Preventing head and neck injury

Gender differences in female and male Australian football concussion injury: A prospective observational study of emergency department presentations

OBJECTIVE

To examine gender differences in Australian football (AF)-related concussion presentations to EDs in regional Australia.

METHODS

A prospective observational study of patients presenting to 1 of the 10 EDs in Western Victoria, Australia, with an AF-related concussion was conducted. Patients were part of a larger study investigating AF injuries over a complete AF season, including pre-season training and practice matches. Information regarding concussion injuries was extracted from patient medical records, including clinical features, concurrent injuries, mechanism and context of injury. Female and male data were compared with chi-squared and Fisher's exact tests. P < 0.05 was considered significant.

RESULTS

From the original cohort of 1635 patients with AF-related injuries (242 female and 1393 male), 231 (14.1%) patients were diagnosed with concussion. Thirty-eight (15.7%) females had concussions versus 193 (13.9%) males (P > 0.05). Females over the age of 16 were more likely to be concussed than males in the same age range (females n = 26, 68.4% vs males n = 94, 48.7%; P = 0.026). Neurosurgically significant head injury was rare (one case). Similar rates of concurrent injury were found between females 15 (39.5%) and males 64 (33.2%), with neck injury the single most common in 24 (10.3%) concussions. Sixty-nine patients (29%) were admitted for observation or to await the results of scans. The majority of concussions occurred in match play (87.9%). Females were more likely injured in contested ball situations (63.2% vs 37.3%; P < 0.05).

CONCLUSION

Concussion rates for community-level AF presentations to regional EDs were similar between genders. Serious head injury was rare, although hospital admission for observation was common. Concurrent injuries were common, with associated neck injury most often identified. Match play accounted for the majority of head injuries.

An Evaluation Study of a New Designed Oscillating Hydraulic Trainer of Neck

In view of the importance of neck strength training and the lack of adequate training equipment, this study designed a new oscillating hydraulic trainer (OHT) of neck based on oscillating hydraulic damper. We used surface electromyography (sEMG) and subjective ratings to evaluate the neck OHT and compared the results with a simple hat trainer (HATT) and traditional weight trainer (TWT) to verify the feasibility and validity of the OHT. Under similar exercise conditions, 12 subjects performed a set of neck flexion and extension exercise with these 3 trainers. The sEMG signals of targeted muscles were collected in real time, and subjects were asked to complete subjective evaluations of product usability after exercise. The results showed that the root mean square (RMS%) of sEMG indicated that the OHT could provide two-way resistance and train the flexors and extensors simultaneously. The overall degree of muscle activation with OHT was higher than that with the other two trainers in one movement cycle. In terms of resistance characteristics exhibited by the sEMG waveform, duration (D) with OHT was significantly longer than HATT and TWT when exercising at a high speed, while Peak Timing (PT) was later. The ratings of product usability and performing usability of OHT were remarkably higher than that of HATT and TWT. Based on the above results, the OHT was proved to be more suitable for strength training, such as neck muscles, which were getting more attention gradually, but lacked mature and special training equipment.

Traumatic dissection of the anterior cerebral artery secondary to a rugby related impact: A case report with emphasis on the usefulness of T1-VISTA

Background

Cerebrovascular injuries (CVIs) are not usually considered in the differential diagnosis of sport-related head injuries (SRHIs). We encountered a rugby player with traumatic dissection of the anterior cerebral artery (ACA) after impact on the forehead. Head magnetic resonance imaging (MRI) with T1-volume isotropic turbo spin-echo acquisition (VISTA) was used to diagnose the patient.

Case Description

The patient was a 21-year-old man. During a rugby tackle, his forehead collided with the forehead of an opponent. He did not have a headache or disturbance of consciousness immediately after the SRHI. On the 2^nd day of illness, he had transient weakness of the left lower limb several times. On the 3^rd day of illness, he visited our hospital. MRI revealed occlusion of the right ACA and acute infarction of the right medial frontal lobe. T1-VISTA revealed intramural hematoma of the occluded artery. He was diagnosed with acute cerebral infarction due to dissection of the ACA and was followed up for vascular changes with T1-VISTA. The vessel had recanalized and the size of the intramural hematoma had decreased 1 and 3 months after the SRHI, respectively.

Conclusion

Accurate detection of morphological changes in cerebral arteries is important for the diagnosis of intracranial vascular injuries. When paralysis or sensory deficits occur after SRHIs, it is difficult to differentiate between concussion from CVI. Athletes with red-flag symptoms after SRHIs should not merely be suspected to have concussion; they should be considered for imaging studies.

Risk Factors of Work-Related Head and Neck Injuries: A National Survey

Background

Occupational accidents made injuries in different parts of the body; two important parts of them are head and neck. We aimed to identify the risk factors of work-related head and neck injuries with using of a nationwide occupational accident data.

Methods

This analytical cross-sectional study was conducted on the nationwide data that was gathered in 2013-2018. The target population was industrialized and non-industrialized adults, aged 18 yr or older. Dependent variable was the head and neck injuries. The independent variables were included, age, sex, education level, work experience, job, shift work, injury cause, referred center, season, accident day, accident time, and action after accident. Univariate logistic regression analyses and subsequently, a multivariate logistic regression model was used for analysis.

Results

Out of the 17066 injured workers, 4072 (23.86%) subjects had head and neck injuries. The results of multivariate logistic regressions model showed, age ranges 30-39 (OR = 1.218; 95% CI: 1.036,1.433; P= 0.017), 40-49 (OR = 1.313; 95% CI: 1.044,1.652; P= 0.020), and >= 60 (OR=1.620; 95%CI: 1.028,2.553; P=0.038) and having male sex (OR = 1.657; 95% CI: 1.075,2.555; P= 0.022) were final work-related risk factors of head and neck injuries in Iran. Also winter season (OR = 1.212; 95% CI: 1.00,1.469; P= 0.050) could increase the head and neck injuries odds.

Conclusion

Older workers in Iran are more vulnerable against the occupational head and neck injuries. Moreover, having male sex was other risk factor of the head and neck injuries.

Evaluation of Protective Properties of Commercially Available Medical Helmets: Are Medical Helmets Protective?

