Myofascial release of the iliotibial tract and the electromyographic behavior of the patellar stabilizing muscles: an experimental study

Abstract

Introduction: The shortening of the iliotibial tract (ITT) has shown a direct relationship with changes of patellar position and pain on the outer side of the knee. One of the cinesiotherapeutic strategies most used to release the constraints of soft tissue is the myofascial technique. On the other hand, there aren´t many studies about the effects resulted by this technique and its possible repercussions on the lower limb. Objective: To evaluate the influence of myofascial release of the iliotibial tract in the behavior of electromyographic signal of the muscles vastus medialis obliquus (VMO), vastus lateralis longus (VLL), vastus lateralis obliquus (VLO) and gluteus medius (GMed) in subjects with shortening iliotibial tract during a functional task. Methods: In this clinical study were included 18 women without pain complaints and who had shortening of the iliotibial tract. All of them were submitted to the electromyographic analysis of the VMO, VLL, VLO, GMed, during the task of step-up and step-down, in the moments of pre- and post-myofascial release, using the Miofibrólise therapy technique. In order to control the projection angle in the frontal plane of the knee, data were collected from knee adduction in a simultaneous way and analyzed using 2D video cinematography. This sequence was repeated 24 hours after the first session. In an effort to analyze the spatial-temporal parameters, the hip adduction and the knee valgus were observed. The data analyzed from EMG were RMS, activation order and duration of the task. The comparison between the pre and post-myofascial release was erformed by the Wilcoxon test, and with a 5% significance level. Results: The results of Ober's test indicated a gain of amplitude of the hip adduction, post-myofascial release, with a significant increase of 6 ° (p = 0.002). Despite the improvement of mobility and also of the iliotibial tract tension, there were no significant differences in the electromyographic behavior of the VMO, VLL, and VLO GMed in the values obtained during the moments pre- and post-myofascial release. On the first day, during step-up task, the data showed that the VMO was proportionally the first muscle to be activated in 42.6% of the signal in the pre- moment and 38.9% in the post- moment. During the task of step-down, it was possible to notice mainly the GMed muscle as the first to be activated, and lower proportion of the activation in the signals of the GMed muscle, from the moment pre-myofascial release 44,4% to the moment of post myofascial 32,5% on the second day. The angle of the hip adduction did not present any difference between the moments of pre and post myofascial release. Conclusion: The ITT myofascial release, despite presenting results in improvement of the mobility and amplitude of movement of the hip adduction, during the Ober’s test, it was not able to change the electromyographic behavior of the VMO, VLL, VLO and GMed.