Concussion Risk Research Articles

Sanctioned illegal high tackles significantly increase concussion risk to both tacklers and ball carriers in elite men’s Rugby Union

ObjectivesTackles making contact above the sternum increase concussion and head injury assessment (HIA) risk in Rugby Union. The sport has introduced harsher sanctions to change tackler behaviours to reduce this...

Abstracts of the 4th Annual Meeting of the Canadian Concussion Network/Réseau Canadien des Commotions (CCN-RCC)

JOURNAL/jhetr/04.03/00001199-990000000-00153/graphic1/v/2024-06-14T213228Z/r/image-jpeg The following abstracts were presented at the 4th Annual Meeting of the Canadian Concussion Network/Réseau Canadien des Commotions (CCN-RCC) in Ottawa, Ontario on May 9-10, 2024. Established in 2020, the CCN-RCC has a vision to establish and guide a coordinated national research and knowledge translation agenda in Canada. This agenda aims to reduce the risk of concussions and their consequences across four broad domains: prevention, detection/diagnosis, prognosis/modifiers, and treatment.

Sport-related concussion (SCR) prevention and the nature of sport: possibilities and limitations

ABSTRACT Concussions are traumatic brain injuries that can result from a blow to the head or a jolt to the body. Athletes in many sports are exposed to concussion risks. There is a growing concern in sport and society about sport-related concussions (SRC) and an increasing awareness of the importance of proper diagnosis, treatment, and prevention. A traditional, reactive approach emphasizes sound protocols in cases of suspected SRC. A proactive approach involves identifying various causes of SRC and implementing preventive measures. For example, to reduce SRC prevalence in Canadian youth ice hockey, a ban on body checking has been introduced. When a preventive SRC measure implies a change in the main rules of a sport, it impacts its nature and alters how it is played. This can lead to tensions between SRC prevention and sporting concerns. By employing an extended consequentialist framework that includes normative analyses of the values of sport, I will examine the possibilities and limitations of preventive SRC measures in terms of constitutive rule changes. More specifically, I will propose a consequentialist framework to determine the conditions under which athlete exposure to SRC risks in a given sport can be considered unacceptable, acceptable, and even valuable.

Quantitative assessment of brain injury and concussion induced by an unintentional soccer ball impact

BackgroundAccidental impact on a player's head by a powerful soccer ball may lead to brain injuries and concussions during games. It is crucial to assess these injuries promptly and accurately on the field. However, it is challenging for referees, coaches, and even players themselves to accurately recognize potential injuries and concussions following such impacts. Therefore, it is necessary to establish a list of minimum ball velocity thresholds that can result in concussions at different impact locations on the head. Additionally, it is important to identify the affected brain regions responsible for impairments in brain function and potential clinical symptoms. MethodsBy using a full human finite element model, dynamic responses and brain injuries caused by unintentional soccer ball impacts on six distinct head locations (forehead, tempus, crown, occiput, face, and jaw) at varying ball velocities (10, 15, 20, 25, 30, 35, 40, and 60 m/s) were simulated and investigated. Intracranial pressure, Von-Mises stress, and first principal strain were analyzed, the ball velocity thresholds resulting in concussions at different impact locations were evaluated, and the damage evolution patterns in the brain tissue were analyzed. ResultsThe impact on the occiput is most susceptible to induce brain injuries compared to all other impact locations. For a conservative assessment, the risk of concussion is present once the soccer ball reaches 17.2 m/s in a frontal impact, 16.6 m/s in a parietal impact, 14.0 m/s in an occipital impact, 17.8 m/s in a temporal impact, 18.5 m/s in a facial impact or 19.2 m/s in a mandibular impact. The brain exhibits the most significant dynamic responses during the initial 10–20 ms, and the damaged regions are primarily concentrated in the medial temporal lobe and the corpus callosum, potentially causing impairments in brain functions. ConclusionsThis work offers a framework for quantitatively assessing brain injuries and concussions induced by an unintentional soccer ball impact. Determining the ball velocity thresholds at various impact locations provides a benchmark for evaluating the risks of concussion. The examination of brain tissue damage evolution introduces a novel approach to linking biomechanical responses with possible clinical symptoms.

An Assessment of Existing Sport-Related Concussion Guidelines in Ireland: The Need for a United Approach.

