title: Gait variability in Parkinson's disease: levodopa and walking direction.
abstract: BACKGROUND
  Levodopa treatment has been shown to improve gait spatio-temporal characteristics in both forward and backward walking. However, effect of levodopa on gait variability during backward walking compared with forward walking has not been reported.
  
  
  OBJECTIVE
  To study the effects of levodopa on gait variability of forward and backward walking in individuals with Parkinson's disease (PD).
  
  
  METHODS
  Forty individuals with PD were studied. Their mean age was 68.70 ± 7.46 year. The average time since diagnosis was 9.41 ± 5.72 year. Gait variability was studied while 'OFF' and 'ON' levodopa when the participants walked forward and backward at their usual speed. Variability in step time, swing time, stride length, double support time, and stride velocity were compared between medication condition and walking direction.
  
  
  RESULTS
  Variability of step time, swing time, stride length, and stride velocity decreased significantly during forward and backward walks (P < 0.001; P < 0.001; P = 0.003, P = 0.001, respectively) after levodopa administration. Variability of double support time was not changed after levodopa administration (P = 0.054).
  
  
  CONCLUSIONS
  Levodopa had positive effects on gait variability of forward and backward walking in individuals with PD. However, variability in double support time was not affected by the levodopa.
authors.affiliation: Research Service, Michael E DeBakey Veterans Affairs Medical Center, Houston, TX, USA.|Department of Physical Medicine and Rehabilitation, Baylor College of Medicine, Houston, TX, USA.|Rehabilitation Sciences, University of Texas Medical Branch, Galveston, TX, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Bryant
authors.affiliation: Department of Physical Medicine and Rehabilitation, Baylor College of Medicine, Houston, TX, USA.
authors.forename: D H
authors.initials: DH
authors.lastname: Rintala
authors.affiliation: Lehigh Neurology, Lehigh Valley Health Network, Allentown, PA, USA.
authors.forename: J G
authors.initials: JG
authors.lastname: Hou
authors.affiliation: Neurology Care Line, Michael E DeBakey Veterans Affairs Medical Center, Houston, TX, USA.|Department of Neurology, Baylor College of Medicine, Houston, TX, USA.
authors.forename: R L
authors.initials: RL
authors.lastname: Collins
authors.affiliation: Rehabilitation Sciences, University of Texas Medical Branch, Galveston, TX, USA.
authors.forename: E J
authors.initials: EJ
authors.lastname: Protas
mesh_terms: D000368:Aged; D000978:Antiparkinson Agents / Q000627:therapeutic use*; D005260:Female; D005684:Gait / Q000187:drug effects*; D020233:Gait Disorders, Neurologic / Q000188:drug therapy* / Q000209:etiology; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000188:drug therapy*
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa
keywords: Parkinson's disease; backward walking; forward walking; gait variability; levodopa