The aim of this study was to determine the influence of Patellofemoral Pain Syndrome (PFPS) on peak torque and work in knee flexor and extensor muscles. In addition to evaluate pain and function of subjects with the disfunction. Fifty two females subjects, 23 with diagnosis of PFPS and 29 control subjects, similar for age, height and body mass, participated in this study. The isokinetic evaluation was performed in concentric mode for knee flexors and extensors at speeds of 60 and 180°/s. In addition, was applied to Visual Numerical Scale before and after each velocity of isokinetic testing and Kujala questionnaire. Data were analyzed by descriptive and inferential statistics (U Mann-Whitney, Wilcoxon and t independent tests) with alpha level at α=0.05. The Patellofemoral Pain Syndrome Group (PFPSG) had lower scores (p=0.01) on Kujala questionnaire (75.7±12.3 points) in relation to Control Group (CG) (100±0.0 points), and lower peak torque of knee flexors (0.82±0.24 Nm/kg; 0.51±0.22 Nm/kg) and extensors (1.85±0.48 Nm/kg; 1.13±0.44 Nm/kg) in 60 and 180°/s and lower total work of knee extensors at 180°/s (6.46±2.54 J/kg) and 60°/s (9.42±3.27 J/kg). In addition, there was exacerbation of pain in PFPSG after the isokinetic evaluation at 180°/s (0.9 cm) and 60°/s (2.3 cm). The results showed that individuals with PFPS have lower functional capacity and lower peak torque and work flexors and knee extensors, suggesting that strengthening these muscles must be considered in the rehabilitation of these subjects.
patellofemoral pain syndrome; knee; torque
