National Defence Academy, Physical Education, Yokosuka, Japan.
Int J Sports Med. 2011 Apr;32(4):292-6. doi: 10.1055/s-0030-1270488. Epub 2011 Mar 4.
The purpose of this study was to investigate the effect of surgery on the gamma-loop in the quadriceps of patients with ACL injuries. We compared the response to vibration stimulation in subjects with ACL repair, subjects with ACL rupture, and normal subjects, by measuring the maximal strength and integrated electromyography (I-EMG) of the quadriceps. Pre-vibration data were obtained from each subject by measuring the MVC of the knee extension and the I-EMG from the vastus medialis, vastus lateralis, and rectus femoris. Vibration stimulation was applied to the infrapatellar tendon, followed immediately by repeating maximal strength and I-EMG recording. The results of this study indicated that alpha motor neuron activity of the intact side of the vastus lateralis in response to prolonged vibration stimulation was altered by surgery, but no effect was detected in the injured side. The results could suggest that abnormality of the gamma-loop existed even in the quadriceps of patients with ACL rupture since the vibration stimulus failed to elicit changes in ACL-rupture group as compared with those of normal subjects. In comparison, abnormality of the gamma-loop in the intact side of the QF was probably induced by the rupture, and further abnormality of gamma-loop was induced by surgery.
本研究旨在探讨手术对 ACL 损伤患者股四头肌γ 环的影响。我们通过测量股四头肌的最大力量和整合肌电图（I-EMG），比较了 ACL 修复组、ACL 撕裂组和正常组对振动刺激的反应。通过测量膝关节伸展的 MVC 和股直肌、股外侧肌和股中间肌的 I-EMG，从每位受试者获得预振动数据。对髌腱施加振动刺激，然后立即重复最大力量和 I-EMG 记录。本研究结果表明，手术改变了健侧股外侧肌对长时间振动刺激的α运动神经元活动，但在患侧未检测到影响。结果表明，即使在 ACL 撕裂患者的股四头肌中也存在γ 环异常，因为与正常组相比，振动刺激未能引起 ACL 撕裂组的变化。相比之下，QF 健侧的γ 环异常可能是由撕裂引起的，进一步的γ 环异常可能是由手术引起的。
