Neck Strength: A Protective Factor Reducing Risk for Concussion in High School Sports

Quality of Life in Adolescent Athletes With Sport-Related Concussion Prescribed Heart Rate-Targeted Aerobic Exercise Within 10 Days of Injury

Individualized aerobic exercise treatment prescribed within 10 days of injury facilitates recovery in adolescents after sport-related concussion (SRC) and reduces incidence of persisting post-concussive symptoms (PPCSs) beyond 4 weeks. The effect of aerobic exercise treatment on quality of life symptoms is, however, unknown. This planned secondary aim of a published randomized controlled trial found that while adolescents prescribed aerobic exercise recovered faster, there was no difference on the Pediatric Quality of Life (PedsQL) questionnaire scores during the 4-week intervention period. Nevertheless, adolescents who experienced PPCS reported significantly worse initial visit (within 10 days of injury) symptoms on the PedsQL than those who recovered within 4 weeks. Higher scores on the PedsQL correlated with greater initial visit concussion symptom burden and more abnormalities on a concussion-relevant visio-vestibular examination. Thus, the PedsQL captures the clinical severity of concussion and is prognostic of risk for delayed recovery when administered early after SRC in adolescents.

Identifying Cervical Predictors of Recreational Mixed Martial Arts Participation: A Case-Control Study

Background: Recreational participation in Mixed Martial Arts (MMA) has rapidly increased. Despite consistent evidence of a high injury prevalence in MMA athletes, the neuromuscular implications of regular MMA training remain underexplored. The cervical spine is particularly vulnerable to trauma due to repetitive impacts and high mechanical demands in combat sports. Methods: This case-control study compared cervical spine function and self-reported symptoms between 25 recreational MMA athletes and 25 matched individuals who engaged in general fitness training. Outcome measures included Neck Disability Index (NDI), Post-Concussion Symptom Scale (PCSS), pain and headache reports, cervical range of motion (ROM), proprioception, isometric strength, and endurance. Multivariate logistic regression analysis was used to identify the predictors of group classification. Results: The MMA group exhibited significantly higher values for post-concussion symptoms (p = 0.012), cervical flexor endurance (p = 0.031), and the number of concussions (p = 0.001) but lower flexion ROM (p = 0.031). No significant differences were observed in strength, proprioception, or NDI scores. Logistic regression identified the number of concussions, age, total cervical ROM, and average rotation strength as significant predictors of group membership (model AUC = 0.96; Nagelkerke R2 = 0.797). Conclusions: Recreational MMA athletes demonstrated higher rates of concussion-related symptoms and reduced cervical flexion ROM than noncontact exercisers despite no statistically significant differences in strength and proprioception. These findings suggest that cumulative exposure to amateur MMA is associated with alterations in cervical neuromuscular characteristics. These results support the implementation of targeted mobility, endurance, and injury prevention programs in recreational MMA training.

Combining evidence and practice to optimise neck training aimed at reducing head acceleration events in sport: a systematic review and Delphi-consensus study

Head acceleration events (HAEs) can potentially have adverse consequences for athlete brain health. In sports, in which head injuries have the highest incidence, identifying strategies to reduce HAE frequency and magnitude is a priority. Neck training is a potential strategy to mitigate against the magnitude of HAEs. This two-part study aimed to (1) systematically review the literature of neck training interventions in sport and (2) undertake an expert Delphi consensus on the best practices for neck training implementation to reduce HAEs in sport. Part I: a systematic search of four databases was undertaken from the earliest records to September 2024. The PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines were followed, and a quality assessment was completed using a modified Downs and Black assessment tool and the GRADE (Grading of Recommendations Assessment, Development and Evaluation). Papers were eligible if they both (1) implemented a reproducible exercise intervention targeting the neck within collision, combat or motor sport, and (2) assessed outcomes relating to either: the physical profile of the neck; head/neck injury incidence; and/or HAEs. Part II: 18 international experts, with experience in research and/or applied practice of neck exercise training, concussion and/or HAEs, reviewed the part I findings before completing a three-round Delphi consensus process. Part I included 21 papers, highlighting the heterogeneity of existing interventions. Part II resulted in 57 statements coded into five categories: contextual factors (n=17), neck training periodisation (n=12), training adaptations (n=10), neck training content (n=15) and athlete adherence (n=3). This study presents recommendations for neck exercise training aiming to reduce HAEs in sport, supporting both practice and future research.

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.

Sport-Related Concussions in High School Athletes: A Comprehensive Update

PURPOSE OF REVIEW

Sport-related concussions (SRC) in high school athletes are a growing public health concern, with recent advancements in epidemiology, pathophysiology, diagnosis, management, and prevention. We concisely summarize SRC in high school athletes, emphasizing current research and clinical implications.

RECENT FINDINGS

Athletes are at significant risk of SRCs, with incidence varying by sport, sex, and competitive setting. Advances in pathophysiology highlight the role of metabolic disruption, inflammation, and axonal injury. Updated diagnostic tools, such as SCAT6, aid clinical evaluation, while advanced neuroimaging and biomarkers remain investigational. Return-to-sport/learn protocols emphasize a gradual, stepwise return. Preventative measures, including policy changes, neuromuscular training, and protective equipment, have reduced SRC incidence. Comprehensive SRC management includes recognition and removal from play followed by a structured return to sport/learning. Future research directions include biomarker validation, optimized prevention strategies, and long-term outcome assessment to reduce the burden of SRC in adolescent athletes.

Incidence and Risk Factors for Sport-Related Concussion in Female Youth Athletes Participating in Contact and Collision Invasion Sports: A Systematic Review

BACKGROUND

The incidence and risk factors for sport-related concussion (SRC) associated with contact and collision invasion sports (CCIS) in female youth are unclear.

OBJECTIVES

This systematic review aimed to identify (i) the incidence of and (ii) risk factors for SRC in female youth athletes playing CCIS.

METHODS

A systematic search of PubMed, CINAHL, Embase, SPORTDiscus and ProQuest to 8 May, 2024 was conducted. Two reviewers independently screened articles against eligibility criteria and assessed risk of bias (Joanna Briggs Institute Critical Appraisal Tool). Aetiological or intervention studies reporting on SRC incidence or risk factors in female youth athletes (aged 13-19 years and under) participating in CCIS were included. Meta-analyses were conducted to explore SRC incidence and risk factors. For each meta-analysis of SRC incidence rate, sub-group analyses were conducted by sport. Where heterogeneity was above 60% for the meta-analysis of SRC risk/protective factors, sensitivity analyses were conducted.

RESULTS

The search yielded 4509 articles; 66 were included. Sport-related concussion incidence or risk factor data for nine CCIS were extracted. Pooled estimates revealed SRC incidence for female youth athletes in CCIS combined was 0.50/1000 match and practice hours (95% confidence interval [CI] 0.34-0.66). When examined by sport classification, SRC incidence in contact invasion sports was 0.12/1000 match and practice hours (95% CI 0.03-0.21), and in collision invasion sports was 2.08/1000 match and practice hours (95% CI 0.90-3.25). Sub-group analysis by individual sport revealed female youth soccer players had the highest overall SRC incidence rate (0.89/1000 match and practice hours, 95% CI - 0.19 to 1.97) amongst contact sports, and rugby union players had the highest overall SRC incidence rate (4.04/1000 match and practice hours, 95% CI 3.03-5.05) among collision sports. Forty-five studies (68%) reported SRC risk factor data, investigating 12 different potential risk factors. Female youth sustained over 7.5 times the rate of SRC in matches compared with practice (incidence rate ratio 7.52, 95% CI 6.32-8.95, p < 0.01) when competing in CCIS; however, considerable heterogeneity existed (I2 = 84.98%). When exploring potential risk factors, no significant difference was found in SRC rate between female youth lacrosse players wearing versus not wearing headgear (p = 0.07). No significant difference was found in SRC rates between female youth athletes competing in younger versus older age groups (incidence rate ratio 0.91, 95% CI 0.52-1.61, p = 0.48, I2 = 0.00%). Insufficient evidence was available to examine remaining risk factors.

