Thompson N S, Baker R J, Cosgrove A P, Corry I S, Graham H K
Department of Orthopaedic Research, Musgrave Park Hospital, Belfast, Northern Ireland.
Dev Med Child Neurol. 1998 Sep;40(9):622-5. doi: 10.1111/j.1469-8749.1998.tb15428.x.
This study aimed to determine the effect of hamstring botulinum toxin A (Btx-A) injection in 10 children with crouch gait in terms of changes in muscle length and lower-limb kinematics. Before Btx-A injection limb kinematics were recorded. Maximum hamstring lengths and excursions were calculated by computer modelling of the lower limb. Data were compared with the averaged hamstring lengths of 10 control children. Hamstrings were defined as short if their length was shorter than the average maximum length minus one standard deviation. Gait analysis was repeated 2 weeks after isolated hamstring Btx-A injection. Pre- and postinjection kinematic data and muscle lengths were then compared. Four of 18 injected limbs in three subjects had short medial hamstring before injection, none of the subjects had short lateral hamstrings. Muscle excursion was significantly reduced in the short and adequate maximum muscle length groups. A significant increase in the semimembranosus and semitendinosus length in all of the injected limbs was noted. Only in the short muscle group was a significant increase in muscle excursion observed. Knee extension improved by 13 degrees in the adequate muscle length group and by 15.6 degrees in the short muscle length group. Pelvic tilt and hip flexion increased in both groups non-significantly. Average walking speed postinjection increased from 0.60 ms(-1) to 0.71 ms(-1). Short hamstrings are over-diagnosed in crouch gait. Hamstring Btx-A injection in patients with crouch gait produces significant, repeatable muscle lengthening and improved ambulatory function.
本研究旨在确定对10名蹲伏步态儿童注射腘绳肌肉毒杆菌毒素A（Btx - A）在肌肉长度和下肢运动学变化方面的效果。在注射Btx - A之前记录下肢运动学数据。通过下肢计算机建模计算腘绳肌的最大长度和移动幅度。将数据与10名对照儿童的腘绳肌平均长度进行比较。如果腘绳肌长度短于平均最大长度减去一个标准差，则定义为短缩。在单独注射腘绳肌Btx - A 2周后重复进行步态分析。然后比较注射前后的运动学数据和肌肉长度。3名受试者的18条注射肢体中，有4条在注射前内侧腘绳肌短缩，没有受试者外侧腘绳肌短缩。短缩和最大肌肉长度正常组的肌肉移动幅度显著降低。所有注射肢体的半膜肌和半腱肌长度均显著增加。仅在短肌肉组中观察到肌肉移动幅度显著增加。在最大肌肉长度正常组中膝关节伸展改善了13度，在短肌肉长度组中改善了15.6度。两组的骨盆倾斜和髋关节屈曲均有非显著性增加。注射后平均步行速度从0.60米/秒提高到0.71米/秒。在蹲伏步态中，腘绳肌短缩被过度诊断。对蹲伏步态患者注射腘绳肌Btx - A可产生显著、可重复的肌肉延长并改善步行功能。
