Rose Holly M, Shultz Sandra J, Arnold Brent L, Gansneder Bruce M, Perrin David H
Washington and Lee University, Lexington, VA.
J Athl Train. 2002 Jun;37(2):133-140.
To evaluate the short-term effect of a semirigid foot orthotic device on response times and activation patterns of knee musculature in individuals with hyperpronation after a lower extremity perturbation in a single-leg, weight-bearing stance. DESIGN AND SETTING: We used a lower extremity perturbation device designed to produce a forward and either internal or external rotation of the trunk and femur on the weight-bearing tibia to evoke a reflex response. Subjects were tested both with and without orthotic devices. SUBJECTS: Seventeen (13 male, 4 female) volunteers (age, 20.6 +/- 1.8 years; height, 181.0 +/- 8.1 cm; weight, 87.4 +/- 19.5 kg; navicular drop, 12.1 +/- 1.8 mm) with a navicular drop greater than 10 mm volunteered for this study. MEASUREMENTS: Long latency reflex times were recorded via surface electromyography for the medial and lateral hamstrings, gastrocnemius, and quadriceps muscles. RESULTS: A dependent-sample t test revealed a significant decrease in navicular drop with orthotic intervention (P <.0001). With that confirmed, separate repeated-measures analyses of variance with 2 within factors (orthotic condition and muscle) revealed no significant difference in muscle response time between orthotic and nonorthotic conditions for either internal or external rotation perturbation. Although we found a main effect for muscle for both internal (P <.0001) and external (P <.0001) rotation, indicating a preferred muscle activation order, this activation order did not differ between orthotic and nonorthotic conditions (internal rotation P =.674, external rotation P =.829). CONCLUSIONS: Our findings suggest that a short-term application of a semirigid orthotic device does not alter muscle response times or activation patterns of the muscles that stabilize the knee. Further research is needed to determine whether changes in activation patterns may occur over time since mechanical adaptations occur with long-term wear.
评估半刚性足部矫形器对单腿负重站立时下肢受到扰动后，过度内旋个体膝关节肌肉反应时间及激活模式的短期影响。
我们使用了一种下肢扰动装置，该装置旨在使负重的胫骨上的躯干和股骨向前并向内或向外旋转，以引发反射反应。受试者在佩戴和不佩戴矫形器的情况下均接受测试。
17名（13名男性，4名女性）志愿者（年龄20.6±1.8岁；身高181.0±8.1厘米；体重87.4±19.5千克；舟骨下降12.1±1.8毫米），舟骨下降大于10毫米，自愿参加本研究。
通过表面肌电图记录半腱肌、半膜肌、腓肠肌和股四头肌的长潜伏期反射时间。
相关样本t检验显示，矫形器干预后舟骨下降显著降低（P<.0001）。在此得到证实后，对2个组内因素（矫形器状况和肌肉）进行单独的重复测量方差分析，结果显示，对于内旋或外旋扰动，矫形器和非矫形器条件下的肌肉反应时间无显著差异。尽管我们发现内旋（P<.0001）和外旋（P<.0001）时肌肉均有主效应，表明存在优先的肌肉激活顺序，但这种激活顺序在矫形器和非矫形器条件之间没有差异（内旋P =.674，外旋P =.829）。
我们的研究结果表明，短期应用半刚性矫形器不会改变稳定膝关节的肌肉反应时间或激活模式。由于长期佩戴会发生机械适应，因此需要进一步研究以确定激活模式是否会随时间发生变化。
