Search

Previous studies on pain experiences in retired contract sport athletes have been cross-sectional, leaving gaps in our understanding of the evolution of pain interference (PI) and factors that influence trajectories decades after sport discontinuation. This study investigated the longitudinal course of PI in former male National Football League (NFL) players over a 19-year period following sport discontinuation and examined factors influencing overall levels and trajectories of PI. Former NFL players completed health surveys in 2001, 2010, and 2019, with PI ratings measured using the 36-Item Short Form Health Survey (2001 and 2010) and the Patient-Reported Outcomes Measurement Information System (2019). Unconditional latent growth curve models analyzed overall PI severity and trajectories. Conditional latent growth curve models explored the influence of musculoskeletal injuries, osteoarthritis (OA), and depression diagnosis on PI. Over 19 years (N = 338; mean age = 48.96 ± 9.35), PI significantly increased (slope = .179, P < .001; mean Patient-Reported Outcomes Measurement Information System PI t-scores 2001 = 54.19, 2010 = 54.64, 2019 = 57.38). Cumulative musculoskeletal injuries (B = .092, P < .001) and baseline depression diagnosis (B = 4.463, P < .001) were associated with overall PI levels but not change over time. OA was significantly associated with overall PI levels (B = 6.536, P < .001) and trajectory (B = -.253, P < .001); those endorsing OA in 2001 had lower PI increases over 19 years. The body region of injury and level of play during injuries mirrored overall injury effects. PI mildly increased over 19 years, with multiple factors independently influencing overall PI levels. Enhancing former contact sport athletes' daily functionality may be achieved through holistic biopsychosocial interventions addressing musculoskeletal injuries, OA, and depression. Future research should identify factors influencing elevated trajectories of long-term PI post-sport discontinuation. PERSPECTIVE: This study assessed PI in former NFL athletes over 2 decades, revealing notable interindividual variability in trajectories over time. Musculoskeletal injuries, depression, and OA correlated with overall PI. Prevention and intervention in these 3 areas present the potential to improve disruptions in daily living due to pain in former athletes., Competing Interests: Disclosures This study (NFL-LONG) was funded by the National Football League (NFL). Dr. Brett reports grants from the National Institute on Aging and the National Institute of Neurological Disorders and Stroke, and honoraria for conference presentations. Dr. Chandran discloses research funding from the National Collegiate Athletic Association as the Director of the NCAA Injury Surveillance Program, and separately from the Atlantic Coast Conference Center for Research on Intercollegiate Athletics, and the University of North Carolina Translational and Clinical Sciences Institute; he also discloses receiving honoraria from the Sports Neuropsychological Society as well as the American Medical Society for Sports Medicine. Dr. Kerr reports grants from the National Institutes of Health, the Centers for Disease Control and Prevention, and the National Football League. Dr. Lempke reports grants from the Eastern Athletic Trainers’ Association, National Athletic Trainers’ Association, and VALD. Dr. Walton reports grant funding from the U.S. Departments of Defense and Veterans Affairs, and unpaid work on projects funded by the National Collegiate Athletic Association, and reports honoraria for conference presentations from the National Athletic Trainers’ Association. Dr. DeFreese reports grants from the Atlantic Coast Conference and the Association for Applied Sport Psychology. Dr. Echemendia is a paid consultant for the National Hockey League and co-chair of the National Hockey League/National Hockey League Players Association Concussion Subcommittee and Major League Soccer, and provides testimony in matters related to mTBI. Dr. Guskiewicz reports compensation from the National Collegiate Athletic Association for other services and grants from Boston Children's Hospital (sub-award from the National Football League). Dr. Meehan receives royalties from ABC-Clio Publishing, Springer International, and Wolters Kluwer. His research is funded by philanthropic support from the National Hockey League Alumni Association through the Corey C. Griffin Pro-Am Tournament and a grant from the National Football League. Dr. McCrea reports researching funding for the Medical College of Wisconsin from the National Institutes of Health, Department of Defense, Department of Veterans Affairs, Centers for Disease Control and Prevention, National Football League, National Collegiate Athletic Association, and Abbott Laboratories. He previously served as a consultant to Neurotrauma Sciences, Inc and is a clinical consultant to the Green Bay Packers professional football club. He also reports honoria and travel support for professional speaking engagements. Dr. Mannix reports grants from the U.S. Department of Defense, the NFL Foundation, and the National Institute of Neurological Disorders and Stroke., (Copyright © 2024 United States Association for the Study of Pain, Inc. Published by Elsevier Inc. All rights reserved.)

Objective: Investigate the relationships between concussion history and years of football participation (repetitive head impact proxy) with alcohol use across multiple decades in former professional football players., Methods: Participants (n = 348; mean age = 49.0 ± 9.4) completed health questionnaires in 2001 and 2019, which included self-reported concussion history and years of participation. Alcohol use frequency and amount per occasion were reported for three timepoints: during professional career, 2001, and 2019. Ordinal logistic regression models were fit to test associations of concussion history and years of participation with alcohol use at each timepoint., Results: There were no significant associations between either concussion history or years of football participation with alcohol use (frequency and amount per occasion) at any timepoint. Effect estimates for concussion history and years of football participation with alcohol use were generally comparable across timepoints., Conclusions: Later life alcohol use by former American football players is not associated with concussion history or years of exposure to football., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.)

Purpose: Investigate the association between self-reported subjective and performance-based cognition among older (50-70 years) former professional American football players, as well as the relationship of cognitive measures with concussion history and years of football participation, as a proxy for repetitive head impact exposure., Methods: Among older former National Football League (NFL) players ( N = 172; mean age = 60.69 ± 5.64), associations of subjective (Patient Reported Outcome Measurement Information System Cognitive Function-Short Form) and performance-based cognitive measures (Brief Test of Adult Cognition by Telephone [BTACT] Executive Function and Episodic Memory indices) were assessed via univariable and multivariable regression models, with a priori covariates of depression and race. A similar univariate and multivariable regression approach assessed associations between concussion history and years of football participation with subjective and performance-based cognitive measures. In a sample subset ( n = 114), stability of subjective cognitive rating was assessed via partial correlation., Results: Subjective ratings of cognition were significantly associated with performance-based assessment, with moderate effect sizes (episodic memory ηp2 = 0.12; executive function ηp2 = 0.178). These associations were weakened, but remained significant ( P s < 0.05), with the inclusion of covariates. Greater concussion history was associated with lower subjective cognitive function ( ηp2 = 0.114, P < 0.001), but not performance-based cognition. The strength of association between concussion history and subjective cognition was substantially weakened with inclusion of covariates ( ηp2 = 0.057). Years of participation were not associated with measures of subjective or objective cognition ( P s > 0.05)., Conclusions: These findings reinforce the importance of comprehensive evaluation reflecting both subjective and objective measures of cognition, as well as the consideration of patient-specific factors, as part of a comprehensive neurobehavioral and health assessment of older former contact sport athletes., (Copyright © 2023 by the American College of Sports Medicine.)

Objective: Investigate associations between the LIfestyle for BRAin Health (LIBRA) risk score with odds of mild cognitive impairment (MCI) diagnosis and cognitive function, incorporating concussion history., Methods: Former National Football League (NFL) players (N = 1050; mean age = 64.8 ± 9.0-years) completed initial testing for integration of concussion history into LIBRA scores (i.e., modified-LIBRA) and completed the Brief Test of Adult Cognition by Telephone (BTACT). Modified-LIBRA score (including concussion history) associations with odds of MCI and cognitive dysfunction were assessed via logistic and linear regression., Results: The highest quartile LIBRA scores were six times more likely to have a diagnosis of MCI compared to the lowest quartile (OR = 6.27[3.61, 10.91], p < 0.001). Modified-LIBRA scores significantly improved model fit for odds of MCI above original LIBRA scores (χ 2 (1) = 7.76, p = 0.005) and accounted for a greater fraction of variance in executive function (ΔR 2  = 0.02, p = 0.003) and episodic memory (ΔR 2  = 0.02, p = 0.002)., Conclusions: Modified-LIBRA score, incorporating concussion history, may help monitoring risk status in former contact sport athletes, by targeting modifiable, lifestyle-related risk factors., (© 2023 the Alzheimer's Association.)

Objectives: Subjective cognitive difficulties (SCDs) are associated with factors commonly reported in older adults and former contact sport athletes, regardless of objective cognitive decline. We investigated the relative contribution of these factors to SCD in former National Football League (NFL)-players with and without a diagnosis of mild cognitive impairment (MCI)., Methods: Former NFL players (n = 907) aged ≥ 50 years (mean = 64.7 ± 8.9), with (n = 165) and without (n = 742) a diagnosis of MCI completed health questionnaires. Multivariable regression and dominance analyses determined the relative importance of SCD factors on SCD: 1) depression, 2) anxiety, 3) sleep disturbance, 4) pain interference, 5) ability to participate in social roles and activities, 6) stress-related events, 7) fatigue, 8) concussion history, and 9) education. SCD outcomes included Neuro-QoL Emotional-Behavioral Dyscontrol and the PROMIS Cognitive Function. Fisher's z-transformation compared comorbid contributing factors to SCD across MCI and non-MCI groups., Results: Complete dominance of anxiety was established over most comorbid factors across the MCI and non-MCI groups. Fatigue also exhibited complete dominance over most comorbid factors, though its influence in the MCI group was less robust (general dominance). Average contributions to variance accounted for by comorbid factors to ratings of SCD across MCI and non-MCI groups did not statistically differ (Z-statistics <1.96, ps>.05)., Conclusions: Anxiety and fatigue are the most robust factors associated with SCD in former professional football players across various combinations of clinical presentations (different combinations of comorbid factors), regardless of documented cognitive impairment. Self-reported deficits may be less reliable in detecting objective impairment in the presence of these factors, with multidimensional assessment being ideal.

Context: Individuals with lower extremity osteoarthritis (OA) have a 25% greater risk of cardiovascular disease (CVD) than those without OA. The prevalence of traumatic joint injuries among National Football League (NFL) players exposes these athletes to an elevated risk for OA and potentially a greater risk of cardiovascular risk factors (CRFs) and CVD., Objectives: To examine the associations between a history of lower extremity joint injury, lower extremity OA, and the prevalence of CRFs and CVD among former NFL athletes., Design: Cross-sectional study., Patients or Other Participants: Former NFL players completed a comprehensive health questionnaire that was used in an ongoing study, the Neurologic Function Across the Lifespan: A Prospective, Longitudinal, and Translational Study for Former NFL Players (NFL-LONG). A subsample of 1738 former players reported lifetime medical diagnoses including CVD or CRFs., Main Outcome Measure(s): Crude and adjusted prevalence ratios (PRsadj) characterized the associations between CVD or CRFs and injury, OA diagnosis, or both among athletes who reported (1) no history of lower extremity joint injury or surgery and no diagnosed OA, (2) a history of lower extremity joint injury or surgery and no diagnosed OA, and (3) a history of lower extremity joint injury or surgery and diagnosed OA., Results: Neither a history of lower extremity joint injury (PRadj = 1.34; 95% CI = 0.86, 2.07) nor a history of lower extremity joint injury and diagnosed OA (PRadj = 1.41; 95% CI = 0.89, 2.25) was significantly associated with CVD. However, CRFs were 30% and 53% more prevalent in former players with lower extremity joint injury and no diagnosed OA (PRadj = 1.30; 95% CI = 1.12, 1.50) and those with lower extremity joint injury and diagnosed OA (PRadj = 1.53; 95% CI = 1.31, 1.78), respectively, versus athletes with no history of either condition., Conclusions: The prevalence of CRFs was highest among former NFL athletes with a history of lower extremity joint injury and diagnosed OA. These findings provide insight regarding the potential pathways to chronic diseases that may be initiated by joint injury early in life., (© by the National Athletic Trainers’ Association, Inc.)

