title: Assessment of arm activity using triaxial accelerometry in patients with a stroke.
abstract: OBJECTIVE
  To study the validity of accelerometry in the assessment of arm activity of patients with impaired arm function after stroke.
  
  
  METHODS
  Cross-sectional concurrent validity study.
  
  
  METHODS
  Rehabilitation center.
  
  
  METHODS
  Patients (N=45) at different stages after stroke.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  All patients wore 2 triaxial accelerometers around their wrists during 3 consecutive days. Arm activity was assessed, based on unilateral (activity of the affected arm) and bilateral accelerometry (ratio between the activity of the affected and nonaffected arm). The Motor Activity Log-26 (MAL-26) Amount of Use (AOU) scale was used as the main external criterion to test the concurrent validity of arm accelerometry. In addition, the MAL-26 Quality of Movement (QOM) scale and the Stroke Impact Scale (SIS) subscale Hand Function were used. To test the divergent validity, the SIS subscale Mobility was used. Spearman correlation coefficients were calculated. In an additional regression analysis, the hypothesized confounding influence of spasm, therapy intensity, and interobserver differences was studied.
  
  
  RESULTS
  Both unilateral (ρ=.58, P<.001) and bilateral (ρ=.60, P<.001) accelerometry were significantly related to the MAL-AOU scale. Associations of both unilateral and bilateral accelerometry with the MAL-QOM and SIS subscale Hand Function corroborated these findings. The SIS subscale Mobility was not significantly associated with unilateral accelerometry (ρ=.41, P=.01) or bilateral accelerometry (ρ=.23, P=.11). None of the hypothesized confounders influenced these associations significantly.
  
  
  CONCLUSIONS
  Based on the results, both the concurrent and divergent validity of unilateral and bilateral arm accelerometry for measuring arm activity after stroke are good.
authors: Adelante, Centre of Expertise in Rehabilitation and Audiology, Hoensbroek, The Netherlands.
authors: Sanne C
authors: SC
authors: van der Pas
authors: Jeanine A
authors: JA
authors: Verbunt
authors: Dorien E
authors: DE
authors: Breukelaar
authors: Rachma
authors: R
authors: van Woerden
authors: Henk A
authors: HA
authors: Seelen
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D001132:Arm / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D018482:Muscle, Skeletal / Q000503:physiopathology; D026741:Physical Therapy Modalities; D020521:Stroke / Q000503:physiopathology; D000071939:Stroke Rehabilitation