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

Neck strength deficit is a risk factor for concussion in high school rugby union and rugby league players

OBJECTIVES

Primary prevention of concussions is a priority in contact sports, with growing interest in the role of neck strength in mitigating the risks of concussion. The aim of this study was to determine if neck function was associated with in-season concussions in adolescent rugby union and league athletes, and to establish clinical values to identify players with increased risk of sustaining a concussion.

DESIGN

Prospective cohort study.

METHODS

Assessment of neck function included isometric strength, endurance and proprioception. In-season concussion injuries were recorded. Preliminary multivariate analysis-of-covariance models were conducted to investigate differences in neck function between players who did and did not sustain an in-season concussion. If significant, receiver operated characteristic curves were used to determine optimal cut-points for each variable to distinguish between concussion groups. Unadjusted odds ratios were estimated from the cross tabulation chi-squared test. Significance was set at p < 0.1.

RESULTS

A total of 43 players (aged 15-18 years) were assessed during preseason. Eleven players sustained a concussion during the season. Players who sustained a concussion during the season had weaker neck extension strength in kilogrammes (p = 0.043, effect size = 0.74) and when normalised to body weight (p = 0.041, effect size = 0.74). The optimal cut-point for extension strength was 32.1 kg (sensitivity 0.64, specificity 0.75) and 3.71 N/kg (sensitivity 0.64, specificity 0.66). Players with a flexor to extensor strength ratio above 0.74 were 3-times more likely to sustain a concussion (p = 0.09). There were no differences for other neck function variables.

CONCLUSIONS

Interventions targeting neck strength could reduce the risk of concussion.

Decreased isometric neck strength is a risk factor for head, neck and face injuries in professional rugby league players

Head, neck and face injuries are a concern in contact sports. This exploratory study aimed to establish 1) injury risk factors for head, neck and face injuries and 2) clinical cut-off values related to strength, endurance and proprioception of the cervical spine in a team of professional rugby league players. Pre-season assessments of isometric strength of the flexor, extensor and lateral flexor muscles, endurance of the flexor muscles and joint position error were conducted. Injuries resulting in games missed were recorded. Cross-tabulations were used to determine the unadjusted odds ratios for the measures as risk factors for playing season injuries. The unadjusted odds ratio (OR) values indicated that if a player had weaker extensors of the neck (<36.4 kg, p = 0.014; <3.4N/kg, p = 0.014) or asymmetry of isometric strength of their lateral flexor muscles (left-to-right ratio <0.91, p = 0.005), their odds of games missed due to season head, neck and face injuries was increased (OR extensors = 8; 95% CI = 1.5-42.5 OR asymmetry of lateral flexor muscles OR = 12.6; 95% CI = 2.0-79.4). As muscle strength is modifiable, the clinical application of this study would involve targeting players in the team beneath the clinical cut-off value.

What do we know about beach soccer injuries? Systematic video analysis of four consecutive years with 580 match injuries

The aim of the present study was to evaluate the characteristics of match injury in male beach soccer players. Video recordings of all official beach soccer tournaments in which the European national male beach soccer teams participated from 2018 to 2021 were analysed by two sports medicine specialists retrospectively. Regarding each injury, data including the mechanism, location of the injury, whether the injury led to time-loss, and the relationship of the injury to the bicycle kick (BK), etc. were documented. A total of 632 injuries were documented, corresponding to 234.9 injuries/1000 player hours. Video footage was available for 580 injuries. Whilst 79.8% of medical attention injuries occurred due to opponent contact, 19.5% of time-loss injuries occurred due to non-contact, and 12.2% of indirect opponent contact (p < 0.01). The most common location of the BK related injury was the head/neck (68.7%), whereas most common location of the BK unrelated injury was the lower extremity (54.1%) (p < 0.01). The findings demonstrated that beach soccer injury incidence was quite high; the most common injury location was head/neck and head/neck injuries were associated with BK. In light of these results, some rule regulations, particularly those associated with BK, and the use of protective equipment should be considered to prevent these injuries.