Background: The age of first exposure (AFE) to American football participation is a growing concern for late-life function. Mixed evidence exists surrounding AFE and may be attributed to varied methods employed across studies., Objective: To examine the associations between AFE to American football participation with measures of cognitive, behavioral, and physical function and brain-related medical diagnoses across age categories among former National Football League players., Methods: We conducted a cross-sectional survey of 1784 former players (age: 52.3 ± 16.3 years, AFE: 11.3 ± 2.9 years, years of football: 17.5 ± 4.5 years, 86.9% ≥ one lifetime concussion). Players completed a general health questionnaire recording demographics, football playing history (including AFE), and diagnoses (anxiety, depression, any form of dementia, mild cognitive impairment). Players completed Patient-Reported Outcomes Measurement Information System (PROMIS) measures assessing domains of cognitive and physical function, anxiety, depression, sleep disturbance, pain interference, and emotional-behavioral dyscontrol. Multivariable linear and binomial regression models were used to examine the associations of AFE and age with PROMIS outcomes and diagnoses, respectively., Results: No significant AFE by age interactions were detected for PROMIS outcomes (p ≥ 0.066) or diagnoses (p ≥ 0.147). Younger AFE associated with higher PROMIS scores of anxiety (B = - 0.22, p = 0.016), depression (B = - 0.22, p = 0.010), sleep disturbances (B = - 0.16, p = 0.007), pain interference (B = - 0.19, p = 0.014), and emotional-behavioral dyscontrol (B = - 0.22, p = 0.019). Age was associated with all PROMIS outcomes (p ≤ 0.042). AFE was not associated with the prevalence of anxiety, depression, dementia, or mild cognitive impairment (p ≥ 0.449), while age was (p ≤ 0.013)., Conclusions: AFE was significantly associated with PROMIS outcomes, albeit low-strength associations (i.e., effect sizes), but not with diagnoses. Our findings indicate AFE is a significant but minor contributing factor for health-related quality of life in this cohort. Future work should incorporate additional characterizations of cumulative head impacts and related factors when examining long-term outcomes associated with football participation., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Objective: Studies have observed variable associations of prior contact sport participation with subjective and objective measures of cognitive function. This study directly investigated the association between subjective self-report and objective performance-based cognition among former collegiate football players, as well as its relationship to self-reported concussion history., Methods: Former collegiate football players (N = 57; mean age = 37.9 years [ SD  = 1.49]) retired from sport 15-years prior were enrolled. Linear regression models examined associations between subjective cognition (Quality of Life in Neurological Disorders Cognitive Functioning-Short Form), and performance on a neuropsychological battery. Domain specific (executive function) metrics of subjective (Behavior Rating Inventory of Executive Function-Adult) and objective cognition were also exclusively examined. Associations between self-reported concussion history with subjective and objective measures were tested. Potential influential factors (sleep quality and distress) were included as covariates., Results: Subjective cognition was not significantly associated with any objective measures of cognitive functioning ( p 's > .05). Greater self-reported concussion history was inversely associated with subjective cognition (B = -2.49, p = .004), but not objective performance-based cognition ( p 's > .05). Distress was significantly related to all metrics of subjective cognition ( p 's < .001) as well as performance on delayed recall and verbal fluency ( p 's < .05). Sleep quality was only significantly related to timed visuospatial sequencing ( p = .033)., Conclusions: Reliance on self-reported measures of cognitive functioning alone is insufficient when assessing cognition in former contact sport athletes. Assessment of other factors known to influence subjective cognitive complaints should also be examined in determining the presence of cognitive deficits.

Background: An association has been identified between concussion and lower extremity musculoskeletal injury (LEMSKI) after return to sports participation. However, the collegiate student-athlete studies have relied on relatively small single-institution studies, which limits generalizability., Purpose: To assess odds of, and time to, LEMSKI after concussion in US collegiate athletes, using the National Collegiate Athletic Association (NCAA) Injury Surveillance Program (ISP)., Study Design: Descriptive epidemiology study., Methods: Data from the NCAA ISP during the 2010-2011 through 2019-2020 athletic seasons were considered for analysis. Frequency distributions were examined for details related to the initial and subsequent injuries (injuries to bone, bursa, joint, ligament, muscle, or tendon). Multivariable logistic regression models and random-effects Poisson regression models examined odds of time loss (TL) and non-time loss (NTL) LEMSKI after concussion, as well as the time interval between initial concussion and subsequent LEMSKI in a single athletic season, or initial musculoskeletal injury (MSKI) and subsequent LEMSKI in a single athletic season. Analyses were performed separately for football and other sports., Results: A total of 31,556 initial injuries were recorded (football: 11,900; other sports: 19,656), which were followed by 0 or 1 injury in the same season. Overall, first injury type was not a significant predictor of subsequent LEMSKI, although certain contrasts yielded significant estimates. In football, the odds of NTL LEMSKI were higher after concussion than after upper extremity MSKI (UEMSKI; adjusted odds ratio [OR Adj ], 1.56; 95% CI, 1.06-2.31). In football, the odds of TL LEMSKI were lower after concussion than after UEMSKI (OR Adj , 0.71; 95% CI, 0.51-0.99). No other significant effect estimates were observed for football or other sports., Conclusion: First injury type, either concussion or upper extremity, was not associated with an elevated risk of LEMSKI. Specifically, the results of this study did not identify an elevated odds of LEMSKI after a concussion. However, the authors observed greater odds of NTL LEMSKI and lower odds of TL LEMSKI in football.

The objective of this study was to examine associations of lifetime concussion history (CHx) and an advanced metric of lifetime repetitive head impact exposure with resting-state functional connectivity (rsFC) across the whole-brain and among large-scale functional networks (Default Mode; Dorsal Attention; and Frontoparietal Control) in former collegiate football players. Individuals who completed at least one year of varsity collegiate football were eligible to participate in this observational cohort study (n = 48; aged 36-41 years; 79.2% white/Caucasian; 12.5±4.4 years of football played; all men). Individuals were excluded if they reported history/suspicion of psychotic disorder with active symptoms, contraindications to participation in study procedures (e.g., MRI safety concern), or inability to travel. Each participant provided concussion and football playing histories. Self-reported concussion history was analyzed in two different ways based on prior research: dichotomous "High" (≥3 concussions; n = 28) versus "Low" (<3 concussions; n = 20); and four ordinal categories (0-1 concussion [n = 19]; 2-4 concussions [n = 8]; 5-7 concussions [n = 9]; and ≥8 concussions [n = 12]). The Head Impact Exposure Estimate (HIEE) was calculated from football playing history captured via structured interview. Resting-state fMRI and T1-weighted MRI were acquired and preprocessed using established pipelines. Next, rsFC was calculated using the Seitzman et al., (2020) 300-ROI functional atlas. Whole-brain, within-network, and between-network rsFC were calculated using all ROIs and network-specific ROIs, respectively. Effects of CHx and HIEE on rsFC values were examined using separate multivariable linear regression models, with a-priori α set to 0.05. We observed no statistically significant associations between rsFC outcomes and either CHx or HIEE (ps ≥ .12). Neither CHx nor HIEE were associated with neural signatures that have been observed in studies of typical and pathological aging. While CHx and repetitive head impacts have been associated with changes in brain health in older former athletes, our preliminary results suggest that associations with rsFC may not be present in early midlife former football players., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: BLB reports grants and support from the National Institute of Neurological Disorders and Stroke and National Institute on Aging under the National Institutes of Health. KMG reports compensation from National Collegiate Athletic Association for other services and grants from Boston Children’s Hospital (sub-award from the National Football League). MAM acknowledges researching funding from the National Institutes of Health, U.S. Department of Defense, Centers for Disease Control and Prevention, National Collegiate Association and National Football League (via subaward from Boston Children’s Hospital). No other conflicts of interest are declared for the remaining authors.

Objectives: To examine the stability of former National Football League (NFL) players' recall of professional football concussion., Methods: Two-hundred-and-nine former NFL players (ceasing football participation before/in 2001) completed surveys in 2001, 2010, and 2019 and reported the number of concussions sustained during their professional careers (0, 1 … 10, >10). Participants were categorized into four 'recall stability' groups, based upon concussion recall [e.g., 'Same' (same number recalled), 'Increased' (more recalled than in prior time point)]. In 2019, participants completed measures of functioning (e.g., PROMIS Cognitive Function, Anxiety, Depression). Fleiss Kappa and generalized linear mixed models (GLMM)-based ordinal measures Kappa assessed stability across time points. 'Recall stability group' functioning scores were compared., Results: Overall, 45.9% recalled more concussions over time; 14.8% reported the same number. Fleiss Kappa and GLMM-based ordinal measures Kappa suggested fair (0.22, 95% CI: 0.26, 0.38) and moderate stability (0.41, 95% CI: 0.35, 0.46), respectively. Higher cognitive functioning (P = 0.002), lower anxiety (P = 0.003), and lower depression (P = 0.007) were observed in the 'Same' vs 'Increased' groups., Conclusions: Despite subtle time-based variations in reporting, professional football concussion history recall was relatively stable. Better cognitive and psychological functioning was associated with greater stability in concussion recall.

Transition from professional sport to nonsport endeavors has implications for postcareer health and well-being of athletes. The purpose of the current study was to examine associations among transition-related psychosocial factors and current mental health outcomes in former National Football League (NFL) players. Participants were former NFL players (n = 1,784; mean age = 52.3 ± 16.3 years) who responded to a questionnaire assessing the nature of their discontinuation from professional football (i.e., any degree of voluntary choice vs. forced discontinuation), prediscontinuation transition planning (yes vs. no), and current symptoms of depression and anxiety. After adjusting for relevant covariates, having an involuntary discontinuation and no transition plan prior to discontinuation were associated with greater depressive and anxiety symptom severity. Autonomy in discontinuation and pretransition planning are important to former NFL football players' mental health. Increasing autonomy in the discontinuation decision and pretransition planning represent psychoeducational intervention targets for this population.

