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Context Clinical reaction-time (RT) measures are frequently used when examining patients with concussion but do not correlate with functional movement RT. We developed the Standardized Assessment of RT (StART) to emulate the rapid cognitive demands and whole-body movement needed in sport. Objective To assess StART differences across 6 cognitive-motor combinations, examine potential demographic and health history confounders, and provide preliminary reference data for healthy collegiate student-athletes. Design Prospective, cross-sectional study. Setting Clinical medicine facilities. Patients or Other Participants A total of 89 student-athletes (56 [62.9%] men, 33 [37.1%] women; age = 19.5 ± 0.9 years, height = 178.2 ± 21.7 cm, mass = 80.4 ± 24 kg; no concussion history = 64 [71.9%]). Main Outcome Measure(s) Student-athletes completed health history questionnaires and StART during preseason testing. The StART consisted of 3 movements (standing, single-legged balance, and cutting) under 2 cognitive states (single task and dual task [subtracting by 6's or 7's]) for 3 trials under each condition. The StART trials were calculated as milliseconds between penlight illumination and initial movement. We used a 3 × 2 repeated-measures analysis of variance with post hoc t tests and 95% CIs to assess StART cognitive and movement differences, conducted univariable linear regressions to examine StART performance associations, and reported StART performance as percentiles. Results All StART conditions differed (P ≤ .03), except single-task standing versus single-task single-legged balance (P = .36). Every 1-year age increase was associated with an 18-millisecond (95% CI = 8, 27 milliseconds) slower single-task cutting RT (P < .001). Female athletes had slower single-task (15 milliseconds; 95% CI = 2, 28 milliseconds; P = .02) and dual-task (28 milliseconds; 95% CI = 2, 55 milliseconds; P = .03) standing RT than male athletes. No other demographic or health history factors were associated with any StART condition (P ≥ .056). Conclusions The StART outcomes were unique across each cognitive-motor combination, suggesting minimal subtest redundancy. Only age and sex were associated with select outcomes. The StART composite scores may minimize confounding factors, but future researchers should consider age and sex when providing normative data.

Objective:To examine the relationships and latent factors within the Standardized Assessment of Reaction Time (StART), and between StART and current clinical assessments.Design:Cross-sectional study.Setting:Clinical medicine facility.Participants:Eighty-nine healthy collegiate student-athletes (63% male, age: 19.5 ± 0.9 years, 28% ≥1 concussion history).Assessment of Risk Factors:Student-athletes completed StART and clinical assessments during preinjury testing.Main Outcome Measures:Standardized Assessment of Reaction Time consisted of 3 conditions (standing, single-leg balance, cutting) under 2 cognitive states (single task and dual task) for 3 trials each condition. Clinical assessments were the Sport Concussion Assessment Tool (SCAT) symptom checklist, Standardized Assessment of Concussion (SAC), tandem gait (single task and dual task), and Immediate PostConcussion Assessment and Cognitive Testing (ImPACT). We used Pearson-r correlation coefficients and exploratory factor analysis (EFA) to examine relationships and latent factors between StART and clinical assessments.Results:Null to moderate correlations presented among the StART outcomes (r range: 0.06-0.70), and null to small correlations between StART and clinical assessments (r range: −0.16 to 0.34). The three-factor EFA for solely StART explained 70.6% total variance: functional movement (cutting), static dual-task (standing and single-leg balance), and static single task (standing and single-leg balance). The five-factor EFA for StART and clinical assessments explained 65.8% total variance: gait (single-task and dual-task tandem gait), functional movement (StART single-task and dual-task cutting), static dual-task (StART standing, single-leg balance), neurocognitive (ImPACT verbal memory, visual memory, visual-motor speed), and static single task (StART standing, single-leg balance). No other outcomes met the factor loading threshold.Conclusions:StART displayed 3 distinct categories and had minimal redundancy within its subtests. StART did not meaningfully correlate with clinical assessments, suggesting that StART provides unique information by examining more functional, reactive movement.