Effectiveness of FIFA 11+ Injury Prevention Programs in Reducing Head and Neck Injuries, Including Concussion, Among Soccer Players: A Systematic Review and Meta-Analysis

The Federation Internationale de Football Association (FIFA) 11+ and 11+ Kids injury prevention programs have shown success in reducing overall injury risk in soccer players, yet their specific impact on head and neck injuries remains inadequately explored.

PURPOSE

To evaluate the effectiveness of FIFA 11+ and 11+ Kids injury prevention programs in reducing the incidence of head and neck injuries among soccer players.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, 2 investigators independently conducted searches in databases (Cochrane Library, PubMed, Web of Science, and PEDro) using keywords like "FIFA 11+," "football," "soccer," and "injury prevention." Only randomized controlled trials assessing FIFA 11+ programs in soccer players were included. Data analysis used the random effects model with RevMan Meta-Analysis software (version 5).

RESULTS

Among 397 studies, 4 met inclusion criteria. Pooled results from 7109 players and 532,341 exposure hours indicated a significant 40% reduction in head and neck injuries per 1000 hours of exposure in the intervention group compared to the control group (injury risk ratio 0.60, 95% CI, 0.41-0.88).

CONCLUSION

Implementing FIFA 11+ injury prevention programs significantly reduces the risk of head and neck injuries in soccer players, offering a compelling alternative to traditional warm-ups. This study contributes valuable evidence for optimizing injury prevention strategies in soccer training regimens.

'Downhill race for a rainbow jersey': the epidemiology of injuries in downhill mountain biking at the 2023 UCI cycling world championships-a prospective cohort study of 230 elite cyclists

Objectives

This study aims to understand the prevalence, incidence rate, anatomical sites, injury severity and main medical actions carried out during official training and racing by elite downhill mountain biking (DHMTB) riders during the 2023 Union Cycliste Internationale (UCI) Cycling World Championships.

Methods

The participants of this prospective, observational study were elite male and female cyclists competing at the UCI DHMTB World Championships located in the Nevis range in Fort William, Scotland, in 2023. This study followed the injury reporting guidelines established by the International Olympic Committee, which include the Strengthening the Reporting of Observational Studies in Epidemiology-Sports Injury and Illness Surveillance (SIIS) and the cycling-specific extension. Injuries were defined as 'tissue damage or other derangement of normal physical function due to participation in sports, resulting from rapid or repetitive transfer of kinetic energy requiring medical attention'. All epidemiological data were collected by the local organising committee medical professionals working at the event through an online survey. All data inputted were screened daily by the lead event physician and UCI medical delegate.

Results

Throughout 5 days of the championships, 10.4% of the 230 cyclists sustained at least one injury. The overall injury incidence rate was 3.3 (95% CI 3.1 to 3.5) per 100 rides. The incidence rates were higher in the training 4.3 (95% CI 4.0 to 4.6)/100 rides than in the racing 2.2 (95% CI 2.1 to 2.3)/100 rides. There was a greater incidence of injury in female cyclists in the training 5.8 (95% CI 5.0 to 6.6)/100 rides and racing 4.5 (95% CI 3.9 to 4.9)/100 rides compared with male cyclists. Female cyclists experienced more severe injuries, with an average of 12.6 (±14, 95% CI 5.66 to 19.54) days lost to injury compared with 5.5 (±1.6 95% CI 1.89 to 9.11) seen in male cyclists. The main event medical actions were lifting, immobilisation and helmet removal.

Conclusion

This study provides insights into the risk of injury to athletes within DHMTB. Our findings suggest more focus should be placed on the female DHMTB athlete. Additionally, this study provides unique information about common medical actions required of medical professionals working at DHMTB events and the importance of pre-event scenario training.

Concussion Reduction in Division I and II Athletes: Effects of Simple Cervical Spine Exercise Regimen

INTRODUCTION

 Primary preventative medicine lacks a consensus on effective concussion prevention strategies for collegiate athletes. Cervical strength has been identified as a potential factor in concussion risk reduction. This study evaluates the impact of a commercially available, portable cervical muscle stretching and strengthening device, NeckX®, on cervical strength, range of motion (ROM), and concussion incidence in collegiate athletes participating in high-concussion-risk sports.