Objective: This study investigated the longitudinal course of depressive symptom severity over 19 years in former American football players and the influence of concussion history, contact sport participation and physical function on observed trajectories., Methods: Former American football players completed a general health questionnaire involving demographic information, medical/psychiatric history, concussion/football history and validated measures of depression and physical function at three time points (2001, 2010 and 2019). Parallel process latent growth curve modelling tested associations between concussion history, years of football participation, and overall and change in physical function on the overall level and trajectory of depressive symptoms., Results: Among the 333 participants (mean(SD) age, 48.95 (9.37) at enrolment), there was a statistically significant, but small increase in depressive symptom severity from 2001 (48.34 (7.75)) to 2019 (49.77 (9.52)), slope=0.079 (SE=0.11), p=0.007. Those with greater concussion history endorsed greater overall depressive symptom severity, B=1.38 (SE=0.33), p<0.001. Concussion history, B<0.001 (SE=0.02), p=0.997 and years of participation, B<0.001 (SE=0.01), p=0.980, were not associated with rate of change (slope factor) over 19 years. Greater decline in physical function, B=-0.71 (SE=0.16), p<0.001, was predictive of a faster growth rate (ie, steeper increase) of depression symptom endorsement over time., Conclusions: Concussion history, not years of participation, was associated with greater depressive symptom severity. Neither factor was predictive of changes over a 19-year period. Decline in physical function was a significant predictor of a steeper trajectory of increased depressive symptoms, independent of concussion effects. This represents one viable target for preventative intervention to mitigate long-term neuropsychiatric difficulties associated with concussion across subsequent decades of life., Competing Interests: Competing interests: BLB acknowledges support from the National Institute of Neurological Disorders and Stroke (Award Number L30NS113158-02) and National Institute on Aging (Award Number K23 AG073528).ZYK reports grants from National Institutes of Health; grants from Centers for Disease Control and Prevention; and grants from National Football League. AC discloses funding from the National Collegiate Athletic Association. RM reports grants from U.S. Department of Defense; grants from NFL Foundation; and grants from National Institute of Neurological Disorders and Stroke. RE is a paid consultant for the NHL and co-chair of the NHL/NHLPA Concussion Subcommittee. He is also a paid consultant for Major League Soccer and Princeton University Athletic Medicine and occasionally provides expert testimony in matters related to MTBI and sports concussion. WM receives royalties from (1) ABC-Clio publishing for the sale of his books, Kids, Sports and Concussion: A guide for coaches and parents, and Concussions; (2) Springer International for the book Head and Neck Injuries in Young Athlete and (3) Wolters Kluwer for working as an author for UpToDate. His research is funded, in part, by philanthropic support from the National Hockey League Alumni Association through the Corey C. Griffin Pro-Am Tournament and a grant from the National Football League.Dr Guskiewicz reports compensation from National Collegiate Athletic Association for other services and grants from Boston Children's Hospital (sub-award from the National Football League). MM acknowledges researching funding from the NIH, US Dept. of Defense, CDC, NCAA and NFL to the Medical College of Wisconsin., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: This study aimed to estimate prevalence of mild cognitive impairment (MCI) and dementia diagnoses in former National Football League (NFL) players ≥50 yr old and examine the relationships among these diagnoses and an array of predictors of long-term brain health., Methods: A cross section of former NFL players (n = 922; mean ± SD age, 64.8 ± 8.9 yr) completed a questionnaire. Prevalence of self-reported medical diagnoses of MCI and dementia was reported alongside U.S. population estimates across 5-yr age intervals (e.g., 60-64 yr). Prevalence ratios (PR) were calculated for multiple predictors of long-term brain health., Results: Overall, MCI prevalence and dementia prevalence were n = 219(23.8%) and n = 82(8.9%), respectively. Each diagnosis was more prevalent in former NFL players across age-groups than U.S. norms, with greater disparities at relatively younger ages (e.g., 65-69 yr) compared with older ages. Greater prevalence of MCI and dementia was associated with self-reported concussion history (10+ vs 0; PRadjusted [95% CI] = 1.66 [1.02-2.71] and 2.61 [1.01-6.71], respectively); recent pain intensity (PRadjusted [95% CI] = 1.13 [1.07-1.20] and 1.15 [1.03-1.28]); and diagnoses of depression (PRadjusted [95% CI] = 2.70 [1.92-3.81] and 3.22 [1.69-6.14]), anxiety (PRadjusted [95% CI] = 1.96 [1.26-3.07] and 3.14 [1.47-6.74]), or both (PRadjusted [95% CI] = 3.11 [2.38-4.08] and 4.43 [2.71-7.25]). Higher MCI prevalence was related to sleep apnea (PRadjusted [95% CI] = 1.30 [1.06-1.60]); higher dementia prevalence was associated with age (5-yr interval, PRadjusted [95% CI] = 1.42 [1.26-1.60]) and race (non-White vs White, PRadjusted [95% CI] = 1.64 [1.07-2.53])., Conclusions: Self-reported MCI prevalence and dementia prevalence were higher in former NFL players than national estimates and were associated with numerous personal factors, including mood-related disorders and a high number of self-reported concussions. Predictors of higher MCI and dementia prevalence may be modifiable and warrant consideration by clinicians and researchers as potential targets to mitigate the onset of these conditions., (Copyright © 2021 by the American College of Sports Medicine.)

Primary Objective: To describe the collaborative development of a New Zealand Rugby Concussion Assessment (NZRCA) for primary care and to provide normative baseline data from a representative group of high school rugby players., Methods: This study, conducted over the 2018 and 2019 community rugby season where players were baseline tested during the pre- or start of season period., Results: Data were collected from 1428 players (males n = 1121, females n = 307) with a mean age of 15.9 ± 1.4 years. The mean ± SD symptom severity score was 11.3 ± 8.6, the mean number of endorsed symptoms was 8.5 ± 5.3 and the percentage feeling "normal" was 80.2 ± 15.3%. Only 5.3% of players reported no symptoms at baseline. The most common reported were: 'distracted easily' (72.5%), 'forgetful' (68.5%), and 'often tired' (62.6%). None of the participants achieved a perfect score for the SAC50. The majority of participants (89.7%) passed the tandem gait test with a time of 12.2 ± 1.7 seconds. Age, gender, and ethnicity were associated with NZRCA performance; albeit weakly., Conclusion: This study provides normative reference values for high-school rugby players. These data will aid healthcare providers in their identification of suspected concussion in the absence of individualized baselines.

Background and Purpose: Postmortem and experimental studies indicate a potential association between repeated concussions and stroke risk in older contact sport athletes. We examined the relationship between concussion and stroke history in former National Football League players aged ≥50 years., Methods: Former professional football players aged ≥50 years who played ≥1 year in the National Football League were enrolled in the cross-sectional study. Indirect standardization was used to calculate overall and decade-specific standardized prevalence ratios. Logistic regression using Firth's bias reduction method examined the association between lifetime concussion history 0 (n=119; 12.2%), 1 to 2 (n=152; 15.5%), 3 to 5 (n=242; 24.7%), 6 to 9 (201; 20.5%), and 10+(n=265; 27.1%) and stroke. Adjusted odds ratios for stroke were calculated for concussion history groups, age, and coronary artery disease and/or myocardial infarction., Results: The 979 participants who met inclusion criteria had a mean age of 65.0±9.0 years (range, 50-99). The prevalence of stroke was 3.4% (n=33), significantly lower than expected based on rates of stroke in US men aged 50 and over (standardized prevalence ratio=0.56, Z= -4.56, P <0.001). Greater odds of stroke history were associated with concussion history (10+ versus 0, adjusted odds ratio [95% CI]=5.51 [1.61-28.95]), cardiovascular disease (adjusted odds ratio [95% CI]=2.24 [1.01-4.77]), and age (1-year-increase adjusted odds ratio [95% CI]=1.07 [1.02-1.11])., Conclusions: The prevalence of stroke among former National Football League players aged ≥50 years was lower than the general population, with significantly increased risk among those with 10 or more prior concussions. Findings add to the evidence suggesting that traumatic brain injuries are associated with increased risk of stroke. Clinically, management of cardio- and cerebrovascular health may be pertinent to those with a history of multiple prior concussions.

Objectives: Years of sport participation (YoP) is conventionally used to estimate cumulative repetitive head impacts (RHI) experienced by contact sport athletes. The relationship of this measure to other estimates of head impact exposure and the potential associations of these measures with neurobehavioral functioning are unknown. We investigated the association between YoP and the Head Impact Exposure Estimate (HIEE), and whether associations between the two estimates of exposure and neurobehavioral functioning varied., Methods: Former American football players (N = 58; age = 37.9 ± 1.5 years) completed in-person evaluations approximately 15 years following sport discontinuation. Assessments consisted of neuropsychological assessment and structured interviews of head impact history (i.e., HIEE). General linear models were fit to test the association between YoP and the HIEE, and their associations with neurobehavioral outcomes., Results: YoP was weakly correlated with the HIEE, p = .005, R2 = .13. Higher YoP was associated with worse performance on the Symbol Digit Modalities Test, p = .004, R2 = .14, and Trail Making Test-B, p = .001, R2 = .18. The HIEE was associated with worse performance on the Delayed Recall trial of the Hopkins Verbal Learning Test-Revised, p = .020, R2 = .09, self-reported cognitive difficulties (Neuro-QoL Cognitive Function), p = .011, R2 = .10, psychological distress (Brief Symptom Inventory-18), p = .018, R2 = .10, and behavioral regulation (Behavior Rating Inventory of Executive Function for Adults), p = .017, R2 = .10., Conclusions: YoP was marginally associated with the HIEE, a comprehensive estimate of head impacts sustained over a career. Associations between each exposure estimate and neurobehavioral functioning outcomes differed. Findings have meaningful implications for efforts to accurately quantify the risk of adverse long-term neurobehavioral outcomes potentially associated with RHI.

The purpose of this study was to investigate the effects of sport participation, concussion history, and age of first exposure to football on preseason cerebrovascular function in adolescent athletes. Athletes (n = 53, age = 15.8 ± 1.2 years) were examined based on three exposure groupings: (1) sport participation (football vs. non-collision), (2) concussion history (none vs. ≥ 1), and (3) age of first exposure (football participants only). Transcranial Doppler assessed cerebrovascular reactivity (CVR) and neurovascular coupling (NVC), and separate independent samples t-tests evaluated group differences in CVR and NVC outcomes. Separate univariate linear regressions determined how age of first exposure related to CVR and NVC outcomes. Linear mixed effects models assessed group differences in CVR and NVC relative response curves. Differential response to NVC visual task response was significantly greater in non-collision sport athletes (F 1,2946 = 38.69, p < 0.0001) and athletes without a concussion history (F 1,2946 = 25.23, p < 0.0001). Older age of first exposure significantly predicted reduced breath-holding CVR response (F 1,1560 = 2.92, p = 0.03). Healthy adolescent athletes have similar pre-season cerebrovascular function despite different sport participation and concussion history. However, age of first exposure may predict CVR in adolescent football athletes. Developmental literature identifies cerebrovascular function as dynamically changing throughout adolescence. Our study provides fundamental data informing the clinical meaningfulness of short- and long-term physiological function changes., (© 2021. Biomedical Engineering Society.)