CONCLUSIONS

This meta-analysis revealed SRC in female youth playing CCIS was higher than previously reported, with SRC rates higher in matches than practice. Soccer had the highest SRC incidence rate for female youth athletes competing in contact invasion sports, whilst rugby union demonstrated the highest SRC incidence rates for collision invasion sports. The results of this review should be interpreted with caution given the lack of representation from some common CCIS codes. Further research is required to examine SRC risk factors in female youth athletes participating in CCIS.

CLINICAL TRIAL REGISTRATION

OSF Registration: osf.io/s573v.

Correlation of King-Devick Test and Helmet Impact Exposures Over a Youth Football Season

BACKGROUND

The cumulative effect of repetitive subconcussive head impacts on neurocognitive function during youth contact sports remains largely unknown. There is a paucity of literature evaluating cumulative helmet forces over a season and their correlation with preseason and postseason cognitive performance tasks such as the King-Devick test (KDT).

HYPOTHESIS

Higher helmet forces recorded throughout a 10-week, 10-game youth football season would correlate with slower performance on postseason KDT.

STUDY DESIGN

Prospective cohort study.

LEVEL OF EVIDENCE

Level 3.

METHODS

A cohort of 58 youth football players (ages 9-13 years) underwent pre- and postseason KDT. Players wore SpeedFlex helmets (Riddell) fitted with InSite Impact Response System helmet accelerometers (Riddell) which recorded impacts of ≥15g. Head impacts were tallied over a season and assigned a score of 1, 2, or 3 based on magnitude of g forces. Suspected concussions were correlated with KDT times and recorded instances of head impact. Pre- and postseason KDT scores were compared.

RESULTS

During the season, 2013 head impacts were recorded. Median (range) total cumulative force score was 24 (5-476); 6 players sustained head impacts concerning for concussion, and 4 were clinically diagnosed with concussions. Overall, postseason KDT times improved compared with preseason, with a median (range) change of -4.8 seconds (-7.6, -1.1). Analysis showed no correlation between changes in KDT time and total cumulative force score over the season.

CONCLUSION

KDT times in youth football players did not change significantly based on head impact exposure over a single youth football season; most players' KDT times improved from preseason to postseason.

CLINICAL RELEVANCE

Although our study did not show significant cognitive impact as measured by KDT over a single youth football season, the long-term effects of concussion on the immature brain and how it can impact cognitive development remains largely unknown and should be an area of ongoing study.

Evaluating a 14-week neck strengthening protocol for neuromuscular indicators associated with head and neck trauma

Increased neck strength has been linked to a potential decrease in traumatic brain injuries (TBI). The purpose was to determine the efficacy of a neck-strengthening protocol using a novel neck-strengthening device to increase isometric neck strength and rate of force development (RFD). Utilizing self-generated centripetal force, participants trained for 14 weeks. A linear mixed model was used to analyze the relationship between post-assessment measurements and pre-assessments measurements, while accounting for repeated measure random effect at the individual level, and a regular random error term. RFD values were 4.344 times higher in the clockwise direction and 5.978 times higher in the counterclockwise direction when comparing pre and post assessment measurements. Isometric neck strength increased significantly (p ​< ​0.05) in the cervical extension (p ​= ​0.010) and left lateral flexion (p ​= ​0.009) directions. The results can be used in strength training and clinical settings to potentially reduce the incidence of TBI.

Factors Associated With Return to Activity After Concussion Among Female Service Academy Members: Findings From the NCAA-DoD CARE Consortium

INTRODUCTION

Service academy members are at high risk for concussions as a result of participation in both sports and military-specific training activities. Approximately 17% of active duty service members are female, and they face unique challenges in achieving timely recovery from concussions. Understanding the unique characteristics affecting return to unrestricted activity (RTA) among female service academy members is imperative for the ever-growing proportion of females across the U.S. military. The goal of this analysis was to determine how specific injury and individual characteristics of concussion affect 2 RTA protocol events in female service academy members: time to protocol initiation and time to protocol completion.

MATERIALS AND METHODS

All data were collected as part of the National Collegiate Athletic Association (NCAA) and the DoD Concussion Assessment, Research and Education Consortium. We examined data from female U.S. military service academy members at the 4 U.S. Service Academy sites who sustained a concussion between Fall 2014 and Spring 2020 (N = 752). Return to unrestricted activity protocol initiation time was defined as the time from injury to when cadets were cleared to begin gradual RTA, while RTA protocol completion time was defined as the time from injury to when cadets were cleared to RTA. Multivariable Cox regression analyses were used to determine the effect of 4 characteristics on RTA event times: (1) service academy members' NCAA status (e.g., student athlete), (2) prior history of concussion, (3) reporting time of concussion, and (4) sport-related concussion (SRC) or non-SRC. Because of missing data, 520 cadets were included in the model of RTA protocol initiation and 556 were included in the model of RTA protocol completion. Chi-squared analyses assessed interactions between reporting time, NCAA status, and SRC or non-SRC.

RESULTS

Service academy members who were NCAA athletes (hazard ratio [95% CI](HR [95% CI]): 1.58 [1.32, 1.90]), immediately reported their injury (HR [95% CI]: 1.40 [1.18, 1.67]), or had an SRC (HR [95% CI]: 1.29 [1.08, 1.54]) were significantly more likely to have initiated or completed the RTA protocol on any given day post-concussion compared to those who were not NCAA athletes, delayed reporting their injury, or had a non-SRC, respectively. We observed that among those with SRCs, a greater proportion of NCAA service academy members immediately reported their injury (53.9%) compared to non-NCAA (37.3%, P < .001); there was no difference in the proportion of NCAA and non-NCAA service academy members with non-SRCs who immediately reported their injury (P = .18).

CONCLUSIONS

A greater proportion of female service academy members who sustained SRCs and were NCAA athletes reported their injuries immediately, which was associated with a greater likelihood of RTA protocol initiation and completion on any given day after injury. This may be attributable to easy and timely access to medical personnel (e.g., athletic trainers) or the presence of individuals trained in identifying concussion (e.g., coaches). Future initiatives among female service academy members should include improved access to medical care across a variety of injury settings and education on the importance of early reporting after concussion.

Efficacy of exercise interventions on prevention of sport-related concussion and related outcomes: a systematic review and meta-analysis

OBJECTIVE

To review the efficacy of exercise interventions on sport-related concussion (SRC) incidence, as well as on linear and rotational head accelerations, and isometric neck strength and to assess reporting completeness of exercise interventions using the Consensus on Exercise Reporting Template (CERT).

DESIGN

Systematic review and meta-analysis, according to the Prisma in Exercise, Rehabilitation, Sport medicine and SporTs science guidelines.

DATA SOURCES

Six databases (MEDLINE, Embase, CINAHL, Scopus, Web of Science CC and SPORTDiscus) were searched up to 26 June 2023.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomised controlled trials (RCTs), cluster RCTs or quasi-experimental studies, evaluating exercise interventions on SRC incidence, linear and rotational head accelerations, and/or isometric neck strength in male and/or female athletes of any age, and/or in a healthy general population.

RESULTS

A total of 26 articles were included. A large effect size was observed for resistance training (RT) on isometric neck strength (standardised mean difference (SMD) 0.85; 95% CI 0.57 to 1.13; high-quality evidence). Non-significant effect sizes were observed for neuromuscular warm-up programmes on SRC incidence (risk ratio 0.69; 95% CI 0.39 to 1.23; low-quality evidence), or for RT on linear head acceleration (SMD -0.43; 95% CI -1.26 to 0.40; very low-quality evidence) or rotational head acceleration (SMD 0.08; 95% CI -0.61 to 0.77; low-quality evidence). No studies assessed the impact of RT on SRC incidence. CERT scores ranged from 4 to 16 (out of 19) with median score of 11.5 (IQR 9-13).

