title: The relationships between the unified Parkinson's disease rating scale and lower extremity functional performance in persons with early-stage Parkinson's disease.
abstract: BACKGROUND
  The Unified Parkinson's Disease Rating Scale (UPDRS) is the "gold standard" assessment tool for characterizing impairments in persons with Parkinson's disease (PD); however, this scale's ability to predict functional capabilities across different functional tasks has not been adequately assessed in persons with early-stage PD.
  
  
  METHODS
  Thirty persons with PD within 3 years of diagnosis and without motor fluctuation performed self-selected walking, fast walking, and sit-to-stand and stair-climbing tasks. Pearson's correlation coefficients were used to calculate correlations with a standard UPDRS examination (P<.05). Simple linear regression models were used to fit each functional performance outcome measure with the UPDRS total predictor scores.
  
  
  RESULTS
  The correlations between the UPDRS motor (section III), UPDRS total scores, and all timed functional performance measures were fair to good (range, 0.45-0.57). Conversely, only greater self-selected time to walk 50 ft correlated with a higher UPDRS activities of daily living (II) score (r=.386; P<.05).
  
  
  CONCLUSIONS
  The UPDRS motor (III) and total scores may be good predictors of overall lower extremity function in persons with early-stage PD. Understanding the relationships between UPDRS scores and functional capabilities may allow clinicians to better quantify early physical functioning, longitudinally assess disease progression, and assess the efficacy of interventions.
authors.affiliation: Musculoskeletal Biomechanics Research Laboratory, Division of Biokinesiology & Physical Therapy, Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA. jooeunso@usc.edu
authors.forename: Jooeun
authors.initials: J
authors.lastname: Song
authors.forename: Beth E
authors.initials: BE
authors.lastname: Fisher
authors.forename: Giselle
authors.initials: G
authors.lastname: Petzinger
authors.forename: Allan
authors.initials: A
authors.lastname: Wu
authors.forename: James
authors.initials: J
authors.lastname: Gordon
authors.forename: George J
authors.initials: GJ
authors.lastname: Salem