OBJECTIVE: To asses the onset (%) of patella stabilizer muscles during maximal isometric contraction exercises (MIC) in individuals with and without signs of patellofemoral pain syndrome (PFPS) in open (OKC) and closed (CKC) kinetic chain exercises. METHOD: Assessments were carried out on 22 women; ten with no complains of anterior knee pain, and 12 with PFPS signs during MIC in OKC and CKC with the knee flexed at 90º. The onset of the electromyographic activity of the vastus mediallis obliquus (VMO), vastus lateralis obliquus (VLO) and vastus lateralis longus (VLL) was identified by means of an algorithm in the Myosystem Br 1 software. The statistical analysis used was Chi-Square test and student's t test, which are both tests with a level of significance at 5%. RESULTS: The VMO and VLO muscles presented a greater onset compared to the VLL during OKC exercises for both groups and for the PFPS group without CCF. No differences were observed between the groups. CONCLUSION: CKC and OKC exercises seem to benefit the synchronism of the musculature that supposedly benefits the patella stabilizer musculature, and can be recommended in physiotherapeutic treatment programs.
Exercise; Patellofemoral pain syndrome; Electromyography
