bluuebunny/crossref_metadata_2025_split huggingface dataset:
Epidemiology of head and neck injuries in elite football – a prospective survey of fifa tournaments between 1998 and 2015
Authors: Prien Annika , Dvorak Jiri , Junge Astrid 
Published: November 2017

ObjectiveRecently the potential long-term effect of sports-related head injuries has been discussed. To develop effective injury prevention strategies, epidemiological information is required. The aim of this study was to analyse the incidence and characteristics of head and neck match injuries.DesignProspective cohort study.SettingFIFA tournaments and Olympic Games.ParticipantsAll football teams participating in FIFA tournaments and Olympic Games between 1998 and 2015 were included in the study. The team physicians reported injuries from 2106 matches from 65 outdoor tournaments (20 women’s and 45 men’s). The average response rate was 96%.Outcome measuresIncidence rates per match and a variety of injury characteristics (type, severity, cause, gender) of head/neck injuries compared to other football injuries were analysed.Main results4756 injuries (2.4 injuries/match) were reported. Most injuries affected the lower extremity (70%), followed by the head/neck (15%), trunk (8%) and upper extremity (7%). Head injuries (n=674; 14.4%) were more frequent than neck injuries (n= 34;0.7%), and the incidence was higher in female (18%) than in male (14%) players. Most head/neck injuries were contusions (n=362; 50.3%) and non-time-loss injuries (n= 164;22.8%). Of the 108 (15%) reported concussions, 62% resulted in time-loss. Only one head injury (fracture) had an estimated time-loss of more than four weeks.ConclusionWhile neck injuries are rare, head injuries are more frequent, and particularly concussions often result in time-loss. No career-ending injuries of the head or neck were reported. Potential long-term effects of head/neck injuries warrant further evaluation in clinical studies.Competing interestsNone.
Incidence of head impacts at elite-level male and female cricket in australia
Authors: Kountouris Alex , Orchard John 
Published: November 2017

ObjectiveTo document the incidence of head impacts at the elite level in the sport of cricket, where there currently is very little epidemiological data regarding concussion.DesignProspective registry of head impacts reported by medical and physiotherapy staff and/or discovered by Chief Medical Officer from clinical record-keeping systems and media reportsSettingElite-level male and female cricket in Australia for one season (2015–16)Main resultsThere were 64 head impacts on the registry for season 2015–16, with 20 of these occurring in List A/First Class men’s matches and 6 occurring in List A women’s matches. The match incidence rates were 3.9 head impacts/1000 player days in elite male cricket and 3.1 head impacts/1000 player days in elite female cricket. The vast majority were caused by ball-helmet(head) impact, with a majority in batters (strikers). The next most common players affected were wicketkeepers and close-in fielders. An incidence rate for concussion is not presented as there were a number of ambiguous head impact cases (clinically not diagnosed as concussion on the field but with symptoms or abnormal Cogsport tests after the match)ConclusionsThe rate of head impact in cricket is perhaps higher than previously appreciated (as it has been traditionally considered a low-risk sport for concussion), although lower than the football codes. Definition of concussion in this sport is quite subjective and problematic, perhaps as it is the only team sport in which injury substitution is not permitted, which may influence the reporting of symptoms by players during the match.Competing interestsChief Medical Officer, Cricket Australia.
Comparison of inertial sensors and bess in balance testing of professional football players with respect to concussion
Authors: Bockisch Christopher , Mani Karin , Weber Konrad , Tarnutzer Alexander , Straumann Dominik , Nina Feddermann 
Published: November 2017

