title: Lower extremity strength and mechanics during jumping in women with patellofemoral pain.
abstract: BACKGROUND
  Lower extremity (LE) weakness might be associated with altered mechanics during weight bearing in subjects with patellofemoral pain syndrome (PFPS).
  
  
  OBJECTIVE
  To analyze LE strength, mechanics, and the association between these variables among women with and without PFPS during a simulated athletic task.
  
  
  METHODS
  Case control.
  
  
  METHODS
  Motion-analysis laboratory.
  
  
  METHODS
  20 women with PFPS and 20 healthy women.
  
  
  METHODS
  Peak isometric lateral trunk-flexion, hip-abduction, hip external-rotation, knee-flexion, and knee-extension strength, as well as hip- and knee-joint excursions and angular impulses during single-leg jumps.
  
  
  RESULTS
  PFPS subjects produced less hip-abduction, hip external-rotation, and trunk lateral-flexion force than the control group. The PFPS group also demonstrated greater hip-adduction excursion and hip-abduction impulses. The association between the strength measurements and LE mechanics was low.
  
  
  CONCLUSIONS
  Women with PFPS demonstrate specific weaknesses and altered LE mechanics. Weakness is not, however, highly correlated with observed differences in mechanics.
authors.affiliation: Physical Therapy Program, University of Wisconsin-LaCrosse, LaCrosse WI 54601, USA.
authors.forename: John D
authors.initials: JD
authors.lastname: Willson
authors.forename: Irene S
authors.initials: IS
authors.lastname: Davis