Objective: To report pre-season baseline concussion assessment performance among senior rugby players and explore associations between assessment performance and player demographics., Design: A cross-sectional study using the New Zealand Rugby Concussion Assessments (NZRCA), comprising symptom, cognitive and dynamic coordination assessments was conducted in the 2018-2019 season., Methods: Players' baseline assessments were characterised using descriptive statistics; effect sizes (ES) and t-tests were used to explore associations between player demographic characteristics and NZRCA performance., Results: A total of 733 players (11.4% female) aged between 16 and 52 years completed the NZRCA. The median (range) value for symptom severity, endorsed symptoms and "percentage normal" was respectively, 5 (0-40), 5 (0-21) and 90% (30-100%). A perfect standardised assessment of concussion score was achieved by one participant; seven achieved ≥27/30 for immediate recall, and 22 achieved a perfect delayed recall score. Most participants (n = 674, 92%) passed the tandem gait test. Associations between NZRCA performance and gender, concussion history, and Pasifika ethnicity were observed with effect sizes ranging from small (0.18) to large (0.70). Six hundred and twenty-three (85%) participants reported at least one symptom., Conclusions: The results from this study could help support decision-making by clinicians, improving the management of concussions in the community setting.

Context: The aim of the National Athletic Trainers' Association Inter-Association Task Force (NATA-IATF) preseason heat-acclimatization guidelines was to acclimatize high school athletes to the environment during the first 2 weeks of the preseason and reduce the risk of exertional heat illness., Objective: To identify barriers and facilitators that high school athletic trainers (ATs) encountered when implementing the NATA-IATF guidelines., Design: Qualitative study., Setting: Individual phone interviews with all participants., Patients or Other Participants: Thirty-three ATs (16 men, 17 women; age = 36.0 ± 12.0 years, athletic training experience = 12.9 ± 10.5 years) representing 19 states (4 with state mandates) were interviewed before data saturation was achieved. Participants were purposefully sampled from a larger investigation based on stratification of US Census region and preidentified high school compliance with the NATA-IATF guidelines., Main Outcome Measure(s): A cross-sectional, semistructured phone interview (6 steps) was conducted with each participant and then transcribed verbatim. A 7-person research team (5 coders, 2 auditors) coded the data into themes and categories, focusing on consensus of data placement to reduce bias and ensure accuracy., Results: Facilitators and barriers that influenced successful guideline implementation were (1) perceived stakeholder access, (2) perceived stakeholder role, (3) capability and capacity, (4) school culture, (5) logistical support, (6) resources, (7) physical environment, and (8) consistency of the guidelines. Overall, participants discussed facilitators and barriers within each category based on their experiences and circumstances., Conclusions: Athletic trainers faced numerous concerns regarding compliance with the NATA-IATF preseason heat-acclimatization guidelines. Multiple levels of influence should be targeted to improve implementation. These include intrapersonal factors by giving ATs the education and self-efficacy to support advocacy for implementation, interpersonal components by establishing strong collaborative networks for change, community and environmental factors by optimizing school culture and community resources for implementation, and policy aspects by establishing consistent guidelines across all bodies., (© by the National Athletic Trainers' Association, Inc.)

Objectives: To examine the relationships among self-reported sport-related concussion (SRC) history and current health-promoting behaviours (exercise frequency, diet quality and sleep duration) with self-reported measures of brain health (cognitive function, symptoms of depression and anxiety and emotional-behavioural dyscontrol) in former NFL players., Methods: In this cross-sectional study, a questionnaire was sent to former NFL players. Respondents reported SRC history (categorical: 0; 1-2; 3-5; 6-9; 10+ concussions), number of moderate-to-vigorous aerobic and resistance exercise sessions per week, diet quality (Rapid Eating Assessment for Participants-Shortened) and average nightly sleep duration. Outcomes were Patient-Reported Outcomes Measurement Information System Cognitive Function, Depression, and Anxiety, and Neuro-QoL Emotional-Behavioral Dyscontrol domain T-scores. Multivariable linear regression models were fit for each outcome with SRC history, exercise frequency, diet quality and sleep duration as explanatory variables alongside select covariates., Results: Multivariable regression models (n=1784) explained approximately 33%-38% of the variance in each outcome. For all outcomes, SRC history (0.144≤|β|≤0.217) was associated with poorer functioning, while exercise frequency (0.064≤|β|≤0.088) and diet quality (0.057≤|β|≤0.086) were associated with better functioning. Sleeping under 6 hours per night (0.061≤|β|≤0.093) was associated with worse depressive symptoms, anxiety and emotional-behavioural dyscontrol., Conclusion: Several variables appear to be associated with mood and perceived cognitive function in former NFL players. SRC history is non-modifiable in former athletes; however, the effects of increasing postplaying career exercise frequency, making dietary improvements, and obtaining adequate sleep represent important potential opportunities for preventative and therapeutic interventions., Competing Interests: Competing interests: BLB acknowledges support from the National Institute of Neurological Disorders and Stroke under the National Institutes of Health under the award NO L301L30NS113158-01. RJE is a paid consultant for the NHL and co-chair of the NHL/NHLPA Concussion Subcommittee. He is also a paid consultant for Major League Soccer and Princeton University Athletic Medicine and occasionally provides expert testimony in matters related to MTBI and sports concussion. WPM receives royalties from 1) ABC-Clio publishing for the sale of his books, Kids, Sports, and Concussion: A guide for coaches and parents, and Concussions; 2) Springer International for the book Head and Neck Injuries in Young Athlete and 3) Wolters Kluwer for working as an author for UpToDate. His research is funded, in part, by philanthropic support from the National Hockey League Alumni Association through the Corey C. Griffin Pro-Am Tournament and a grant from the National Football League., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Context: Little research has examined health-related quality of life in former National Football League (NFL) players., Objective: Examine the association of musculoskeletal injury history and current self-reported physical and mental health in former NFL players., Setting: Cross-sectional questionnaire., Patients or Other Participants: Historical cohort of 2,103 former NFL players that played at least one season between 1940 and 2001., Intervention: Players were grouped by self-reported professional career musculoskeletal injury history and whether injuries affected current health: (1) no musculoskeletal injury history; (2) musculoskeletal injury history, currently affected by injuries; and (3) musculoskeletal injury history, not currently affected by injuries., Main Outcome Measure: The Short Form 36 Measurement Model for Functional Assessment of Health and Well-Being (SF-36) yielded physical and mental health composite scores (PCS and MCS, respectively); higher scores indicated better health. Multivariable linear regression computed mean differences (MD) among injury groups. Covariates included demographics, playing history characteristics, surgical intervention for musculoskeletal injuries, and whether injury resulted in premature end to career. MD with 95% CI excluding 0.00 were deemed significant., Results: Overall, 90.3% reported at least one musculoskeletal injury during their professional football careers, of which 74.8% reported being affected by their injuries at time of survey completion. Adjusting for covariates, mean PCS in the "injury and affected" group was lower than the "no injury" (MD = -3.2; 95% CI: -4.8, -1.7) and "injury and not affected" groups (MD = -4.3; 95% CI: -5.4, -3.3); mean MCS did not differ., Conclusion: Many players reported musculoskeletal injuries, highlighting the need for developing and evaluating injury management interventions.

Objective: To determine which intrinsic and extrinsic exertional heat illness (EHI) risk factors exist in youth American football players and observe perceptual and physiological responses of players during events (games and practices)., Methods: Cross-sectional cohort study observing 63 youth football players, varying in position. Independent variables were league (weight-restricted (WR, n = 27) and age-restricted (AR, n = 36)) and event type. Dependent variables were anthropometrics, work-to-rest ratio, and wet bulb globe temperature. Descriptive variables included preparticipation examination and uniform configuration. A subset of 16 players participated in physiological variables (heart rate and gastrointestinal temperature). Data collection occurred on 7 AR and 8 WR nonconsecutive practices and the first 3 games of the season., Results: Mean values for anthropometric variables were higher (p < 0.05) in the AR league than the WR league. Work time (χ 2 (1,111) = 4.232; p = 0.039) and rest time (χ 2 (1,111) = 43.41; p < 0.001) were significantly greater for games, but ratios were significantly higher for practices (χ 2 (1,111) = 40.62; p < 0.001). The majority of events (77%) observed were in black and red flag wet bulb globe temperature risk categories. A total of 57% of the players had a preparticipation examination, and up to 82% of events observed were in full uniforms. Individual gastrointestinal temperature and heart rate responses ranged widely and no players reached critical thresholds., Conclusion: Extrinsic (disproportionate work ratios, environmental conditions) and intrinsic (higher body mass index) EHI risk factors exist in youth football. Certain risk factors may be influenced by event and league type. National youth football organizations need to create thorough guidelines that address EHI risk factors for local leagues to adopt., (Copyright © 2019. Production and hosting by Elsevier B.V.)

Context: Athletic trainers (ATs) are educated and trained in appropriate exertional heat-stroke (EHS) management strategies, yet disparities may exist between intended and actual uses in clinical practice., Objective: To examine the intended and actual uses of EHS management strategies among those who did and those who did not treat patients with suspected cases of EHS during the 2017 high school (HS) American football preseason., Design: Cross-sectional study., Setting: Online questionnaire., Patients or Other Participants: A total of 1016 ATs who oversaw patient care during the 2017 HS American football preseason., Main Outcome Measure(s): Responding HS ATs recorded whether they had or had not managed patients with suspected EHS events during the 2017 HS American football preseason. Those who had managed patients with suspected cases of EHS reported the management strategies used; those who had not managed such patients described their intended management strategies. For each management strategy, z tests compared the proportions of actual use among ATs who managed patients with suspected EHS with the proportions of intended use among ATs who did not manage such patients., Results: Overall, 124 (12.2%) ATs treated patients with suspected EHS cases during the 2017 HS American football preseason. Generally, the proportions of intended use of management strategies among ATs who did not treat patients with suspected EHS were higher than the actual use of those strategies among ATs who did. For example, ATs who did treat patients with suspected EHS were more likely than those who did not treat such patients to intend to take rectal temperature (19.6% versus 3.2%, P < .001) and immerse the athlete in ice water (90.1% versus 51.6%, P < .001)., Conclusions: Inconsistencies occurred between intended and actual use of EHS management strategies. The standard of care for managing patients with suspected cases of EHS was not consistently used in clinical practice, although ATs who did not treat EHS stated they intended to use these management strategies more frequently. Future researchers should identify factors that preclude ATs from using the standard of care when treating patients with suspected cases of EHS., (© by the National Athletic Trainers' Association, Inc.)