CONCLUSION

RT increases isometric neck strength, but the effect on SRC incidence is unknown. More adequately powered and rigorous trials are needed to evaluate the effect of exercise interventions on SRC incidence, and on linear and rotational head accelerations. Future studies should follow CERT guidelines, as the included interventions were generally not reported in sufficient detail for accurate replication.

PROSPERO REGISTRATION NUMBER

CRD42023435033.

Reliability of a novel neck external loading dynamometer

Cervistab is an electro-pneumatic device that produces flexion push-loading events in an ecological rugby position (i.e. similar to on-pitch position) to assess neck extensors muscle response to a flexion perturbation. This response is important for preventing head/neck injuries in Rugby, however there is a clear lack of validated devices in the literature. This study tested the reliability of this new device designed to investigate the extensor neck muscle response to flexion head push-loading event. Twelve healthy volunteers were tested with Cervistab in a test/retest protocol. Participants experienced push-loading events with preloading on extensors muscles at 50 % and 20 % of their maximum voluntary isometric extension strength. Muscle mechanical latency, non-reflex and reflex rates of force development were measured twice, 7 days apart. Reliability was assessed by intraclass correlation coefficient (ICC), coefficient of variation (CV), and the Bland and Altman graphical approach. For both preloading conditions, muscle mechanical latency showed good ICC values from 0.81 to 0.88 and good CV (3.5%). Non-reflex and reflex rates of force development showed good reliability with ICC ranging from 0.78 to 0.89, and moderate CV values ranging from 8.5% to 14.5%, depending on the preloading condition (20% and 50% of maximal isometric extension contraction respectively). Bland and Altman plots showed no significant fixed or proportional bias. Overall, the reliability of measurements obtained with Cervistab is good. Cervistab can be used in practice to improve our understanding of the neuromechanical factors that influence neck stability, to help prevent head/neck injuries and to guide the decision to return to play after a head or neck injury.

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.

Concussion in Female Athletes of Contact Sports: A Scoping Review

Background

Recent studies have described higher incidences of concussion, with more severe symptoms and worse outcomes in female athletes compared with male athletes.

Purpose

To compile current knowledge about sex-specific differences in incidence, biomechanics, biomarkers, imaging, and outcomes of concussion in athletes participating in contact sports to better understand which fields should be explored in more detail.

Study Design

Scoping review; Level of evidence, 3.

Methods

The PubMed database was searched for articles published between January 2000 and November 2020 using the Medical Subject Headings terms "craniocerebral trauma" and "brain concussion" combined with the contact sports "football,""soccer,""hockey," and "boxing." Eligibility criteria were based on the recommendations of the Scottish Intercollegiate Guidelines Network. It focused on sex-specific differences within 5 major topics: (1) epidemiology, (2) biomechanics, (3) biomarkers, (4) imaging, and (5) specific concussion outcome variables, including neurocognitive performance, injury severity, and behavioral and psychological symptoms.

Results

A total of 22 studies were included. Eight studies investigated the incidence of concussion, with 4 of the 8 finding a significantly higher incidence rate for female versus male athletes. Six studies that focused on biomechanics found that female athletes received fewer impacts with lower magnitudes. One study addressed biomarkers, showing that S100 calcium-binding protein B and neuron-specific enolase were increased after a game in female athletes, and the level of increase was similar to the changes found in male athletes. Based on the 3 imaging studies, affected brain tissue was greatest in areas associated with tau pathology in chronic traumatic encephalopathy. One study showed a lower hypointensity burden index after a season of ice hockey for female athletes, while another study showed more regions with white matter alterations. Seven studies examined concussion outcomes, with 4 studies showing more severe neuropsychological deficits; in addition, female athletes reported more and worse symptoms than male athletes.

Conclusion

The results of this review indicated that female athletes had a higher risk of sustaining a concussion, although they received fewer impacts with lower magnitudes than male athletes. Biomarkers were able to be used equally for both sexes. Female athletes also had a higher neuropsychological deficit and increasingly worse symptoms after a concussion.

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.

Testing in Intermittent Sports-Importance for Training and Performance Optimization in Adult Athletes

ABSTRACT

Performance in intermittent sports relies on the interplay between multiple physiological systems determining the capacity to perform short explosive efforts as well as repeated intense actions with limited recovery over the course of an entire game. Testing should reflect these demands to allow for sport- and position-specific capacity analyses that eventually may translate into optimized training and improved performance. This may include individual load management and optimized training prescription, intensity targeting for specific positions or individual athletes, as well as benchmarking for monitoring of training progression and enhanced engagement of athletes. This review provides an overview of available tests in different exercise domains identified as relevant (from assessment of single explosive actions to intermittent endurance capacity), forming the basis for recommendations on how to compose a comprehensive yet feasible test battery that may be integrated into the seasonal competition and training plan. The test procedures should cover the performance spectrum of relevance for the individual athlete-also in team sports to account for positional differences. We emphasize the benefits of sport-specific tests, highlight parameters of importance for test standardization, and discuss how the applied test battery may be supplemented with secondary tests directed toward specific energy systems to allow for more in-depth analyses when required (e.g., in terms of an underperforming athlete). The synergy between testing and tracking of match performance (utilizing time-motion or global positioning systems) is highlighted, and although tracking cannot substitute for testing, combining the tools may provide a comprehensive overview of the physiological demands and performance during competition contextualized to the athletes' maximal exercise capacity.

Position comparison of sport-related concussions in female youth soccer players

OBJECTIVES

Youth soccer participation, particularly among females, continues to grow worldwide. With the high incidence of sport-related concussion (SRC) in soccer, it is important to investigate if SRC occurs disproportionally by positions. Our hypothesis was to see no positional differences in SRCs, SRC-related characteristics, and outcomes among in female youth soccer athletes.

METHODS

Data were prospectively collected from participants at a single sports medicine institution between August 2015-April 2021. Female participants aged 8-18 diagnosed with SRC sustained during an organized soccer practice, scrimmage, or game were separated into 4 groups based on position: Forward, Midfielder, Defender, and Goalkeeper. Demographics, medical history, injury-related details, and outcomes were reviewed. A chi-square test or Fisher's exact test was used for categorical variables. Continuous variables were compared with Mann-Whitney or Kruskal-Wallis test.

RESULTS

Two hundred fourteen participants were included: 52 Forwards, 65 Midfielders, 63 Defenders, and 34 Goalkeepers. There were no significant differences between the groups in age, race, ethnicity, or previous concussion history. Differences in mechanism existed with Goalkeepers most commonly reporting Head to Body Part. Goalkeepers, which make up 1/11 of the total positions on the field, had a significantly higher proportion of SRCs compared to Field Positions. (9.1% vs 15.9%)At 3-month post-enrollment, there were no significant differences in reported symptoms or return-to-play between the different positions.

CONCLUSION

In youth female soccer players, goalkeepers sustained a higher proportion of sport-related concussions compared to field players based upon the composition of a soccer team. The mechanism of injury also differed among the different soccer positions. However, no differences in concussion characteristics, outcomes, or RTP were seen across the different soccer positions.

Evaluating Neck-Strengthening Protocols to Reduce the Incidence of Traumatic Brain Injury: Traditional vs. Nontraditional Neck-Strengthening Techniques

ABSTRACT

Schroeder, LH, McDaniel, AT, Wang, Y, Dickens, GM, Pantani, V, and Kubinak, H. Evaluating neck-strengthening protocols to reduce the incidence of traumatic brain injury: traditional vs. nontraditional neck-strengthening techniques. J Strength Cond Res 38(7): 1266-1274, 2024-A common cause of traumatic brain injuries (TBIs) is the head's kinematic response to rapid movement, which can be reduced with dynamic neck strengthening. This study aimed to determine the most effective neck-strengthening program by comparing a traditional and nontraditional program. Isometric neck strength was assessed in 32 subjects randomly assigned to one of the traditional and nontraditional neck-strengthening programs. The nontraditional program used a novel neck-strengthening device. After weeks 6 and 10 of training, isometric neck strength was reassessed. With the collected data, linear mixed models were established to compare the changes in neck strength between the 2 groups during the 10-week training period. Statistical analysis results suggest that, for both cervical extension (CE) and cervical flexion (CF), subjects in the novel neck-strengthening device group had a significantly higher gain of strength during the 10 weeks than the traditional group. With test statistics of -2.691 and -3.203 and corresponding 2-sided p -value of 0.01289 and 0.003889, respectively, we conclude that there is a statistically significant difference in the linear slopes of increase for both CE and CF between the 2 groups. As to left cervical lateral flexion and right cervical lateral flexion, the novel neck strength group had increased strength gains compared with the traditional group. However, the increase was not enough to demonstrate significant findings. Results were considered significant at p < 0.05. The results of this study show that the novel neck-strengthening device may be an effective mechanism for preventing mild TBIs.

