Department of Rehabilitation and Movement Science, University of Vermont, Burlington, VT, USA.
J Electromyogr Kinesiol. 2012 Feb;22(1):13-20. doi: 10.1016/j.jelekin.2011.10.006. Epub 2011 Nov 18.
There is increasing evidence that individuals with non-specific low back pain (LBP) have altered movement coordination. However, the relationship of this neuromotor impairment to recurrent pain episodes is unknown. To assess coordination while minimizing the confounding influences of pain we characterized automatic postural responses to multi-directional support surface translations in individuals with a history of LBP who were not in an active episode of their pain. Twenty subjects with and 21 subjects without non-specific LBP stood on a platform that was translated unexpectedly in 12 directions. Net joint torques of the ankles, knees, hips, and trunk in the frontal and sagittal planes as well as surface electromyographs of 12 lower leg and trunk muscles were compared across perturbation directions to determine if individuals with LBP responded using a trunk stiffening strategy. Individuals with LBP demonstrated reduced peak trunk torques, and enhanced activation of the trunk and ankle muscle responses following perturbations. These results suggest that individuals with LBP use a strategy of trunk stiffening achieved through co-activation of trunk musculature, aided by enhanced distal responses, to respond to unexpected support surface perturbations. Notably, these neuromotor alterations persisted between active pain periods and could represent either movement patterns that have developed in response to pain or could reflect underlying impairments that may contribute to recurrent episodes of LBP.
越来越多的证据表明，非特异性下腰痛（LBP）患者的运动协调性发生了改变。然而，这种神经运动损伤与复发性疼痛发作之间的关系尚不清楚。为了评估协调性，同时最大限度地减少疼痛的混杂影响，我们在没有处于疼痛活跃期的 LBP 病史个体中，对多方向支撑面平移的自动姿势反应进行了特征描述。20 名有非特异性 LBP 病史的受试者和 21 名无 LBP 病史的受试者站在一个平台上，该平台意外地向 12 个方向平移。在 12 个下肢和躯干肌肉的表面肌电图上比较了额状面和矢状面踝关节、膝关节、髋关节和躯干的净关节转矩，以确定是否存在 LBP 个体使用了一种躯干僵硬策略。LBP 个体在受到干扰后，峰值躯干转矩降低，躯干和踝关节肌肉反应的激活增强。这些结果表明，LBP 个体通过躯干肌肉的共同激活，辅助以增强的远端反应，采用躯干僵硬的策略来应对意外的支撑面干扰。值得注意的是，这些神经运动的改变在疼痛活跃期之间仍然存在，这可能是对疼痛的反应形成的运动模式，也可能反映了可能导致复发性 LBP 的潜在损伤。
