Health And Performance Promotion in Youth Sport (HAPPY): Concussion Incidence Rates, Initial Management, Symptoms, and Missed Activities in Danish Youth Handball Players

<b>OBJECTIVES:</b> To estimate concussion incidence rates, and describe initial management, symptoms, and missed activities after concussion in community handball players aged 11-17 years over one season. <b>DESIGN:</b> 30-week prospective cohort study. <b>METHODS:</b> Each week, youth handball players self-reported handball exposure (training and match) and possible concussions using the Oslo Sports and Trauma Research Health questionnaire and a concussion question defined according to the 5th Concussion in Sport Group Consensus Statement. Possible concussions were confirmed via telephone interviews using the Acute Concussion Evaluation form within 1 week of self-report. Incidence rates ratios (IRRs) were calculated using Poisson regressions considering observations clustered within clubs. We compared results between sex and age groups. <b>RESULTS:</b> Among 945 players (55% female), the incidence rate was 0.8/1,000 exposure hours (95% CI [0.6, 1.0]) with no sex difference, female versus male: IRR = 1.6 (95% CI [0.8, 3.0]). The IRRs were higher in the U15 and U17 age groups compared to U13 (U15 vs. U13: IRR = 1.6 (95% CI [1.0, 2.7]), and U17 vs. U13: IRR = 2.3 (95% CI [1.2, 4.1]). Players reported a median of 7 (interquartile range: 3-11) symptoms, mostly headaches (96%, 95% CI [84%, 98%]). Forty-nine percent (95% CI [36%, 63%]) continued to play after the incident, with 96% (95% CI [75%, 100%]) of these players deciding independently and 19% (95% CI [10%, 32%]) consulting a health professional. One in four players missed at least one school day (25%, 95% CI [15%, 38%]) or sports activity (23%, 95% CI [13%, 36%]). <b>CONCLUSION:</b> Concussions were common in youth handball and occurred more often in older age groups, with no differences by sex. Half of handball players continued playing immediately post-injury, mainly deciding independently, and one in four missed school or sports. <i>J Orthop Sports Phys Ther 2025;55(12):1-9. Epub 16 October 2025. doi:10.2519/jospt.2025.13399</i>.