The Validation of the Actigraph GT3X Step Counter in Youth Who Are Blind

By Elizabeth K. Lenz, Brooke E. Starkoff, Lauren J. Lieberman, and Danny Too

Preferred Citation

Lenz, E. K., Starkoff, B. E., Lieberman, L. J., & Too, D. (2021). The Validation of the Actigraph GT3X Step Counter in Youth Who Are Blind. Journal of Blindness Innovation & Research, 11(1). Retrieved from http://dx.doi/10.5241/11-202


Background: Identifying valid tools to assess physical activity in youth who are blind is paramount.

Methods: Nine participants who were blind (14.1±2.1 years old) completed two, 400-meter laps around a track. Steps were recorded via accelerometer (ACC) and direct observation (DO). Analyses examined the relationship between number of steps measured by DO and ACC, and between mean number of steps for each.

Results: Average steps by ACC and DO were 664.9±72.7 and 683.4±96.3, respectively. Pearson correlations revealed significant relationships between laps for ACC (r=0.978, p<0.00) and DO (r=0.998, p<0.00), and between ACC and DO (r=0.955, p<0.00). Paired t-tests revealed no differences between trials for ACC, DO, and DO compared to ACC (p=0.146-0.841). Regression analysis revealed no proportional bias between differences in steps taken between trials (p=0.158-0.977), but there was proportional bias (p=0.04) between steps taken with DO and ACC. 

Conclusion: Accelerometry can be used to measure steps for youth who are blind.


accelerometer, blind, youth, validation, direct observation

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DOI: http://dx.doi/10.5241/11-202

The Journal of Blindness Innovation and Research is copyright (c) 2021 to the National Federation of the Blind.