Center for Human Movement Studies, School of Applied Physiology, Georgia Institute of Technology, 555, 14th Street, Atlanta, GA 30332-0356, USA.
Hum Mov Sci. 2012 Dec;31(6):1670-87. doi: 10.1016/j.humov.2012.04.003. Epub 2012 Nov 15.
Infants with myelomeningocele (MMC) increase step frequency in response to modifications to the treadmill surface. The aim was to investigate how these modifications impacted the electromyographic (EMG) patterns. We analyzed EMG from 19 infants aged 2-10 months, with MMC at the lumbosacral level. We supported infants upright on the treadmill for 12 trials, each 30 seconds long. Modifications included visual flow, unloading, weights, Velcro and lcriction. Surface electrodes recorded EMG from tibialis anterior, lateral gastrocnemius, rectus femoris and biceps femoris. We determined muscle bursts for each stride cycle and from these calculated various parameters. Results indicated that each of the five sensory conditions generated different motor patterns. Visual flow and friction which we previously reported increased step frequency impacted lateral gastrocnemius most. Weights, which significantly decreased step frequency increased burst duration and co-activity of the proximal muscles. We also observed an age effect, with all conditions increasing muscle activity in younger infants whereas in older infants visual flow and unloading stimulated most activity. In conclusion, we have demonstrated that infants with myelomeningocele at levels which impact the myotomes of major locomotor muscles find ways to respond and adapt their motor output to changes in sensory input.
脊髓脊膜膨出（MMC）婴儿会增加步频以响应跑步机表面的变化。本研究旨在探讨这些变化如何影响肌电图（EMG）模式。我们分析了 19 名 2-10 个月大、腰骶部 MMC 婴儿的 EMG。我们在跑步机上支持婴儿直立 12 次，每次 30 秒。修改包括视觉流、卸载、重量、魔术贴和摩擦力。表面电极记录胫骨前肌、外侧腓肠肌、股直肌和股二头肌的肌电图。我们确定了每个步幅周期的肌肉爆发，并从这些爆发中计算出各种参数。结果表明，五种感觉条件中的每一种都会产生不同的运动模式。我们之前报道过的视觉流和摩擦力增加了步频，对外侧腓肠肌的影响最大。显著降低步频的重量增加了爆发持续时间和近端肌肉的协同活动。我们还观察到年龄效应，所有条件都会增加年轻婴儿的肌肉活动，而在年长婴儿中，视觉流和卸载刺激了大部分活动。总之，我们已经证明，在影响主要运动肌肉肌节的水平上患有脊髓脊膜膨出的婴儿会找到应对的方法，并调整其运动输出以适应感觉输入的变化。