OBJECTIVES

The aims of the study were to evaluate and to compare protective properties of commercially available medical helmets for a set of standardized head injury risk measures.

METHODS

Eleven helmet types were evaluated to represent the variety of commercially available medical helmet designs and manufacturers. A test mannequin and sensor apparatus were used to simulate a backward-standing fall. The head/neck size, mass, and "standing" height of the mannequin (5'9″) were representative of a 50th percentile male. A triaxial array was placed at the head center of mass to position 3 linear accelerometers and 3 angular rate sensors. Data were collected for 5 single trials for each helmet, as well as 5 repeated trials. Five trials were also collected with no helmet scenarios. Three head injury risk measures were examined (linear acceleration, angular acceleration, and head injury criterion). Data were analyzed by clinical cutoff thresholds and continuous values.

RESULTS

Helmets varied in their performance across head injury risk measures. All helmets provided higher levels of protection compared with no helmet scenarios. No helmets were protective for subdural hematoma (measured by angular acceleration). All helmets lost protective properties with repeated falls. Results for skull fracture risk were inconsistent between linear acceleration and head injury criterion injury risk measures.

CONCLUSIONS

No helmets were protective across all head injury risk measures. Medical helmets may reduce some fall injury severity but may not prevent all types of head injury. All helmets exhibited worsening of protective properties with repeated falls. We recommend medical helmets be replaced after each fall incident where the helmet impacts another surface.

Injury Reduction Programs for Reducing the Incidence of Sport-Related Head and Neck Injuries Including Concussion: A Systematic Review

BACKGROUND

Sport-related head and neck injuries, including concussion, are a growing global public health concern with a need to explore injury risk reduction strategies such as neck exercises.

OBJECTIVES

To systematically review the literature to investigate: (1) the relationship between neck strength and sport-related head and neck injuries (including sport-related concussion (SRC); and (2) whether neck exercise programs can reduce the incidence of (a) sport-related head and neck injuries; and (b) SRC.

METHODS

Five databases (Ovid MEDLINE, CINAHL, EMBASE, SPORTDiscus, and Web of Science) and research lists of included studies were searched using a combination of medical subject headings and keywords to locate original studies which reported the association between incidence of head and/or neck injury and neck strength data, or included a neck exercise intervention either in isolation or as part of a more comprehensive exercise program.

RESULTS

From an initial search of 593 studies, six were included in this review. A narrative synthesis was performed due to the heterogeneity of the included studies. The results of two observational studies reported that higher neck strength, but not deep neck flexor endurance, is associated with a lower risk of sustaining a SRC. Four intervention studies demonstrated that injury reduction programs that included neck exercises can reduce the incidence of sport-related head and neck injuries including SRC.

CONCLUSION

Consideration should be given towards incorporating neck exercises into injury reduction exercise programs to reduce the incidence of sport-related head and neck injuries, including SRC.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO (registration number: 194217).

Analysis of HIC and Hydrostatic Pressure in the Human Head during NOCSAE Tests of American Football Helmets

Brain damage is a serious economic and social burden. Contact sports such as American football, are one of the most common sources of concussions. The biomechanical response of the head-helmet system caused by dynamic loading plays a major role. The literature has focused on measuring the resultant kinematics that act on the head and helmet during tackles. However, few studies have focused on helmet validation tests, supported by recent findings and emerging numerical approaches. The future of helmet standards could benefit from insights at the level of injury mechanisms, using numerical tools to assess the helmets. Therefore, in this work, a numerical approach is employed to investigate the influence of intracranial pressure (ICP) on brain pathophysiology during and after helmeted impacts, which are common in American football. The helmeted impacts were performed at several impact locations according to the NOCSAE standard (configurations A, AP, B, C, D, F, R, UT). In order to evaluate the ICP levels, the αHEAD finite element head and brain model was combined with a Hybrid III-neck structure and then coupled with an American football helmet to simulate the NOCSAE impacts. In addition, the ICP level was analyzed together with the resulting HIC value, since the latter is commonly used, in this application and others, as the injury criterion. The obtained results indicate that ICP values exceed the common threshold of head injury criteria and do not correlate with HIC values. Thus, this work raises concern about applying the HIC to predict brain injury in American football direct head impacts, since it does not correlate with ICP predicted with the FE head model.

Subconcussive head impact exposure between drill intensities in U.S. high school football

USA Football established five levels-of-contact to guide the intensity of high school football practices. The objective of this study was to examine head impact frequency and magnitude by levels-of-contact to determine which drills had the greatest head impact exposure. Our primary hypothesis was that there would be an incremental increase in season-long head impact exposure between levels-of-contact: air<bags<control<thud<live. This observational study included 24 high-school football players during all 46 practices, 1 scrimmage, 9 junior varsity and 10 varsity games in the 2019 season. Players wore a sensor-installed mouthguard that monitored head impact frequency, peak linear acceleration (PLA), and rotational acceleration (PRA). Practice/game drills were filmed and categorized into five levels-of-contact (air, bags, control, thud, live), and head impact data were assigned into one of five levels-of-contact. Player position was categorized into lineman, hybrid, and skill. A total of 6016 head impacts were recorded during 5 levels-of-contact throughout the season. In the overall sample, total number of impacts, sum of PLA, and PRA per player increased in a near incremental manner (air<bags<control = thud<live), where live drills had significantly higher cumulative frequency (113.7±17.8 hits/player) and magnitude [2,657.6±432.0 g (PLA), and 233.9 ± 40.1 krad/s² (PRA)] than any other levels-of-contact, whereas air drills showed the lowest cumulative frequency (7.7±1.9 hits/player) and magnitude [176.9±42.5 g (PLA), PRA 16.7±4.2 krad/s² (PRA)]. There was no significant position group difference in cumulative head impact frequency and magnitude in a season. Although there was no difference in average head impact magnitude across five levels-of-contact and by position group PLA (18.2–23.2g) and PRA (1.6–2.3krad/s²) per impact], high magnitude (60-100g and >100g) head impacts were more frequently observed during live and thud drills. Level-of-contact influences cumulative head impact frequency and magnitude in high-school football, with players incurring frequent, high magnitude head impacts during live, thud, and control. It is important to consider level-of-contact to refine clinical exposure guidelines to minimize head impact burden in high-school football.