In 2014, an Irish parliament white paper called for greater addressing of sport-related concussions (SRCs) in Ireland, requesting the adoption of the Concussion in Sport Group's (CISGs) guidelines and greater consistency in SRC return to play (RTP) management. Ten years later, it is unclear how these requests have been addressed. Recently, the United Kingdom's government centralised guidelines to one SRC document for all grassroots sports. This study aimed to investigate all publicly available SRC guidance in Irish sports and national governing bodies (NGBs) to determine if centralised guidelines are warranted. Sport Ireland and the Irish Federation of Sports were searched for all recognised NGBs and sports in Ireland. Websites were searched for any information pertaining to SRCs and data were extracted and collated in Microsoft Excel. In total, 15 of 83 sports and/or NGBs included SRC guidance, nine of which provided RTP protocols. Various iterations of the CISGs guidance and tools were implemented. Several sports with a documented SRC risk had no guidelines present. The findings indicate disjointed and outdated guidance across Irish sport. Additionally, there are sports with a documented concussion risk that have no SRC guidance available. This study provides support for centralised guidelines to be adopted in Irish grassroots sports.

Concussion management in pediatric patients – ethical concerns

ABSTRACT Collision sports pose a high risk of concussion. How to respond to this risk is more ethically complex when considering children and adolescents due to a) incomplete evidence regarding the impact of concussion on developing brains, b) physiological and social vulnerability, and c) the young person’s reliance on proxy decision-makers, usually parents. There is also a lack of clear definitions of (a) collision sport (vs. contact sport) and (b) what constitutes a child or adolescent. We consider whether parents should be free to allow their children/adolescents to play contact or collision sport. The article analyses the harms and benefits of collision sport and methods of determining risk, before outlining our support for the precautionary principle. We then consider whether the ‘best interests’ or ‘right to an open future’ framework ought to be applied to the issue of childhood participation in collision sport. Rather than supporting a ban of child/adolescent participation in collision sport, we argue that permissibility should be decided on a sport-by-sport basis. Moreover, we apply the ‘Accountability of Reasonableness’ framework to ensure that sound ethical values guide and support protections for this vulnerable group in the absence of high-quality evidence.

A study into the feasibility of replicating and improving the mechanical properties of the Wavecel helmet liner using additively manufactured auxetic structures

In the event of a cycling accident, there is evidence supporting the bicycle helmet’s role in reducing the risk of traumatic brain injury (TBI). Despite this, there is ambiguity surrounding the effectiveness and integrity of specific helmet liner technologies which claim to reduce concussion risk, such as Wavecel. This research project seeks to explore the feasibility of replicating the mechanical properties of the Wavecel metamaterial using an additively manufactured (AM) honeycomb structure. Wavecel, introduced in 2019 by Trek Bicycle Co. as part of the Bontrager sub-brand, is a helmet liner technology. Consisting of a collapsible cellular metamaterial, it functions through a network of interconnected shock absorbers that link the user’s head to the helmet shell. Upon its announcement, Wavecel claimed that its cellular lattice structure helmet liner is up to 48× more effective at preventing concussion than a standard helmet, reducing the likelihood of concussion to 1.2% during a laboratory simulated head impact (Bliven et al., 2019, Acc Analysis Prev, 124, 58-65). As one of the most commercially successful metamaterial helmet liners available on the consumer market, Wavecel is a clear demonstration that a metamaterial protection system can be mass-produced, well received by consumers and profitable for a business. To conduct this research, the properties of the Wavecel liner will be defined through impact testing. Computer-aided design (CAD) will then be used to produce several prototypes of a honeycomb structure. These prototypes will then undergo identical impact tests, aiming to replicate the mechanical properties of the Wavecel helmet liner. Comparisons will include elastic stiffness, column buckling, and response to off-axis impact. The collected data will serve as evidence for evaluating the performance and mechanical attributes of these structures, contributing to the advancement of next-generation helmet liners and sports personal protective equipment (PPE). The findings will also benefit businesses looking to develop helmets incorporating metamaterials in their liner technology.

Influence of Long-Term Use of American Football Helmets on Concussion Risk.

In this study, to discuss the influence of concussion risk from the long-term use of American football helmets on collegiate teams, accident cases during the game are replicated based on game videos by simulations using whole-body numerical models and helmeted finite element human head models. The concussion risks caused by collisions were estimated using the mechanical parameters inside the skull obtained from finite element analyses. In the analyses, the different material properties of helmets identified by free-fall experiments using headform impactor-embedded helmets were used to represent brand-new and long-term-use helmets. After analyzing the five cases, it was observed that wearing a new helmet instead of a long-term-use one resulted in a reduction in the risk of concussion by 1 to 44%. More energy is attenuated by the deformation of the liners of the brand-new helmet, so the energy transferred to the head is smaller than that when wearing the long-term-use helmet. Thus, the long-term use of the helmet reduces its ability to protect the head.

