title: Trunk and Lower Extremity Kinematics During Stair Descent in Women With or Without Patellofemoral Pain.
abstract: BACKGROUND
  There is limited evidence indicating the contribution of trunk kinematics to patellofemoral pain (PFP). A better understanding of the interaction between trunk and lower extremity kinematics in this population may provide new avenues for interventions to treat PFP.
  
  
  OBJECTIVE
  To compare trunk and lower extremity kinematics between participants with PFP and healthy controls during a stair-descent task.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Research laboratory.
  
  
  METHODS
  Twenty women with PFP (age = 22.2 ± 3.1 years, height = 164.5 ± 9.2 cm, mass = 63.5 ± 13.6 kg) and 20 healthy women (age = 21.0 ± 2.6 years, height = 164.5 ± 7.1 cm, mass = 63.8 ± 12.7 kg).
  
  
  METHODS
  Kinematics were recorded as participants performed stair descent at a controlled velocity.
  
  
  METHODS
  Three-dimensional joint displacement of the trunk, hip, and knee during the stance phase of stair descent for the affected leg was measured using a 7-camera infrared optical motion-capture system. Pretest and posttest pain were assessed using a visual analogue scale. Kinematic differences between groups were determined using independent-samples t tests. A 2 × 2 mixed-model analysis of variance (group = PFP, control; time = pretest, posttest) was used to compare knee pain.
  
  
  RESULTS
  We observed greater knee internal-rotation displacement for the PFP group (12.8° ± 7.2°) as compared with the control group (8.9° ± 4.4°). No other between-groups differences were observed for the trunk, hip, or other knee variables.
  
  
  CONCLUSIONS
  We observed no difference in trunk kinematics between groups but did note differences in knee internal-rotation displacement. These findings contribute to the current knowledge of altered movement in those with PFP and provide direction for exercise interventions.
authors.affiliation: The College of William and Mary, Williamsburg, VA;
authors.forename: Brandi G
authors.initials: BG
authors.lastname: Schwane
authors.affiliation: Sports Medicine Research Laboratory, Georgia State University, Atlanta;
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Goerger
authors.affiliation: Sports Medicine Research Laboratory.
authors.forename: Shiho
authors.initials: S
authors.lastname: Goto
authors.affiliation: Neuromuscular Research Laboratory, and.
authors.forename: J Troy
authors.initials: JT
authors.lastname: Blackburn
authors.affiliation: Department of Exercise and Sport Science, The University of North Carolina at Chapel Hill.
authors.forename: Alain J
authors.initials: AJ
authors.lastname: Aguilar
authors.affiliation: Sports Medicine Research Laboratory.
authors.forename: Darin A
authors.initials: DA
authors.lastname: Padua
mesh_terms: D001696:Biomechanical Phenomena; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000502:physiology; D035002:Lower Extremity / Q000502:physiology*; D009068:Movement / Q000502:physiology; D010147:Pain Measurement; D046788:Patellofemoral Pain Syndrome / Q000503:physiopathology*; D012399:Rotation; D060726:Torso / Q000502:physiology*; D016138:Walking / Q000502:physiology*; D055815:Young Adult
keywords: anterior knee pain; knee internal rotation; neuromuscular control