Objective : To determine chronic traumatic encephalopathy (CTE)-related publication characteristics associated with higher Altmetric scores. Methods : A systematic review of the CTE literature was conducted using PubMed. Publications were coded for: journal impact factor (JIF); publication type (primary versus non-primary data collection); discussion of American football; contact sport-CTE association conclusion (yes versus no/neutral); and Altmetric score. Multivariable ordinal logistic regression identified predictors of higher Altmetric scores. Results : Most of the 270 CTE-related publications did not include primary data collection (60%). The median Altmetric score was 12 (range = 0-3745). Higher Altmetric scores were associated with primary data collection [Odds ratio (OR) Adjusted  = 2.29; 95% confidence interval (CI) = 1.35-3.89] and discussing American football (OR Adjusted  = 2.11; 95%CI = 1.24-3.59). Among publications concluding contact sport-CTE associations, higher Altmetric scores were associated with higher JIF (3-point-JIF-increase OR Adjusted = 2.11; 95%CI = 1.24-3.59); however, the association of higher Altmetric scores with higher JIF was not found among neutral publications or those concluding no contact sport-CTE associations (3-point-JIF-increase OR Adjusted  = 1.07; 95%CI = 0.94-1.22). Conclusions : Most CTE-related publications (60%) did not involve primary data collection. Publication characteristics such as higher JIF and concluding contact sport-CTE associations were associated with higher Altmetric scores. It is important for the academic community to consider strategies to counter publication and promotion bias in the presentation of CTE literature.

Context: Ankle injuries are common at all levels of American football, and retired National Football League (NFL) players have a high prevalence of osteoarthritis (OA), but little is known about how ankle injuries influence OA prevalence and daily activities in this population or how surgical interventions for such injuries alter the risk of OA., Objective: To examine (1) the association of ankle-injury history with OA prevalence, (2) the association of surgical intervention after ankle injury with OA prevalence, and (3) the relationships among ankle injuries, reported OA, and daily activities in retired NFL players., Design: Case-control study., Setting: Survey., Patients or Other Participants: Data from the Retired NFL Players General Health Survey., Main Outcome Measure(s): We created a 7-category main exposure variable that differentiated respondents by football-related ankle injury and surgical intervention. Multivariable binomial regression models were used to estimate prevalence ratios and 95% confidence intervals. Among those reporting OA, we examined the distribution of responses regarding whether OA affected daily activities., Results: Among the 2446 respondents, 920 participants experienced OA in any joint during their lifetime. Compared with those reporting no ankle injuries, the prevalence of OA was higher among those with a history of ankle injury. Also, the prevalence of OA was higher among those who had undergone surgery versus those who had not. The number of retired NFL players who reported that OA often affected their daily activities increased with the number of ankle injuries., Conclusions: Among former NFL players, a history of ankle injury increased the prevalence of OA. More ankle injuries increased the probability that OA negatively affected daily activities. Future prospective research is needed to better determine the influence of surgical intervention at the ankle or foot on OA.

Background: Osteoarthritis is a substantial cause of disability. Joint replacement prevalence relates to the burden of severe osteoarthritis, and identifying risk factors for end-stage disease may indicate intervention opportunities. American football has high youth and elite participation, and determining risk factors for severe osteoarthritis may support future morbidity prevention., Purpose: To (1) determine the prevalence of hip and knee replacement in retired National Football League (NFL) athletes, (2) examine risk factors for replacement, and (3) identify the association between knee injuries and knee replacement., Study Design: Case-control study; Level of evidence, 3., Methods: Retired NFL athletes who participated in a general health survey were included. This historical cohort included those playing between 1929 and 2001. The association between self-reported playing or injury history, and replacement after retirement, was assessed with prevalence ratios (PRs). Models were adjusted for potential confounders of age and weight., Results: Data for 2432 retired male NFL players (69.3% response rate) who had participated in football for a mean 15.2 years were included, in which 277 players reported replacement after retirement (11.4%). More participants reported knee replacement (7.7%) than hip replacement (4.6%). The majority of participants reported previous severe knee injury (53%), and the most prevalent was meniscal tear (32.2%). In multivariable models, age (10-year increase, PR, 2.23; 95% CI, 1.99-2.51), current weight (PR, 1.10; 95% CI, 1.06-1.14), and reporting 1 (PR, 1.78; 95% CI, 1.14-2.77), 2 (PR, 1.91; 95% CI, 1.16-3.15), or ≥3 knee injuries (PR, 3.44; 95% CI, 2.33-5.09) were associated with knee replacement. Age (10-year increase, PR, 1.86; 95% CI, 1.59-2.18), linemen (PR, 1.62; 95% CI, 1.03-2.55), and reporting 1 (PR, 1.72; 95% CI, 1.05-2.80), 2 (PR, 2.77 95% CI, 1.58-4.84), or ≥3 (PR, 2.44; 95% CI, 1.52-3.91) hip injuries were associated with hip replacement. Each reported knee injury type was cross-sectionally associated with replacement after retirement ( P < .05)., Conclusion: Knee replacement was more prevalent than hip replacement. Risk factors differed between the hip and the knee, with age and severe joint injury associated with hip and knee replacement, weight with knee replacement, and playing position associated with hip replacement. Joint injury and weight management may be prevention opportunities to reduce morbidity and end-stage osteoarthritis in this population.

Context: Exertional heat stroke (EHS) is a leading cause of sudden death in high school football players. Preparedness strategies can mitigate EHS incidence and severity., Objective: To examine EHS preparedness among high school football programs and its association with regional and state preseason heat-acclimatization mandates., Design: Cross-sectional study., Setting: Preseason high school football programs, 2017., Patients or Other Participants: A total of 910 athletic trainers (ATs) working with high school football (12.7% completion rate)., Main Outcome Measure(s): We acquired data on high school football programs' EHS preparedness strategies in the 2017 preseason via an online questionnaire, looking at (1) whether schools' state high school athletic associations mandated preseason heat-acclimatization guidelines and (2) heat safety region based on warm-season wet-bulb globe temperature, ranging from the milder region 1 to the hotter region 3. Six EHS-preparedness strategies were assessed: EHS recognition and treatment education; policy for initiating emergency medical services response; emergency response plan enactment; immersion tub filled with ice water before practice; wet-bulb globe temperature monitoring; and hydration access. Multivariable binomial regression models estimated the prevalence of reporting all 6 strategies., Results: Overall, 27.5% of ATs described their schools as using all 6 EHS-preparedness strategies. The highest prevalence was in region 3 schools with state mandates (52.9%). The multivariable model demonstrated an interaction in which the combination of higher heat safety region and presence of a state mandate was associated with a higher prevalence of reporting all 6 strategies ( P = .05). Controlling for AT and high school characteristics, the use of all 6 strategies was higher in region 3 schools with state mandates compared with region 1 schools without state mandates (52.9% versus 17.8%; prevalence ratio = 2.68; 95% confidence interval = 1.81, 3.95)., Conclusions: Our findings suggest a greater use of EHS-preparedness strategies in environmentally warmer regions with state-level mandates for preseason heat acclimatization. Future researchers should identify factors influencing EHS preparedness, particularly in regions 1 and 2 and in states without mandates.

Context: Cervical muscle strains are an often-overlooked injury, with neck- and spine-related research typically focusing on spinal cord and vertebral injuries., Objective: To examine the rates and distributions of cervical muscle strains in collegiate and high school football athletes., Design: Descriptive epidemiology study., Setting: Collegiate and high school football teams., Patients or Other Participants: The National Collegiate Athletic Association Injury Surveillance Program (NCAA-ISP) collected data from collegiate football athletes. The High School National Athletic Treatment, Injury and Outcomes Network (HS NATION) and High School Reporting Information Online (HS RIO) collected data from high school football athletes. Data from the 2011-2012 through 2013-2014 academic years were used., Main Outcome Measure(s): Athletic trainers collected injury and exposure data for football players. Injury counts, injury rates per 10 000 athlete-exposures (AEs), and injury rate ratios with 95% confidence intervals (CIs) were calculated., Results: The NCAA-ISP reported 49 cervical muscle strains (rate = 0.96/10 000 AEs), of which 28 (57.1%) were TL (time loss; rate = 0.55/10 000 AEs). High School NATION reported 184 cervical muscle strains (rate = 1.66/10 000 AEs), of which 33 (17.9%) were TL injuries (rate = 0.30/10 000 AEs). The HS RIO, which collects only TL injuries, reported 120 TL cervical muscle strains (rate = 0.51/10 000 AEs). The overall injury rate was lower in the NCAA-ISP than in HS NATION (injury rate ratio = 0.58; 95% CI = 0.42, 0.79); when restricted to TL injuries, the overall injury rate was higher in the NCAA-ISP (injury rate ratio = 1.83; 95% CI = 1.11, 3.03). No differences were found when comparing TL injuries in HS RIO and the NCAA-ISP. Cervical muscle-strain rates were higher during competitions than during practices across all 3 surveillance systems for all injuries. Most cervical muscle strains were due to player contact (NCAA-ISP = 85.7%, HS NATION = 78.8%, HS RIO = 85.8%)., Conclusions: The incidence of cervical muscle strains in football players was low compared with other injuries. Nonetheless, identifying and implementing interventions, particularly those aimed at reducing unsafe player contact, are essential to further decrease the risk of injury and associated adverse outcomes.

Context: In 2009, the National Athletic Trainers' Association Inter-Association Task Force (NATA-IATF) released preseason heat-acclimatization guidelines for gradually acclimatizing high school (HS) athletes to the environment during the first 2 weeks of the preseason and reducing the risk of exertional heat illness. However, researchers who studied the 2011 preseason found a low level of overall compliance., Objective: To assess compliance with the NATA-IATF guidelines during the 2017 preseason and compare the findings with 2011 preseason data and between states mandating and not mandating the guidelines., Design: Cross-sectional study., Setting: Preseason HS football, 2017., Patients or Other Participants: A total of 1023 athletic trainers working with HS football (14.2% response rate)., Main Outcome Measure(s): Using a survey, we acquired information from athletic trainers on their HS football programs, including location and compliance with 17 NATA-IATF guidelines during the 2017 football preseason. The outcome measures were full compliance with all 17 NATA-IATF guidelines and compliance with ≥10 NATA-IATF guidelines. Prevalence ratios (PRs) with 95% confidence intervals (CIs) compared findings between (1) the 2017 and 2011 preseasons and (2) states whose HS athletic associations imposed a full or partial or no mandate to follow the NATA-IATF guidelines., Results: Overall, 3.9% reported full compliance with NATA-IATF guidelines; 73.9% complied with ≥10 guidelines. The proportion reporting full compliance was higher in 2017 than in 2011 but not statistically different (3.9% versus 2.5%; PR = 1.54; 95% CI = 0.96, 2.46). However, the proportion reporting compliance with ≥10 guidelines was higher in 2017 (73.9% versus 57.9%; PR = 1.28; 95% CI = 1.20, 1.36). The proportion of respondents reporting their HSs were fully compliant was highest among the with-mandate group (9.4%), followed by the partial-mandate group (4.6%) and the without-mandate group (0.6%). Group differences retained significance when we examined compliance with ≥10 guidelines., Conclusions: Although full compliance with NATA-IATF guidelines remained low, many HS football programs complied with ≥10 guidelines.

