Muscle activation of patellar and hip stabilizers during different open and closed kinetic chain exercises in women with patellofemoral dysfunction

Abstract

Introduction: The patellofemoral pain syndrome (PPS) is a most frequent knee disorders in young adult women. Although etiological factors of PPS are not well established. Authors suggest that alterations in patellofemoral and pelvic stabilizers as the mainly causal factors. A conservative intervention is often indicated to treatment of these individuals, covering the open kinetic chain
and closed kinetic chain. Objective: The objective of this study was analyze the electrical activity of the patellofemoral and pelvic stabilizing muscles, during different open kinetic chain and closed kinetic chain exercises in individuals with patellofemoral pain syndrome. Methods: Were analyzed clinically healthy young (n=22) and symptomatic PPS (n=24) women using electromyographic test of the vastus medialis obliquus, vastus lateralis longus, vastus lateralis obliquus and gluteus medius during maximal voluntary isometric contraction exercises in straight leg raise and squat conventional, associated with lateral hip rotation and squatting adduction and abduction of the hip. Three repetitions of each exercise and maximal voluntary isometric contraction maintained for 6 seconds were realized, with an interval between them of 2 minutes. The electromyographical signals were collected with acquisition frequency of 4000 Hz, digitally filtered between 20 and 1000 Hz and the square root mean (RMS) was calculated to represent the amplitude of muscle activation. The electromyographic activity of the muscles were normalized by RMS of the CIVM knee extension with 90 degree knee flexion position and muscle function test of the GMed. The processing electromyographic signal was performed
using the program SuiteMyo 1.0.0.3. Results: Our data demonstrated increased vastus lateralis obliquus muscle activity during SLR and SLR-RE to patellofemoral pain syndrome group. However it was not observed for this group differences between portions of the quadriceps. In relation the simultaneous activity among GMed and quadriceps portions (vastus medialis obliquus, vastus
lateralis obliquus and vastus lateralis longus), SLR and SLR-RE exercises was more effective in both groups. The closed kinetic chain exercises that showed greater activity of patellar stabilizers and pelvic were squat and squat-ADD-ABD in both groups. Conclusion: Based on this data and in the literature, rehabilitation programs that include exercises such as SLR and SLR-RE, and AGA-AGA-ADD and ABD could be used for patients with PPS, aiming to increase the activity of the pelvic stabilizer muscles and patellar as well as reduce pain symptoms.