title: Quantifying Real-World Upper-Limb Activity in Nondisabled Adults and Adults With Chronic Stroke.
abstract: BACKGROUND
  Motor capability is commonly assessed inside the clinic, but motor performance in real-world settings (ie, outside of the clinic) is seldom assessed because measurement tools are lacking.
  
  
  OBJECTIVE
  To quantify real-world bilateral upper-limb (UL) activity in nondisabled adults and adults with stroke using a recently developed accelerometry-based methodology.
  
  
  METHODS
  Nondisabled adults (n = 74) and adults with chronic stroke (n = 48) wore accelerometers on both wrists for 25 to 26 hours. Motor capability was assessed using the Action Research Arm Test (ARAT). Accelerometry-derived variables were calculated to quantify intensity of bilateral UL activity (ie, bilateral magnitude) and the contribution of both ULs to activity (magnitude ratio) for each second of activity. Density plots were used to examine each second of bilateral UL activity throughout the day.
  
  
  RESULTS
  Nondisabled adults demonstrated equivalent use of dominant and nondominant ULs, indicated by symmetrical density plots and a median magnitude ratio of -0.1 (interquartile range [IQR] = 0.3), where a value of 0 indicates equal activity between ULs. Bilateral UL activity intensity was lower (P < .001) and more lateralized in adults with stroke, as indicated by asymmetrical density plots and a lower median magnitude ratio (-2.2; IQR = 6.2, P < .001). Density plots were similar between many stroke participants who had different ARAT scores, indicating that real-world bilateral UL activity was similar despite different motor capabilities.
  
  
  CONCLUSIONS
  Quantification and visualization of real-world bilateral UL activity can be accomplished using this novel accelerometry-based methodology and complements results obtained from clinical tests of function when assessing recovery of UL activity following neurological injury.
authors.affiliation: Washington University School of Medicine in St Louis, MO, USA.
authors.forename: Ryan R
authors.initials: RR
authors.lastname: Bailey
authors.affiliation: Washington University School of Medicine in St Louis, MO, USA.
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Klaesner
authors.affiliation: Washington University School of Medicine in St Louis, MO, USA langc@wustl.edu.
authors.forename: Catherine E
authors.initials: CE
authors.lastname: Lang
mesh_terms: D061725:Accelerometry; D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D002908:Chronic Disease; D015928:Cognitive Behavioral Therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D012111:Residence Characteristics; D020521:Stroke / Q000175:diagnosis* / Q000503:physiopathology*; D000071939:Stroke Rehabilitation; D034941:Upper Extremity / Q000503:physiopathology*
keywords: accelerometry; bilateral upper limb activity; motor capability; motor performance; outcomes assessment; real-world activity