) of the M. Longissimus. Underlying mechanisms were characterized using system identification.

Results

LBP patients showed lower admittance, i.e., less displacement per unit of force applied, mainly due to higher position, velocity and acceleration feedback gains. Among patients, lower trunk admittance and higher reflex gains were associated with more negative pain-related cognitions.

Conclusion

Trunk stabilization differs between LBP patients and controls, with the same perturbations causing less trunk movement in patients, due to stronger reflexes. We interpret these changes as reflecting protective behavior.

Graphic abstract

These slides can be retrieved under Electronic Supplementary Material.

中文翻译：

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确定腰痛患者躯干稳定的内在和反射性贡献：病例对照研究。

摘要

目的

本研究的目的是评估腰痛 (LBP) 患者与健康对照组之间在腰部稳定性和潜在机制方面的差异。据推测，躯干稳定性不足可能通过高组织应变和/或撞击导致 LBP。支持这一点的证据并不一致，并非所有用于研究躯干稳定性的方法都同样适用。我们最近开发了一种方法来评估对躯干稳定的内在和反射性贡献，旨在规避先前研究的局限性。

方法

49 名患有慢性 LBP 的参与者和一个由 50 名健康受试者组成的对照组参加了这项研究。躯干稳定性是使用直接应用于躯干的力控制扰动来测量的。测量了执行器和受试者之间的执行器位移和接触力，以及 M. Longissimus 的肌电图 (EMG)。使用系统识别来表征潜在机制。

结果

LBP 患者表现出较低的导纳，即每单位施加的力的位移较小，这主要是由于较高的位置、速度和加速度反馈增益。在患者中，较低的躯干导纳和较高的反射增益与更多的负面疼痛相关认知相关。

结论

LBP 患者和对照组的躯干稳定性不同，由于反射更强，相同的扰动导致患者躯干运动较少。我们将这些变化解释为反映保护行为。

图形摘要

这些幻灯片可以在电子补充材料下检索。