Smeulders Mark J C, Kreulen Michiel, Hage J Joris, Huijing Peter A, van der Horst Chantal M A M
Department of Plastic, Reconstructive and Hand Surgery, Academic Medical Center, Suite G4-226, PO Box 22700, Amsterdam 1100 DE, The Netherlands.
J Orthop Res. 2004 Nov;22(6):1331-5. doi: 10.1016/j.orthres.2004.04.006.
To answer the question whether the muscle contracture in patients with cerebral palsy is caused by overstretching of in-series sarcomeres we studied the active and passive force-length relationship of the flexor carpi ulnaris muscle (FCU) in relation to its operating length range in 14 such patients with a flexion deformity of the wrist. Force-length relationship was measured intra-operatively using electrical stimulation, a force transducer, and a data-acquisition system. Muscle length was measured in maximally flexed and maximally extended position of the wrist. The spastic FCU was found to exert over 80% of its maximum active force at maximal extension of the wrist and this indicates abundant overlap of the sarcomeres. At maximal wrist extension, FCU passive force corresponded with only 0.7-18% of maximum active force. Both findings imply that the FCU sarcomeres are not overstretched when the wrist is extended. We conclude that the overstretching of in-series sarcomeres appears not to be the cause of contracture of the spastic FCU.
为了回答脑瘫患者的肌肉挛缩是否由串联肌节过度拉伸所致这一问题，我们研究了14例患有腕关节屈曲畸形的此类患者尺侧腕屈肌（FCU）的主动和被动力-长度关系及其工作长度范围。术中使用电刺激、力传感器和数据采集系统测量力-长度关系。在腕关节最大屈曲和最大伸展位置测量肌肉长度。发现痉挛性尺侧腕屈肌在腕关节最大伸展时可发挥其最大主动力的80%以上，这表明肌节有大量重叠。在腕关节最大伸展时，尺侧腕屈肌的被动力仅相当于最大主动力的0.7%-18%。这两个发现都表明，腕关节伸展时尺侧腕屈肌的肌节并未过度拉伸。我们得出结论，串联肌节的过度拉伸似乎不是痉挛性尺侧腕屈肌挛缩的原因。