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.

The Prevalence and Influence of New or Worsened Neck Pain After a Sport-Related Concussion in Collegiate Athletes: A Study From the CARE Consortium

BACKGROUND

Neck pain in a concussion population is an emerging area of study that has been shown to have a negative influence on recovery. This effect has not yet been studied in collegiate athletes.

HYPOTHESIS

New or worsened neck pain is common after a concussion (>30%), negatively influences recovery, and is associated with patient sex and level of contact in sport.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Varsity-level athletes from 29 National Collegiate Athletic Association member institutions as well as nonvarsity sport athletes at military service academies were eligible for enrollment. Participants completed a preseason baseline assessment and follow-up assessments at 6 and 24 to 48 hours after a concussion, when they were symptom-free, and when they returned to unrestricted play. Data collection occurred between January 2014 and September 2018.

RESULTS

A total of 2163 injuries were studied. New or worsened neck pain was reported with 47.0% of injuries. New or worsened neck pain was associated with patient sex (higher in female athletes), an altered mental status after the injury, the mechanism of injury, and what the athlete collided with. The presence of new/worsened neck pain was associated with delayed recovery. Those with new or worsened neck pain had 11.1 days of symptoms versus 8.8 days in those without (P < .001). They were also less likely to have a resolution of self-reported symptoms in ≤7 days (P < .001). However, the mean duration of the return-to-play protocol was not significantly different for those with new or worsened neck pain (7.5 ± 7.7 days) than those without (7.4 ± 8.3 days) (P = .592).

CONCLUSION

This novel study shows that neck pain was common in collegiate athletes sustaining a concussion, was influenced by many factors, and negatively affected recovery.

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.

Understanding Abnormal Examination Findings During Concussion Recovery: A Retrospective Chart Review

Background and Objective

Physical examination findings in athletes with sport-related concussion (SRC) are not well described in the literature. The objective of this study was to describe physical examination findings during the first month following concussion in athletes, with a focus on the effect of sex, age, and time since injury.

Methods

This was a retrospective electronic medical record (EMR) review of physical examination findings in 500 patients aged 6-24 who were initially seen within 15 days of SRC at a multidisciplinary outpatient academic concussion clinic between 2017 and 2019. A standardized concussion examination built in the EMR recorded mental status, cranial nerve, vestibulo-ocular motor screen, and balance findings for all patients. The primary outcome was the frequency of abnormal examination findings during the first 30 days postinjury, which was further analyzed by sex, age, and time since injury using mixed logistic regression models.

Results

The most common abnormal examination findings overall were eyes-closed single-leg stance, vestibular-ocular reflex, visual motion sensitivity, the neck examination, and eyes-closed tandem stance. Abnormal findings were more frequent in female athletes for vestibular ocular reflex and visual motion sensitivity. The frequency of abnormal findings increased with age for vestibulo-ocular reflex, visual motion sensitivity, the neck examination, convergence testing, and eyes-open single-leg stance, whereas abnormalities decreased in frequency with age for eyes-open tandem stance and tandem gait. The frequency of abnormal findings generally decreased with time over the first 4 weeks following injury.

Discussion

A comprehensive physical examination is pivotal for evaluation of athletes with concussion. These findings highlight high-yield components of the concussion examination and support use of these examination components as injury markers. Future work should investigate associations between physical examination findings and postconcussion symptoms and recovery outcomes.

Classification of Evidence

This retrospective cohort study provides Class IV evidence that neurologic examination with specifically designed clinical tests are helpful for diagnosis of traumatic brain injury in young athletes at age 6-24.

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.

The characteristics and risk factors of fatal falls among adults aged 60 and above in Southwest China

Falls constitute a leading cause of unintentional injury deaths among older adults. This study aimed to examine the comprehensive characteristics of fatal falls among older individuals in Yunnan Province, China, to highlight the challenges faced in elderly care. A total of 22,798 accidental fall-related deaths were extracted from China's National Disease Surveillance Points System aged 60 and above between 2015 and 2019. Quantitative and textual data were analyzed to assess the incidence rates of initiating factors, locations, symptoms, and overall survival (OS) outcomes after falling. Hypertension emerged as the most significant intrinsic factor, especially among individuals aged between 70 and 79, female older adults, and urban residents (P < 0.001). Home was identified as the most common location where fatal falls occurred (61.19%). The head was the most commonly injured body region (58.75%). The median of OS for all fatal falls was 2 days (0.13, 30), of which deaths occurred within 24 h [9287 (49.36%)]. There were instances where timely discovery after falling did not occur in 625 cases; their median of OS was significantly shorter compared to those discovered promptly after falling (P < 0.001). Targeted interventions focusing on fall prevention and post-fall care are equally crucial for the well-being of older adults.

Youth handball concussion prevention strategies: a workshop-based study with experts and end users

Sport-related concussion (SRC) is a serious injury in youth team sports, including handball. While research on the prevention of SRC has made progress over the past 5 years, prevention strategies are lacking in handball. The aim was to explore and develop strategies focusing on information, rules and training that may prevent concussion in youth handball by incorporating knowledge from experts and end users. Using a participatory methodology, experts (physiotherapy, biomechanics: n=3) and end users (players, coaches, referees, coach educators: n=7) contributed their experience and knowledge in a 2-hour online workshop. Participants were given three videos illustrating typical high-risk concussion scenarios from handball games and a youth player's accompanying fictional written scenario. In group discussions inspired by the brainwriting method, participants were asked to provide ideas for possible SRC prevention strategies related to information, rules and/or training. Data were collected on a digital whiteboard and analysed using reflexive thematic analysis. Three themes were derived: (1) 'Coaches' responsibility: raise awareness of the risk of injury and act to promote safe environments'; (2) 'Players' responsibility: safe defence and attack'; and (3) 'Improvement of personal skills'. Experts and end users found information about high-risk situations and SRC symptoms, stricter rules and safe playing strategy training for goalkeepers, attacking and defending players, respectively, may effectively reduce SRC in handball. Information and stricter rules could be delivered through education and dissemination activities, whereas safe playing strategies should be trained at regular handball practice.

Exploring the relationship between contraceptive medication use and concussion recovery in female collegiate athletes: a LIMBIC MATARS consortium investigation

OBJECTIVE

While recovery from concussion is variable, women are more likely to report symptoms, experience worse outcomes, and have longer recovery trajectories following concussion than men. Preliminary data suggest that hormonal fluctuations, specifically progesterone, may be associated with this variability. This study aimed to understand the effect of contraceptive medication on concussion recovery.

METHODS

A retrospective chart review using consensus-based common data elements was conducted at 11 NCAA institutions as part of the LIMBIC MATARS consortium. Participants included female collegiate athletes diagnosed with a concussion who did (n = 117) or did not report (n = 339) contraceptive medication use. Number of days between diagnosis and symptom resolution were compared using Mann-Whitney U tests. Self-reported diagnosis of attention deficit hyperactivity disorder, concussion history, anxiety, and depression was compared using Chi-squared tests.

RESULTS

The proportions of participants who did or did not take contraceptive medication were similar across covariates. Female athletes regardless of contraceptive medication use recovered similarly following a concussion.

