The Preliminary Criterion Validity of the Activ8 Activity Monitor to Measure Physical Activity in Youth Using a Wheelchair

Purpose: The aim of this study was to assess the criterion validity of the Activ8 to detect "active wheelchair use" and to distinguish 6 types of wheelchair activities using video recordings as a gold standard. Methods: Ten participants who use a manual wheelchair were participants in this study. Data of 2 participants were used for adapting the algorithm and data of 7 participants were used for assessing the criterion validity. Results: Criterion validity for detecting "active wheelchair use" had a relative time difference of 7.4%, agreement of 96%, sensitivity of 98.3%, and positive predictive value of 90%. Results for distinguishing 6 types of wheelchair activities had an agreement of 73%, sensitivity of 67.1%, and positive predictive value of 65.5%. Conclusions: The Activ8 is able to detect "active wheelchair use" in youth using a manual wheelchair. Further development of the algorithm is necessary to distinguish between different types of wheelchair activities.