Background: The risk of heat-related illness and death may continue to increase in many locations as a consequence of climate change, but information on the effectiveness of policies to protect populations from the adverse effects of excessive heat is limited. In 2009, the National Athletic Trainers' Association Inter-Association Task Force (NATA-IATF) released guidelines to reduce exertional heat illness (EHI) among U.S. high school athletes participating in preseason sports activities, including preseason practice sessions for American football. A subset of state high school athletic associations have implemented state-mandated guidelines consistent with the 2009 NATA-IATF recommendations, but their effectiveness for reducing preseason EHI is unknown., Objectives: This study examines the association between the enactment of state high school athletic association-mandated NATA-IATF guidelines and the rate of EHI among high school students during preseason American football practice sessions., Methods: We performed a quasi-experimental interrupted time-series study of EHI during high school American football practices in the 2005/2006-2016/2017 school years. We estimated state-level EHI rates using High School Reporting Information Online injury and athlete-exposure data, and used generalized estimating equations Poisson regression models to estimate incidence rate ratios (IRRs) and 95% confidence intervals (CIs) comparing state-years with and without mandated NATA-IATF guidelines. State-level covariates included state-year-specific average August temperatures, yearly deviations from each state's August average temperature across the study period, and school year., Results: Data were available for 455 state-years from 48 states, including 32 state-years (7.0%) from 8 states when mandated guidelines consistent with the NATA-IATF recommendations were implemented. During an estimated 2,697,089 athlete-exposures, 190 EHIs were reported. Estimated preseason EHI rates were lower during state-years with versus without mandated guidelines (adjusted [Formula: see text], 95% CI: 0.23, 0.87)., Conclusions: Our findings suggest that high school athletes would benefit from enactment of the 2009 NATA-IATF guidelines. Similar analyses of the effectiveness of other public health policies to reduce adverse health effects from ambient heat are warranted. https://doi.org/10.1289/EHP4163.

Background: Although data exist on injuries in youth football leagues, there are limited recent data on injury incidence in middle school football. Updated injury incidence estimates can help drive the development of injury prevention strategies., Purpose: Describe the epidemiology of injuries in middle school football during school years 2015-2016 to 2017-2018., Study Design: Descriptive epidemiology study., Methods: Data originated from 9 public middle schools in Virginia during school years 2015-2016 to 2017-2018. Certified athletic trainers collected injury and athlete-exposure (AE) data from school-sanctioned games and practices in boys', football. Injury counts and rates per 1000 AEs were calculated. Injury rate ratios with 95% CIs compared rates between games and practices., Results: Overall, 664 middle school boys', football injuries were reported, leading to an overall injury rate of 20.54 per 1000 AEs (95% CI, 18.98-22.11). The time loss injury rate (inclusive of injuries with participation restriction time ≥24 hours) was 9.28 per 1000 AEs (95% CI, 8.23-10.33). The injury rate was higher in competition than practice (36.19 vs 17.97 per 1000 AEs; injury rate ratio, 2.01; 95% CI, 1.69-2.40). Most injuries were to the head/face (competition, 20.6%; practice, 15.8%) and hand/wrist (competition, 18.8%; practice, 16.4%) and were diagnosed as contusions (competition, 30.9%; practice, 25.9%) and sprains (competition, 19.4%; practice, 12.6%). Competitions also had a large proportion of concussions (10.3%). Overall, 80.0% and 66.9% of injuries were due to contact in competition and practice, respectively; of these contact-related injuries, 62.1% and 41.6% were specifically player contact., Conclusion: Injury distributions parallel those found in previous research from middle school and other sport settings. Injury rates in middle school football were higher than those reported in previous findings in high school and college. However, caution must be taken when interpreting findings in relation to other surveillance systems with varying methodologies. Still, the findings highlight the need for injury prevention strategies within middle school football, particularly as related to contact-related mechanisms.

This study aimed to determine if gameplay performance in the National Football League (NFL) is adversely affected after returning to play from a sport-related concussion (SRC). Players who sustained a SRC between the 2007-2008 and 2013-2014 seasons were identified. Concussed players were matched to nonconcussed control players in a 2:1 (control-case) fashion by position, season, experience, age, body mass index, and time missed. Gameplay statistics were recorded for the three games before and after returning from SRC. When compared with the control group, the majority of NFL players did not demonstrate any performance-based deficits on returning to play after SRC. However, concussed quarterbacks (QBs) displayed a reduced QB rating compared with controls. These results indicate that performance immediately following return from SRC may be adversely affected in certain populations and circumstances, though the overwhelming majority of players showed no decline in performance. (Journal of Surgical Orthopaedic Advances 27(3):187-197, 2018).

Context:: The advent of Web-based sports injury surveillance via programs such as the High School Reporting Information Online system and the National Collegiate Athletic Association Injury Surveillance Program has aided the acquisition of football injury data., Objective:: To describe the epidemiology of injuries sustained in high school football in the 2005-2006 through 2013-2014 academic years and collegiate football in the 2004-2005 through 2013-2014 academic years using Web-based sports injury surveillance., Design:: Descriptive epidemiology study., Setting:: Online injury surveillance from football teams of high school boys (annual average = 100) and collegiate men (annual average = 43)., Patients or Other Participants:: Football players who participated in practices and competitions during the 2005-2006 through 2013-2014 academic years in high school or the 2004-2005 through 2013-2014 academic years in college., Main Outcome Measure(s):: Athletic trainers collected time-loss injury (≥24 hours) and exposure data. Injury rates per 1000 athlete-exposures (AEs), injury rate ratios (IRRs) with 95% confidence intervals (CIs), and injury proportions by body site and diagnosis were calculated., Results:: The High School Reporting Information Online system documented 18 189 time-loss injuries during 4 539 636 AEs; the National Collegiate Athletic Association Injury Surveillance Program documented 22 766 time-loss injuries during 3 121  476 AEs. The injury rate was higher among collegiate than high school (7.29 versus 4.01/1000 AEs; IRR = 1.82; 95% CI = 1.79, 1.86) athletes. Most injuries occurred during competitions in high school (53.2%) and practices in college (60.9%). The competition injury rate was higher than the practice injury rate among both high school (IRR = 5.62; 95% CI = 5.46, 5.78) and collegiate (IRR = 6.59; 95% CI = 6.41, 6.76) players. Most injuries at both levels affected the lower extremity and the shoulder/clavicle and were diagnosed as ligament sprains and muscle/tendon strains. However, concussion was a common injury during competitions among most positions., Conclusions:: Injury rates were higher in college than in high school and higher for competitions than for practices. Concussion was a frequent injury sustained during competitions, which confirms the need to develop interventions to mitigate its incidence and severity.

Background: Previous research has examined associations between concussion history and adverse health outcomes among former professional football players. Less is known about the potential effects of concussion among former college football players without additional exposure at the professional level., Purpose: To examine the association between concussion and adverse health outcomes in a cohort of former college football players without exposure to professional football, 15 years after their playing careers ended., Study Design: Cross-sectional study; Level of evidence, 3., Methods: A sample of 204 former collegiate football players (23.4% of eligible athletes with available contact information)-all of whom played at least 1 season of football from 1999 to 2001 in the National Collegiate Athletic Association (NCAA) and had no professional football exposure-completed a general health survey that assessed lifetime concussion history and included the following: the Veterans RAND 36 Item Health Survey, containing a physical composite score (PCS) and mental composite score (MCS); the depression module of the Patient Health Questionnaire; and the 4-item CAGE alcohol dependence questionnaire (for "cutting down, annoyance by criticism, guilty feeling, and eye-openers"). Multivariable binomial regression models estimated adjusted prevalence ratios (PRs) with 95% CIs while controlling for demographics and playing history covariates through forward selection model building., Results: Most participants reported a concussion history (84.3%). Overall, 22.1% and 39.2% of participants reported a PCS and an MCS <50, respectively (indicating worse health than the US national average); 19.1% reported Patient Health Questionnaire scores ≥10 (indicating moderate/severe depression); and 24.8% reported CAGE scores ≥2 (indicating alcohol dependence). The prevalence of having an MCS <50 was higher among those reporting ≥3 versus 0 concussions (PR, 2.5; 95% CI, 1.3-4.9). Controlling for body mass index (BMI), the prevalence of moderate/severe depression was higher among those reporting ≥3 versus 0 concussions (PR, 4.2; 95% CI, 1.0-16.3). Controlling for BMI, the prevalence of having a PCS <50 was higher among those reporting ≥3 versus 1 or 2 concussions (PR, 2.6; 95% CI, 1.3-5.0) but not 0 concussions (PR, 1.5; 95% CI, 0.6-3.6). No associations were found for alcohol dependence., Conclusion: Associations between a history of multiple concussions and adverse health outcomes were found among former collegiate football players without professional football exposure but were limited to those reporting ≥3 prior concussions. Because only 23.4% of eligible athletes responded to the survey, the possibility of ascertainment bias exists, and our findings should thus be interpreted with some caution. Continued examination within nonprofessional football populations is needed, but findings highlight the need for prevention efforts to reduce concussion incidence.

Purpose: Elevated rates of cardiometabolic diseases have been observed in former American football players. The current study sought to determine whether change in body mass index (ΔBMI) after retirement influences the prevalence of CHD, diabetes, or high blood pressure (HBP) in former professional football players., Methods: Retired professional football players (n = 3729) were sent a survey with questions regarding health status, playing history, and demographic information. Self-reported BMI at the time of retirement was subtracted from current self-reported BMI to calculate ΔBMI. Prevalence of CHD, diabetes, and HBP were determined by asking participants if they had ever been diagnosed by a health care professional. Binomial regression with a Poisson residual and robust variance estimation was used to compute crude prevalence ratios (PR) and 95% confidence intervals (CI) for each outcome. Adjusted PR values were calculated by adjusting for BMI at the time of retirement, age, years of football experience, race, exercise habits, alcohol use, steroid history, smoking history, and playing position., Results: Complete data were available for 2062 respondents. Prevalence of CHD increased 25%-31% for each five-point increase in ΔBMI after retirement (crude PR = 1.25, 95% CI = 1.03-1.52, P = 0.026; adjusted PR = 1.31, 95% CI = 1.11-1.55, P = 0.001). Diabetes prevalence increased 69%-88% for each five-point ΔBMI increase (crude = 1.88, 95% CI = 1.45-2.44, P < 0.001; adjusted = 1.69, 95% CI = 1.32-2.15, P < 0.001). A five-point increase in ΔBMI was associated with a 35%-40% increase in HBP prevalence (crude = 1.40, 95% CI = 1.27-1.53, P < 0.001; adjusted = 1.35, 95% CI = 1.24-1.47, P < 0.001)., Conclusions: After controlling for relevant covariates, postretirement ΔBMI was positively and independently associated with prevalence of CHD, diabetes, and HBP. Postretirement interventions using diet and/or exercise to influence body composition may improve long-term health in retired football players.