Risk Factors for Chronic Traumatic Encephalopathy: A Proposed Framework

Chronic traumatic encephalopathy (CTE) is a progressive neurodegenerative disease that has been neuropathologically diagnosed in contact and collision sport athletes, military veterans, and others with a history of exposure to repetitive head impacts (RHI). Identifying methods to diagnose and prevent CTE during life is a high priority. Timely diagnosis and implementation of treatment and preventative strategies for neurodegenerative diseases, including CTE, partially hinge upon early and accurate risk characterization. Here, we propose a framework of risk factors that influence the neuropathological development of CTE. We provide an up-to-date review of the literature examining cumulative exposure to RHI as the environmental trigger for CTE. Because not all individuals exposed to RHI develop CTE, the direct and/or indirect influence of nonhead trauma exposure characteristics (e.g., age, sex, race, genetics) on the pathological development of CTE is reviewed. We conclude with recommendations for future directions, as well as opinions for preventative strategies that could mitigate risk.

Head and neck injury in major trauma in Ireland: a multicentre retrospective analysis of patterns and surgical workload

PURPOSE

Head and neck injuries are common in major trauma patients, but the prevalence is poorly documented in the literature. This study aims to investigate this further, particularly in the context of increasing development of Irish and European trauma systems.

AIMS

To determine the prevalence of, and patterns behind head and neck injury in major trauma in an Irish population.

MATERIALS AND METHODS

The Trauma Audit Research Network database was analysed for major trauma patients (injury severity score > 15) with head and neck injuries admitted to any of the 26 participating hospitals in the Republic of Ireland between 2014 and 2017. The data was studied for patterns in the epidemiology of injuries and outcomes.

RESULTS

A total of 5364 patients were identified. Males were affected more than females (M:F 2.1:1). The most common mechanism of injury was falls. There were 1272 counts of soft tissue injury, and 5814 counts of bony injury recorded within the cohort. Twenty-six percent of patients underwent some form of surgical procedure. Median length of hospital stay was 8 days, and the 30-day survival rate was 90%.

CONCLUSIONS

A substantial number of Irish major trauma patients of all ages and genders sustain some form of head and neck injury. It produces significant injury and surgical workload involving input from multiple disciplines.

Could a Compliant Foam Anvil Characterize the Biofidelic Impact Response of Equestrian Helmets?

The performance of equestrian helmets to protect against brain injuries caused by fall impacts against compliant surfaces such as turf has not been studied widely. We characterize the kinematic response of simulated fall impacts to turf through field tests on horse racetracks and laboratory experiments. The kinematic response characteristics and ground stiffness at different going ratings (GRs) (standard measurement of racetrack condition) were obtained from 1 m and 2 m drop tests of an instrumented hemispherical impactor onto a turf racetrack. The "Hard" rating resulted in higher peak linear accelerations and stiffness, and shorter impact durations than the "Soft" and "Heavy" ratings. Insignificant differences were found among the other GRs, but a strong overall relationship was evident between the "going rating" and the kinematic response. This relationship was used to propose a series of three synthetic foam anvils as turf surrogates in equestrian falls corresponding to ranges of GRs of (i) heavy-soft (H-S), (ii) good-firm (G-F), and (iii) firm-hard (F-H). Laboratory experiments consisted of a helmeted headform being dropped onto natural turf and the turf surrogate anvils using a monorail drop rig. These experiments revealed that the magnitudes and durations of the linear and rotational accelerations for helmeted impacts to turf/turf surrogates were similar to those in concussive sports falls and collisions. Since the compliance of an impacted surface influences the dynamic response of a jockey's head during a fall impact against the ground, it is important that this is considered during both accident reconstructions and helmet certification tests.

Recommendations for Fall-Related Injury Prevention: A 1-Year Review of Fall-Related Root Cause Analyses in the Veterans Health Administration

BACKGROUND

Injurious falls continue to challenge health care. Causes of serious falls from the largest health care system in the United States can direct future prevention efforts.

PURPOSE

This article analyzes injurious falls in the Veterans Health Administration and provides generalizable recommended actions to prevent future events.

METHODS

We categorized root cause analysis (RCA) reports and coded injury type, fall type, location, and root causes. We describe interventions during the fall and provide resources for future prevention.

RESULTS

There were 154 reported fall RCAs during this time. Most (83%, n = 128) resulted in major injury: hip fractures (43%, n = 66), other fractures (25%, n = 38), and head injury (16%, n = 24). Most falls were unwitnessed (75%, n = 116).

CONCLUSIONS

Patients who fell were not wearing hip or head protection. Most falls were unwitnessed, and none were on 1:1 observation. Such interventions may help prevent future injurious falls.

Head and Neck Trauma in a Rapidly Growing African Metropolis: A Two-Year Audit of Hospital Admissions

Understanding injury-related burdens is an essential part of trauma quality improvement programs aimed at decreasing morbidity and mortality. This is especially the case in low and middle-income country settings where data on injuries remains limited. The aim of this study was to audit the types of head and neck injuries, which have been diagnosed among patients admitted to a major national hospital in the context of a rapidly growing sub Saharan city. Data were collected retrospectively for head and neck trauma from the Muhimbili National Hospital (MNH) in Dar es Salaam, Tanzania from the years 2016 and 2017. Distribution of ICD-10 codes by age and sex for the five most common diagnoses were determined using frequencies and percentages. The most common diagnosis was ICD-10-S02 (fracture of skull and facial bones) with 277 cases (44.1%), which was followed by S05 (injury of the eye and orbit), 114 cases (18.2%), and S09 (other and unspecified injuries of head) 77 cases (12.3%). The mean ages of admission for these three diagnoses were 28.1 (SD: 11.6), 23.8 (SD: 18.9), and 30.8 (SD: 18.0) years, respectively. This study provides information on the overall burden of head and neck trauma at a major regional tertiary care facility. It provides an initial understanding of the burden of head and neck trauma and suggests follow-up in the form of clarification of injury mechanisms and contextual factors for future work.