CONCLUSIONS

Our findings suggest that contraceptive medication use did not significantly impact concussion recovery. Future prospective investigations should examine documentation practices and operationalize terminology for hormonal contraceptive medication to better understand their role on recovery from sport-related concussion in female collegiate athletes.

Access to athletic trainers and sex as modifiers of time to reach clinical milestones after sport-related concussion in collegiate athletes

OBJECTIVE

Investigate whether an athlete's biological sex and exposure to a dedicated athletic trainer (AT) were related to clinical milestones after a sports-related concussion (SRC).

DESIGN

Retrospective chart review.

METHODS

Medical charts of collegiate athletes (n = 196 [70.9% female]) diagnosed with SRC were reviewed to extract: biological sex, dedicated AT exposure for their sport (yes/no), and time (days) to reaching clinical milestones (diagnosis, symptom resolution, unrestricted return to sport [RTS]). Mann-Whitney U tests were used to determine whether time to clinical milestones differed by sex, AT exposure, or their interaction. Proportions of same-day diagnoses and times to diagnosis, symptom resolution, and unrestricted RTS were evaluated with chi-squared and spearman's rank correlations, respectively.

RESULTS

There were no significant differences in times to reaching any clinical milestone by sex, AT exposure, or their interaction (ps > 0.05). Forty-three percent of participants were diagnosed on the day of their SRC. This did not differ by sex or AT exposure (ps > 0.29). Longer times to SRC diagnosis were associated with more days to symptom resolution (ρ = 0.236, p = 0.001) and unrestricted RTS (ρ = 0.223, p < 0.001).

CONCLUSIONS

Athlete sex and AT exposure were not associated with times to reach any clinical milestone; however, delayed diagnosis was associated with longer times to reach clinical recovery.

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.

Sport-related concussion in soccer -a scoping review of available guidelines and a call for action to FIFA & soccer governing bodies

Introduction

Sport-related concussions (SRC) have been a concern in all sports, including soccer. The long-term effects of soccer-related head injuries are a public health concern. The Concussion in Sport Group (CISG) released a consensus statement in 2017 and several soccer governing associations have published their own SRC guidelines while referring to it but it is unclear whether this has been universally adopted.

Research question

We aimed to investigate whether guidelines published by soccer associations have any discrepancies; and the extent to which they follow the CISG recommendations.

Materials and methods

A scoping review of available soccer-specific SRC guidelines was performed via databases PubMed, Google Scholar, and official soccer association websites via web browser Google. The inclusion criteria were soccer-specific SRC guidelines. Comparisons between guidelines were made concerning the following index items: initial (on-site) assessment, removal from play, re-evaluation with neuroimaging, return-to-sport protocol, special populations, and education.

Results

Nine soccer associations with available guidelines were included in this review. Guidelines obtained were from official associations in the United Kingdom, United States of America, Canada, Australia, and New Zealand. When compared to each other and the CISG recommendations, discrepancies were found within guidelines regarding the index items. Additionally, major soccer associations in some countries famous for soccer were found to have not published any publicly available guidelines.

Discussion and conclusion

SRC guidelines from different soccer associations contain discrepancies which may be detrimental to athletes, both short and long-term. We recommend that all major soccer governing associations publish guidelines that are standardised and accessible to all athletes.

Examining the influence of the Get aHEAD Safely in Soccer™ program on head impact kinematics and neck strength in female youth soccer players

The objective was to examine the efficacy of the Get aHEAD Safely in Soccer™ intervention on head impact kinematics and neck strength in female youth soccer players. The control group (CG) consisted of 13 players (age: 11.0 ± 0.4 yrs), while the experimental group (EG) consisted of 14 players (age: 10.6 ± 0.5 yrs). Head impact kinematics included peak linear acceleration (PLA), peak rotational acceleration (PRA), and peak rotational velocity (PRV). Pre- and post-season measures included strength measures of neck/torso flexion (NF/TF) and extension (NE/TE). Data were analysed using a multilevel linear model and ANOVA techniques. No differences in PLA, PRA, or PRV were observed between groups. The EG showed significant improvement in NF strength while the CG showed significant improvement in NE strength. Both groups significantly improved in TF pre- to post-season. The foundational strength components of the Get aHEAD Safely in Soccer program appear to show a benefit in youth soccer players beginning to learn the skill of purposeful heading.

Characteristics of potential concussive events in elite hurling: a video-analysis study

BACKGROUND

High-impact sports such as hurling place participants at risk of sport-related concussion (SRC).

AIMS

This study will evaluate the characteristics of potential concussive events (PCEs) that occur in elite male hurling to acquire an understanding of how they occur.

METHODS

The authors recorded PCEs and their characteristics throughout two seasons of inter-county GAA competition using broadcast footage based on a previously validated protocol.

RESULTS

A total of 183 PCEs were identified over 82 inter-county matches (2.23 per match; 59.5 per 1000 h of exposure). PCEs that occurred in the 4th quarter were significantly more likely to result in signs of SRC. Players most often intended to receive/control the sliotar (36.4%, n = 64) prior to PCEs. The most frequently observed mechanism was shoulder-to-head (20.2%, n = 37). Impacts to the lateral aspect of the head were 2.7 times more likely to result in visible signs than impacts to anteroposterior regions.

CONCLUSIONS

Players appear to be at a higher risk of SRC later in the match or when receiving the sliotar. Strikes to the lateral aspect of the head and those involving the shoulder appear to produce severe events. These findings provide initial guidance for the development of targeted player protection strategies.

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.

Sex differences in college students' knowledge of concussion and concussion education sources

Aim

To understand sex differences and sources of concussion education for college students. The literature for college students primarily focuses on sports concussions and general knowledge. Understanding how non-students-athletes learn is critical to developing interventions to improve concussion knowledge.

Participants

A random sample of 208 students from four-year institutions.

Methods

A 22-question online survey explored postsecondary students' current knowledge and education regarding concussions.

Results

Findings indicated that sex differences emerged with concussion knowledge and sources of concussion knowledge (e.g., leaflets, pamphlets, parents, and television). The top choices for where they wanted to learn about concussions were health educators, health centers, and campus peer educators.

Conclusion

This study provides an initial evaluation and implications for future research on providing concussion education.

Reference Values for Cervical Muscle Strength in Healthy Women Using a Hand-Held Dynamometer and the Association with Age and Anthropometric Variables

Knowledge of reference values for cervical muscle strength is a key tool for clinicians to use as a clinical reference measure and to establish goals during rehabilitation. The objective was to establish reference values for the maximal strength of cervical muscles in healthy women using a handheld dynamometer and verify the association of cervical muscle strength with age and anthropometric measurements. A hundred women were classified into four groups (n = 25) according to age: 18-29 years, 30-39 years, 40-49 years, and 50-60 years. Maximal muscle strength of the cervical spine was measured using a Lafayette® handheld dynamometer for flexion, extension, and bilateral lateral flexion. No differences in cervical muscle strength were observed among the groups (p > 0.05). However, the 18-29-year-old group took less time to reach the peak of force for flexion than the 50-60-year-old group. Moderate correlations were observed between cervical flexor strength and weight, body mass index, and neck circumference, and between cervical extensor strength and weight and body mass index (r = 0.43-0.55; p < 0.05). Reference values for cervical muscle strength in healthy women were established using a handheld dynamometer, and the association between muscle strength and anthropometric data was moderate.

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.

