Brigham Young University, Provo, UT 84602.
J Athl Train. 1998 Oct;33(4):328-35.
To determine the electromyographic (EMG) activity of the vastus medialis oblique (VMO), vastus lateralis (VL), semitendinosus and semimembranosus (ST), and biceps femoris (BF) muscles during 4 elastic-tubing closed kinetic chain exercises in postoperative patients with anterior cruciate ligament (ACL)-reconstructed knees.
A 4 x 4 repeated-measures analysis of variance design guided this study. Independent variables were type of exercise and muscle; the dependent variable was EMG activity.
Fifteen patients, 5 to 24 weeks after ACL reconstruction.
Subjects performed 4 exercises (front pull, back pull, crossover, reverse crossover) with elastic tubing attached to the foot of the uninjured leg. Time-and amplitude- normalized EMG activity was recorded from the VMO, VL, ST, and BF muscles of the injured leg. The hamstrings: quadriceps ratio was calculated.
The normalized VMO, VL, and BF EMG activity ranged from 25% to 50% of maximum voluntary isometric contraction for the 4 exercises. The ST ranged from 12% on the back pull to 58% on the front pull. The hamstrings: quadriceps ratios were 137% (front pull), 115% (crossover), 70% (back pull), and 60% (reverse crossover).
We suggest that clinicians use these exercises during early ACL rehabilitation since they incorporate early weightbearing with hamstring and quadriceps coactivation.
在 ACL 重建术后患者中，确定股四头肌内侧头（VMO）、股外侧肌（VL）、半腱肌和半膜肌（ST）以及股二头肌（BF）在 4 种弹性管闭链运动中的肌电图（EMG）活动。
本研究采用 4 x 4 重复测量方差分析设计。独立变量为运动类型和肌肉，因变量为 EMG 活动。
15 名 ACL 重建后 5 至 24 周的患者。
受试者使用弹性管将受伤腿的脚固定，进行 4 种运动（前拉、后拉、交叉、反向交叉）。从受伤腿的 VMO、VL、ST 和 BF 肌肉记录时间和幅度归一化的 EMG 活动。计算腘绳肌：股四头肌比值。
4 种运动的归一化 VMO、VL 和 BF 的 EMG 活动范围为最大随意等长收缩的 25%至 50%。ST 的范围从前拉的 12%到后拉的 58%。腘绳肌：股四头肌比值为 137%（前拉）、115%（交叉）、70%（后拉）和 60%（反向交叉）。
我们建议临床医生在 ACL 康复的早期使用这些运动，因为它们结合了早期负重和腘绳肌与股四头肌的共同激活。
