title: Is there a valid app for that? Validity of a free pedometer iPhone application.
abstract: BACKGROUND
  This study examined the validity of a selected free pedometer application (iPedometer; IP) for the iPhone that could be used to assess physical activity.
  
  
  METHODS
  Twenty college students (10 men, 10 women; mean age: 21.85 ± 1.57 yrs) wore an iPhone at 3 locations (pocket, waist, arm) and a StepWatch 3 Step Activity Monitor (SW) on their right ankle while walking on a treadmill at 5 different speeds (54, 67, 80, 94, 107 m·min(-1)). A research assistant counted steps with a tally counter (TC).
  
  
  RESULTS
  Statistical significance between the TC, SW, and IP was found during every condition except IP in the pocket at 107 m·min(-1) (F(2,38) = .64, P = .54). Correlations involving the IP revealed only 1 positive correlation (IP on arm at 54 m·min(-1)) for any of the conditions (r = .46, P = .05).
  
  
  CONCLUSIONS
  The IP application was not accurate in counting steps and recorded significantly lower step counts than the SW and TC. Thus, the free pedometer application used is not a valid instrument for monitoring activity during treadmill walking.
authors.affiliation: Dept of Health, Physical Education, and Recreation, Missouri Western State University, St. Joseph, MO, USA.
authors.forename: Randall J
authors.initials: RJ
authors.lastname: Bergman
authors.forename: Justin W
authors.initials: JW
authors.lastname: Spellman
authors.forename: Michael E
authors.initials: ME
authors.lastname: Hall
authors.forename: Shawn M
authors.initials: SM
authors.lastname: Bergman
mesh_terms: D056044:Actigraphy / Q000295:instrumentation*; D040421:Cell Phone; D005080:Exercise Test / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D057386:Search Engine; D012984:Software / Q000592:standards*; D016138:Walking; D055815:Young Adult