Neurological Sciences Institute, Oregon Health & Science University, Beaverton, OR, USA.
Hum Mov Sci. 2011 Feb;30(1):74-89. doi: 10.1016/j.humov.2010.10.002. Epub 2010 Dec 23.
Gurfinkel and colleagues (2006) recently found that healthy adults dynamically modulate postural muscle tone in the body axis during anti-gravity postural maintenance and that this modulation is inversely correlated with axial stiffness. Our objective in the present study was to investigate whether dynamic modulation of axial postural tone can change through training. We examined whether teachers of the Alexander Technique (AT), who undergo "long-term" (3-year) training, have greater modulation of axial postural tone than matched control subjects. In addition, we performed a longitudinal study on the effect of "short-term" (10-week) AT training on the axial postural tone of individuals with low back pain (LBP), since short term AT training has previously been shown to reduce LBP. Axial postural tone was quantified by measuring the resistance of the neck, trunk and hips to small (±10°), slow (1°/s) torsional rotation during stance. Modulation of tone was determined by the torsional resistance to rotation (peak-to-peak, phase-advance, and variability of torque) and axial muscle activity (EMG). Peak-to-peak torque was lower (∼50%), while phase-advance and cycle-to-cycle variability were enhanced for AT teachers compared to matched control subjects at all levels of the axis. In addition, LBP subjects decreased trunk and hip stiffness following short-term AT training compared to a control intervention. While changes in static levels of postural tone may have contributed to the reduced stiffness observed with the AT, our results suggest that dynamic modulation of postural tone can be enhanced through long-term training in the AT, which may constitute an important direction for therapeutic intervention.
古尔芬克尔和同事们(2006 年)最近发现,健康成年人在进行抗重力姿势维持时会动态调节身体轴线上的姿势肌肉张力,并且这种调节与轴向刚度呈反比。我们本研究的目的是探究通过训练是否可以改变轴向姿势张力的动态调节。我们研究了亚历山大技术(AT)的教师,他们是否经过“长期”(3 年)的训练,具有比匹配的对照组更大的轴向姿势张力调节。此外,我们还对短期(10 周)AT 训练对腰痛(LBP)个体轴向姿势张力的影响进行了纵向研究,因为先前的研究表明短期 AT 训练可以减轻 LBP。轴向姿势张力通过测量颈部、躯干和臀部在站立时对小(±10°)、缓慢(1°/s)扭转旋转的阻力来量化。通过扭转阻力(峰值到峰值、相位提前和扭矩的循环变化)和轴向肌肉活动(EMG)来确定音调的调制。与匹配的对照组相比,AT 教师在轴的所有水平上的峰值到峰值扭矩均较低(约为 50%),而相位提前和循环到循环变化则更高。此外,与对照组干预相比,LBP 患者在接受短期 AT 训练后,躯干和臀部的僵硬度降低。虽然姿势张力的静态水平的变化可能导致 AT 观察到的僵硬度降低,但我们的结果表明,通过长期的 AT 训练可以增强姿势张力的动态调节,这可能是治疗干预的一个重要方向。