ObjectiveBalance problems are a frequent symptom after head trauma including concussion, and the Balance Error Scoring System (BESS) is routinely used as a subjective screening test. Low-cost inertial sensors are an attractive objective alternative to elaborative force plates in objective testing balance in athletes.DesignCase series.SettingTraining area of professional players.Participants310 professional male and female football players from highest league in Switzerland (19/20 (95%) teams).InterventionSubjects were scored on their ability to maintain posture while standing in the six BESS conditions. Errors were counted by a test administrator, while an IPOD worn in a waist belt recorded linear acceleration and rotational velocity.Outcome measuresA variety of measures of stability (e.g., area of 2D surface plot, normalised path length (NPL)) were computed. In order to determine which measure was most sensitive to changes in balance, receiver operating characteristic (ROC) curves were created comparing firm to foam surfaces, and then the area under the ROC was calculated.Main resultsBESS and inertial measures correlated well overall (>0.7). Inertial measurements perform well in easier conditions (ROC area >0.95 for double stance), whereas BESS is insensitive to subtle changes in balance (ROC area=0.5). BESS, however, performs better on difficult conditions (ROC area >0.9 for single stance).ConclusionsAccelerometer assisted balance tests are a useful laboratory test in assessing balance problems. Normative values for athletes should be established.Competing interestsNone.
History of multiple sport-related concussions alters variability of heart rate response to activity
Authors: Wright Alexander D , Grewal Harjas S , Smirl Jonathan D , Bryk Kelsey , Donkelaar Paul van 
Published: November 2017

ObjectiveTo examine the effect of multiple previous concussions on heart rate variability (HRV) in contact-sport athletes.DesignRetrospective Cohort.SettingLaboratory.Participants136 male elite contact-sport (hockey and football) athletes were recruited for this study. Forty-one had no previous concussion history (Hx-), while nineteen had a history of three or more concussions (Hx+). All testing was preformed prior to the start of the competitive seasonInterventionsHRV was assessed during 5-minutes of quiet stance, and while actively squatting at 0.10 Hz via a 3-lead electrocardiogram, using Kubios software. Independent variables included condition (rest vs active) and group (Hx+ vs Hx-)Outcome measuresTime-Domain: square root of mean squared differences of successive R-R intervals (RMSSD), percentage of successive R-R intervals that differ by more than 50 milliseconds (pNN50). Frequency-Domain: total power.Main resultsMixed ANOVA revealed repeated squat-stand manoeuvres challenged the autonomic system, increasing total power by 2477 milliseconds2(95% CI: 1153–3801, p<0.001). A significant interaction effect was observed for RMSSD (p=0.031) and pNN50 (p=0.012), characterised by a greater increase in HRV in the Hx+ group than in Hx- from rest to squatting (95%CIs for group differences, RMSSD: 13.2–26.3 ms, p=0.006; pNN50: 3.6–15.1%, p=0.002)ConclusionsA history of multiple sport-related concussions impairs the ability of the autonomic system to respond to an everyday stressor applied to the cardiovascular system (squatting and standing). This is an important finding, as it reveals that cumulative concussions may impart long-term impairments in the ability to accurately regulate the autonomic system.Competing interestsNone.
Is concussion a risk factor for epilepsy?
Authors: Wennberg Richard , Hiploylee Carmen , Tator Charles H 
Published: November 2017

ObjectiveIt has been stated that concussion is a risk factor for the development of post-traumatic epilepsy, but few data exist to support or refute this statement. We analysed the incidence and prevalence of epilepsy in a large cohort of post-concussion patients.DesignRetrospective cohort study.SettingAcademic tertiary care centre.Participants330 consecutive post-concussion patients followed by one concussion specialist (CHT). Exclusion criteria: abnormal brain CT/MRI, GCS ≤ 12 >1 hr post-injury, hospitalisation>48 hrs. Mean number of concussions/patient 3.3 (±2.5), mean age at first clinic visit 28 years (±14.7), mean follow-up after first concussion 7.6 years (±10.8).Assessment of risk factorIndependent variable, concussion.Outcome measuresEpilepsy incidence (dependent variable); prevalence.Main resultsEight patients had medical record documentation of seizures or convulsions or epilepsy. Upon detailed review by an epilepsy specialist (RW) none met criteria for a definite diagnosis of epilepsy: 4 had episodic symptoms incompatible with epileptic seizures (multifocal paraesthesiae, multimodality hallucinations, classic migraine) and normal EEG/MRI investigations; 4 had clear histories of syncopal (n=2) or concussive (n=2) convulsions. Compared to epilepsy prevalence (6.6/1000 individuals) and annual incidence (0.5/1000 individuals) in the general population, there was no difference in this post-concussion cohort (Chi-square=0.218, d.f.1, corr.cont., p=0.64).ConclusionsIn this large cohort of post-concussion patients we found no evidence of an increased incidence of epilepsy, and the prevalence of epilepsy was lower than in the general population. Concussion is not a significant risk factor for the development of post-traumatic epilepsy, at least in the first decade post-injury.Competing interestsNone.
Depth perception differences in athletes reporting a concussion history
Authors: Mihalik Jason P , Wasserman Erin B 
Published: November 2017