METHODS

 A single-arm prospective cohort study was conducted with 162 collegiate athletes from various sports. Participants underwent a 12-week neck exercise protocol using the NeckX® device. Clinical data, including neck strength and ROM, were collected at weeks 0, 6, and 12. Concussion incidence was self-reported by participants and cross-referenced with records from the athletic department. Data were analyzed for significant neck strength and ROM changes throughout the 12-week study. A two-way analysis of variance multiple comparisons with the Tukey-Kramer significant difference test was utilized, using the Holm-Sidak method, with an alpha of 0.05.

RESULTS

 All athletic teams experienced a significant increase in cervical strength during the 12-week intervention (α = 0.05, p < 0.05). Increases in cervical flexion and extension force were most consistent between teams. Cervical ROM increased significantly in male and female soccer players (α = 0.05, p < 0.05). The overall incidence of head and neck injuries, including concussions, was reduced to 6.60% during the study period, the lowest recorded value in the university's athletic department history.

CONCLUSION

 The use of the NeckX® device for 12 weeks was effective in enhancing pericervical muscle strength and ROM while reducing concussion incidence in collegiate athletes participating in high-concussion-risk sports. Interestingly, the positive outcomes were consistent for both males and females, indicating the universal advantages of neck training among collegiate athletes. These findings support existing research on the benefits of cervical strengthening exercises for reducing concussions in collegiate athletes and highlight the convenience and affordability of using this device.

High school rugby coaches' knowledge and opinions of concussion in Kwa-Zulu Natal province in South Africa: an ecological cross-sectional study

BACKGROUND

Concussions in Rugby Union are common with an increased risk to adolescent players. Coaches are key to injury prevention and a greater understanding of their knowledge and sentiments may guide future initiatives. There is a lack of data on rugby coaches, especially in South Africa. This study aimed to investigate the knowledge and opinions of high school rugby coaches regarding concussion management.

METHODS

This cross-sectional study of 37 high school rugby coaches in South Africa, was conducted via a self-reported questionnaire. Concussion knowledge was scored for correct answers only with closed-question scaling methods to measure the importance of items of concussion management using a graphical rating scale. An attitude scale (Likert) was used to assess self-reported opinions and behaviours. Associations were calculated for participant characteristics and overall concussion injury knowledge.

RESULTS

More participants showed good overall knowledge of ≥ 75% (n = 22, 59% vs. n = 15, 40%), especially those with greater coaching experience (p = 0.021). Player welfare was perceived more important than player performance (185 vs. 164), with concussion prevention most important (184 of 185). Appealing characteristics of an injury prevention programme were the improvement of player skill (173, SD ± 0.75, mean 4.68), being adaptable (171, ± 0.86, 4.62), and being completed in the warm-up (167, ± 0.93, 4.51). The biggest perceived barriers were duration (138, ± 1.59, mean 3.73), effort (130, ± 1.56, 3.51), compliance and lack of knowledge (both 127, ± 1.68, 3.43).

CONCLUSION

These results support the implementation of ongoing concussion education for rugby coaches and identify areas for promoting awareness and knowledge of concussion injury prevention, identification, and specific management of younger athletes. Appealing characteristics and barriers are highlighted and may allow for improved implementation and adherence to concussion prevention programmes.

Head Kinematics and Injury Analysis in Elite Bobsleigh Athletes Throughout a World Cup Tour

CONTEXT

The neurocognitive health effects of repetitive head impacts have been examined in many sports. However, characterizations of head impacts for sliding-sport athletes are lacking.

OBJECTIVE

To describe head impact kinematics and injury epidemiology in elite athletes during the 2021-2022 Bobsleigh World Cup season.

DESIGN

Cross-sectional study.

SETTING

On-track training and competitions during the Bobsleigh World Cup season.

PATIENTS OR OTHER PARTICIPANTS

Twelve elite bobsleigh athletes (3 pilots [1 female], 9 push athletes [5 females]; age = 30 ± 5 years; female height and weight = 173 ± 8 cm and 75 ± 5 kg, respectively; male height and weight = 183 ± 5 cm and 101 ± 5 kg, respectively).