A review of impact testing methods for headgear in sports: Considerations for improved prevention of head injury through research and standards

Standards for sports headgear were introduced as far back as the 1960s and many have remained substantially unchanged to present day. Since this time, headgear has virtually eliminated catastrophic head injuries such as skull fractures and changed the landscape of head injuries in sports. Mild traumatic brain injury (mTBI) is now a prevalent concern and the effectiveness of headgear in mitigating mTBI is inconclusive for most sports. Given that most current headgear standards are confined to attenuating linear head mechanics and recent brain injury studies have underscored the importance of angular mechanics in the genesis of mTBI, new or expanded standards are needed to foster headgear development and assess headgear performance that addresses all types of sport-related head and brain injuries. The aim of this review is to provide a basis for developing new sports headgear impact tests for standards by summarizing and critiquing: 1) impact testing procedures currently codified in published headgear standards for sports and 2) new or proposed headgear impact test procedures in published literature and/or relevant conferences. Research areas identified as needing further knowledge to support standards test development include defining sports-specific head impact conditions, establishing injury and age appropriate headgear assessment criteria, and the development of headgear specific head and neck surrogates for at-risk populations.

Regional mechanical and biochemical properties of the porcine cortical meninges

The meninges are pivotal in protecting the brain against traumatic brain injury (TBI), an ongoing issue in most mainstream sports. Improved understanding of TBI biomechanics and pathophysiology is desirable to improve preventative measures, such as protective helmets, and advance our TBI diagnostic/prognostic capabilities. This study mechanically characterised the porcine meninges by performing uniaxial tensile testing on the dura mater (DM) tissue adjacent to the frontal, parietal, temporal, and occipital lobes of the cerebellum and superior sagittal sinus region of the DM. Mechanical characterisation revealed a significantly higher elastic modulus for the superior sagittal sinus region when compared to other regions in the DM. The superior sagittal sinus and parietal regions of the DM also displayed local mechanical anisotropy. Further, fatigue was noted in the DM following ten preconditioning cycles, which could have important implications in the context of repetitive TBI. To further understand differences in regional mechanical properties, regional variations in protein content (collagen I, collagen III, fibronectin and elastin) were examined by immunoblot analysis. The superior sagittal sinus was found to have significantly higher collagen I, elastin, and fibronectin content. The frontal region was also identified to have significantly higher collagen I and fibronectin content while the temporal region had increased elastin and fibronectin content. Regional differences in the mechanical and biochemical properties along with regional tissue thickness differences within the DM reveal that the tissue is a non-homogeneous structure. In particular, the potentially influential role of the superior sagittal sinus in TBI biomechanics warrants further investigation. STATEMENT OF SIGNIFICANCE: This study addresses the lack of regional mechanical analysis of the cortical meninges, particularly the dura mater (DM), with accompanying biochemical analysis. To mechanically characterise the stiffness of the DM by region, uniaxial tensile testing was carried out on the DM tissue adjacent to the frontal, parietal, temporal and occipital lobes along with the DM tissue associated with the superior sagittal sinus. To the best of the authors' knowledge, the work presented here identifies, for the first time, the heterogeneous nature of the DM's mechanical stiffness by region. In particular, this study identifies the significant difference in the stiffness of the DM tissue associated with the superior sagittal sinus when compared to the other DM regions. Constitutive modelling was carried out on the regional mechanical testing data for implementation in Finite Element models with improved biofidelity. This work also presents the first biochemical analysis of the collagen I and III, elastin, and fibronectin content within DM tissue by region, providing useful insights into the accompanying macro-scale biomechanical data.

A novel Cervical Spine Protection device for reducing neck injuries in contact sports: design concepts and preliminary in vivo testing

Head and neck injuries are common in contact sports such as American football. Different mechanisms can produce such injuries, including compressive impact forces on the crown of the helmet with the neck in a flexed chin-down position. The aim of this paper was developing and testing a novel Cervical Spine Protection Device (CSPD) designed to keep the neck within its safe physiological range. The cervical spine range of motion (ROM) of ten participants was measured under four conditions: free; wearing a football gear; wearing the CSPD; and wearing the CSPD underneath the gear. The CSPD was tested in terms of passive and active restraint of head motion, and for its capability to improve endurance time of the neck extensor muscles. Wearing the CSPD resulted in a significant 40-60% reduction in ROM across the three anatomical planes, and in increased endurance of the neck extensor muscles (FREE: 114 ± 57 s; CSPD: 214 ± 95 s; p = 0.004). In quasi-static loading conditions the CSPD was capable of keeping the neck within its physiological range, thus it may be used to decrease the risk of severe injuries due to dangerous chin-down positions.

Inconsistent anticipatory postural adjustments (APAs) in rugby players: a source of injuries?

Background

We are developing since 2010 with Thales and the Fédération Française de Rugby (FFR) M-Rex, a new kind of rugby scrum simulator. The study questioned whether it could improve safety and protect players from injury by using it as a tool for training/coaching the packs.

Aim

To explore the anticipatory postural adjustments (APAs) during the engagement of the ruck, because these predictive neck and back muscles contractions protect the spinal cord at the time of impacts, which is crucial to prevent injuries.

Methods

We quantified the kinematics and the EMG activities in high-level front row players during their initial engagement, when scrummaging with M-Rex. All studies were performed with one player interacting with the robot, at first, and then with the three players acting together.

Results

For most of the tested high-level players, the APA latencies were highly variable from trial to trial even though the engagement resulted in similar impacts. At time, the onset of the electromyography activity in the neck and back muscles showed latencies inferior to 50 ms or even close to zero prior to the impact, which rendered muscle contractions inefficient as APAs. We were also unable to identify clear muscular synergies underlying the APAs because of their great variability on a trial-to-trial basis. Finally, the APAs were not related to the amplitude of the ensuing impact and were asymmetric in most trials. All these characteristics held true, whether the player was playing alone or with two other frontline players.

Conclusion

Our result suggest that APAs should be systematically tested in high-level rugby players as well as in any high-level sport men at risk of neck and back injuries. Because APAs can be efficiently trained, our study paves the way to design individual position-specific injury prevention programme.

