Physical Therapy Department, University of Rhode Island, Kingston, RI, USA.
J Electromyogr Kinesiol. 2012 Apr;22(2):223-7. doi: 10.1016/j.jelekin.2011.09.006. Epub 2011 Oct 13.
Circumferential pressure (CP) was shown to decrease muscle activity in subjects without neuromuscular disorders and in individuals with spinal cord injury and cerebrovascular accidents. The mechanism for this decrease is unknown although it is hypothesized to be spinal in origin. The purpose of this study was to investigate the effect CP has on the soleus F-wave. Results will help determine the mechanism CP uses to effect motoneuron reflex excitability. Thirty-seven healthy volunteers participated. A 16cm air-splint was placed around the calf and during the pressure phase of the experiment it was inflated to 40-45mm Hg. F-waves were evoked by supra maximally stimulating (20%>Mmax) the tibial nerve with a 0.1ms pulse at 0.2Hz using a bipolar surface electrode on the skin of the popliteal fossa. Fifty F-waves were recorded before (baseline), during, and 3) after CP was applied. F-waves were then identified and mean latency, persistence, and mean F/Mmax amplitude ratios were measured and calculated. Friedman Repeated Measures on Ranks tests were conducted on each of the three parameters (p⩽0.05). No statistically significant difference was found for any of the F-wave parameters evaluated. These results were contrary to previous CP studies that observed a significant decrease in muscle activity. Possible reasons for this discrepancy are discussed.
环周压力（CP）已被证明可降低无神经肌肉疾病的受试者和脊髓损伤及脑血管意外患者的肌肉活动。尽管据推测其起源于脊髓，但这种减少的机制尚不清楚。本研究旨在探讨 CP 对比目鱼肌 F 波的影响。研究结果将有助于确定 CP 影响运动神经元反射兴奋性的机制。 37 名健康志愿者参与了本研究。在小腿周围放置一个 16cm 的气夹板，在实验的压力阶段，将其充气至 40-45mmHg。通过在皮肤的窝用双极表面电极以 0.1ms 的脉冲以 0.2Hz 的频率对胫骨神经进行超最大刺激（20%>Mmax）来诱发 F 波。在 CP 应用之前（基线）、期间和之后 3）记录了 50 个 F 波。然后识别 F 波，并测量和计算平均潜伏期、持续时间和平均 F/Mmax 幅度比。对每个三个参数（p ⩽0.05）进行 Friedman 重复测量等级检验。评估的任何 F 波参数均未发现统计学上的显著差异。这些结果与先前观察到肌肉活动明显减少的 CP 研究结果相反。对这种差异的可能原因进行了讨论。