Purpose To better understand the relationship between exposure to concussive and subconcussive head impacts, white matter integrity, and functional task-related neural activity in former U.S. football athletes. Materials and Methods Between 2011 and 2013, 61 cognitively unimpaired former collegiate and professional football players (age range, 52-65 years) provided informed consent to participate in this cross-sectional study. Participants were stratified across three crossed factors: career duration, concussion history, and primary playing position. Fractional anisotropy (FA) and blood oxygen level-dependent (BOLD) percent signal change (PSC) were measured with diffusion-weighted and task-related functional magnetic resonance imaging, respectively. Analyses of variance of FA and BOLD PSC were used to determine main or interaction effects of the three factors. Results A significant interaction between career duration and concussion history was observed; former college players with more than three concussions had lower FA in a broadly distributed area of white matter compared with those with zero to one concussion (t29 = 2.774; adjusted P = .037), and the opposite was observed for former professional players (t29 = 3.883; adjusted P = .001). A separate interaction between concussion history and position was observed: Nonspeed players with more than three concussions had lower FA in frontal white matter compared with those with zero to one concussion (t25 = 3.861; adjusted P = .002). Analysis of working memory-task BOLD PSC revealed a similar interaction between concussion history and position (all adjusted P < .004). Overall, former players with lower FA tended to have lower BOLD PSC across three levels of a working memory task. Conclusion Career duration and primary playing position seem to modify the effects of concussion history on white matter structure and neural recruitment. The differences in brain structure and function were observed in the absence of clinical impairment, which suggested that multimodal imaging may provide early markers of onset of traumatic neurodegenerative disease. © RSNA, 2017 Online supplemental material is available for this article.

Background: The inherent risk of any time loss from physical injury in football has been extensively discussed, with many such injuries having a profound effect on the lives of National Collegiate Athletic Association (NCAA) football players. However, the incidence of fractures in collegiate football has not been well established., Purpose: To examine the epidemiology of fractures in NCAA football., Study Design: Descriptive epidemiology study., Methods: Fracture data reported in college football during the 2004-2005 to 2013-2014 academic years were analyzed from the NCAA Injury Surveillance Program (NCAA-ISP). Fracture rates per 1000 athlete-exposures, surgery and time loss distributions, injury rate ratios, injury proportion ratios (IPRs), and 95% CIs were reported., Results: Overall, 986 fractures were reported. The rate of competition fractures was larger than the rate of practice fractures (1.80 vs 0.17 per 1000 athlete-exposures; injury rate ratio = 10.56; 95% CI, 9.32-11.96). Fractures of the hand/fingers represented 34.6% of all injuries, while fibula fractures (17.2%) were also common. A majority (62.5%) of all fractures resulted in time loss >21 days. Altogether, 34.4% of all fractures required surgery, and 6.3% were recurrent. The proportion of fractures resulting in time loss >21 days was higher for fractures requiring surgery than fractures not requiring surgery (85.0% vs 50.7%; IPR = 1.68; 95% CI, 1.53-1.83). The proportion of recurrent and nonrecurrent fractures requiring surgery did not differ (35.5% vs 34.3%; IPR = 1.03; 95% CI, 0.73-1.46); however, recurrent fractures were more likely to require surgery than nonrecurrent fractures when restricted to the hand/fingers (66.7% vs 27.2%; IPR = 2.45; 95% CI, 1.36-4.44)., Conclusion: Fractures in collegiate football were sustained at a higher rate in competition than practice and frequently required extended time lost from participation, particularly among those requiring surgery. Prevention strategies are warranted to reduce incidence and severity of fractures.

An integral part of the Heads Up Football (HUF) educational program is the Player Safety Coach (PSC), who is responsible for teaching other coaches within a youth football league about safer blocking/tackling and injury prevention. This study examines the association between youth football coaches' interactions with the PSC (i.e., attending the PSC clinic at the beginning of the season and seeing the PSC on-field during practices) and their subsequent implementation of the HUF educational program. Data were collected via online questionnaire completed by 1,316 youth football coaches from HUF leagues. Data were analyzed with frequencies and logistic regression. Nearly half of coaches (44.8%) did not attend the PSC clinic; 25.9% reported not seeing their league's PSC on the field on a regular basis. The lack of PSC on-site presence was significantly associated with worse implementation for "concussion recognition and response," "heat preparedness and hydration," and "sudden cardiac event preparedness." PSC clinic attendance was not associated with implementation. Opportunities exist for improvement in the HUF educational program as there appears to be inconsistent implementation. Further research is warranted to understand how to optimize the role of the PSC in the youth sports context.

Background: Despite a focus on the incidence and effects of concussion, nondisclosure of sports-related concussions among retired players from the National Football League (NFL) has yet to be examined., Purpose: Examine the prevalence of and factors associated with nondisclosure of sports-related concussions in former NFL athletes., Study Design: Cross-sectional study; Level of evidence, 3., Methods: A sample of 829 former NFL players completed a general health survey. This historical cohort included players who had played before World War II to 2001. Respondents retrospectively recalled sports-related concussions that they sustained during their professional careers and whether at least one of these sports-related concussions was not reported to medical staff. We computed the prevalence of nondisclosure among those recalling sport-related concussions during their professional careers. Multivariable binomial regression estimated adjusted prevalence ratios (PR) with 95% confidence intervals (CIs) controlling for race/ethnicity, number of years played, primary position played, professional career concussion history, and playing era. Playing era was categorized by whether the majority of a player's career was before or after a 1976 rule change to limit contact ("spearing")., Results: Overall, 417 (50.3%) respondents reported they had sustained a concussion and did not inform medical staff at least once during their professional playing career. Nonwhite respondents had a higher prevalence of nondisclosure than white/non-Hispanic respondents (adjusted PR = 1.19; 95% CI, 1.02-1.38). An interaction between professional career concussion history and playing era was also found ( P = .08). Compared with those in the pre-spearing rule change group with 1 or 2 concussions, all other groups had larger prevalences of nondisclosure (increases ranging from 41% to 153% in multivariable models). Across concussion strata, nondisclosure prevalence was generally higher in the post-spearing rule change group than the pre-spearing rule change group, with the largest differences found among those with 1 or 2 concussions or those with 3 or 4 concussions., Conclusion: A large proportion of former NFL players in this historical cohort reported at least one instance of not disclosing sports-related concussions to medical staff. Future research on concussion nondisclosure needs to identify mechanisms to improve football players' intentions to disclose concussion-related symptoms to health care providers and to equip health care providers with more effective strategies for timely identification of concussion.

Our study describes youth football (YFB) environmental conditions and the associated heat index (HI) risk category. An observational research design was utilized. Independent variables included month, time, event, and geographic location. Main outcome variables were frequency of events, average HI, and corresponding risk categorization. The HI was recorded with the day and time for each YFB event across 2 YFB seasons. Nearly half (49.8%) of events were in a high HI risk category and 20.0% should have been cancelled. The hottest HI values were recorded in July and August (83.2 ± 9.4°F to 87.2 ± 10.9°F; 24.0% of YFB events). The 7 to 10 am time frame was cooler (67.7 ± 14.5°F; 6.3% of YFB events) than other time frames ( P < .001). Hotter HI values were recorded in practices versus games (75.9 ± 14.1°F vs 70.6 ± 14.6°F; t = -6.426, P < .001). Starting the YFB season in September and holding weekend events in the early morning hours can decrease exposure to environmental heat stress.

Context:   Although an association between concussion and musculoskeletal injury has been described in collegiate and professional athletes, no researchers have investigated an association in younger athletes., Objective:   To determine if concussion in high school athletes increased the risk for lower extremity musculoskeletal injury after return to activity., Design:   Observational cohort study., Setting:   One hundred ninety-six high schools across 26 states., Patients or Other Participants:   We used data from the National Athletic Treatment, Injury and Outcomes Network surveillance system. Athletic trainers provided information about sport-related concussions and musculoskeletal injuries in athletes in 27 sports, along with missed activity time due to these injuries., Main Outcome Measure(s):   Three general estimating equations were modeled to predict the odds of sustaining (1) any lower extremity injury, (2) a time-loss lower extremity injury, or (3) a non-time-loss lower extremity injury after concussion. Predictors were the total number of previous injuries, number of previous concussions, number of previous lower extremity injuries, number of previous upper extremity injuries, and sport contact classification., Results:   The initial dataset contained data from 18 216 athletes (females = 39%, n = 6887) and 46 217 injuries. Lower extremity injuries accounted for most injuries (56.3%), and concussions for 4.3% of total injuries. For every previous concussion, the odds of sustaining a subsequent time-loss lower extremity injury increased 34% (odds ratio [OR] = 1.34; 95% confidence interval [CI] = 1.13, 1.60). The number of previous concussions had no effect on the odds of sustaining any subsequent lower extremity injury (OR = 0.97; 95% CI = 0.89, 1.05) or a non-time-loss injury (OR = 1.01; 95% CI = 0.92, 1.10)., Conclusions:   Among high school athletes, concussion increased the odds of sustaining subsequent time-loss lower extremity injuries but not non-time-loss injuries. By definition, time-loss injuries may be considered more severe than non-time-loss injuries. The exact mechanism underlying the increased risk of lower extremity injury after concussion remains elusive and should be further explored in future research.

Context:   High-intensity sport training at the youth level has led to increased concern for overuse conditions. Few researchers have examined overuse conditions in youth sports., Objective:   To examine the rates, risks, and distributions of overuse conditions between youth and high school football players., Design:   Descriptive epidemiologic study., Setting:   Youth and high school football teams., Patients or Other Participants:   The Youth Football Safety Study (YFSS) investigated youth football athletes from age 5 to 14 years. The National Athletic Treatment, Injury and Outcomes Network (NATION) focused on high school football athletes 14 to 18 years old. The YFSS data consisted of 210 team-seasons, and the NATION data consisted of 138 team-seasons., Main Outcome Measure(s):   Athletic trainers collected football injury and exposure data during the 2012 and 2013 seasons. Injury rates, risks, and distributions were calculated, with injury rate ratios, risk ratios, and injury proportion ratios with 95% confidence intervals (CIs) comparing youth and high school football players., Results:   The YFSS reported 1488 injuries, of which 53 (3.6%) were overuse conditions. The NATION reported 12 013 injuries, of which 339 (2.8%) were overuse conditions. The overuse condition rate did not differ between high school and youth football (3.93 versus 3.72/10 000 athlete-exposures; injury rate ratio = 1.06; 95% CI = 0.79, 1.41). However, the 1-season risk of overuse condition was higher in high school than in youth football players (2.66% versus 1.05%; risk ratio = 2.53; 95% CI = 1.84, 3.47). Compared with high school football players, youth football players had greater proportions of overuse conditions that were nontime loss (ie, <24 hours participation-restriction time; 83.0% versus 67.0%; injury proportion ratio = 1.24; 95% CI = 1.07, 1.43) and affecting the lower extremity (92.5% versus 62.5%; injury proportion ratio = 1.48; 95% CI = 1.32, 1.65)., Conclusions:   Overuse conditions may not present a primary concern in youth and high school football players. However, differences existed between the 2 levels of competition. Although additional research on the incidence of overuse conditions across all youth and high school sports is needed, these findings may highlight the need for programming that is specific to competition level.

