We evaluated the capacity of the Mobile Universal Lexicon Evaluation System (MULES, rapid picture naming) and Staggered Uneven Number (SUN) testing to be effective during pre-season baseline testing in a cohort of youth athletes using a novel and freely-available app (Mobile Integrated Cognitive Kit, MICK) and paper-pencil testing.

Participants from a youth hockey league (n=59, median age 13 years, range 6-17) underwent pre-season testing.  Each participant completed two trials of MULES and SUN.  Children <10 years of age completed paper versions, while children aged 10 or greater used the MICK app.  The app records completion times for each trial and is semi-automated for use while supervised by research staff. 

As noted in prior studies, learning effects were noted between the two baseline trials for both the MULES (median improvement=11.3 sec, range=-32.3-92.0 sec, p<0.001, Wilcoxon sign-rank test) and SUN (median improvement=0.78 sec, range=-8.0-15.1 sec, p=0.002).  Median best baseline for the MULES was 50.4 sec (range=34.2-141.0 sec) and for SUN 71.1 sec (range=36.6-200.0 sec). Age was a predictor of best baseline times for both tests, with longer times for younger participants for MULES (p<0.001, r_s=-0.67, Spearman rank correlation) and SUN (p<0.001, r_s=-0.54).  Degrees of learning effect did not vary across age groups in this cohort (p=0.14, r_s=-0.20). 

Vision-based RAN tasks, such as the MULES and SUN, can be feasibly administered using the MICK app during pre-season baseline testing in youth sports teams. These data provide a foundation for post-injury sideline testing among youth athletes.