Neck Muscle EMG-Force Relationship and Its Reliability During Isometric Contractions

BACKGROUND

Susceptible to injury, the neck is subject to scientific investigations, frequently aiming to elucidate possible injury mechanisms via surface electromyography (EMG) by indirectly estimating cervical loads. Accurate estimation requires that the EMG-force relationship is known and that its measurement error is quantified. Hence, this study examined the relationship between EMG and isometric force amplitude of the anterior neck (AN), the upper posterior neck (UPN), and the lower posterior neck (LPN) and then assessed the relationships' test-retest reliability across force-percentiles within and between days.

METHODS

EMG and force data were sampled from 18 participants conducting randomly ordered muscle contractions at 5-90% of maximal voluntary force during three trials over 2 days. EMG-force relationships were modeled with general linear mixed-effects regression. Overall fitted lines' between-trial discrepancies were evaluated. Finally, the reliability of participants' fitted regression lines was quantified by an intraclass correlation coefficient (ICC) and the standard error of measurement (SEM).

RESULTS

A rectilinear model had the best fit for AN while positively oriented quadratic models had the best fit for UPN and LPN, with mean adjusted conditional coefficients of determination and root mean square errors of 0.97-0.98 and 4-5%, respectively. Overall EMG-force relationships displayed a maximum 6% between-trial discrepancy and over 20% of maximal force, and mean ICC was above 0.79 within day and 0.27-0.61 between days across areas. Corresponding SEM was below 12% both within and between days across areas, excluding UPN between days, for which SEM was higher.

CONCLUSIONS

EMG-force relationships were elucidated for three neck areas, and provided models allow inferences to be drawn from EMG to force on a group level. Reliability of EMG-force relationship models was higher within than between days, but typically acceptable for all but the lowest contraction intensities, and enables adjustment for measurement imprecision in future studies.

Mechanisms and Factors Associated With Tackle-Related Injuries in South African Youth Rugby Union Players

BACKGROUND

The majority of injuries in rugby union occur during tackle events. The mechanisms and causes of these injuries are well established in senior rugby union.

PURPOSE

To use information from an injury database and assess video footage of tackle-related injuries in youth rugby union matches to identify environmental factors and mechanisms that are potentially confounding to these injuries.

STUDY DESIGN

Descriptive epidemiological study.

METHODS

Injury surveillance was conducted at the under-18 Craven Week rugby tournament. Tackle-related injury information was used to identify injury events in match video footage (role-matched noninjury tackle events were identified for the cohort of injured players). Events were coded using match situational variables (precontact, contact, and postcontact). Relative risk ratio (RRR; ratio of probability of an injury or noninjury outcome occurring when a characteristic was observed) was reported by use of logistic regression.

RESULTS

In comparison with the first quarter, injury risk was greater in the third (RRR = 9.75 [95% CI, 1.71-55.64]; P = .010) and fourth quarters (RRR = 6.97 [95% CI, 1.09-44.57]; P = .040) for ball carriers and in the fourth quarter (RRR = 9.63 [95% CI, 1.94-47.79]; P = .006) for tacklers. Ball carriers were less likely to be injured when they were aware of impending contact (RRR = 0.14 [95% CI, 0.03-0.66]; P = .012) or when they executed a moderate fend (hand-off) (RRR = 0.22 [95% CI, 0.06-0.84]; P = .026). Tacklers were less likely to be injured when performing shoulder tackles (same side as leading leg) in comparison to an arm-only tackle (RRR = 0.02 [95% CI, 0.001-0.79]; P = .037). Ball carriers (RRR = 0.09 [95% CI, 0.01-0.89]; P = .040) and tacklers (RRR = 0.02 [95% CI, 0.001-0.32]; P =.006) were less likely to be injured when initial contact was made with the tackler's shoulder/arm instead of his head/neck.

CONCLUSION

The relative risk of tackle-related injury was higher toward the end of matches. Incorrect technique may contribute to increased injury risk. Implementing recovery strategies between matches, training safe and effective techniques, and improving levels of conditioning may counter the negative effects of fatigue. These findings may assist stakeholders in youth rugby to formulate injury prevention strategies and may improve the preparation of field-side medical staff for managing tackle-related injuries at these or similar tournaments.

Concussed or Not? An Assessment of Concussion Experience and Knowledge Within Elite and Semiprofessional Rugby Union

OBJECTIVE

The primary aim was to assess experience and knowledge of adult concussion among international, professional and semiprofessional players, coaches, medical staff, and referees within Rugby Union. The secondary aim was to identify preferred education dissemination routes.

DESIGN

Questionnaires devised specifically for players, coaches, medical staff, and referees.

SETTING AND PARTICIPANTS

A total of 370 players, 44 coaches, 40 medical staff, and 33 referees from within Wales were surveyed.

MAIN OUTCOME MEASURES

Knowledge of the signs and symptoms of concussion, return to play guidelines and consequences of concussion were investigated along with experiences of, and attitudes towards, concussion.

RESULTS

The respondents had extensive experience of sustaining or witnessing rugby-related concussion. Medical staff had the greatest level of concussion knowledge, with coaches having the least. Players and coaches exhibited a disconnection between being "knocked-out" and practically applying this when managing concussion. Almost half of the players and coaches did not indicate concussion could impair performance. Eighty percent of medical staff had felt pressured to clear a concussed player. Most players (82%), coaches (66%), and referees (64%) incorrectly believed protective equipment prevents concussion. Players and coaches prefer concussion education from medical staff, whereas medical staff and referees prefer such education from governing body Web sites or training courses.

CONCLUSIONS

Several role-specific misconceptions and deficiencies in concussion knowledge were identified and should be targeted through education. Medical staff had the highest level of concussion knowledge and were the preferred sources of education for players and coaches. Therefore, they are encouraged to play a greater role in providing concussion education.

The efficacy of a movement control exercise programme to reduce injuries in youth rugby: a cluster randomised controlled trial

Background

Injuries to youth rugby players have become an increasingly prominent health concern, highlighting the importance of developing and implementing appropriate preventive strategies. A growing body of evidence from other youth sports has demonstrated the efficacy of targeted exercise regimens to reduce injury risk. However, studies have yet to investigate the effect of such interventions in youth contact sport populations like rugby union.

Objective

To determine the efficacy of an evidence-based movement control exercise programme compared with a sham exercise programme to reduce injury risk in youth rugby players. Exercise programme compliance between trial arms and the effect of coach attitudes on compliance will also be evaluated.

