title: Proximal mechanics during stair ascent are more discriminate of females with patellofemoral pain than distal mechanics.
abstract: Several hypotheses have been proposed to explain the pathomechanisms underlying patellofemoral pain (PFP). Concurrent evaluation of lower limb mechanics in the same PFP population is needed to determine which may be more important to target during rehabilitation. This study aimed to investigate possible differences in rearfoot eversion, hip adduction, and knee flexion during stair ascent; the relationship between these variables; and the discriminatory capability of each in identifying females with PFP.
  
  
  
  Thirty-six females with PFP and 31 asymptomatic controls underwent three-dimensional kinematic analyses during stair ascent. Between-group comparisons were made for peak rearfoot eversion, hip adduction, and knee flexion. Pearson's correlation coefficients were calculated to evaluate relationships among these parameters. Receiver operating characteristic curves were applied to identify the discriminatory capability of each.
  
  
  
  Females with PFP ascended stairs with reduced peak knee flexion, greater peak hip adduction and peak rearfoot eversion. Peak hip adduction (>10.6°; sensitivity=67%, specificity=77%) discriminated females with PFP more effectively than rearfoot eversion (>5.0°; sensitivity=58%, specificity=67%). Reduced peak hip adduction was found to be associated with reduced peak knee flexion (r=0.54, p=0.002) in females with PFP.
  
  
  
  These findings indicate that proximal, local, and distal kinematics should be considered in PFP management, but proximally targeted interventions may be most important. The relationship of reduced knee flexion with reduced hip adduction also indicates a possible compensatory strategy to reduce patellofemoral joint stress, and this may need to be addressed during rehabilitation.
authors.affiliation: Physical Therapy Department, School of Science and Technology, University of São Paulo State, Presidente Prudente, Brazil.
authors.forename: Danilo
authors.initials: D
authors.lastname: de Oliveira Silva
authors.affiliation: Lower Extremity Gait Studies, La Trobe University, Australia; Centre for Sports and Exercise Medicine, Queen Mary University of London, London, UK.
authors.forename: Christian John
authors.initials: CJ
authors.lastname: Barton
authors.affiliation: Physical Therapy Department, School of Science and Technology, University of São Paulo State, Presidente Prudente, Brazil.
authors.forename: Marcella Ferraz
authors.initials: MF
authors.lastname: Pazzinatto
authors.affiliation: Physical Therapy Department, School of Science and Technology, University of São Paulo State, Presidente Prudente, Brazil.
authors.forename: Ronaldo Valdir
authors.initials: RV
authors.lastname: Briani
authors.affiliation: Physical Therapy Department, School of Science and Technology, University of São Paulo State, Presidente Prudente, Brazil. Electronic address: micolis@fct.unesp.br.
authors.forename: Fábio Mícolis
authors.initials: FM
authors.lastname: de Azevedo
mesh_terms: D000328:Adult; D019540:Area Under Curve; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D005260:Female; D005528:Foot / Q000503:physiopathology*; D006621:Hip Joint / Q000503:physiopathology*; D006801:Humans; D021621:Imaging, Three-Dimensional; D007719:Knee Joint / Q000503:physiopathology*; D057071:Patellofemoral Joint / Q000503:physiopathology; D046788:Patellofemoral Pain Syndrome / Q000503:physiopathology*; D000072799:Stair Climbing / Q000502:physiology*; D055815:Young Adult
keywords: Biomechanics; Hip; Kinematics; Knee; Patellofemoral pain; Stair ascent