Sex differences in the extent of acute axonal pathologies after experimental concussion

Although human females appear be at a higher risk of concussion and suffer worse outcomes than males, underlying mechanisms remain unclear. With increasing recognition that damage to white matter axons is a key pathologic substrate of concussion, we used a clinically relevant swine model of concussion to explore potential sex differences in the extent of axonal pathologies. At 24 h post-injury, female swine displayed a greater number of swollen axonal profiles and more widespread loss of axonal sodium channels than males. Axon degeneration for both sexes appeared to be related to individual axon architecture, reflected by a selective loss of small caliber axons after concussion. However, female brains had a higher percentage of small caliber axons, leading to more extensive axon loss after injury compared to males. Accordingly, sexual dimorphism in axonal size is associated with more extensive axonal pathology in females after concussion, which may contribute to worse outcomes.

Tackle Risk Factors for Head Injury Assessments (HIAs) in Sub-Elite Rugby League and Recommendations for Prevention: Head Contacts from Upright Tackles Increase the HIA Risk to Both Ball Carrier and Tackler

BackgroundThe rugby league tackle has been identified as the game event with the greatest propensity for a clinically diagnosed concussion. This study aims to replicate the work conducted in professional rugby league and rugby union by examining Head Injury Assessment (HIA) events to determine the associated tackle characteristics that increase concussion risk in sub-elite rugby league players. This comparison between competition levels is important due to the less developed physiological and tackle proficiency characteristics of sub-elite rugby league players and the fewer resources available for an on-field diagnosis, compared to the elite level of the sport.ResultsTackles resulting in Head Injury Assessments (HIAs, n = 131) and 2,088 tackles that did not result in a head injury were identified and coded from one season of the 2019 Queensland Cup. The body position of both ball carrier and tackler, tackle height, and body contact areas were evaluated. The propensity for tacklers to undergo a head injury assessment was 1.49 HIAs per 1,000 tackles, equating to a 2.5-fold higher risk than that of the ball carrier (0.59 HIAs per 1,000 tackles). The risk for an HIA was 2.75-fold greater when the tackler was upright (2.89 HIAs per 1,000 tackles) compared to a bent-at-the-waist tackler (1.05 HIAs per 1,000 tackles). The greatest risk for the tackler and ball carrier sustaining an HIA occurred when the tackle height was high, with head-to-head contact having the greatest propensity for an HIA (44.37 HIAs per 1,000 tackles). HIA risk was also greater for both players when the ball carrier did not employ an evasion strategy (3.73 HIAs per 1,000 tackles).ConclusionsThe study replicates results from research in elite rugby league and rugby union. A combination of higher head contact/proximity and upright body position significantly increase an HIA risk. Tackler head position and ball carrier evasion behaviours also affect risk, suggesting that injury prevention strategies designed to reduce tackle height and improve tackle technique by focusing on head position, body position, and in a novel finding, ball carrier evasion, may reduce head injury risk in sub-elite rugby league players.

The influence of helmet certification in motorcycle helmets protective performance

The convenience of online shopping has increased access to a vast array of helmet options and deals for motorcyclists. However, the e-commerce enables an influx of unverified and potentially hazardous helmets lacking the rigorous quality control into the market, hence, placing unaware bargain seekers at risk. The non-certified variants questions in terms of impact protection abilities because they visually look similar to certified helmets. This study compared certified full face and open face helmets against their non-certified counterparts by analysing injury predictor metrics. Using a test rig simulating 5.58 ± 0.29 m/s impacts, an anthropomorphic test device wearing both helmet types and certification statuses measured peak resultant linear and angular accelerations, head injury criterion alongside brain injury criteria scores. The data revealed comparable side and rear impact performance between non-certified and certified helmets. However, frontal impacts exposed deficiencies without certification. The non-certified full face helmets registered over twice the peak linear acceleration of certified while open face types still exceeded certified by 40% in frontal impacts. Additionally, non-certified full face helmets indicated up to 100% predicted concussion risks in side and frontal crashes based on the angular accelerations. The poorer frontal impact and elevated injury odds demonstrate certification's key safety advantages that certification should not be ignored while it still providing more protection than no helmet. However, individual needs to carefully select helmets due to performance differences of helmets. Riders should ultimately prioritize proven protection given the severe consequences of head trauma though non-certified may suffice for some low-risk environments.

