Correlation between quadriceps to hamstring ratio and functional outcomes in patellofemoral pain

BackgroundThe aim of this study was to investigate the correlation between quadriceps to hamstring (Q:H) ratio and the functional outcomes in Patellofemoral Pain (PFP) patients.MethodsThe study included forty-four women diagnosed with unilateral PFP. Eccentric and concentric quadriceps and hamstring strength were recorded. Conventional Q:H ratio was calculated as the concentric quadriceps to concentric hamstring peak torque (Ratio 1). Functional ratios were calculated as the eccentric quadriceps to concentric hamstring peak torque (Ratio 2) and as the concentric quadriceps to eccentric hamstring torque (Ratio 3). Functional levels of the patients were determined by using Kujala scores, hop test and step test. Pain levels during activities were recorded. The relationship among Ratio 1, Ratio 2 and Ratio 3 with functional outcomes and pain levels were evaluated using Spearman's correlation coefficient test.ResultsEccentric and concentric quadriceps and hamstring strength were lower on involved side than uninvolved side. Ratio 2 correlated stronger with Kujala score (r = 0.69) than Ratio 1 (r = 0.49) and Ratio 3 (r = 0.30). Step test (r = 0.35) and hop test (r = 0.38) only correlated with Ratio 2. Pain levels correlated more with Ratio 2 (r values ranged between 0.38 and 0.48).ConclusionEccentric quadriceps to concentric hamstring ratio was observed more related to the functional outcomes and painful activities in patients with PFP.Level of evidence IIICross-sectional study.