title: Effect of ActiGraph GT3X+ Position and Algorithm Choice on Step Count Accuracy in Older Adults.
abstract: Accelerometer step count accuracy may be affected by gait speed, device positioning, and analysis algorithm selection. We assessed ActiGraph GT3X+ step count accuracy related to device placement and analysis algorithm in older adults with walking aids (n = 13) and without walking aids (n = 22). Participants (81.5 ± 5.0 years of age) completed a timed 100-m walk wearing five GT3X+ monitors (hips, ankles, lumbar spine). Individuals with walking aids had slower gait speeds (0.8 ± 0.20 m/s versus 1.2 ± 0.20 m/s without walking aids, p < .001). Intraclass correlation coefficient values for observed versus monitored steps were highest when ankle placement and the low frequency extension (LFE) algorithm were used (left ankle ICC = .989, right ankle ICC = .998). Using the GT3X+ ankle placement and analyzing data with the LFE algorithm resulted in the most accurate step counts in older adults.
authors.affiliation: School of Physical Therapy, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
authors.forename: Sheila M
authors.initials: SM
authors.lastname: Korpan
authors.forename: Jenessa L
authors.initials: JL
authors.lastname: Schafer
authors.forename: Kaylie C
authors.initials: KC
authors.lastname: Wilson
authors.forename: Sandra C
authors.initials: SC
authors.lastname: Webber
mesh_terms: D061725:Accelerometry / Q000295:instrumentation; D056044:Actigraphy / Q000295:instrumentation*; D000369:Aged, 80 and over; D000465:Algorithms; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D009983:Orthopedic Equipment