MAIN OUTCOME MEASURE(S)

Athletes wore an accelerometer-enabled mouthguard to quantify 6-degrees-of-freedom head impact kinematics. Isometric absolute and relative neck strength, number of head acceleration events (HAEs), workload (J), peak linear velocity (m·s-1), peak angular velocity (rad·s-1), peak linear acceleration (g), and peak angular acceleration (rad·s-2) were derived from mouthguard manufacturer algorithms. Linear mixed-effect models tested the effects of sex (male versus female), setting (training versus competition), and position (pilot versus push athlete) on the kinematic variables.

RESULTS

A total of 1900 HAEs were recorded over 48 training and 53 competition days. No differences were found between the number of HAEs per run per athlete by sex (incidence rate ratio [IRR] = 0.82, P = .741), setting (IRR = 0.94, P = .325), or position (IRR = 1.64, P = .463). No sex differences were observed for workload (mean ± SD: males = 3.3 ± 2.2 J, females = 3.1 ± 1.9 J; P = .646), peak linear velocity (males = 1.1 ± 0.3 m·s-1, females = 1.1 ± 0.3 m·s-1; P = .706), peak angular velocity (males = 4.2 ± 2.1 rad·s-1, females = 4.7 ± 2.5 rad·s-1; P = .220), peak linear acceleration (male = 12.4 ± 3.9g, females = 11.9 ± 3.5g; P = .772), or peak angular acceleration (males = 610 ± 353 rad·s-2, females = 680 ± 423 rad·s-2; P = .547). Also, no effects of setting or position on any kinematic variables were seen. Male athletes had greater peak neck strength than female athletes for all neck movements, aside from right-side flexion (P = .085), but no sex differences were noted in relative neck strength.

CONCLUSIONS

We provide a foundational understanding of the repetitive HAEs that occur in bobsleigh athletes. Future authors should determine the effects of repetitive head impacts on neurocognitive function and mental health.

Neck strength alone does not mitigate adverse associations of soccer heading with cognitive performance in adult amateur players

OBJECTIVES

Soccer heading is adversely associated with neurocognitive performance, but whether greater neck strength or anthropometrics mitigates these outcomes is controversial. Here, we examine the effect of neck strength or anthropometrics on associations of soccer heading with neurocognitive outcomes in a large cohort of adult amateur players.

METHODS

380 adult amateur league soccer players underwent standardized measurement of neck strength (forward flexion, extension, left lateral flexion, right lateral flexion) and head/neck anthropometric measures (head circumference, neck length, neck circumference and neck volume). Participants were assessed for heading (HeadCount) and cognitive performance (Cogstate) on up to 7 visits over a period of two years. Principal components analysis (PCA) was performed on 8 neck strength and anthropometric measures. We used generalized estimating equations to test the moderation effect of each of the three PCs on 8 previously identified adverse associations of 2-week and 12-month heading estimates with cognitive performance (psychomotor speed, immediate verbal recall, verbal episodic memory, attention, working memory) and of unintentional head impacts on moderate to severe central nervous system symptoms.

RESULTS

3 principal components (PC's) account for 80% of the variance in the PCA. In men, PC1 represents head/neck anthropometric measures, PC2 represents neck strength measures, and PC3 represents the flexor/extensor (F/E) ratio. In women, PC1 represents neck strength, PC2 represents anthropometrics, and PC3 represents the F/E ratio. Of the 48 moderation effects tested, only one showed statistical significance after Bonferroni correction, which was not robust to extensive sensitivity analyses.

CONCLUSION

Neither neck strength nor anthropometrics mitigate adverse associations of soccer heading with cognitive performance in adult amateur players.

