RT Journal Article SR Electronic T1 7.14 Do head injury biomechanics predict injury recovery? JF British Journal of Sports Medicine JO Br J Sports Med FD BMJ Publishing Group Ltd and British Association of Sport and Exercise Medicine SP A38 OP A39 DO 10.1136/bjsports-2023-concussion.102 VO 58 IS Suppl 1 A1 Mihalik, Jason P A1 Chandran, Avinash A1 Powell, Jacob R A1 Roby, Patricia R A1 Stemper, Brian D A1 Shah, Alok S A1 Rowson, Steve A1 Duma, Stefan A1 Harezlak, Jaroslaw A1 Riggen, Larry A1 Broglio, Steven P A1 McAllister, Thomas W A1 McCrea, Michael YR 2024 UL http://bjsm.bmj.com/content/58/Suppl_1/A38.2.abstract AB Objective To test whether higher head injury biomechanics are associated with symptom resolution time (SRT) and return-to-participation time (RTP).Design Retrospective cohort study.Setting Six United States NCAA Division 1 colleges.Participants We studied 51 college American football players who sustained an incident concussion while participating in a multi-site study. There were no exclusion criteria based on age, sex, or race.Interventions (or Assessment of Risk Factors) Head injury linear accelerations were categorized as mild (<66g), moderate (66g-106g), or severe (>106g). Head impact locations, event type, and player race/ethnicity were included as model covariates.Outcome Measures SRT and RTP were measured in days. Kruskal-Wallis tests examined SRT and RTP differences by head impact severity. Multivariable negative binomial regression models analyzed associations between higher head impact severity and SRT and RTP. Effect estimates (ratios) with 95% confidence intervals (CI) excluding 1.00 were considered significant.Main Results Median linear acceleration was 66.7g, with 9 cases (17.7%) resulting from a severe (>106g) linear acceleration. Median SRT and RTP were 6.1 days (IQR=5.8) and 12.3 days (IQR=7.8), respectively. No SRT (χ2=1.9; p=0.38) or RTP (χ2=0.38; p=0.83) differences were observed across impact severities. Multivariable models revealed no associations between higher head impact severity and SRT (Ratio=0.96; 95%CI=[0.71,1.30]) or RTP (Ratio=0.91; 95%CI=[0.62,1.34]), after adjusting for covariate effects.Conclusions Head injury biomechanics do not predict injury recovery. Future work should consider the role pre-injury repeated head impact exposure has on predicting SRT and RTP time given injury head impacts alone are not associated with SRT or RTP.