Pierce Samuel R, Barbe Mary F, Barr Ann E, Shewokis Patricia A, Lauer Richard T
Research Department, Shriners Hospital for Children, 3551 North Broad Street, Philadelphia, PA 19140, USA.
Clin Biomech (Bristol). 2007 Nov;22(9):1045-8. doi: 10.1016/j.clinbiomech.2007.08.003. Epub 2007 Sep 17.
Co-contraction is an impairment commonly reported in children with cerebral palsy. However, co-contraction has not been investigated during passive movements which may be used to assess spasticity in children with cerebral palsy. The purpose of this study was to examine the frequency of co-contraction and the relationship between reflex activity and co-contraction during passive movements of the knee joint in children with cerebral palsy.
Twenty children with cerebral palsy participated in this study. One set of ten continuous passive movements from 90 degrees of knee flexion to 25 degrees of knee flexion and from 25 degrees of knee flexion to 90 degrees of knee flexion was completed at 15 degrees /s, 90 degrees /s, and 180 degrees /s. The mean percentage of the range of motion of each movement and mean percentage of the number of movements which exhibited electromyographic activity of the vastus lateralis, medial hamstrings, and co-contraction were calculated for each set of movements.
The number of the movement repetitions and the percentage of the range of motion which exhibited co-contraction were considerable regardless of the direction and speed of motion. Significant positive correlations were found between the percentage of the passive range of motion with medial hamstrings activation, vastus lateralis activation, and co-contraction during passive movements into both knee flexion and knee extension at a velocity of 15 degrees /s, 90 degrees /s, and 180 degrees /s (P<0.001).
Co-contraction commonly occurs during passive movements of the knee in children with cerebral palsy. The presence of co-contraction may influence measurements of spasticity which use passive movements to assess spasticity.
共同收缩是脑瘫患儿中常见的一种功能障碍。然而，在可能用于评估脑瘫患儿痉挛状态的被动运动过程中，共同收缩尚未得到研究。本研究的目的是检查脑瘫患儿膝关节被动运动期间共同收缩的频率以及反射活动与共同收缩之间的关系。
20名脑瘫患儿参与了本研究。以15度/秒、90度/秒和180度/秒的速度完成一组从膝关节屈曲90度到膝关节屈曲25度以及从膝关节屈曲25度到膝关节屈曲90度的十次连续被动运动。计算每组运动中每个运动的平均运动范围百分比以及表现出股外侧肌、半腱肌内侧肌电图活动和共同收缩的运动次数的平均百分比。
无论运动方向和速度如何，运动重复次数和表现出共同收缩的运动范围百分比都相当可观。在以15度/秒、90度/秒和180度/秒的速度进行膝关节屈伸的被动运动期间，被动运动范围百分比与半腱肌内侧肌激活、股外侧肌激活和共同收缩之间发现显著正相关（P<0.001）。
脑瘫患儿膝关节被动运动期间通常会出现共同收缩。共同收缩的存在可能会影响使用被动运动来评估痉挛状态的测量结果。