A Profile of Isometric Cervical Strength in Elite Professional Male Rugby Players

OBJECTIVES: To (1) provide position-specific normative data for isometric cervical muscle strength and endurance in professional, male rugby players and (2) assess the relationship between age, height, weight, and playing position with cervical muscle strength and endurance. DESIGN: Cross-sectional study. METHODS: Professional rugby players completed peak isometric cervical strength testing followed by a test of cervical muscle endurance. Descriptive statistics for continuous variables with strength normalized to body weight were performed. Multiple linear regression was used to estimate associations between strength measurements. RESULTS: In total, 136 players participated including front-row forwards (27%), other forwards (28%), and backs (45%). Front-row forwards had significantly greater peak isometric cervical muscle strength than other position groups, with backs having the lowest strength. Extension produced the highest force for all 3 position groups (429 N ± 104 N), whereas flexion produced the least (275 N ± 65 N). Age was associated with increased isometric cervical muscle strength. There was a statistically significant relationship between peak flexion strength and flexion endurance (P = .003). The average time for the endurance tests were 55.7 (±17.1) seconds and 52.9 (±20.1) seconds for extension and flexion, respectively. Other forwards had lower cervical extension muscle endurance than backs and front-row forwards. CONCLUSIONS: Normative values for peak and endurance isometric strength in professional rugby players illustrate significant differences between playing position. Consider age, body weight, and intraindividual variability when interpreting cervical strength and endurance results. J Orthop Sports Phys Ther 2024;54(3):1-8. Epub 29 January 2024. doi:10.2519/jospt.2024.11830.

Preliminary evidence for neck musculature in shaping functional stereotypes of men's relationship motives

Neck musculature is reliably diagnostic of men's formidability and central to several inferences of their physical prowess. These inferences facilitate stereotypes of men's social value from which perceivers estimate their abilities to satisfy reproductive goals related to mate acquisition and parental care. Participants evaluated men's interest in various mating and parenting strategies, wherein men varied in the size of visible neck musculature through trapezii and sternocleidomastoids for perceivers to identify potential reproductive interests and goals. Large trapezii elicited perceptions of men as more effective at protecting offspring, albeit at the expense of nurturance and interest in long-term pair bonds. Results extend previous findings implicating formidability as central to relationship decisions by considering a novel modality.

The Relationship Between Neck Strength and Sports-Related Concussion in Team Sports: A Systematic Review With Meta-analysis

OBJECTIVE: We aimed to quantify the relationship between neck strength and sports-related concussion (SRC) for athletes participating in team sports. DESIGN: Etiology systematic review with meta-analysis. LITERATURE SEARCH: PubMed, PsycINFO, MEDLINE, CINAHL, CENTRAL, and Scopus were searched on March 17, 2022, and updated on April 18, 2023. STUDY SELECTION CRITERIA: Team sports where an opponent invades the player's territory (eg, football, rugby, basketball) that reported at least 1 measure of neck strength, and 1 measure of SRC incidence, using cohort, case-control, or cross-sectional study designs. The Newcastle-Ottawa scale was used to assess risk of bias; certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation approach. DATA SYNTHESIS: Studies were summarized qualitatively and quantitatively. To understand the relationship between neck strength and future SRC incidence, random-effects meta-analysis was conducted on prospective longitudinal studies. RESULTS: From a total of 1445 search results, eight studies including 7625 participants met the inclusion criteria. Five studies reported a relationship between greater neck strength or motor control and reduced concussion incidence. Pooled results from 4 studies indicated small (r = 0.08-0.14) nonsignificant effects with substantial heterogeneity (I2>90%). The considerable heterogeneity is likely a result of synthesized studies with vastly different sample characteristics, including participant age, playing level, and sports. CONCLUSIONS: There was very low-certainty evidence suggesting a small, nonsignificant relationship between greater neck strength and a lower risk of sustaining a SRC. J Orthop Sports Phys Ther 2023;53(10):1-9. Epub: 10 July 2023. doi:10.2519/jospt.2023.11727.

Predictive Contribution of the Superficial Neck Muscles to Short-Latency Rate of Force Development of the Head and Neck

PURPOSE

To evaluate the contribution of splenius capitis, sternocleidomastoid, and upper fibers of trapezius activation to the gains in rate of force development (RFD) of the head and neck during maximum voluntary ballistic contractions.