The role of concussion history and biological sex on baseline concussion clinical profile symptoms in adolescent rugby players

BackgroundAccurate concussion monitoring requires access to preinjury baseline data. This is particularly important in adolescent athletes who have a high risk of concussion and are prone to prolonged recovery. As Rugby Union is governed by similar laws for men and women, it is also an ideal population to rigorously examine the impact of biological sex on concussion symptoms.AimsTo evaluate self-reported concussion symptoms at baseline in adolescent rugby union players, and examine if subtype-specific symptoms are affected by concussion history and biological sex.MethodsAdolescent rugby union players aged 16–18 years were recruited during the 2022–2023 playing season. Participants completed a series of questionnaires covering post-concussion symptoms, concussion clinical profiles, anxiety, depression and fear avoidance behaviours. Independent variables of interest in analysis were biological sex and concussion history.Results149 participants (75% male) were included. 42% (63/149) reported at least one previous concussion (average time since concussion: 18.7 months, range 1–72). Adolescents with a concussion history reported significantly higher scores than those with no history, across two clinical profiles (ocular and sleep), concussion symptom severity, and depression, all based on medium effect sizes (SMD 0.3–0.5). Females had significantly higher scores across cognitive/fatigue, ocular and sleep clinical profiles, concussion symptoms, anxiety and depression, each with large effect sizes (SMD > 0.5).ConclusionsConcussion history and sex are associated with higher baseline scores on specific concussion clinical profile, concussion symptom severity, and anxiety symptoms. These findings highlight the importance of considering baseline differences when interpreting post-injury clinical profile symptoms in adolescent rugby players. (Trial registration: ACTRN12622000931774).

Assessing the feasibility of a neck‐strength training intervention in university women's rugby

AbstractCervical muscle strength has been demonstrated to reduce concussion risk in high school athletes, and interventions to improve this in male rugby players have elicited strength improvements. However, the feasibility of introducing neck‐strengthening interventions into women's rugby has not been investigated. This study sought to pilot a neck‐strength intervention in university‐level women's rugby players. A fixed‐frame dynamometer was used to assess the multi‐directional isometric neck‐strength of 14 university women's rugby players (20.3 ± 1.0 years). Between baseline and end‐of‐season testing, a neck‐strengthening program was completed. Interviews were conducted with six players and two coaches to understand program engagement. Interviews were transcribed verbatim and processed via inductive content analysis. Increases in absolute neck‐strength post‐intervention in left and right lateral flexion (left 85.4 ± 29.7 N to 108.2 ± 41.6 N, p = 0.02, right 87.4 ± 33.3 N to 110.5 ± 40.3 N, p = 0.01) and flexion (128.4 ± 28.8 N to 147.9 ± 30.5 N, p = 0.01) were perceived positively by the players although there were suggestions that greater adaptability according to training age and more variety was required. Participants initially demonstrated limited awareness of neck‐strength training but engaged well with the exercises once the potential benefits were understood. This intervention shows promise as an effective, palatable strategy to improve neck‐strength in university women's rugby players. Further research is needed to establish whether such improvements in neck‐strength are associated with meaningful reductions in head impact occurrence.

The Effect of Exercise-Induced Central Fatigue on Cervical Spine Joint Position Error, Strength, and Endurance.

Fatigue is common in sports, impairing performance and increasing injury risk, yet little is known regarding fatigue and concussion. Impaired neck neuromuscular function may contribute to concussion at baseline, where central fatigue may further impair neck function resulting in increased concussion risk. These effects may be magnified in athletes with a history of concussion. To determine the effect of exercise induced central fatigue on neck joint position error, strength, and endurance in healthy subjects and those with a history of concussion. The investigators hypothesized that EICF would have a negative effect on all variables. Healthy subjects were examined using a single factor, within-subjects repeated measures design. Concussion history subjects were examined using a single-subject design. Nineteen healthy subjects and five subjects with a history of concussion were recruited for the study. Cervical joint position error, muscle strength, and neck flexor endurance were tested before and after exercise induced fatigue. There was a significant increase in constant (p = 0.0027) and absolute joint position error (JPE) (p < 0.001); decrease in neck flexor endurance (p < 0.001); and decrease neck strength into cervical flexion (p = 0.01) in healthy subjects following fatigue. Among concussion history subjects, five demonstrated a significant increase in absolute and constant JPE (p < 0.05); four demonstrated a significant decrease in neck flexor endurance (p < 0.05); one in neck flexion muscle strength (p < 0.05); and three in neck extension and rotation muscle strength (p < 0.05) following fatigue. Cervical neuromuscular function deteriorated following fatigue in healthy subjects. Resulting impairments may affect force alterations in cervical control, potentially increasing concussion risk. Concussion history subjects descriptively demonstrated similar results, however further research should examine formal comparisons involving subjects with and without concussion history. 3b.

