title: An accelerometry-based methodology for assessment of real-world bilateral upper extremity activity.
abstract: BACKGROUND
  The use of both upper extremities (UE) is necessary for the completion of many everyday tasks. Few clinical assessments measure the abilities of the UEs to work together; rather, they assess unilateral function and compare it between affected and unaffected UEs. Furthermore, clinical assessments are unable to measure function that occurs in the real-world, outside the clinic. This study examines the validity of an innovative approach to assess real-world bilateral UE activity using accelerometry.
  
  
  METHODS
  Seventy-four neurologically intact adults completed ten tasks (donning/doffing shoes, grooming, stacking boxes, cutting playdough, folding towels, writing, unilateral sorting, bilateral sorting, unilateral typing, and bilateral typing) while wearing accelerometers on both wrists. Two variables, the Bilateral Magnitude and Magnitude Ratio, were derived from accelerometry data to distinguish between high- and low-intensity tasks, and between bilateral and unilateral tasks. Estimated energy expenditure and time spent in simultaneous UE activity for each task were also calculated.
  
  
  RESULTS
  The Bilateral Magnitude distinguished between high- and low-intensity tasks, and the Magnitude Ratio distinguished between unilateral and bilateral UE tasks. The Bilateral Magnitude was strongly correlated with estimated energy expenditure (ρ = 0.74, p<0.02), and the Magnitude Ratio was strongly correlated with time spent in simultaneous UE activity (ρ = 0.93, p<0.01) across tasks.
  
  
  CONCLUSIONS
  These results demonstrate face validity and construct validity of this methodology to quantify bilateral UE activity during the performance of everyday tasks performed in a laboratory setting, and can now be used to assess bilateral UE activity in real-world environments.
authors: Program in Physical Therapy, Washington University School of Medicine in St. Louis, St. Louis, Missouri, United States of America.
authors: Ryan R
authors: RR
authors: Bailey
authors: Program in Physical Therapy, Mallinckrodt Institute of Radiology, Department of Biomedical Engineering, Washington University School of Medicine in St. Louis, St. Louis, Missouri, United States of America.
authors: Joseph W
authors: JW
authors: Klaesner
authors: Program in Physical Therapy, Program in Occupational Therapy, Department of Neurology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, United States of America.
authors: Catherine E
authors: CE
authors: Lang
mesh_terms: D061725:Accelerometry / Q000379:methods*; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D034941:Upper Extremity