METHODS

RFD gain was facilitated by a single-session intervention for maximum voluntary ballistic contractions in the anterior direction, oriented at 45° to the midsagittal plane, which require active restraint of axial rotation. Muscle activation for the agonist (sternocleidomastoid) and 2 antagonists (splenius capitis and upper fibers of trapezius) was evaluated. The study sample included 12 physically active men (mean age, 22.6 y). RFD (N·m·s-1; 0-100 ms) and integrated muscle activity (50 ms before and 100 ms after force onset) were measured at 10 minutes, 20 minutes, and 2 days postintervention, relative to baseline. Muscle activation predictive of RFD gains was evaluated by linear regression analysis. RFD reproducibility was evaluated using the coefficient of variation of the typical error.

RESULTS

The intervention yielded a 1.95- to 2.39-fold RFD gain (P ≤ .05), with greater RFD gain for participants with a lower peak moment of force (<10.9 N·m) than those with a higher peak moment (≥10.9 N·m) at baseline (P ≤ .002). For the low group, 65% to 74% of the RFD gain was predicted by ipsilateral sternocleidomastoid activation, with ipsilateral splenius capitis activation predicting 77% to 92% of RFD gain for the high group. Absolute peak and impulse of static force were greater for the high than for the low group (P ≤ .04). RFD reproducibility was high (coefficient of variation of the typical error ≤ 14.4%).

CONCLUSIONS

The agonist- and antagonist-focused synergies might reflect different functional priorities, higher RFD gain compared with higher head-neck force.

Where are We Headed? Evidence to Inform Future Football Heading Guidelines

Given the scientific and public concern regarding the short-, medium- and long-term consequences of heading on brain health, being proactive about developing and implementing guidelines that help reduce the burden (volume, impact magnitude and injury risk) of heading in young and beginner players appears justified. This narrative review explores the evidence underpinning strategies that could be incorporated into future heading guidelines to reduce heading burden in players across all levels of football. A four-step search strategy was utilised to identify all data-based papers related to heading in football. Eligibility criteria for inclusion were: (1) original data, (2) study population included football players, (3) outcome measures included one or more of the following: number of headers, measurement of head acceleration during heading, or head/brain injury incidence, and (4) published in English or English translation available. In total, 58 papers were included that outlined strategies based on (1) game or team development, (2) player skill development and (3) equipment. In particular, greater emphasis existed for small-sided games (particularly in young players) where fewer headers are observed when compared with the conventional 11 versus 11 game, as well as reducing headers from goal kicks and corners. Evidence also existed for developing a heading coaching framework that focusses on technical proficiency as well as neuromuscular neck exercises integrated into general injury reduction exercise programs, enforcement of rules related to deliberate head contact and using lower-pressure match and training balls. To mitigate potential risks of heading on brain health, a number of pragmatic strategies have been examined in scientific studies and may be considered as part of future heading guidelines.

Injury-Reduction Programs Containing Neuromuscular Neck Exercises and the Incidence of Soccer-Related Head and Neck Injuries

CONTEXT

Concern is growing among soccer players, coaches, and parents regarding head and neck injuries, including concussion, particularly from heading a ball. Thus, we need to explore soccer-specific head injury risk-reduction initiatives. One such initiative is to condition the neck musculature of young players by adding neuromuscular neck exercises to existing injury-reduction exercise programs.

OBJECTIVE

To investigate the effect of neuromuscular neck exercises completed as part of an injury risk-reduction exercise program on the incidence of soccer-related head and neck injuries in adolescent soccer players.

DESIGN

Prospective cohort study.

SETTING

Two sports high schools and 6 soccer clubs during the 2021 soccer season.

PATIENTS OR OTHER PARTICIPANTS

A total of 364 male and female soccer players, aged 12 to 18 years.

INTERVENTION(S)

Members of 1 sports high school and 2 soccer clubs performed neuromuscular neck exercises as part of an injury-reduction program during training (neck training group). Members of another sports high school and 4 soccer clubs performed an injury-reduction program but without neck exercises (comparison group).

MAIN OUTCOME MEASURE(S)

Self-reported injury data were collected from each player at the end of the season and used to calculate incidence rate ratios (IRRs) with 95% CIs.