‘The highest confidence that repetitive head collisions causes chronic traumatic encephalopathy’? Analysing the scientific knowledge in the Rugby Union concussion litigation of England and Wales

295 rugby players have begun legal proceedings against World Rugby, the Rugby Football Union and the Welsh Rugby Union. The claimants report they are suffering from chronic traumatic encephalopathy. Among the allegations against the defendants is that the player safety regulations (i.e. the Pitch Side Concussion Assessment and Return to Play protocols) in place at the time of injury were done without proper medical foresight and increased the risks of concussion to players. World Rugby’s safety regulations are informed by the work of the Concussion in Sport Group which maintains that the link between collisions and concussion is unclear. However, recent studies report an unprecedented confidence that sports-related concussion causes brain disease. In 2022, the Concussion in Sport Groups lead author resigned due to 10 counts of plagiarism. This saga risks damaging public respect for both the safety regulations and the science underpinning it. This article examines the state of the scientific literature and considers the challenges in proving (1) the governing bodies breached their duty of care and; (2) the causal link between collisions and brain injury. This article argues that 2022 marked the year that defendants can no longer deny the dangers of sports-related concussion, however, defining the moment when the risks ought to be known remains onerous. On causation, this article examines the principles of material contribution, doubling of the risk, and the material increase in risk. The article concludes with policy considerations inviting an extension of the material increase in risk principle to sports settings.

An Urgent Call for Concussion Incidence Measures in Para Sport for Athletes with Vision Impairment: A Narrative Review.

Concussion in para athletes with vision impairment (VI) is poorly understood. Recently published studies have suggested that athletes with VI may be more likely to sustain sport-related concussions compared to non-disabled athletes and athletes with other impairment types. There is a critical need for objective concussion incidence measures to determine concussion injury rates and risks more accurately. The aim of this review was to examine the limited available evidence of concussion incidence rates across six different para sports for athletes with VI and encourage the future collection of concussion incidence data and the adoption of injury prevention strategies in VI para sport. A literature search was conducted using four unique databases, which formed the basis of this narrative review. Injury prevention strategies such as modifying sport rules, introducing protective equipment, and incorporating additional safety measures into the field of play have been introduced sporadically, but the effectiveness of most strategies remains unknown. More prospective, sport-specific research examining mechanisms of injury and risk factors for concussion injuries in athletes with VI in both training and competition is needed. This research will help inform the development of targeted injury prevention strategies to reduce the likelihood of concussion for athletes with VI.

Concussion Care in Teenage Athletes.

Concussion is a form of traumatic brain injury that occurs commonly in pediatric patients. One group at higher risk for concussion is adolescent and teenage athletes. Athletes may sustain one or more concussions throughout their athletic careers, and these injuries may lead to significant morbidities for children. Although most concussion symptoms will resolve in less than 1 month, there is a subset of patients for whom symptoms may persist. Given the increased interest in preventing long-term sequelae related to concussion, legislation has been passed across the United States that aims to identify concussion promptly and remove participants from play after an injury has occurred. Care and treatment for concussion is evolving, with newer recommendations stating that complete or extreme rest may be unnecessary during the recovery period. Pediatricians and those who interact with young athletes should be aware of the guidelines surrounding return-to-play and return-to-learn in their geographic area of practice. [Pediatr Ann. 2024;53(2):e39-e41.].

Association between sports-related concussions and the risk of self-injury thoughts and behaviors: Who, and under what circumstances?

