LAUSR

CONTEXT Clinical reaction time (RT) measures are frequently used when examining concussion, but do not correlate with functional movement RT. We developed the Standardized Assessment of RT (StART) to emulate the rapid cognitive and whole-body movement needed in sport. PURPOSE To 1) assess StART differences across six cognitive-motor combinations, 2) examine potential demographic and health history confounders and 3) provide preliminary reference data among healthy collegiate student-athletes. DESIGN prospective, cross-sectional study. SETTING Clinical medicine facilities. PATIENTS OR OTHER PARTICIPANTS student-athletes (n=89, 62.9% male, age:19.5±0.9yrs, 71.9% no concussion history). MAIN OUTCOME MEASURES Student- athletes completed health-history questionnaires and StART during pre-season testing. StART consisted of 3 movements (standing, single-leg balance, cutting) under 2 cognitive states (single-task, dual-task [subtracting by 6's or 7's]) for 3 trials each condition. StART trials were calculated as milliseconds between penlight illumination and initial movement. We used a 3x2 repeated-measures ANOVA with post-hoc t-tests and 95% confidence intervals (95%CI) to assess StART movement and cognitive differences, univariable linear regressions to examine StART performance associations, and reported StART performance into percentiles. RESULTS All StART conditions significantly differed (p's≤0.034), except single-task standing versus single-task single-leg balance (p=0.361). Every 1-year age increase was associated with 18ms slower single-task cutting RT (p<0.001, 95%CI:8-27ms). Females had slower single-task (p=0.021, 15ms, 95%CI:2-28) and dual-task standing RT (p=0.031, 28ms, 95%CI:2-55) than males. No other demographic or health history factors were associated with any StART condition (p≥0.059). CONCLUSION StART outcomes were unique across each cognitive-motor combination, suggesting minimal subtest redundancy. Only age and sex were associated with select outcomes, while no other demographic or health history factors were. StART composite scores may minimize confounding factors, but future research should consider age and sex when providing normative data.