title: Correlation between quadriceps to hamstring ratio and functional outcomes in patellofemoral pain.
abstract: BACKGROUND
  The 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.
  
  
  METHODS
  The 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.
  
  
  RESULTS
  Eccentric 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).
  
  
  CONCLUSIONS
  Eccentric quadriceps to concentric hamstring ratio was observed more related to the functional outcomes and painful activities in patients with PFP.
  
  
  METHODS
  Cross-sectional study.
authors.affiliation: Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Hacettepe University, 06100 Ankara, Turkey. Electronic address: hande.guney@hacettepe.edu.tr.
authors.forename: Hande
authors.initials: H
authors.lastname: Guney
authors.affiliation: Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Dogu Akdeniz University, Gazimagosa, Cyprus.
authors.forename: Inci
authors.initials: I
authors.lastname: Yuksel
authors.affiliation: Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Uskudar University, 34662 Istanbul, Turkey.
authors.forename: Defne
authors.initials: D
authors.lastname: Kaya
authors.affiliation: Department of Orhopaedics and Traumatology, Faculty of Medicine, Hacettepe University, 06100 Ankara, Turkey.
authors.forename: Mahmut Nedim
authors.initials: MN
authors.lastname: Doral
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D000070633:Hamstring Muscles / Q000503:physiopathology*; D006801:Humans; D009119:Muscle Contraction; D053580:Muscle Strength; D010147:Pain Measurement; D046788:Patellofemoral Pain Syndrome / Q000503:physiopathology*; D052097:Quadriceps Muscle / Q000503:physiopathology*; D020127:Recovery of Function; D019415:Torque; D055815:Young Adult
keywords: Functional outcome; Patellofemoral pain; Q:H ratio