title: Involuntary contralateral upper extremity muscle activation pattern during unilateral pinch grip following stroke.
abstract: METHODS
  Repeated measures design.
  
  
  BACKGROUND
  Mirror activity refers to emergence of motion not only in the intended, but also in the contralateral limb.
  
  
  OBJECTIVE
  To characterize post-stroke mirror activities across multiple muscles during unilateral pinch.
  
  
  METHODS
  Chronic stroke survivors performed unilateral pinch grip using the paretic and nonparetic hand, while four muscles' EMGs were recorded for both hands.
  
  
  RESULTS
  During the paretic hand grip, the relaxed nonparetic hand showed mirror activity that was more pronounced for the intrinsic (FDI and thenar eminence) than extrinsic muscles (FDS and EDC). During the nonparetic hand grip, mirror activity in the paretic hand was suppressed for the intrinsic than extrinsic muscles.
  
  
  CONCLUSIONS
  Chronic stroke survivors' relaxed hand did not mirror the task hand's muscle activation pattern, but displayed altered muscle activation patterns depending on muscles and sides, possibly mediated by disturbed interhemispheric inhibition and relative reliance on corticospinal tracts among muscles.
  
  
  METHODS
  N/A.
authors.affiliation: Department of Industrial Engineering & Occupational Science and Technology, University of Wisconsin-Milwaukee, 3200 N. Cramer Street, Milwaukee, WI 53211, USA. seon@uwm.edu
authors.forename: Na Jin
authors.initials: NJ
authors.lastname: Seo
mesh_terms: D000328:Adult; D004576:Electromyography; D006801:Humans; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology*; D010291:Paresis / Q000503:physiopathology; D052581:Pinch Strength / Q000502:physiology*; D020521:Stroke / Q000503:physiopathology*; D034941:Upper Extremity / Q000503:physiopathology*
keywords: Associated mirror movement; Electromyography; Hand grip; Motor overflow