title: The effect of bracing on patellofemoral joint stress during free and fast walking.
abstract: BACKGROUND
  Although several studies have demonstrated decreases in patellofemoral pain (PFP) with the application of bracing, the mechanism by which bracing reduces symptoms has not been elucidated.
  
  
  OBJECTIVE
  Individuals who responded favorably to bracing will exhibit decreased patellofemoral stress during level walking.
  
  
  METHODS
  Repeated measures, cross-sectional.
  
  
  METHODS
  Fifteen subjects with a diagnosis of PFP completed two phases of data collection: 1) MRI assessment of patellofemoral contact area and 2) gait analysis. Data were obtained under braced and nonbraced conditions. Variables obtained from both data collection sessions were used as input variables into a mathematical model to quantify patellofemoral stress.
  
  
  RESULTS
  Subjects reported a 56% reduction in pain following bracing. Bracing significantly reduced peak stress during free and fast walking (17% and 27%, respectively). The decrease in stress was the result of increased contact area as patellofemoral joint reaction forces were increased following bracing.
  
  
  CONCLUSIONS
  Bracing resulted in a larger increase in patellofemoral contact area than the increase in joint reaction force, resulting in a decrease in joint stress.
  
  
  CONCLUSIONS
  The results of this study suggest a possible mechanism by which bracing may be effective in reducing PFP and provides experimental support for the use of this treatment method.
authors.affiliation: Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, California 90089-9006, USA.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Powers
authors.forename: Samuel R
authors.initials: SR
authors.lastname: Ward
authors.forename: Yu-jen
authors.initials: YJ
authors.lastname: Chen
authors.forename: Li-der
authors.initials: LD
authors.lastname: Chan
authors.forename: Michael R
authors.initials: MR
authors.lastname: Terk
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D001915:Braces; D003430:Cross-Sectional Studies; D005260:Female; D005269:Femur / Q000503:physiopathology; D005684:Gait / Q000502:physiology; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D010147:Pain Measurement; D010329:Patella / Q000503:physiopathology; D016138:Walking / Q000502:physiology*