Setting

School rugby coaches in England will be the target of the researcher intervention, with the effects of the injury prevention programmes being measured in male youth players aged 14–18 years in school rugby programmes over the 2015–2016 school winter term.

Methods

A cluster-randomised controlled trial with schools randomly allocated to either a movement control exercise programme or a sham exercise programme, both of which are coach-delivered. Injury measures will derive from field-based injury surveillance, with match and training exposure and compliance recorded. A questionnaire will be used to evaluate coach attitudes, knowledge, beliefs and behaviours both prior to and on the conclusion of the study period.

Outcome measures

Summary injury measures (incidence, severity and burden) will be compared between trial arms, as will the influence of coach attitudes on compliance and injury burden. Additionally, changes in these outcomes through using the exercise programmes will be evaluated.

Trial registration number

ISRTCNN13422001.

Return to play management after concussion in football: recommendations for team physicians

A concussion is a rare but potentially serious injury of football players. Thus, an immediate and valid diagnosis, estimate of severity and therapeutic management is required. To summarise the published information on management of concussion with respect to a safe return to play (RTP), a literature search was conducted. Current guidelines on concussion in sports and significant studies on concussion in football were analysed. After concussion, management and RTP decision should remain in the area of clinical judgement on an individualised basis according to the current international guidelines. If a concussion is suspected, the player should not be allowed to RTP the same day. The RTP programme should follow a gradual step-wise procedure. A concussed player should not RTP unless he/she is asymptomatic and the neurological and neuropsychological examinations are normal. Untimely RTP bears an increased risk of sustaining another more severe brain injury and repetitive brain injury of long-term sequelae. In football, the management of concussion should primarily follow the recommendations proposed by the Concussion in Sports Group. Information and education of players and their medical and coaching team help to protect the players' health. Future studies on concussion should include validated and detailed information on RTP protocols.

An evidence-driven approach to scrum law modifications in amateur rugby played in South Africa

BACKGROUND

In 2012, the South African Rugby Union (SARU) approved a new set of scrum laws for amateur rugby played in the country, to be implemented at the start of the 2013 rugby season. These law changes were primarily based on the relatively high proportion of scrum-related catastrophic injury data collected as part of the BokSmart National Rugby Safety Programme (BokSmart) over the preceding 4 years (2008-2011).

AIM

To describe the scrum-related catastrophic injury data in South Africa over the past 5 years (2008-2012), and to discuss how this evidence justifies the change in the Amateur Scrum Laws to make this aspect of the game safer in South Africa.

METHODS

Catastrophic injury data were collected through BokSmart at amateur and professional levels, during training and matches over 5 years (2008-2012).

RESULTS

The scrum phase accounted for 33% (n=20 of 60) of all catastrophic injuries between 2008 and 2012. Eighteen of the 20 scrum injuries (90%) were confirmed as acute spinal cord injuries, with 13 of these being permanent injuries. For the scrum injury mechanisms that were provided (n=19), 'impact on the engagement' was the most frequently reported (n=11 of 19, 58%), followed by 'collapsed scrum' (n=7 of 19, 37%) and 'popping out' (n=1 of 19, 5%).

CONCLUSIONS

Based on these scrum-related catastrophic injury data, a change in the Amateur Scrum Laws of South African Rugby was justified. The main purpose of these scrum law changes is to reduce the number of scrum-related catastrophic injuries in the country, by minimising the opportunity for impact injury and subsequent scrum collapse in amateur rugby in South Africa, thereby making this aspect of the game of rugby safer.

Risk modifiers for concussion and prolonged recovery

Context:

Currently, no consensus exists for grading the severity of concussions. Identification of risk factors that may affect concussion risk and the likelihood of prolonged recovery can be of value to providers who manage concussion.

Evidence Acquisition:

Relevant studies were identified through MEDLINE (1996-2011) using the keywords concussion, postconcussive syndrome, and risk or risk factor. Targeted searches for specific risk factors were conducted with additional keywords, such as gender and migraine. Manual review of reference lists was also performed to identify pertinent literature.

Results:

For risk factors of concussion, history of prior concussion and female sex have the most supporting evidence. Sports with consistently high risk for sustaining a concussion include football, men’s ice hockey, and women’s soccer. Younger athletes appear to be more susceptible to concussion, but data are limited and inconsistent. Protective equipment does not definitively alter concussion risk, though it protects against other injuries. Symptoms such as long headaches, migraines, amnesia, and multiple symptoms appear to be associated with prolonged recovery. Younger age may also increase the risk of prolonged concussion.

Conclusion:

High-quality evidence for risk modifiers in concussion remains sparse. Prior concussion, collision sports, female sex, and women’s soccer are the strongest known risk factors. Evidence for most other factors is inconclusive.

The Incidence of Concussion in a Professional Australian Rugby League Team, 1998-2012

Background. Rugby league is a physically demanding team sport and the National Rugby League is the highest-level competition of rugby league in Australia. Frequent tackles and collisions between players result in a high incidence of injury to players. Concussion injuries have been the source of much debate, with reporting varying greatly depending on the definition used. Method. Injury records of 239 players from one professional National Rugby League were analysed during a continuous period of 15 years, with particular interest in the incidence and recurrence of concussions and the change in incidence over time. Result. A total of 191 concussions were recorded, affecting 90 players. The incidence of concussion injuries was found to be 28.33 per 1000 player match hours, with an increase over time (P = 0.0217). Multiple concussions were recorded for 51 players. Conclusion. A statistically significant increase in the incidence of concussion injuries was found, without a concurrent increase in the number of head injuries or total injuries. New rules which mandate removal of players from the field may be beneficial for protection of players on the long term, although they risk being counterproductive, if they make players less likely to report their symptoms during matches.