Our purpose was to determine concussion mechanism and activity differences among three cohorts of football players: youth, high school, and college. Participants in this prospective cohort study were youth (ages 5-14 years, 118 teams, 310 team-seasons), high school (96 teams, 184 team-seasons), and college (34 teams, 71 team-seasons) football players. Athletic trainers collected athlete-exposure (AE) and concussion data during the 2012-2014 seasons. Injury mechanism referred to the object that made contact with the concussed player, resulting in the concussion. Injury activity referred to the type of football-specific activity that the player was involved in when the concussion was sustained. Injury proportion ratios (IPR) compared distributions of concussion mechanisms and activities among age levels. A total of 1429 concussions were reported over 1,981,284 AE across all levels (Rate: 0.72/1000AE). Overall, most concussions were caused by player contact (84.7%). During games, a greater proportion of youth football concussions (14.7%) were caused by surface contact than high school (7.3%, IPR = 2.02; 95% confidence interval [CI]: 1.10-3.72) and college (7.1%, IPR = 2.07, 95% CI: 1.02-4.23) football. Compared with college football concussions (90.2%), a smaller proportion of youth (80.0%, IPR = 0.89, 95% CI: 0.79-0.99) and high school (83.2%, IPR = 0.92, 95% CI: 0.86-0.99) football concussions were caused by player contact. A greater proportion of game youth football concussions (42.1%) occurred while an individual was being tackled than occurred in high school (23.2%, IPR = 1.81, 95% CI: 1.34-2.45) and college (23.0%, IPR = 1.83, 95% CI: 1.29-2.62) football. Findings were similar during practices. Compared with college football game concussions (15.8%), a smaller proportion of youth (6.3%, IPR = 0.40, 95% CI: 0.17-0.93) and high school (9.5%, IPR = 0.60, 95% CI: 0.38-0.95) football game concussions occurred while an individual was being blocked. Concussion mechanism and activity differences should be considered when developing concussion prevention and sport-safety methods specific to different age levels, in order to maximize effectiveness.

Context:   Whereas researchers have provided estimates for the number of head impacts sustained within a youth football season, less is known about the number of plays across which such impact exposure occurs., Objective:   To estimate the number of plays in which youth football players participated during the 2013 season and to estimate injury incidence through play-based injury rates., Design:   Descriptive epidemiology study., Setting:   Youth football., Patients or Other Participants:   Youth football players (N = 2098; age range, 5-15 years) from 105 teams in 12 recreational leagues across 6 states., Main Outcome Measure(s):   We calculated the average number of athlete-plays per season and per game using independent-samples t tests to compare age groups (5-10 years old versus 11-15 years old) and squad sizes (<20 versus ≥20 players); game injury rates per 1000 athlete-exposures (AEs) and per 10 000 athlete-plays; and injury rate ratios (IRRs) with 95% confidence intervals (CIs) to compare age groups., Results:   On average, youth football players participated in 333.9 ± 178.5 plays per season and 43.9 ± 24.0 plays per game. Age groups (5- to 10-year-olds versus 11- to 15-year-olds) did not differ in the average number of plays per season (335.8 versus 332.3, respectively; t 2086.4 = 0.45, P = .65) or per game (44.1 versus 43.7, respectively; t 2092.3 = 0.38, P = .71). However, players from smaller teams participated in more plays per season (373.7 versus 308.0; t 1611.4 = 8.15, P < .001) and per game (47.7 versus 41.4; t 1523.5 = 5.67, P < .001). Older players had a greater game injury rate than younger players when injury rates were calculated per 1000 AEs (23.03 versus 17.86/1000 AEs; IRR = 1.29; 95% CI = 1.04, 1.60) or per 10 000 athlete-plays (5.30 versus 4.18/10 000 athlete-plays; IRR = 1.27; 95% CI = 1.02, 1.57)., Conclusions:   A larger squad size was associated with a lower average number of plays per season and per game. Increasing youth football squad sizes may help reduce head-impact exposure for individual players. The AE-based injury rates yielded effect estimates similar to those of play-based injury rates.

Context:   Dynamic balance deficits have been described postconcussion, even after athletes return to play. Lower extremity (LE) musculoskeletal injury rates increase for up to 1 year after concussion, but the long-term musculoskeletal implications of concussion are unclear., Objective:   To (1) examine the association of concussion and LE injury histories with osteoarthritis (OA) prevalence in retired National Football League players and (2) examine the association of concussion and LE injury histories with OA prevalence in those ≤55 years of age., Design:   Case-control study., Setting:   Survey., Patients or Other Participants:   We administered the Health Survey of Retired National Football League Players, which collects information about demographics, OA, LE injury, and concussion history., Main Outcome Measure(s):   Twelve discrete categories were created based on concussion and LE injury history, ranging from 0 concussions and 0 LE injuries (referent group) to 3+ concussions and 2+ LE injuries. Binomial regression analysis modeled lifetime OA prevalence. Covariates were body mass index, age at the time of the survey, and total years playing professional football., Results:   Complete data were available for 2696 participants. Lifetime OA prevalence was smallest in the referent group (21.1%) and largest in the 3+ concussion and 2+ LE group (50.6%; 2.5 times the referent; 95% confidence interval [CI] = 2.1, 3.1). Participants in all concussion groups (1, 2, 3+) who reported a history of 0 LE injuries had a greater OA prevalence than the referent group. When participants were stratified by age, the ≤55 years of age, 3+ concussions, and 2+ LE injuries group prevalence ratio (3.6; 95% CI = 2.7, 5.2) was larger than that of the >55 years of age, 3+ concussions, and 2+ LE injuries group (1.8; 95% CI = 1.3, 2.4) compared with the respective referent groups., Conclusions:   Concussion with or without a history of LE injury may be an important moderator of OA. Future researchers should seek to better understand the mechanisms that influence the association among concussion, LE injury, and OA.

Context:   Variations in knee-sprain incidence among competition levels are unclear but may help inform prevention strategies in American football players., Objective:   To describe the epidemiology of knee sprains in youth, high school, and collegiate football players., Design:   Descriptive epidemiology study., Setting:   Injury and athlete-exposure (AE) data were collected from 3 injury-surveillance programs at the youth, high school, and collegiate competition levels., Patients or Other Participants:   Data from 310 youth, 184 high school, and 71 collegiate football team-seasons were collected during the 2012 through 2014 seasons., Main Outcome Measure(s):   Knee-sprain rates and risks were calculated for each competition level. Injury rate ratios (IRRs) and risk ratios (RRs) compared knee-sprain rates by competition level. Injury proportion ratios (IPRs) compared differences in surgery needs, recurrence, injury mechanism, and injury activity by competition level., Results:   Knee-sprain rates in youth, high school, and collegiate football were 0.16/1000 AEs, 0.25/1000 AEs, and 0.69/1000 AEs, respectively. Knee-sprain rates increased as the competition level increased (high school versus youth: IRR = 1.60; 95% confidence interval [CI] = 1.12, 2.30; collegiate versus high school: IRR = 2.73; 95% CI = 2.38, 3.96). Knee-sprain risk was highest in collegiate (4.3%), followed by high school (2.0%) and youth (0.5%) athletes. Knee-sprain risk increased as the competition level increased (high school versus youth: RR = 3.73; 95% CI = 2.60, 5.34; collegiate versus high school: RR = 2.14; 95% CI = 1.83, 2.51). Collegiate football had the lowest proportion of knee sprains that were noncontact injuries (collegiate versus youth: IPR = 0.54; 95% CI = 0.31, 0.95; collegiate versus high school: IPR = 0.59; 95% CI = 0.44, 0.79) and the lowest proportion that occurred while being tackled (collegiate versus youth: IPR = 0.44; 95% CI = 0.26, 0.76; collegiate versus high school: IPR = 0.71; 95% CI = 0.51, 0.98)., Conclusions:   Knee-sprain incidence was highest in collegiate football. However, level-specific variations in the distributions of knee sprains by injury activity may highlight the need to develop level-specific policies and prevention strategies that ensure safe sports play.

Introduction: USA Football has made the Heads Up Football (HUF) concussion education program available for coaches of youth football players. Existing evidence about the effectiveness of the HUF coach education program is equivocal. For HUF and other programs, there is growing concern that even effective interventions can increase inequalities if there is different uptake or impact by SES or other demographic factors. Understanding how adoption is patterned along these lines is important for understanding equity issues in youth football. This study tested the hypothesis that there will be lower adoption of HUF among coaches of youth football players in lower-SES communities., Methods: The authors conducted a cross-sectional study of the association between community-level characteristics and number of USA Football youth league coaches who have completed HUF. Data were collected in 2014 and analyzed in 2015-2016., Results: Implementation of the HUF program was patterned by community-level socioeconomic characteristics. Leagues located in communities with a higher percentage of families with children aged <18 years living below the poverty line and a smaller percentage of non-Hispanic white residents tended to have leagues with smaller percentages of HUF-certified coaches., Conclusions: As interventions are developed that reduce the risks of youth football, it is important to consider not just the effectiveness of these interventions, but also whether they reduce or exacerbate health inequities. These results suggest that relying on voluntary adoption of coach education may result in inequitable implementation. Further study is required to identify and remedy organizational and contextual barriers to implementation of coach education in youth sport., (Copyright © 2017 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.)

Background: Variations in ankle injury rates and distributions among competition levels are unclear, but such data may help inform strategies to prevent ankle sprains during American football., Purpose: To describe the epidemiological patterns of ankle sprains in youth, high school (HS), and collegiate American football., Study Design: Descriptive epidemiological study., Methods: Data regarding youth, HS, and college football athletes were collected from 3 injury surveillance programs: (1) the Youth Football Safety Study (YFSS), (2) the National Athletic Treatment, Injury and Outcomes Network (NATION), and (3) the National Collegiate Athletic Association (NCAA) Injury Surveillance Program (ISP). During the 2012-2014 seasons, the YFSS, NATION, and NCAA ISP included 310, 184, and 71 football team-seasons, respectively. Athletic trainers (ATs) attended each practice and game and reported injuries and athlete-exposures (AEs) via their preferred injury documentation application. Ankle sprain rates for each type of ankle sprain were calculated overall, by event type (ie, practices and games), and specifically for severe injuries (ie, participation restriction time >21 days) and recurrent injuries (as defined by ATs). Rate ratios (RRs) were used to compare ankle sprain rates by competition level and event type. Injury proportion ratios (IPRs) were used to compare differences in severity, surgical needs, recurrence, injury mechanism, and injury activity by competition level. RRs and IPRs with 95% confidence intervals excluding 1.00 were considered statistically significant., Results: A total of 124, 897, and 643 ankle sprains were reported in youth, HS, and college football, respectively. This led to respective rates of 0.59, 0.73, and 1.19 sprains per 1000 AEs. The ankle sprain rate in college football was higher than the rates in HS (RR = 1.64; 95% CI, 1.48-1.82) and youth (RR = 2.01; 95% CI, 1.65-2.43) football. The proportion of ankle sprains that were recurrent in youth football was higher than the proportions in HS (IPR = 2.73; 95% CI, 1.68-4.50) and college (IPR = 2.19; 95% CI, 1.33-3.61) football., Conclusion: Ankle sprain rates were highest in college athletes. However, level-specific variations in ankle sprain severity and recurrence may highlight the need to develop level-specific policies and prevention strategies to reduce injury incidence.