ObjectiveVision testing is becoming more commonplace in concussion assessment. The purpose of our study was to determine vision domain deficits in athletes reporting a concussion history.DesignCross-sectional.SettingClinical research centre.SubjectsHigh school and college student-athletes (n=224; 183 males) completed a multi-modal vision and sensory performance assessment.InterventionParticipants completed a valid and reliable visual performance evaluation (Nike SPARQ Sensory Station). Participants were categorised by self-reported concussion history: no history (n=158) vs. 1 or more concussions (n=66).Outcome measuresThe Nike SPARQ Sensory Station measures visual acuity, contrast sensitivity, depth perception, near-far quickness, target capture, perception span, eye-hand coordination, go/no-go, and reaction time. We employed Wilcoxon two-sample nonparametric analyses comparing concussion history groups for each outcome.ResultsStudent-athletes with a concussion history (median=1553 ms) responded more slowly to primary gaze depth perception tasks than student-athletes with no concussion history (median=1363 ms;P=0.02). Left gaze depth perception also yielded significant differences between those with concussion history (median=1383 ms) and those without concussion history (median=1162 ms;P=0.03), but not right gaze depth perception (P=0.07). No other significant differences were observed (P>0.05).ConclusionsDepth perception is worse in student-athletes with concussion history, suggesting the eyes’ ability to work in tandem may be compromised following concussion. It is also possible that observed visual performance differences may have previously existed and subsequently placed those athletes at a higher risk for concussion. Future prospective studies should explore the predictive value of visual performance screening in reducing concussion risk.Competing interestsWasserman – None.Dr. Mihalik has an equity interest in Senaptec LLC, a licensee of the intellectual property employed in this study.
Exposure to rotational acceleration over the course of one athletic season is related to impairments in an index of dynamic cerebral autoregulation
Authors: Wright Alexander D , Smirl Jonathan D , Jakovac Michael , Fraser Sarah K , Bryk Kelsey , Grewal Harjas S , Dierijck Jill , Donkelaar Paul van 
Published: November 2017

ObjectiveTo examine the relationship between cerebral autoregulation changes and impact exposuresthroughout a season of contact sports (hockey or football).DesignProspective Cohort.SettingLaboratory.Participants40 male contact sport athletes (19.4±1.2 years); to date, 3 cross-country athletes (20.0±1.0 years) have completed testing (non-contact controls).InterventionParticipants completed testing prior to the start of their athletic seasons (T1), and again after the conclusion of each season (T2). Blood pressure (BP) oscillations were driven by stand-squat manoeuvres at 0.05 and 0.10 Hz. BP and cerebral blood velocity (CBV) in the middle cerebral artery were indexed non-invasively using finger photoplethysmography and transcranial Doppler ultrasound, respectively. RM-ANOVA independent variables included time (2) and frequency (2).Outcome measuresPoint-estimates ofcoherence(correlation),phase(synchronisation), andgain(amplitude buffer) transfer function analysis metrics were calculated. Biomechanical data on head-impact exposure was estimated in a subset of contact-sport athletes (n=29) using the xPatch (X2 Biosystems), affixed to the right mastoid.ResultsSignificant frequency-time interaction forgainin contact-sport athletes (p=0.048) but not controls (p=0.213). Simple effects analysis revealed a time effect at 0.10 Hz (p<0.001), wherebygainincreased at T2 (95% CI: 0.070–0.229%/%). The ΔgainT2-T1at 0.10 Hz was correlated withestimated cumulativerotational acceleration exposure (r=0.462, p=0.015).ConclusionsThese findings suggest cumulative exposure to the rotational component of sustained head-impactsduring participation in a season of contact-sport (hockey or football) impairs the ability of the cerebrovasculature to buffer BP challenges experienced during everyday activities.Competing interestsNone.
Heart rate variability reductions following a season of sub-concussive head hits are related to the magnitude of impacts experienced
Authors: Smirl Jonathan D , Wright Alexander D , Grewal Harjas S , Jakovac Michael , Bryk Kelsey , Donkelaar Paul van 
Published: November 2017