The Relationship of Anthropometric and Physical Performance Characteristics on Competitive Success in Amateur, Elite, and Professional Rodeo Athletes

ABSTRACT

Oranchuk, DJ, Gullett, LK, Kicia, M, Thome, B, and Game, A. The relationship of anthropometric and physical performance characteristics on competitive success in amateur, elite, and professional rodeo athletes. J Strength Cond Res 37(7): 1495-1506, 2023-Reference anthropometric and physical performance qualities can improve understanding of sporting needs and streamline preparation and rehabilitation programs. However, these data and their relationships with competitive success are absent in rodeo athletes. We hypothesized that riding performance would be most correlated with hip adductor, neck, and grip strength, whereas jump, reactive strength index (RSI), and change of direction abilities would best predict bull-fighting performance. Forty-three amateur ( n = 9), professional ( n = 23), or internationally ranked ( n = 11) male rodeo athletes (bareback = 9, bull riders = 16, saddle bronc = 7, bullfighters = 11) (26.8 ± 5.6 years) volunteered for this study. Anthropometrics included body mass, height, and body fat percentage. Performance measures included isometric hip adduction and abduction, neck flexion and extension, handgrip strength, squat and countermovement jump heights, eccentric utilization ratio, reactive strength index, change of direction, bike sprints, and several pneumatic power measures. Bullfighters were taller and heavier than bull riders (effect size [ES] = 0.84-0.87, p = 0.008-0.017). Bull riders were leaner than bullfighters (ES = 0.74, p = 0.012). Fighters had greater RSI than riders (ES = 0.73-1.47, p < 0.001-0.030). Competitive level of rodeo riders ( n = 32) correlated with age, rodeo experience (ρ = 0.37-0.43, p = 0.013-0.049), bent-leg abduction (ρ = 0.43, p = 0.014), straight-leg hip adduction and abduction (ρ = 0.49-0.56, p < 0.001-0.005), neck flexion force (ρ = 0.43, p = 0.016), and rotational power (ρ = 0.50, p = 0.004). The competitive level of the fighters correlated with age (ρ = 0.64, p = 0.036) and time trial performance (ρ = -0.76, p = 0.006). This is the first study providing normative and correlational strength and power performance data in a rodeo population. These data highlight the need for more event-specific physical preparation. Riders should focus their physical preparation on hip and neck strength and rotational power. Bullfighters should prioritize stiffness and anaerobic power.

Axial muscle activation provides stabilization against perturbations while running

Incidence of traumatic brain injury is an important hazard in sports and recreation. Unexpected (blind-sided) impacts with other players, obstacles, and the ground can be particularly dangerous. We believe this is partially due to the lack of muscular activation which would have otherwise provided protective bracing. In this study participants were asked to run on the treadmill while undergoing perturbations applied at the waist which pulled participants in the fore-aft and lateral directions. To determine the effect of unexpected impacts, participants were given a directional audio-visual warning 0.5 s prior to the perturbation in half of the trials and were unwarned in the other half of the trials. Perturbations were given during the start of the stance phase and during the start of the flight phase to examine two distinct points within the locomotor cycle. Muscle activity was monitored in axial muscles before, during, and after the perturbations were given. We hypothesized that the presence of a warning would allow for voluntary axial muscle activity prior to and during perturbations that would provide bracing of the body, and decreased displacement and acceleration of the head compared to unwarned perturbations. Our results indicate that when a warning is given prior to perturbation, the body was displaced significantly less, and the linear acceleration of the head was also significantly lessened in response to some perturbations. The perturbations given in this study caused significant increases in axial muscle activity compared to activity present during control running. We found evidence that cervical and abdominal muscles increased activity in response to the warning and that typically the warned trials displayed a lower reflexive muscle activity response. Additionally, we found a stronger effect of the warnings on muscle activity within the perturbations given during flight phase than those given at stance phase. Results from this study support the hypothesis that knowledge regarding an impending perturbation is used by the neuromuscular system to activate relevant core musculature and provide bracing to the athlete.

Neck Strength Assessment Offers No Clinical Value in Predicting Concussion in Male Professional Rugby Players: A Prospective Cohort Study

OBJECTIVE: To determine if neck muscle strength and endurance are associated with concussion injuries in professional, male rugby players. Playing position, history of previous concussion, and age were also considered. DESIGN: Prospective cohort study METHODS: One hundred thirty-six male, professional rugby players completed neck strength testing that comprised a peak isometric test, an endurance test, and a concussion screening questionnaire. Electronic medical records were analyzed for head injury data. RESULTS: Out of 136 players (mean age, 25.3 ± 3.4 years; height, 186 ± 7 cm; weight, 103 ± 13.2 kg), 40 players suffered from 51 concussions in the 2017/18 playing season. A history of concussion was reported by 65% of the cohort. Multiple logistic regression analysis found that peak isometric flexion strength was not associated with concussion risk. Increased peak isometric extension strength was associated with significantly greater odds of sustaining a concussion (odds ratio [OR] = 1.01; 95% CI: 1.00, 1.01, does not include 1; P = .04) that is likely too small to be clinically relevant. Players with a self-reported history of concussion had over 2 times greater odds of sustaining a concussion (OR = 2.25; 95% CI: 0.73, 6.22). More than 2 concussions in the past 12 months was associated with almost tenfold greater odds of concussion (OR = 9.51; 95% CI: 1.66, 54.55). Age, playing position, and neck muscle endurance were not associated with concussion. CONCLUSION: The strongest predictor of concussion injury was previous concussion. Players who sustained concussions in season had similar neck muscle strength to players who had not sustained a concussion. J Orthop Sports Phys Ther 2023;53(5):1-7. Epub: 5 April 2023. doi:10.2519/jospt.2023.11723.

Neck strength and force in reaction time task of adolescent athletes with and without concussion history: A pilot study

OBJECTIVES

Assess the impact of concussion by comparing reaction time, peak force recruitment, and rate of force development of adolescent athletes returning from concussion against age- and sex-matched controls in visual-elicited neck movement.

DESIGN

Athletes sat secured in a custom-built isometric device with their heads secured in a helmet and attached to a 6-axis load cell. They performed neck flexion, extension, and lateral flexion in response to a visual cue. Three trials in each direction were used for statistical analyses; peak force and rate of force development were normalized against athlete mass.

SETTING

Laboratory.

PARTICIPANTS

26 adolescent/young adult athletes (8F/18M), either recently concussed (and cleared for return to sport) or an age- and sex-matched healthy control.

MAIN OUTCOME MEASURES

Reaction time, angle, standard deviation of angle, deviation from target angle, peak force, and RFD over 50, 100, 150,and 200 ms of movement were measured for each trial.

RESULTS

Concussed athletes had decreased normalized peak force (P = 0.008) and rate of force development (P < 0.001-0.007). In neck extension, concussed athletes also had decreased movement precision (P = 0.012).

CONCLUSIONS

Concussion is associated with alterations of neck biomechanics that decrease overall neck strength.

A comparison of clinical assessment with common diagnostic tools for monitoring concussion recovery in adolescent rugby union players

OBJECTIVES

To characterise the incidence, severity and recovery of sport-related concussion (SRC) in schoolboy rugby players and explore whether the Sports Concussion Assessment Tool (SCAT), Cogstate Brief Battery (CBB) and the King-Devick test (K-D test) can be used to monitor concussion status through to full recovery.

DESIGN

Prospective cohort study.

SETTING

Rugby union has a high rate of SRC; however, there is little research investigating how concussion affects adolescent rugby players.

PARTICIPANTS

Schoolboy rugby players.

MAIN OUTCOME MEASURES

Participants completed baseline tests in the preseason. Participants diagnosed with SRC during the season attended for post-concussion testing on a weekly basis until recovered.

RESULTS

135 schoolboy rugby players (16.7 ± 0.82y) participated in the study. There were 18 SRCs in 16 participants. Concussion incidence was 9/1000 player hours. CBB and K-D tests were poorly associated with clinical assessment and produced high false negative rates (0.58 and 0.52 respectively).

CONCLUSIONS

This study reports a relatively high match SRC incidence for an adolescent population. Analysis of clinical recovery with CBB and K-D test revealed a relatively poor ability to accurately monitor concussion status compared to clinical assessment suggesting that these tools should not be used in isolation for monitoring SRC recovery in adolescents.