BackgroundUnderstanding the association between sport-related concussions and the risk of suicidal and non-suicidal self-injury thoughts and behaviors (SITBs), including non-suicidal self-injury (NSSI), suicidal ideation (SI), suicidal plan (SP), and suicidal attempt (SA), is crucial for suicide prevention. We aimed to identify the circumstances in which individuals with or without a concussion are vulnerable to SITBs. MethodsThe cross-sectional study included 85,469 students from 63 Chinese university with a mean age of 19.6 years. Firstly, propensity score matching, and inverse probability of treatment weighting (IPTW) were used to match the concussion and non-concussion group based on a range of biological, social, and psychological factors. Subsequently, multivariable logistic regression and a decision tree algorithm were employed to evaluate the interaction and cumulative impact of these risk factors and concussion on the probability of SITBs. ResultsIn the unmatched sample, concussion exposures were associated with all SITBs, with NSSI (OR, 1.41), SI (OR, 1.10), SP (OR, 1.23), and SA (OR, 1.28). However, the matched and weighted sample only had a significant association with NSSI and SI. The decision tree model revealed that, in the unmatched sample, among individuals without depressive symptoms or childhood emotional abuse, the risk of concussion on SITBs increased from 45.5 % to 65.2 % (χ2, 9.370; adjusted P = .002) after experiencing sexual abuse and verbal bullying. In the matched sample, the risk increased from 46.2 % to 64.6 % (χ2, 6.848; adjusted P = .009). ConclusionOur study revealed that individuals who suffered concussions exhibited a significantly higher risk of SITBs.

Investigation of Head Kinematics and Brain Strain Response During Soccer Heading Using a Custom-Fit Instrumented Mouthguard

Association football, also known as soccer in some regions, is unique in encouraging its participants to intentionally use their head to gain a competitive advantage, including scoring a goal. Repetitive head impacts are now being increasingly linked to an inflated risk of developing long-term neurodegenerative disease. This study investigated the effect of heading passes from different distances, using head acceleration data and finite element modelling to estimate brain injury risk. Seven university-level participants wore a custom-fitted instrumented mouthguard to capture linear and angular acceleration-time data. They performed 10 headers within a laboratory environment, from a combination of short, medium, and long passes. Kinematic data was then used to calculate peak linear acceleration, peak angular velocity, and peak angular acceleration as well as two brain injury metrics: head injury criterion and rotational injury criterion. Six degrees of freedom acceleration-time data were also inputted into a widely accepted finite element brain model to estimate strain-response using mean peak strain and cumulative strain damage measure values. Five headers were considered to have a 25% concussion risk. Mean peak linear acceleration equalled 26 ± 7.9 g, mean peak angular velocity 7.20 ± 2.18 rad/s, mean peak angular acceleration 1730 ± 611 rad/s2, and 95th percentile mean peak strain 0.0962 ± 0.252. Some of these data were similar to brain injury metrics reported from American football, which supports the need for further investigation into soccer heading.

Concussion risk and symptomology severity in adolescents are associated with pre-season drowsiness and emotional complaints.

Concussions are an ever present risk for many sports. Underlying emotional disturbances and drowsiness are associated with worse post-concussion symptom scores. Yet, not study has examined associations of both emotional disturbances and drowsiness on concussion severity and symptomology. Examine the associations between baseline sleepiness, emotional complaints, and concussion risk and symptom severity in adolescent athletes. A cohort of 626 adolescent athletes underwent baseline/pre-season concussion screening. Those who experienced a physician diagnosed concussion underwent follow up concussion symptomology assessment. Over 90% of players were seen within two weeks of the concussion incident. Linear regression examined for associations between concussion symptom scores and baseline drowsiness and baseline emotional symptoms. Logistic regression examined for association between each symptom and baseline drowsiness and baseline emotional symptoms. Of the 626 athletes that underwent baseline testing, 292 experienced a concussion. Of those 292 athletes, 174 (59.6%) reported baseline drowsiness and 183 (62.7%) baseline emotional symptoms. Baseline drowsiness and emotional complaints were associated with a 2.6 (95% confidence interval = 1.9 to 3.6) and 2.8 (95% confidence interval = 2.0 to 3.9) times greater odds of sustaining a concussion respectively. Increased symptomology after concussion was associated with both baseline drowsiness (unstandardised b = 4.6, p < 0.01) and baseline emotional complaints (unstandardised b = 6.0, p < 0.01). Preseason drowsiness and emotional complaints in adolescent athletes are associated with higher risk of adverse clinical outcomes following concussion. Therefore, clinicians and coaches should be aware, and properly screen, for sleep and emotional problems as part of pre-season/baseline health screening.