title: Impact of time on quality of motor control of the paretic upper limb after stroke.
abstract: OBJECTIVE
  To establish the time course of recovery regarding smoothness of upper limb movements in the first 6 months poststroke.
  
  
  METHODS
  Cohort study with 3-dimensional kinematic measurements in weeks 1, 2, 3, 4, 5, 8, 12, and 26 poststroke.
  
  
  METHODS
  Onsite 3-dimensional kinematic measurements in stroke units, rehabilitation centers, nursing homes, and patients' homes.
  
  
  METHODS
  Patients (N=44; 19 women, 25 men; mean age ± SD, 58±12y) with a first-ever unilateral ischemic stroke and incomplete upper limb paresis (27 left sided, 17 right sided) were included.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  In each measurement, an electromagnetic motion tracker acquired hand and finger trajectories during a reach-to-grasp task. Movement duration was determined, and smoothness of hand transport and grasp aperture was quantified by normalized jerk. With the use of random coefficient analysis, the effect of progress of time on smoothness of hand transport and grasp aperture was investigated.
  
  
  RESULTS
  During the first 5 weeks poststroke, there was a significant contribution of progress of time to reductions in movement duration and normalized jerk of hand transport and grasp aperture (P<.01).
  
  
  CONCLUSIONS
  The present longitudinal 3-dimensional kinematic study showed that smoothness of paretic upper limb movements improves in the first 8 weeks poststroke. This improvement suggests that motor control normalizes in the first 8 weeks poststroke and can be mostly explained by spontaneous neurologic recovery that occurs typically in the first weeks poststroke. Future 3-dimensional kinematic studies should investigate whether therapies starting early after stroke can improve the quality of motor control beyond spontaneous neurologic recovery.
authors.affiliation: Department of Rehabilitation Medicine, MOVE Research Institute Amsterdam, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Joost
authors.initials: J
authors.lastname: van Kordelaar
authors.affiliation: Department of Rehabilitation Medicine, MOVE Research Institute Amsterdam, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Erwin
authors.initials: E
authors.lastname: van Wegen
authors.affiliation: Department of Rehabilitation Medicine, MOVE Research Institute Amsterdam, VU University Medical Center, Amsterdam, The Netherlands; Amsterdam Rehabilitation Research Center, Reade Centre for Rehabilitation and Rheumatology, Amsterdam, The Netherlands. Electronic address: g.kwakkel@vumc.nl.
authors.forename: Gert
authors.initials: G
authors.lastname: Kwakkel
mesh_terms: D001696:Biomechanical Phenomena; D004185:Disability Evaluation; D055590:Electromagnetic Phenomena; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010291:Paresis / Q000503:physiopathology* / Q000534:rehabilitation*; D020127:Recovery of Function; D020521:Stroke / Q000503:physiopathology*; D000071939:Stroke Rehabilitation; D013997:Time Factors; D034941:Upper Extremity / Q000503:physiopathology*
keywords: Biomechanics; MD; NJ; Rehabilitation; Stroke; Upper extremity; movement duration; normalized jerk