title: Effect of gravity on robot-assisted motor training after chronic stroke: a randomized trial.
abstract: OBJECTIVE
  To determine the efficacy of 2 distinct 6-week robot-assisted reaching programs compared with an intensive conventional arm exercise program (ICAE) for chronic, stroke-related upper-extremity (UE) impairment. To examine whether the addition of robot-assisted training out of the horizontal plane leads to improved outcomes.
  
  
  METHODS
  Randomized controlled trial, single-blinded, with 12-week follow-up.
  
  
  METHODS
  Research setting in a large medical center.
  
  
  METHODS
  Adults (N=62) with chronic, stroke-related arm weakness stratified by impairment severity using baseline UE motor assessments.
  
  
  METHODS
  Sixty minutes, 3 times a week for 6 weeks of robot-assisted planar reaching (gravity compensated), combined planar with vertical robot-assisted reaching, or intensive conventional arm exercise program.
  
  
  METHODS
  UE Fugl-Meyer Assessment (FMA) mean change from baseline to final training.
  
  
  RESULTS
  All groups showed modest gains in the FMA from baseline to final with no significant between group differences. Most change occurred in the planar robot group (mean change ± SD, 2.94 ± 0.77; 95% confidence interval [CI], 1.40-4.47). Participants with greater motor impairment (n=41) demonstrated a larger difference in response (mean change ± SD, 2.29 ± 0.72; 95% CI, 0.85-3.72) for planar robot-assisted exercise compared with the intensive conventional arm exercise program (mean change ± SD, 0.43 ± 0.72; 95% CI, -1.00 to 1.86).
  
  
  CONCLUSIONS
  Chronic UE deficits because of stroke are responsive to intensive motor task training. However, training outside the horizontal plane in a gravity present environment using a combination of vertical with planar robots was not superior to training with the planar robot alone.
authors.affiliation: Veterans Affairs Maryland Health Care System, Research Service, University of Maryland School of Medicine, Baltimore, USA. susan.conroy@va.gov
authors.forename: Susan S
authors.initials: SS
authors.lastname: Conroy
authors.forename: Jill
authors.initials: J
authors.lastname: Whitall
authors.forename: Laura
authors.initials: L
authors.lastname: Dipietro
authors.forename: Lauren M
authors.initials: LM
authors.lastname: Jones-Lush
authors.forename: Min
authors.initials: M
authors.lastname: Zhan
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Finley
authors.forename: George F
authors.initials: GF
authors.lastname: Wittenberg
authors.forename: Hermano I
authors.initials: HI
authors.lastname: Krebs
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Bever
mesh_terms: D000368:Aged; D001132:Arm; D002908:Chronic Disease; D005081:Exercise Therapy / Q000295:instrumentation* / Q000379:methods*; D005260:Female; D006112:Gravitation; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D020127:Recovery of Function; D012371:Robotics / Q000295:instrumentation*; D016037:Single-Blind Method; D000071939:Stroke Rehabilitation