How well can we detect cervical driven sensorimotor dysfunction in concussion patients? An observational study comparing patients with idiopathic neck pain, whiplash associated disorders and concussion

BACKGROUND

Patients with mild traumatic brain injury (mTBI) suffer from sensorimotor impairments. Evidence is emerging that cervical spine plays an important role in mTBI, but it is not known how cervicocephalic kinaesthetic sensibility measured during dynamic unpredictable head movements and measures of position sense, cervical induced postural balance and eye movement control differ between mTBI, whiplash associated disorders (WAD) patients, idiopathic neck pain patients and healthy controls.

RESEARCH QUESTION

Are cervical sensorimotor deficits present in mTBI patients and do they differ from sensorimotor deficits found in traumatic and nontraumatic neck pain patients and whether they differ from healthy controls.

METHODS

Twenty idiopathic neck pain patients, 18 WAD, 17 mTBI and 20 healthy controls were enroled in the study. Frequency and velocity of centre of pressure movements were measured during parallel stance in the neutral and neck torsion positions, gain and smooth pursuit neck torsion difference of eye movements during smooth pursuit neck torsion test (SPNTT) and cervicocephalic kinaesthesia using Butterfly and head-to-neutral relocation test.

RESULTS

Statistically significant differences in postural balance, both tests of cervicocephalic kinaesthesia and SPNTT were observed between healthy controls and all patient groups. No differences were observed between patient groups for SPNTT, Butterfly and head-to-neutral relocation test, but differences were present in postural balance between mTBI and both groups of patients with neck pain disorders. Differences were found in the ML direction for mTBI, but not differences were found for AP direction.

SIGNIFICANCE

Results of our study show that mTBI present with similar impairment in cervical driven sensorimotor deficits as patients with neck pain disorders, but they differ from healthy individuals. Clinical practice would benefit from identifying cervical spine related sensorimotor impairments in patients with mTBI. This could enable to design more targeted prevention and rehabilitation programs to minimise cervical spine related disorders in concussion patients.

Predictors of concussion reporting intentions in adolescent hockey players

Young athletes who do not report a concussion injury are at greater risk for a prolonged recovery time and further neurocognitive impairments. Despite the seriousness of the issue and the scale of the problem, not enough is known about the behavioural underpinnings of concussion underreporting in minor athletes. This paper aims to apply the Knowledge, Attitude, and Behaviour (KAB) framework to the issue of injury reporting in adolescents, with the specific purpose of exploring to which degree concussion knowledge, concussion attitudes, and gender affect concussion reporting intentions of both male and female athletes. We recruited 97 young athletes between the ages of 14 and 19 (M = 16.22, SD = 11.06) from the Okanagan Hockey Academy (Canada) and employed a self-administered supervised survey approach to measuring the target variables. A hierarchical multiple regression was conducted, and consistent with the prior literature, females were more likely to report a sport-related concussion than males. It was further found that attitudes around concussions (i.e., taking concussions seriously) were significant predictors of concussion reporting intention. At the same time, there was no significant relationship between concussion knowledge and concussion reporting intention. These results highlight that knowledge about concussion symptoms is insufficient to warrant proper injury reporting. It will therefore be essential to work on changing the attitudes of young athletes regarding the significance of concussions to achieve meaningful behavioural change.

Biomechanics of Traumatic Head and Neck Injuries on Women: A State-of-the-Art Review and Future Directions

The biomechanics of traumatic injuries of the human body as a consequence of road crashes, falling, contact sports, and military environments have been studied for decades. In particular, traumatic brain injury (TBI), the so-called "silent epidemic", is the traumatic insult responsible for the greatest percentage of death and disability, justifying the relevance of this research topic. Despite its great importance, only recently have research groups started to seriously consider the sex differences regarding the morphology and physiology of women, which differs from men and may result in a specific outcome for a given traumatic event. This work aims to provide a summary of the contributions given in this field so far, from clinical reports to numerical models, covering not only the direct injuries from inertial loading scenarios but also the role sex plays in the conditions that precede an accident, and post-traumatic events, with an emphasis on neuroendocrine dysfunctions and chronic traumatic encephalopathy. A review on finite element head models and finite element neck models for the study of specific traumatic events is also performed, discussing whether sex was a factor in validating them. Based on the information collected, improvement perspectives and future directions are discussed.

Sex Differences on the Concussion Clinical Profiles Screening in Adolescents With Sport-Related Concussion

CONTEXT

Sex differences influence symptom presentations after sport-related concussion and may be a risk factor for certain concussion clinical profiles.

OBJECTIVE

To examine sex differences on the Concussion Clinical Profile Screen (CP Screen) in adolescents after sport-related concussion.

DESIGN

Cross-sectional study.

SETTING

A concussion specialty clinic.

PATIENTS OR OTHER PARTICIPANTS

A total of 276 adolescent (age = 15.02 ± 1.43 years; girls = 152 [55%]) athletes with a recently diagnosed concussion (≤30 days).

MAIN OUTCOME MEASURE(S)

The 5 CP Screen profiles (anxiety mood, cognitive fatigue, migraine, vestibular, ocular) and 2 modifiers (neck, sleep), symptom total, and symptom severity scores were compared using a series of Mann-Whitney U tests between boys and girls.

RESULTS

Girls (n = 152) scored higher than boys (n = 124) on the cognitive fatigue (U = 7160.50, z = -3.46, P = .001) and anxiety mood (U = 7059, z = -3.62, P < .001) factors but not on the migraine (U = 7768, z = -2.52, P = .01) factor. Girls also endorsed a greater number of symptoms (n = 124; U = 27233, z = -3.33, P = .001) and scored higher in symptom severity (U = 7049, z = -3.60, P < .001) than boys.

CONCLUSIONS

Among adolescents, symptom endorsement on the CP Screen varied based on sex, and clinicians need to be aware of these differences, especially when evaluating postconcussion presentation in the absence of baseline data.

Anticipatory head control mechanisms in response to impact perturbations: An investigation of club rugby players with and without a history of concussion injury

OBJECTIVES

The primary objective of this study was to examine rugby players anticipatory and compensatory head control during predictable and unpredictable impact events.

METHODS

An observational cross-sectional study design. Fifty-one (17_healthy 34_concussion) male rugby players were exposed to external predictable and unpredictable impact perturbations at mid-chest level. Surface EMG of the upper-trapezius (UT), splenius-capitis (Spl) and sternocleidomastoid (Scm) was recorded and analysed across three temporal epochs typical for anticipatory and compensatory postural control. Synchronized sagittal head-kinematics were measured from high-speed video (500 fps). Nonparametric tests were used to examine within and between group effects.

RESULTS

Anticipatory head control was evident in predictable conditions, expressed by early posterior head displacement and activation of the Spl. Compared to unpredictable conditions, muscle amplitudes were significantly lower, as was head acceleration. Compared to Healthy, the Concussion athletes lacked early activation of the Spl, exhibited delayed anticipatory head adjustments and experienced higher head accelerations in predictable conditions.

CONCLUSION

Rugby players with concussion injuries have significant deficits in cervical spinal motor control. The concussed motor control strategy leads to higher inertial head accelerations and delayed anticipatory head displacements. Effects may persist for two or more years following injury, which may indicate re-injury vulnerability in these athletes.

Intra and Inter-Rater Reliability of a Novel Isometric Test of Neck Strength

There is no single, universally accepted method of measuring isometric neck strength to inform exercise prescription and injury risk prediction. This study aimed to establish the inter- and intra-rater reliability of a commercially available fixed frame dynamometer in measuring peak isometric neck strength. A convenience sample of male (n = 16) and female (n = 20) university students performed maximal isometric contractions for flexion (Flex), extension (Ext), left- (LSF) and right-side flexion (RSF) in a quadruped position over three sessions. The intra-rater reliability results were good-to-excellent for both males (ICC = 0.83−0.90) and females (ICC = 0.86−0.94) and acceptable (CV < 15%) across all directions for both males and females. The inter-rater reliability results were excellent (ICC = 0.96−0.97) and acceptable (CV < 11.1%) across all directions. Findings demonstrated a significant effect for sex (p ≤ 0.05): males were stronger in all four directions, and a significant effect for direction (p ≤ 0.05): Ext tested stronger (193 N) than Flex (176 N), LSF (130 N) and RSF (125 N). The findings show that the VALD fixed frame dynamometer can reliably assess isometric neck strength and can provides reference values for healthy males and females.