RESULTS

In total, 364 players completed the study, including 146 players in the neck training group and 218 players in the comparison group. Despite players in the neck training group being less likely to self-report a concussion (IRR = 0.23; 95% CI = 0.03, 1.04) and pain on heading a ball (IRR = 0.62; 95% CI = 0.34, 1.07), only a lower incidence of possible concussive events (IRR = 0.38; 95% CI = 0.14, 0.90; P < .05) was significant.

CONCLUSIONS

Integrating neuromuscular neck exercises into injury-reduction exercise programs has the potential to reduce the risk of adolescent soccer players sustaining a possible concussive event, concussion, or pain on heading a ball.

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.

Reliability of a neck strength test in schoolboy rugby players

BACKGROUND

In rugby union, a bracing mechanism of the neck and trunk is normally adopted in contact situations where high linear and angular forces are produced, which may contribute to the risk for sports-related concussion (SRC).

OBJECTIVES

To examine the feasibility of and test-retest reliability, both inter-rater and intra-rater reliability, of a novel neck strength test in schoolboy rugby players and to summarize neck strength values for this cohort, including rugby position-specific estimates.

MATERIALS AND METHODS

52 male schoolboy rugby union players completed the neck strength test protocol twice, eight days apart using a novel device.

RESULTS

Intra-class correlation coefficients (ICCs) were good to excellent for test-retest reliability (range from 0.86 to 0.92) in all four directions. Intra-rater (ICCs range from 0.706 to 0.981) and inter-rater (ICCs range from 0.669 to 0.982) ranges were calculated. Significant differences were identified between forwards and backs for non-normalised force measures but no significant difference when normalised to bodyweight. The flexor:extensor ratio was 0.68 (SD 0.2) for forwards, 0.71 (SD 0.16) for backs and 0.67 (SD 0.16) for the cohort.

DISCUSSION & CONCLUSION

While there is limited direct evidence to support a direct link between neck strength and SRC risk at present, investigating the relationship of neck strength, stiffness and impact anticipation might be a useful direction for further research. In conclusion, we describe a portable, user-friendly and safe neck strength test with good-to-excellent test-retest reliability, and intra-, inter-rater reliability. Test-retest ICC values compare favourably to gold standard fixed-frame dynamometry and are superior to hand-held dynamometry.

Head and Neck Characteristics as Risk Factors For and Protective Factors Against Mild Traumatic Brain Injury in Military and Sporting Populations: A Systematic Review

BACKGROUND

Investigators have proposed that various physical head and neck characteristics, such as neck strength and head and neck size, are associated with protection from mild traumatic brain injury (mTBI/concussion).

OBJECTIVES

To systematically review the literature and investigate potential relationships between physical head and neck characteristics and mTBI risk in athletic and military populations.

METHODS

A comprehensive search of seven databases was conducted: MEDLINE, EMBASE, CINAHL, Scopus, SPORTDiscus, Cochrane Library, and Web of Science. Potential studies were systematically screened and reviewed. Studies on military and athletic cohorts were included if they assessed the relationship between physical head-neck characteristics and mTBI risk or proxy risk measures such as head impact kinematics.

RESULTS

The systematic search yielded a total of 11,723 original records. From these, 22 studies met our inclusion criteria (10 longitudinal, 12 cross-sectional). Relevant to our PECO (Population, Exposure, Comparator, and Outcomes) question, exposures included mTBI incidence and head impact kinematics (acceleration, velocity, displacement) for impacts during sport play and training and in controlled laboratory conditions. Outcome characteristics included head and neck size (circumference, mass, length, ratios between these measures), neck strength and endurance, and rate of force development of neck muscles.

DISCUSSION

We found mixed evidence for head and neck characteristics acting as risk factors for and protective factors against mTBI and increased susceptibility to head impacts. Head-neck strength and size variables were at times associated with protection against mTBI incidence and reduced impact kinematics (14/22 studies found one or more head-neck variable to be associated with protection); however, some studies did not find these relationships (8/22 studies found no significant associations or relationships). Interestingly, two studies found stronger and larger athletes were more at risk of sustaining high impacts during sport. Strength and size metrics may have some predictive power, but impact mitigation seems to be influenced by many other variables, such as behaviour, sex, and impact anticipation. A meta-analysis could not be performed due to heterogeneity in study design and reporting.