ObjectiveTo examine the effect of repetitive contact sport-related head trauma on indices ofheart rate variability (HRV).DesignProspective Cohort.SettingLaboratory.ParticipantsForty-ninemale contact-sport (hockey or football) and four non-contact control athletes (age range: 17–22).InterventionPrior to (T1) and upon completion of (T2) the competitive athletic season, a three-lead electrocardiogram and Kubios software (Kuopio, Finland) were used to assess heart rate variability during 5-minutes of quiet stance and while actively squatting at 0.10 Hz. Independent variables included condition (rest-vs-active) and time (T1-vs-T2).Outcome measuresTime-Domain: square root of mean squared differences of successive R-R intervals (RMSSD), percentage of successive R-R intervals that differ by more than 50 milliseconds (pNN50); Non-Linear: approximateentropy (ApEn). In a subset of participants (n=29) biomechanical head-impact exposure data was estimated usingthe xPatch (X2 Biosystems), affixed to the right mastoid.Main resultsRM-ANOVA indicateda significant main effect of timein contact sport but not control athletes (all p>0.133). HRV metrics were decreased post-season relative to baseline (95% CI:s for differences: MeanRR4–48 ms, p=0.045; RMSSD 1–9 ms, p=0.018; pNN50 0.689–5.98, p=0.010; ApEn 0.022–0.163, p=0.044). Significant correlations were observed between the average peak linear acceleration per hit experienced and the change in MeanRR(R²=0.1382), and RMSSD (R²=0.1525).ConclusionsExposure to repetitive subconcussive impacts overone season of contact-sport leads to decreases in heart rate variability. The magnitude of HRV reduction is related to the average magnitude of the linear component of hits to the head experienced during playCompeting interestsNone.
Descriptive analysis of head impact kinetics in a simulated rugby union tackle: preliminary findings
Authors: Danielle Salmon , Pinfold Jayden , Sullivan S John , Andrew Gray , Lodge Ed , Hamish Osborne , Darryl Tong 
Published: November 2017

ObjectiveThe tackle is a key component in rugby union and carries some of the highest risk for concussions. The purpose this study was to observe the acceleration profile of the head during a simulated tackle and to determine if these forces vary by playing position.DesignObservational.SettingLaboratory.ParticipantsMale rugby players (n=41) age 21.8±3.4 years.ProtocolParticipants were asked to perform 5 tackles with each shoulder. For each tackle the 50 kg bag was released on a pendulum and the players completed a 3 m run-up to make contact with the bag at its peak speed (4.3 ±.13 m/s). For each tackle the linear and rotational acceleration were captured using a head positioning system (HPS) anchored over the mastoid bone.Outcome measuresThe magnitude and variability of the mean resultant linear and rotational acceleration forces over the 10 tackles were examined using the peak acceleration values and were compared with Mann-Whitney-Wilcoxon tests.Main resultsThe overall mean peak linear force was 82.9 Gz with a range of 20.1–236.6 Gz. For the forwards (n=23) the peak linear and rotational accelerations were 83.0±36.3 Gz and 2537.8±477.7 m/s2, while for the backs (n=18) were 77.6±33.8 Gz and 2501.9±519.6 m/s2. There were no significant differences between forwards/backs, or those with a history of concussion (p≥0.054).ConclusionsWith growing evidence implicating the importance of sub-concussive impacts in later brain health, understanding the exposure load of players during trainings and games is essential. This is the first study to document the impact forces recorded at the head during a simulated rugby tackle.Competing interestsNone.Ed Lodge is CEO of CSx Concussion Management Systems, who developed and provided the Head positioning system that was used to measure head impact kinetics in real time.
The effect of prior concussion history on dual-task gait following a concussion
Authors: Howell David R , Beasley Michael , Vopat Lisa , Meehan William P 
Published: November 2017

