Department of Physical Medicine & Rehabilitation, University of Texas Health Science Center at Houston, Houston, TX, USA.
Clin Neurophysiol. 2012 Mar;123(3):558-68. doi: 10.1016/j.clinph.2011.08.001. Epub 2011 Oct 1.
We investigated the effect of various doses of vertical oscillation (vibration) on soleus H-reflex amplitude and post-activation depression in individuals with and without SCI. We also explored the acute effect of short-term limb vibration on skeletal muscle mRNA expression of genes associated with spinal plasticity.
Six healthy adults and five chronic complete SCI subjects received vibratory stimulation of their tibia over three different gravitational accelerations (0.3g, 0.6g, and 1.2g) at a fixed frequency (30Hz). Soleus H-reflexes were measured before, during, and after vibration. Two additional chronic complete SCI subjects had soleus muscle biopsies 3h following a single bout of vibration.
H-reflex amplitude was depressed over 83% in both groups during vibration. This vibratory-induced inhibition lasted over 2min in the control group, but not in the SCI group. Post-activation depression was modulated during the long-lasting vibratory inhibition. A single bout of mechanical oscillation altered mRNA expression from selected genes associated with synaptic plasticity.
Vibration of the lower leg inhibits the H-reflex amplitude, influences post-activation depression, and alters skeletal muscle mRNA expression of genes associated with synaptic plasticity.
Limb segment vibration may offer a long term method to reduce spinal reflex excitability after SCI.
我们研究了不同剂量的垂直摆动（振动）对 SCI 患者和非 SCI 患者比目鱼肌 H 反射幅度和后激活抑制的影响。我们还探讨了短期肢体振动对与脊柱可塑性相关的骨骼肌基因 mRNA 表达的急性影响。
6 名健康成年人和 5 名慢性完全性 SCI 受试者分别在 3 种不同重力加速度（0.3g、0.6g 和 1.2g）和固定频率（30Hz）下接受胫骨振动刺激。在振动前、振动中和振动后测量比目鱼肌 H 反射。另外 2 名慢性完全性 SCI 受试者在单次振动后 3 小时进行比目鱼肌活检。
两组在振动过程中 H 反射幅度均降低了 83%以上。在对照组中，这种振动诱导的抑制持续了 2 分钟以上，但在 SCI 组中没有。后激活抑制在长时间的振动抑制中被调节。单次机械振动改变了与突触可塑性相关的选定基因的 mRNA 表达。
小腿振动抑制 H 反射幅度，影响后激活抑制，并改变与突触可塑性相关的骨骼肌基因 mRNA 表达。
肢体振动可能为 SCI 后降低脊髓反射兴奋性提供一种长期方法。