The neuropathology and neurobiology of traumatic brain injury

The acute and long-term consequences of traumatic brain injury (TBI) have received increased attention in recent years. In this Review, we discuss the neuropathology and neural mechanisms associated with TBI, drawing on findings from sports-induced TBI in athletes, in whom acute TBI damages axons and elicits both regenerative and degenerative tissue responses in the brain and in whom repeated concussions may initiate a long-term neurodegenerative process called dementia pugilistica or chronic traumatic encephalopathy (CTE). We also consider how the neuropathology and neurobiology of CTE in many ways resembles other neurodegenerative illnesses such as Alzheimer's disease, particularly with respect to mismetabolism and aggregation of tau, β-amyloid, and TDP-43. Finally, we explore how translational research in animal models of acceleration/deceleration types of injury relevant for concussion together with clinical studies employing imaging and biochemical markers may further elucidate the neurobiology of TBI and CTE.

Closed head injury

Closed head injuries vary from the very minor to the catastrophic. It is often difficult to differentiate the severity at initial presentation. Serial assessment is very valuable. Awareness of facial injuries is aided by familiarity with facial bone anatomy and the clinical presentation of orbital, zygomatic, maxillary, and mandibular fracture. Functional injury such as concussion may coexist with other injuries. This article will discuss closed head trauma and outline specific injuries to the face, brain, skull, and its surroundings.

Effectiveness of interventions to reduce aggression and injuries among ice hockey players: a systematic review

BACKGROUND

The increasing incidence of injuries related to playing ice hockey is an important public health issue. We conducted a systematic review to evaluate the effectiveness of interventions designed to reduce injuries related to aggressive acts in ice hockey.

METHODS

We identified relevant articles by searching electronic databases from their inception through July 2012, by using Internet search engines, and by manually searching sports medicine journals, the book series Safety in Ice Hockey and reference lists of included articles. We included studies that evaluated interventions to reduce aggression-related injuries and reported ratings of aggressive behaviour or rates of penalties or injuries.

RESULTS

We identified 18 eligible studies. Most involved players in minor hockey leagues. Of 13 studies that evaluated changes in mandatory rules intended to lessen aggression (most commonly the restriction of body-checking), 11 observed a reduction in penalty or injury rates associated with rule changes, and 9 of these showed a statistically significant decrease. The mean number of penalties decreased by 1.2-5.9 per game, and injury rates decreased 3- to 12-fold. All 3 studies of educational interventions showed a reduction in penalty rates, but they were not powered or designed to show a change in injury rates. In 2 studies of cognitive behavioural interventions, reductions in aggressive behaviours were observed.

INTERPRETATION

Changes to mandatory rules were associated with reductions in penalties for aggressive acts and in injuries related to aggression among ice hockey players. Effects of educational and cognitive behavioural interventions on injury rates are less clear. Well-designed studies of multifaceted strategies that combine such approaches are required.

Neuropathology of mild traumatic brain injury: relationship to neuroimaging findings

Neuroimaging identified abnormalities associated with traumatic brain injury (TBI) are but gross indicators that reflect underlying trauma-induced neuropathology at the cellular level. This review examines how cellular pathology relates to neuroimaging findings with the objective of more closely relating how neuroimaging findings reveal underlying neuropathology. Throughout this review an attempt will be made to relate what is directly known from post-mortem microscopic and gross anatomical studies of TBI of all severity levels to the types of lesions and abnormalities observed in contemporary neuroimaging of TBI, with an emphasis on mild traumatic brain injury (mTBI). However, it is impossible to discuss the neuropathology of mTBI without discussing what occurs with more severe injury and viewing pathological changes on some continuum from the mildest to the most severe. Historical milestones in understanding the neuropathology of mTBI are reviewed along with implications for future directions in the examination of neuroimaging and neuropathological correlates of TBI.

Life after the game--injury profile of past elite Australian football players

OBJECTIVES

To investigate the long-term health and well-being of past elite Australian Football League (AFL) players, with particular emphasis on the effect of playing injuries on current lifestyle.

DESIGN

Cross sectional survey.

METHODS

A health and well-being survey, completed by past AFL players (n=592) with mean (±SD) age of 55.1 y (±15.8) and playing career of 7.7 y (±4.1) sought information on demographics, education and employment, subjective well-being, lifestyle behaviours, physical health, disease prevalence, community and social structures, and playing history.

RESULTS

A majority of past players experienced serious injuries (76%) and concussion (73%) throughout their career, both increasing significantly with the number of games played. Of those who received injuries, 60% require on-going treatment, yet only 6% receive treatment costs covered by their club or the AFL Players' Association. A large proportion (64%) of respondents are affected in daily life from previous AFL injuries.

CONCLUSIONS

AFL careers are compounded by high injury rates, including loss of consciousness with a high incidence of multiple concussions amongst those players reporting a serious injury. Greater number of injuries received will further the likelihood of requiring on-going treatment and being affected later in life. Additional research and planning may be important in assisting other improvements in the quality of life of past AFL players.

Measuring the risk of sustaining injury in sport a novel approach to aid the re-design of personal protective equipment

Despite the possibilities offered by new approaches in design and advances in materials and manufacturing methods, few items of Personal Protective Equipment (PPE) used in sport have seen significant change for many decades. A major reason for this is the tradition and conservative attitudes associated with many sports, although the absence of appropriate tools and techniques to assist the design and development process has also played a large part. The aim of this study was to develop the first stage of a method of identifying specific regions of the human anatomy that are at the greatest risk of sustaining injury during participation in sports in which the player is subjected to multiple ballistic impacts. It is proposed that the findings could be used to confirm future designs of sports PPE. Previous studies have identified the amount and the location of the protection provided by current commercially available products but, until now, no evidence has been reported to determine what protection is required based on an understanding of the likely impact and the anatomy of the athlete. Using the leg and cricket as examples of an anatomical feature and a sporting application respectively, the severity and probability of injury due to ball impacts typically observed in play are quantified, with respect to their location on the leg, to estimate the level of risk in that region. Results show that the level of risk is greatest in the shin regions of the front leg, suggesting that this region should be offered the greatest degree of protection, as is generally the case in commercially available leg guard designs. Conversely, however, the inner region of the mid shin of the back leg is at the lowest risk, suggesting that protection in this region might be substantially reduced, a feature which is certainly not included in current product; such a reduction may significantly enhance the ergonomic performance of the leg guard design. The findings of this preliminary study indicate that the method offers the potential to quantify the relative risk of sustaining injury, in a sports specific application, as a function of location on the body and is thus a potentially useful design tool for design engineers of sports PPE. Given the embryonic nature of this approach, however, a number of assumptions and additional considerations is presented which reveal that, whilst the technique offers additional design insight, further research is required before it should be applied to equipment design.