ObjectiveTo examine gait characteristics among patients following their first lifetime concussion, second or greater lifetime concussion, and individuals with no concussion history.DesignProspective observational study.SettingRegional sport-concussion clinic.ParticipantsFourteen patients presented following their first lifetime concussion (57% female; 15.6 [95% CI:=13.0, 17.2] years of age; 11.1 [8.3, 13.9] days post-concussion), 21 following their second or greater lifetime concussion (52% female; 16.9 [15.5, 18.4] years of age; 8.6 [6.2, 11.1] days post-concussion), and thirty-one controls without a concussion history (65% female; 15.0 [14.2, 15.8] years of age). Exclusion criteria included a current lower extremity injury or diagnosed learning disability.Interventions/independent variablesParticipants completed gait evaluations and medical history questionnaires. MANCOVAs evaluated between-group gait differences; correlations were calculated between the number of lifetime concussions and gait.Outcome measuresParticipants recorded their number of prior concussions. Three inertial sensors quantified single and dual-task gait; variables included average gait speed, cadence, and stride length.Main resultsDuring dual-task gait, patients reporting for their ≥ second lifetime concussion walked significantly slower (0.81 [0.75, 0.89] m/s vs. 0.92 [0.86, 0.97] m/s;p=0.009) and with smaller stride lengths (0.98 [0.92, 1.04] m vs. 1.08 [1.04, 1.13] m;p=0.02) compared to controls. A moderate correlation was detected between dual-task gait speed and the number of prior concussions (ρ= 0.44,p= 0.04).ConclusionsPatients with a prior concussion history demonstrated altered dual-task gait strategies relative to controls. Dual-task gait velocity and number of prior concussions were moderately correlated, suggesting a worsening effect from multiple concussions across the lifetime.Competing interestsNone.Dr. Meehan receives royalties from ABC-Clio publishing for the sale of his book,Kids, Sports, and Concussion: A guide for coaches and parents, and royalties from Wolters Kluwer for working as an author forUpToDate. He is under contract with ABC-Clio publishing for a future book entitled,Concussions, and with Springer International publishing for a future book entitled,Head and Neck Injuries in Young Athletes. His research is funded, in part, by a grant from the National Football League Players Association and by philanthropic support from the National Hockey League Alumni Association through the Corey C. Griffin Pro-Am Tournament. Drs. Howell, Beasley, and Vopat have no conflicts of interest to report.
Association between initial post-concussion presentation and persistent symptoms at 1–month post-concussion
Authors: Register-Mihalik Johna , Herzog Mackenzie , Bloom O Josh , Fonseca Janna , Phillips Kristen , De Maio Valerie 
Published: November 2017

ObjectiveTo examine associations between acute post-concussion measures and 1-month persistent symptom presence among paediatric concussion patients.DesignProspective cohort.SettingThree family medicine clinics, from the same practice, in an urban/suburban area of the USA.SubjectsPaediatric concussion patients (n=179); ages 8-18 years (median age=15; IQR: 13-16) presenting within three days of injury.InterventionParticipants completed a systematic evaluation during their initial visit and a 4-6 week follow-up survey (80% follow-up; n=144). The initial visit variables included age, gender, previous head injury, total symptom severity, Immediate Postconcussion Assessment and Cognitive Test (ImPACTTM) composite scores, and near point convergence (NPC).Outcome measuresThe primary outcome was 1-month follow-up persistent symptom presence, determined using the Rivermead Postconcussion Symptoms Questionnaire. We assessed univariate relationships for each variable with persistent symptoms. Variables significant in univariable analyses (p<0.10) were included in a multivariable logistic regression model.ResultsPersistent symptoms were reported for 27.1% (n=39) of participants. Females were more likely to have persistent symptoms (OR=1.9; 95% CI: 0.9, 4.0; p=0.086). Initial visit total symptom severity (Z=4.2; p<0.001) was higher in those with persistent symptoms. Initial visit verbal memory (Z=−1.7; p=0.083), processing speed (Z=−1.7; p=0.093), and reaction time (Z=2.8; p=0.001) were worse in those with persistent symptoms. Total symptom severity was the only factor significant in the multivariable model (OR=1.04; 95% CI=1.02–1.07).ConclusionsGender, acute symptom burden and post-concussion neurocognitive deficits have significant relationships with persistent symptom presence. Clinicians should be mindful of these factors when considering treatment.Competing interestsThe current study was funded in part by the National Operating Committee on Standards for Athletic Equipment.Dr. Bloom is employed at the study setting.Ms. Fonseca is employed at the study setting.Ms. Phillips is employed at the study setting.