The aim of this study was to compare the efficacy of muscular strengthening in the functional recovery of patellofemoral syndrome (PFS) patients. Twenty female patients with PFS were divided into two groups: Group 1 (G1) performing quadriceps femoris strengthening exercises in open kinetic chain (OKC) and Group 2 (G2) in closed kinetic chain (CKC), twice a week for eight weeks. Pain, functional capacity, flexibility, hamstring tightness, Q angle and electromyography (EMG) were measured for vastus medialis (VM) and vastus lateralis (VL) muscles during isometric leg extension. The data obtained before and after treatment were analyzed by Wilcoxon test, and the data between groups by t-test for independent samples or Friedman Anova or Manova (á<0.05). After treatment, the results showed a significant improvement in terms of functional capacity, hamstring tightness and flexibility. However, only G1 showed decreased pain and improved EMG activity of VL muscle, while both groups showed unchanged Q angles. These data suggest that treatments based on exercises for quadriceps femoris strengthening produced improvements on a number of PFS signals and symptoms, with no evidences of differences between OKC and CKC exercises.
Knee injuries; Questionnaires; Pain measurement; Electromyography; Joint range of motion; Exercise therapy
