Rodriquez A A, Agre J C, Harmon R L, Franke T M, Swiggum E R, Curt J T
Department of Rehabilitation Medicine, University of Wisconsin-Madison Medical School 53792, USA.
Arch Phys Med Rehabil. 1995 Nov;76(11):989-93. doi: 10.1016/s0003-9993(95)81034-x.
Post-polio subjects experience functional deterioration many years after developing acute poliomyelitis and have been shown previously to have a deficit in strength recovery after isometric activity. This study characterized the size and stability of the motor units in a group of post-polio subjects with macro and single fiber electromyography (EMG) and correlated these variables with isometric strength, endurance, "work capacity," and strength recovery after fatiguing isometric exercise.
A cohort of 12 post-polio subjects was tested for neuromuscular function. Electromyographic variables were determined on a separate day.
Volunteers were recruited from the community and tested in our neuromuscular research laboratory.
A volunteer sample was obtained from advertisements. All subjects acknowledged post-polio syndrome symptoms.
Neuromuscular variables were isometric knee extension peak torque, endurance (time to exhaustion) at 40% of maximal torque, tension time index, and recovery of torque at 10 minutes. Electromyographic variables were macro EMG and single fiber EMG (percent blocking and jitter).
Macro EMG amplitude was ninefold the control value, and both jitter and blocking were greatly increased in comparison to control values. Isometric strength significantly (p < .05) correlated negatively with macro EMG amplitude.
The weakest subjects had the greatest number of muscle fibers within the motor unit (as measured by macro EMG amplitude). Jitter and blocking did not correlate with neuromuscular function.
小儿麻痹后遗症患者在患急性脊髓灰质炎多年后会出现功能衰退，并且此前已有研究表明，他们在进行等长运动后力量恢复存在缺陷。本研究通过宏观肌电图和单纤维肌电图对一组小儿麻痹后遗症患者的运动单位大小和稳定性进行了表征，并将这些变量与等长肌力、耐力、“工作能力”以及疲劳性等长运动后的力量恢复情况进行了关联分析。
对12名小儿麻痹后遗症患者进行了神经肌肉功能测试。肌电图变量在另一天进行测定。
从社区招募志愿者，并在我们的神经肌肉研究实验室进行测试。
通过广告获得志愿者样本。所有受试者均认可小儿麻痹后遗症综合征症状。
神经肌肉变量包括等长伸膝峰值扭矩、最大扭矩40%时的耐力（疲劳时间）、张力时间指数以及10分钟时的扭矩恢复情况。肌电图变量包括宏观肌电图和单纤维肌电图（阻滞百分比和颤抖）。
宏观肌电图振幅是对照组值的9倍，与对照组值相比，颤抖和阻滞均显著增加。等长肌力与宏观肌电图振幅显著负相关（p < 0.05）。
最弱的受试者运动单位内的肌纤维数量最多（通过宏观肌电图振幅测量）。颤抖和阻滞与神经肌肉功能无关。