CONCLUSION

There is mixed evidence in the literature for the protective capacity of head and neck characteristics. We suggest field-based mTBI research in the future should include more dynamic anthropometric metrics, such as neck stiffness and response to perturbation. In addition, laboratory-based mTBI studies should aim to standardise design and reporting to help further uncover these complicated relationships.

Electrodeposited Ni/TiN-SiC Nanocomposites on the Dumbbell: Reducing Sport Injuries

Sports are becoming an important part of everyday life. In this study, an excellent Ni-SiC nanocomposite was prepared on the dumbbell surface using the pulse electrodeposition (PE) method to improve the durability of sports equipment and prevent sports injuries. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), abrasion testing, triboindentry, and X-ray diffraction (XRD) were used to evaluate the impact of plating conditions upon the microhardness, microstructure, morphology, and wear behavior of the fabricated coatings. The obtained results showed that several SiC and TiN nanoparticles were incorporated into Ni/TiN-SiC nanocomposites obtained at 4 A/dm2. SiC and TiN nanoparticles had mean diameters of 37.5 and 45.6 nm, respectively. The Ni/TiN-SiC nanocomposite produced at 4 A/dm2 showed an excellent mean microhardness value of 848.5 HV, compared to the nanocomposites produced at 2 and 6 A/dm2. The rate of wear for Ni/TiN-SiC nanocomposite produced at 4 A/dm2 was 13.8 mg/min, demonstrating outstanding wearing resistance. Hence, it has been suggested that the Ni/TiN-SiC nanocomposite can effectively reduce sports injuries.

The Effect of the FIFA 11 + with Added Neck Exercises on Maximal Isometric Neck Strength and Peak Head Impact Magnitude During Heading: A Pilot Study

BACKGROUND

Higher neck strength has been postulated to reduce head impact magnitude during purposeful heading in football.

OBJECTIVES

This pilot trial explored the effect of a neck exercise programme on (1) neck strength and (2) head impact magnitude during heading in male and female adolescent football players.

METHODS

Boys and girls (aged 12-17 years) were randomised by team to the intervention (5 weeks of supervised neuromuscular neck exercises integrated into part 2 of the FIFA 11 + , completed three times per week) or the control group (usual part 2 of the FIFA 11 + , no neck exercises). Outcomes included isometric neck strength and head impact magnitude (peak linear acceleration and peak angular velocity) during standardised heading from a throw-in (at baseline and 6 weeks) plus completion of an evaluation survey by intervention players and coaches.

RESULTS

In total, 52 players (n = 31 intervention; n = 21 control) completed the study. Mixed-model analysis of variance (ANOVA) revealed significant differences in neck strength variables (p < 0.001), peak linear acceleration (p = 0.04) and peak angular velocity (p = 0.04) between the intervention and control groups over time. Intervention players demonstrated increases in mean composite neck strength (53.8% intervention vs 15.6% control) as well as decreases in mean peak linear head acceleration during heading (- 11.8% vs - 5.0%) from baseline to follow-up. Reduction in peak angular velocity was more pronounced in girls (- 27.7%) than boys (- 11.5%) in the intervention group. The addition of neck exercises into part 2 of the FIFA 11 + was feasible and accepted by players and coaches.

CONCLUSION

On average, players who completed neck exercises demonstrated an increase in isometric neck strength and a decrease in head impact magnitude during heading. These exercises were easily incorporated into usual training. Australian New Zealand Clinical Trials Registry (no: ACTRN12619001375145).

Lessons from NATURE: methods for traumatic brain injury prevention

Multiple species obtain repetitive head collisions throughout the course of their lifetimes with minimal neurologic deficit. Nature has allowed the unique development of multiple protective mechanisms to help prevent neurotrauma. In this review, we examine the concept of rapid brain movement within the skull 'Slosh' and what nature teaches on how to prevent this from occurring. We look at individual animals and the protective mechanisms at play. Marching from macroscopic down to the molecular level, we pinpoint key elements of neuroprotection that are likely contributing. We also introduce new concepts for neuroprotection and address avenues of further discovery.