Abstract

In this study ten subjects, whose age, weight and height were respectively 25+/-3 years (mean+/-standard deviation), 71.1+/-6.5 kg and 179.7+/-4.2 cm were recruited after they had been fully informed about the purposes of the research. They were all accustomed to sporting activity and had reported an isolated or associated breakage of the anterior cruciate ligament (ACL), surgically treated through arthroscopy. Each subject was asked to perform a series of 6 maximal isometric leg contractions at the height of the thigh with an articular angle standardized at 90°, both with the injured limb and the healthy counterpart, during which we recorded the value of the maximal isometric force as well as the electromyographic superficial signal (EMG) of the Vastus Medialis Obliquus (VMO) and the Vastus Lateralis (VL). The deficiency of the force in the injured limb was equal to 30.27+/-21.655 (p<0.005), the EMG VMO/VL Ratio of the healthy limb and of the injured limb were equal to, respectively, 1.12+/-0.08 and 0.95+/-0.04: the difference was statistically significant (p<0.006). The results show that following the ACL reconstruction there is a greater contractile deficiency in the VMO compared to that of the VL, leading to a modification of the EMG Ratio, which in turn is a sign of an alteration in the patterns of the neuromuscular activation. Verf.-Referat