GRCTH, EA4497, CIC-IT 805, CHU Raymond Poincaré, 92380 Garches, France.
J Electromyogr Kinesiol. 2013 Oct;23(5):1036-43. doi: 10.1016/j.jelekin.2013.07.002. Epub 2013 Aug 6.
This study was designed to evaluate the effects of botulinum toxin type-A (BoNTA) injection of the rectus femoris (RF) muscle on the electromyographic activity of the knee flexor and extensor and on knee and hip kinematics during gait in patients with hemiparesis exhibiting a stiff-knee gait.
Two gait analyses were performed on fourteen patients: before and four weeks after BoNTA injection. Spatiotemporal, kinematic and electromyographic parameters were quantified for the paretic limb.
BoNTA treatment improved gait velocity, stride length and cadence with an increase of knee angular velocity at toe-off and maximal knee flexion in the swing phase. Amplitude and activation time of the RF and co-activation duration between the RF and biceps femoris were significantly decreased. The instantaneous mean frequency of RF was predominantly lower in the pre-swing phase.
The results clearly show that BoNTA modified the EMG amplitude and frequency of the injected muscle (RF) but not of the synergist and antagonist muscles. The reduction in RF activation frequency could be related to increased activity of slow fibers. The frequency analysis of EMG signals during gait appears to be a relevant method for the evaluation of the effects of BoNTA in the injected muscle.
本研究旨在评估股直肌肉毒毒素 A 型（BoNTA）注射对偏瘫患者僵硬步态时的膝关节屈肌和伸肌肌电图活动以及步态期间膝关节和髋关节运动学的影响。
对 14 名患者进行了两次步态分析：注射 BoNTA 前和 4 周后。对患侧肢体进行时空、运动学和肌电图参数的量化。
BoNTA 治疗可改善步态速度、步幅和步频，增加足离地时的膝关节角速度和摆动相的最大膝关节屈曲度。RF 的振幅和激活时间以及 RF 和股二头肌的共同激活持续时间显著降低。RF 的瞬时平均频率在预摆阶段主要较低。
结果清楚地表明，BoNTA 改变了注射肌肉（RF）的肌电图幅度和频率，但没有改变协同肌和拮抗肌的肌电图。RF 激活频率的降低可能与慢纤维活动增加有关。步态期间肌电图信号的频率分析似乎是评估注射肌肉中 BoNTA 效果的一种相关方法。
