Our purpose in this study was to document the criterion validity of the Fitbit Zip for measuring steps taken by youth with visual impairments (VI). A secondary purpose was to determine whether walking pace, mounting position, or relative position to the user's mobility device impacted the criterion validity of the device. Fourteen adolescent-aged individuals (Mage = 15.4; 13 male and 1 female) with VI participated in this study. Participants wore four Fitbit Zips at different mounting positions and completed two, 2-min walking trials while the lead investigator hand tallied steps. Measurement validity was analyzed using absolute percent error (APE), intraclass correlation coefficients estimated level of conformity, and paired samples t tests and Cohen's d effect sizes assessed APE relative to mounting positions. Results supported the use of the Fitbit Zip during regular-paced walking; however, caution must be used during activities exceeding regular walking speeds, as devices consistently underestimated steps.
Keywords: blindness/visual impairment; pedometer studies; physical activity; validity.