van der Krogt Marjolein M, Doorenbosch Caroline A M, Harlaar Jaap
Department of Rehabilitation Medicine, Research Institute MOVE, VU University Medical Center, Amsterdam, The Netherlands.
Gait Posture. 2009 Jun;29(4):640-4. doi: 10.1016/j.gaitpost.2009.01.007. Epub 2009 Feb 20.
Children with cerebral palsy often walk with reduced knee extension in terminal swing, which can be associated with short length or slow lengthening velocity of hamstrings muscles during gait. This study investigated the role of two factors that may contribute to such short and slow hamstrings: walking speed and spasticity. 17 children with spastic cerebral palsy and 11 matched typically developing children walked at comfortable, slow, and fast walking speed. Semitendinosus muscle-tendon length and velocity during gait were calculated using musculoskeletal modeling. Spasticity of the hamstrings was tested in physical examination. Peak hamstrings length increased only slightly with walking speed, while peak hamstrings lengthening velocity increased strongly. After controlling for these effects of walking speed, spastic hamstrings acted at considerably shorter length and slower velocity during gait than normal, while non-spastic hamstrings did not (all P<0.001). These data are important as a reference for valid interpretation of hamstrings length and velocity data in gait analyses at different walking speeds. The results indicate that the presence of spasticity is associated with reduced hamstrings length and lengthening velocity during gait, even at constant walking speed.
患有脑瘫的儿童在摆动末期膝关节伸展通常会减少，这可能与步态中腘绳肌长度短或延长速度慢有关。本研究调查了可能导致腘绳肌短而慢的两个因素的作用：步行速度和痉挛。17名痉挛型脑瘫儿童和11名匹配的正常发育儿童以舒适、缓慢和快速的步行速度行走。使用肌肉骨骼模型计算步态期间半腱肌腱长度和速度。在体格检查中测试腘绳肌的痉挛情况。腘绳肌峰值长度仅随步行速度略有增加，而腘绳肌峰值延长速度则显著增加。在控制了步行速度的这些影响后，痉挛性腘绳肌在步态期间的长度明显短于正常情况，速度也慢于正常情况，而非痉挛性腘绳肌则没有这种情况（所有P<0.001）。这些数据对于在不同步行速度下的步态分析中有效解释腘绳肌长度和速度数据具有重要参考价值。结果表明，即使在恒定步行速度下，痉挛的存在也与步态期间腘绳肌长度缩短和延长速度减慢有关。