Recreational helmet use as a predictor of noncranial injury

BACKGROUND

The effect of helmet use in the prevention of head injury has been clearly shown. However, the relationship between helmet compliance and other bodily (noncranial) injury has not been explored, yet may have important impact on strategies for injury prevention. The purpose of this study was to examine helmet use in an injured population to evaluate its association with noncranial trauma.

METHODS

All entries in the Canadian National Trauma Registry were surveyed from 2000 to 2004 and limited to injuries sustained in recreational sports associated with helmet use.

RESULTS

Over the 5-year period, 2,205 injuries met inclusion criteria. Cycling-related injuries were most frequent (43.5%). Alcohol consumption correlated significantly with lack of helmet use. Nonhelmeted individuals suffered significantly more noncranial injuries (85% vs. 68%, p < 0.0001) and had twice as many severe head injuries (Glasgow Coma Scale score ≤ 8) (odds ratio [OR]: 2.13, 95% confidence interval [CI]: 1.35-3.37) or any abnormal Glasgow Coma Scale score (OR: 1.96, 95% CI: 1.55-2.47). While controlling for age, sex, or type of sport activity performed, multivariate regression confirmed a reduction in associated noncranial injuries when helmets were used (OR: 0.86, 95% CI: 0.83-0.89).

CONCLUSIONS

Within an injured population from sports-related activities, helmet use is associated with fewer noncranial injuries of all types suggesting reduced overall risk of injury in this group. In addition, use of helmets is associated with less frequent and less severe head injury. Alcohol consumption is related to increased risk of injury and is more prevalent in injured individuals who abstain from helmet use.

LEVEL OF EVIDENCE

III, prognostic study.

Helmets and mouth guards: the role of personal equipment in preventing sport-related concussions

Millions of athletes in the United States experience concussions annually. Although helmets and mouth guards have decreased the risk of catastrophic head injuries, their protective effects on concussions are less clear. This article evaluates the current literature on the effect of equipment on concussions. Understanding the role that these equipment play in preventing concussions is complicated by many factors, such as selection bias in nonrandomized studies, variations in playing style, and risk compensation in sports with mandatory protective equipment. Improving coach and player education about proper concussion management, encouraging neck-strengthening exercises, and minimizing high-risk impacts may reduce concussions in sports.

Fall and injury incidence rates of jockeys while racing in Ireland, France and Britain

This article presents and analyses injury incidence rates for amateur and professional racing jockeys in Ireland, France and Britain by means of a retrospective study and review of published data. Amateur jump racing was seen to have the highest fall risk in these three countries (between 115 and 140 falls/1000 rides). Jump racing also had the highest rates of injury/ride amongst both amateur and professional jockeys. Flat racing, however, had the highest rates of injuries/fall (34-44%). Of all the injuries in both jump and flat racing populations of amateur and professional jockeys, 15% were concussive head injuries, and more than half of these involved loss of consciousness. Professional jump jockeys in Ireland fell less frequently than those in France or Britain. Their injury/fall rate and injury/ride rate were highest in Britain. Professional flat racing jockeys in France had the lowest rates of injuries/fall and injuries/ride, while those in Ireland had the highest.

Incidence, risk, and protective factors of mild traumatic brain injury in a cohort of Australian nonprofessional male rugby players

BACKGROUND

Mild traumatic brain injury (mTBI) is an emerging public health issue in high-contact sports. Understanding the incidence along with the risk and protective factors of mTBI in high-contact sports such as rugby is paramount if appropriate preventive strategies are to be developed.

PURPOSE

To estimate the incidence and identify the risk and protective factors of mTBI in Australian nonprofessional rugby players.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A cohort of 3207 male nonprofessional rugby players from Sydney, Australia, was recruited and followed over 1 or more playing seasons. Demographic information, history of recent concussion, and information on risk and protective factors were collected. The incidence of mTBI was estimated and the putative risk and protective factors were modeled in relation to mTBI.

RESULTS

The incidence of mTBI was 7.97 per 1000 player game hours, with 313 players (9.8%) sustaining 1 or more mTBIs during the study. Players who reported always wearing protective headgear during games were at a reduced risk (incident rate ratio [IRR], 0.57; 95% confidence interval [CI], 0.40-0.82) of sustaining an mTBI. In contrast, the likelihood of mTBI was almost 2 times higher among players who reported having sustained either 1 (IRR, 1.75; 95% CI, 1.11-2.76) or more mTBIs (IRR, 1.65; 95% CI, 1.11-2.45) within the 12 months before recruitment.

CONCLUSION

Nonprofessional rugby has a high incidence of mTBI, with the absence of headgear and a recent history of mTBI associated with an increased risk of subsequent mTBI. These findings highlight that both use of headgear and the management of prior concussion would likely be beneficial in reducing the likelihood of mTBI among nonprofessional rugby players, who compose more than 99% of rugby union players in Australia.

From psychoneurosis to ICHD-2: an overview of the state of the art in post-traumatic headache

Post-traumatic headache (PTH) is an important public health issue - head injuries are common, headache is the most common sequelae of head injuries, and PTH can be particularly disabling. Fortunately, for most individuals with PTH, the headache gradually dissipates over a period of several days, weeks, or months either spontaneously or aided by non-pharmacologic and/or pharmacologic management. Regrettably, for a minority of head-injured individuals, the PTH is intractable and disabling despite aggressive and comprehensive treatment. Unfortunately, there are many prejudices against individuals with PTH. Frequently, the presence or absence of litigation and/or the mechanism of head injury (sports-related trauma, slip-and-fall injury, motor vehicle accident, or military service-related injury) biases physicians' views on the legitimacy of the patient's PTH. Accordingly, this review attempts to summarize the state of the art of our understanding of PTH. This clinical review highlights: (a) views on PTH throughout the last few centuries, (b) the ICHD-2 classification of PTH, (c) the epidemiology of head injuries and PTH, (d) the clinical characteristics of PTH, (e) PTH related postconcussive symptoms, (f) pathophysiology of PTH, (g) evaluation of PTH, and (h) management of PTH.