Department of Surgical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA.
BMC Musculoskelet Disord. 2010 Jul 7;11:154. doi: 10.1186/1471-2474-11-154.
The effects of lumbosacral orthoses (LSOs) on neuromuscular control of the trunk are not known. There is a concern that wearing LSOs for a long period may adversely alter muscle control, making individuals more susceptible to injury if they discontinue wearing the LSOs. The purpose of this study was to document neuromuscular changes in healthy subjects during a 3-week period while they regularly wore a LSO.
Fourteen subjects wore LSOs 3 hrs a day for 3 weeks. Trunk muscle activity prior to and following a quick force release (trunk perturbation) was measured with EMG in 3 sessions on days 0, 7, and 21. A longitudinal, repeated-measures, factorial design was used. Muscle reflex response to trunk perturbations, spine compression force, as well as effective trunk stiffness and damping were dependent variables. The LSO, direction of perturbation, and testing session were the independent variables.
The LSO significantly (P < 0.001) increased the effective trunk stiffness by 160 Nm/rad (27%) across all directions and testing sessions. The number of antagonist muscles that responded with an onset activity was significantly reduced after 7 days of wearing the LSO, but this difference disappeared on day 21 and is likely not clinically relevant. The average number of agonist muscles switching off following the quick force release was significantly greater with the LSO, compared to without the LSO (P = 0.003).
The LSO increased trunk stiffness and resulted in a greater number of agonist muscles shutting-off in response to a quick force release. However, these effects did not result in detrimental changes to the neuromuscular function of trunk muscles after 3 weeks of wearing a LSO 3 hours a day by healthy subjects.
目前尚不清楚腰骶矫形器（LSO）对躯干神经肌肉控制的影响。人们担心，如果长时间佩戴 LSO，可能会对肌肉控制产生不利影响，从而使个体在停止佩戴 LSO 后更容易受伤。本研究的目的是在佩戴 LSO 的 3 周内，记录健康受试者的神经肌肉变化。
14 名受试者每天佩戴 LSO 3 小时，共 3 周。在 0、7 和 21 天的 3 次测试中，通过肌电图测量快速力释放（躯干扰动）前后的躯干肌肉活动。使用纵向、重复测量、析因设计。肌肉反射对躯干扰动的反应、脊柱压缩力以及有效躯干刚度和阻尼是因变量。LSO、扰动方向和测试会话是自变量。
LSO 显著（P < 0.001）增加了所有方向和测试会话的有效躯干刚度 160 Nm/rad（27%）。佩戴 LSO 7 天后，与拮抗剂肌肉同时产生起始活动的肌肉数量显著减少，但这种差异在第 21 天消失，且可能不具有临床意义。与不佩戴 LSO 相比，佩戴 LSO 后快速力释放后关闭的主动肌数量明显增加（P = 0.003）。
LSO 增加了躯干的刚度，并导致在快速力释放时更多的主动肌关闭。然而，这些影响并没有导致健康受试者每天佩戴 LSO 3 小时 3 周后，躯干肌肉的神经肌肉功能产生有害变化。