The association between contact sport exposure and cervical sensorimotor dysfunction: a scoping review of implications for future musculoskeletal injury risk

BACKGROUND

While morphological changes to the cervical spine have been observed for over 40 years in response to contact sport participation, little is known about the secondary effects of the cervical impairment on future musculoskeletal injury and disability.

OBJECTIVES AND DESIGN

A scoping review was performed to discuss the relationship between contact sport participation and morphological changes to the cervical spine. Moreover, the correlation between morphological changes in the musculoskeletal structures of the cervical spine and resultant deficits in cervical sensorimotor and neuromotor function are discussed. Lastly, how alterations in cervical sensorimotor function may affect overall risk of musculoskeletal injury is discussed.

METHODS

The scientific literature was searched in PubMed, Sport Discus, and Web of Science pertaining to contact-sport athletes and/or cervical pathology and the cervicocephalic network. The Asksey and O'Malley's framework and PRISMA for Scoping Reviews were used to conduct and report the following review. Included articles were grouped into three categories: (1) Morphological changes to the cervical spine in contact sport athletes. (2) The role of the neuromotor pathways of the cervical spine in maintenance of postural tone and coordination of the extremities. (3) The correlation between altered cervical sensorimotor function and a resultant increase in musculoskeletal injury risk.

RESULTS

Our search identified 566 documents, of which 405 underwent full-text screening, resulting in 54 eligible studies for the review. Widespread cervical sensorimotor dysfunction was observed in contact sport athletes. Independently, cervical sensorimotor function was demonstrated to play a critical role in postural control and limb coordination. However, limited research exists exploring the interaction between contact sport participation and altered cervical sensorimotor function, as well as an associated increase in musculoskeletal injury risk.

CONCLUSIONS

Limited evidence exists linking cervical injury and/or observed deficits in cervical sensorimotor and neuromotor function to musculoskeletal injury risk. Longitudinal studies combining imaging measures (e.g., MRI, DEXA), cervical functional test, and prospective injury risk are needed to further explore the correlation between resultant cervical sensorimotor deficits following contact sport impacts and future musculoskeletal injury risk.

Exploring the Effects of a Neck Strengthening Program on Purposeful Soccer Heading Biomechanics and Neurocognition

Background

Cervical (neck) strengthening has been proposed as an important factor in concussion prevention. The purpose of the study was to determine if a six-week cervical strengthening program affected neurocognition and purposeful soccer heading biomechanics. The hypothesis was that the neck strengthening program would improve strength, maintain neurocognition, and alter purposeful soccer heading biomechanics.

Study Design

Randomized controlled trial.

Methods

Twenty collegiate soccer athletes (8 males, 12 females, age=20.15±1.35 years, height=171.67±9.01 cm, mass=70.56±11.03 kg) volunteered to participate. Time (pre, post) and group (experimental, control) served as the independent variables. Four composite scores from the CNS Vital Signs computer based neurocognitive test (CNSVS; verbal memory, visual memory, executive function, reaction time) and aspects of heading biomechanics from inertial measurement units (xPatch; peak linear acceleration, peak rotational acceleration, duration, Gadd Severity Index [GSI]) served as the dependent variables. Each athlete completed a baseline measure of neck strength (anterior neck flexors, bilateral anterolateral neck flexors, bilateral cervical rotators) and CNSVS after heading 10 soccer balls at two speeds (11.18 and 17.88 m/s) while wearing the xPatch. The experimental group completed specific cervical neck strengthening exercises twice a week for six weeks using a Shingo Imara™ cervical neck resistance apparatus while the control group did not. After six weeks, the participants completed the same heading protocol followed by measurement of the same outcome variables. The alpha value was set to p<0.05 a priori.

Results

The interaction between time and group was significant for visual memory (F1,17=5.16, p=0.04, η2=0.23). Interestingly, post hoc results revealed visual memory decreased for the control group from pretest (46.90±4.46) compared to posttest (43.00±4.03; mean difference=3.90, 95% CI=0.77-7.03, p=0.02). Interactions for all other dependent variables were not statistically significant (p>0.05).

Conclusions

The cervical neck strengthening protocol allowed maintenance of visual memory scores but did not alter other neurocognitive measures or heading biomechanics. The link between cervical neck strengthening and concussion predisposition should continue to be explored.

Level of Evidence

Level 1b.

Cervical spine characteristics differ in competitive combat athletes compared with active control participants

BACKGROUND

Injury to the head and neck are common in combat sport athletes. Impairments of the cervical spine have been found in some athletes who participate in sports with high forces and collisions. There is a lack of research on the effects of combat sports on the cervical spine.

OBJECTIVE

The primary study aim was to investigate differences in cervical spine characteristics between combat athletes and a similarly aged active control group. The secondary aim was to investigate the relationship between symptom-based outcome measures and characteristics of the cervical spine.

DESIGN

Cross-sectional.

METHOD

40 male adult combat sport athletes and 40 male adult control participants were recruited from 4 combat sport clubs and a university campus, Australia. Cervical spine assessments were conducted at a private physiotherapy clinic. The Neck Disability Index and the Post-Concussion Symptom Scale were used as symptom-based outcome measures.

RESULTS

Combat sport athletes had a reduced range of cervical motion, but greater isometric strength and endurance compared with a control group (p < 0.05). The Neck Disability Index and Post-Concussion Symptom Scale were negatively correlated with cervical spine range of motion and isometric strength, meaning that higher scores correlated with a reduction in function.

CONCLUSIONS

Differences were observed in characteristics of the cervical spine in combat sport athletes compared with a control group. Higher symptom-based outcome scores correlated with reduced range of motion and strength of cervical spine muscles. Further investigation to establish clinical cut-off scores for functional impairment may be warranted.

Neck Strength Evaluated With Fixed and Portable Dynamometers in Asymptomatic Individuals: Correlation, Concurrent Validity, and Agreement

OBJECTIVE

The purpose of this study was to assess the correlation, concurrent validity, and agreement between the isometric cervical force measurements obtained with fixed and portable dynamometers in asymptomatic individuals.

METHODS

Fifty asymptomatic individuals performed 3 maximal isometric contractions for flexion, extension, and lateral flexion of the cervical spine using fixed and portable dynamometers. The correlation and concurrent validity for the measurements of the portable and fixed dynamometers were analyzed using Spearman's correlation coefficient and the intraclass correlation coefficient (ICC), respectively. The agreement between the force values of the portable and fixed dynamometers was measured using the Bland-Altman method.

RESULTS

Isometric cervical force measurements obtained with the fixed dynamometer and portable dynamometer showed a moderately to highly significant correlation for flexion (r_s = 0.74), extension (r_s = 0.82), right lateral flexion (r_s = 0.74), and left lateral flexion (r_s = 0.68). The concurrent validity was moderate to good for all measurements (ICC_2,3 = 0.67-0.80). The fixed and portable dynamometers did not agree, with a significant mean difference between the methods of 2.8 kgf (95% confidence interval [CI], 2.1-3.4 kgf) for cervical flexion, 5.3 kgf (95% CI, 4.2-6.4 kgf) for extension, and 9.1 kgf (95% CI, 0.4-2.1 kgf) for left lateral flexion. The limits of agreement were broad for all movements, with errors that varied between 61% and 77% of the mean force obtained with the fixed dynamometer.

CONCLUSION

The neck strength measurements obtained with the fixed and portable dynamometers demonstrated high to moderate correlation and had moderate to good comparability for asymptomatic participants. However, they did not agree in that the 2 methods did not provide equivalent measurements, and, therefore, based on these findings, the same equipment should always be used when reassessing an individual.