Katz Amir, Tirosh Emanuel, Marmur Rachel, Mizrahi Joseph
Department of Biomedical Engineering, Israel Institute of Technology, Haifa.
J Child Neurol. 2008 Mar;23(3):259-67. doi: 10.1177/0883073807308695. Epub 2007 Dec 26.
The objectives of this study were to compare the effects of low-intensity electrical stimulation of the quadriceps muscle in children with cerebral palsy in the following 2 modes: reconditioning by long-term training of the muscle versus real-time assist to the muscle during motion. To evaluate the force enhancement in the assist mode, we developed a method to dissociate the volitional and the induced components from the total electromyographic signal. The study group, including 5 children with cerebral palsy (mean age, 3.3 years; 0.4 SD), underwent 2 testing sessions: 1 before and 1 after 3-month training by electrical stimulation. Each session included 2 series of trials: 1 with electrical stimulation, as an orthotic assist, and 1 without electrical stimulation. The tests included flexion-extension movements of the knee at a self-selected pace. The results showed that, compared to before training, there was a significant increase in the average motion velocity and a decrease in motion jerk and in knee torque after training in both the electrical stimulation- assisted and -unassisted modes. Of special interest was the significant decrease in quadriceps-hamstrings co-contraction following training by electrical stimulation but not during electrical stimulation-assisted motion. The results obtained for the group with cerebral palsy were statistically different from those of the control group, but this difference decreased after long-term training by electrical stimulation. It was concluded that, in children with cerebral palsy, electrical stimulation is more beneficial in long-term training than when used as a real-time motion assist. Although muscle strength is not affected, more centrally controlled attributes such as co-contraction are improved.
通过肌肉长期训练进行康复与运动过程中对肌肉的实时辅助。为了评估辅助模式下的力量增强情况，我们开发了一种方法，从总的肌电信号中分离出自愿和诱发成分。研究组包括5名脑瘫患儿（平均年龄3.3岁；标准差0.4），接受了2次测试：1次在电刺激3个月训练前，1次在训练后。每次测试包括2组试验：1组有作为矫形辅助的电刺激，1组无电刺激。测试包括以自选速度进行的膝关节屈伸运动。结果显示，与训练前相比，电刺激辅助和非辅助模式下训练后平均运动速度显著增加，运动急动度和膝关节扭矩降低。特别值得关注的是，电刺激训练后股四头肌-腘绳肌共同收缩显著降低，但在电刺激辅助运动期间未降低。脑瘫组获得的结果与对照组在统计学上有差异，但经电刺激长期训练后这种差异减小。得出的结论是，对于脑瘫患儿，电刺激在长期训练中比用作实时运动辅助更有益。虽然肌肉力量不受影响，但更多由中枢控制的属性如共同收缩得到改善。
