Musculoskeletal Research Unit, Department of Rehabilitation Sciences, University of Leuven (K.U. Leuven), Tervuursevest 101, Leuven, Belgium.
Spine (Phila Pa 1976). 2010 May 1;35(10):1088-94. doi: 10.1097/BRS.0b013e3181bee5c3.
A 2-group experimental design.
To determine postural stability and proprioceptive postural control strategies of healthy subjects and subjects with recurrent low back pain (LBP) during acute inspiratory muscles fatigue (IMF).
People with LBP use a more rigid proprioceptive postural control strategy than control subjects during postural perturbations. Recent evidence suggests that respiratory movements create postural instability in people with LBP. The role of the respiratory muscles in postural control strategies is unknown, but can be studied by inducing acute IMF.
Postural control was evaluated in 16 people with LBP and 12 healthy controls, both before and after IMF. Center of pressure displacement was determined on a force plate to evaluate postural stability. Proprioceptive postural control strategies were examined during vibration of the triceps surae muscles or lumbar paraspinal muscles, while standing on both a stable and unstable support surface and without vision. Proprioceptive postural control strategies were determined by examining the ratio of mean center of pressure displacement measured during triceps surae muscles vibration to that measured during lumbar paraspinal muscles vibration. RESULTS.: After IMF, control subjects showed a significantly larger sway compared to the unfatigued condition while standing on an unstable support surface (P < 0.05). IMF induced an increased reliance on proprioceptive signals from the ankles, which resembled the postural control strategy used by people with LBP (P < 0.05). Subjects with LBP showed that same ankle steered postural control strategy in the unfatigued and IMF states (P > 0.05).
After IMF, control subjects use a rigid proprioceptive postural control strategy, rather than the normal "multisegmental" control, which is similar to people with LBP. This results in decreased postural stability. These results suggest that IMF might be a factor in the high recurrence rate of LBP.
2 组实验设计。
确定健康受试者和复发性腰痛（LBP）受试者在急性吸气肌疲劳（IMF）期间的姿势稳定性和本体感受姿势控制策略。
与对照组相比，LBP 患者在姿势扰动期间使用更刚性的本体感受姿势控制策略。最近的证据表明，呼吸运动在 LBP 患者中会导致姿势不稳定。呼吸肌在姿势控制策略中的作用尚不清楚，但可以通过诱导急性 IMF 来研究。
在 IMF 前后，对 16 名 LBP 患者和 12 名健康对照者进行了姿势控制评估。通过力板确定质心位移来评估姿势稳定性。在稳定和不稳定的支撑表面上以及在没有视觉的情况下，通过振动小腿三头肌或腰椎旁肌肉来检查本体感受姿势控制策略。本体感受姿势控制策略通过检查振动小腿三头肌时测量的平均质心位移与振动腰椎旁肌肉时测量的平均质心位移之比来确定。结果：IMF 后，与非疲劳状态相比，对照组在不稳定支撑表面上站立时的摆动明显更大（P <0.05）。IMF 导致对来自脚踝的本体感觉信号的依赖增加，这类似于 LBP 患者使用的姿势控制策略（P <0.05）。LBP 患者在非疲劳和 IMF 状态下表现出相同的脚踝引导姿势控制策略（P >0.05）。
IMF 后，对照组使用刚性本体感受姿势控制策略，而不是正常的“多节段”控制，这与 LBP 患者相似。这会导致姿势稳定性降低。这些结果表明 IMF 可能是 LBP 高复发率的一个因素。
