Need a break? The locomotor and tackle pacing profile and loads of women's rugby league match-play following various between-match turnaround durations

OBJECTIVES

The study investigated the locomotor and tackle pacing profile and loads of female rugby league players following various between-match turnaround durations. Specifically, the study examined the (1) pacing of locomotor and tackle loads across the time-course of a match and; (2) whole-match and peak locomotor and tackle loads of match-play.

METHODS

Microtechnology data were collected from elite female rugby league players (n = 172) representing all National Rugby League Women's teams (n = 6 teams) across two seasons. Players were categorised into backs, adjustables, forwards or interchange players. Data was calculated for the whole-match (m), per minute (m.min-1) and peak (running: m.min-1; acceleration: m.s-2) locomotor and tackle loads (number and efficiency (%)) of match-play. The pacing as well as the locomotor and tackle loads of match-play were examined following short (≤6 days), normal (7 days) or long (≥8 days) turnarounds.

RESULTS

The pacing profile of playing positions varied across short, normal and long match turnarounds. Trivial to moderate differences existed in the whole-match, per minute and peak locomotor loads across match turnaround durations (effect size ≤ 1.2).

CONCLUSIONS

Following various between-match turnaround durations (i.e., short, normal and long match turnarounds), there were variations in the locomotor and tackle pacing profile and loads whereby, the pacing profile of positional groups was more affected than the load profile. The findings can be used in applied settings to guide the recovery strategies and training plans of female rugby league players to optimise performance and wellbeing across various match turnaround durations.

The Use of Biofluid Markers to Evaluate the Consequences of Sport-Related Subconcussive Head Impact Exposure: A Scoping Review

BACKGROUND

Amidst growing concern about the safety of sport-related repetitive subconcussive head impacts (RSHI), biofluid markers may provide sensitive, informative, and practical assessment of the effects of RSHI exposure.

OBJECTIVE

This scoping review aimed to systematically examine the extent, nature, and quality of available evidence from studies investigating the effects of RSHI on biofluid markers, to identify gaps and to formulate guidelines to inform future research.

METHODS

PRISMA extension for Scoping Reviews guidelines were adhered to. The protocol was pre-registered through publication. MEDLINE, Scopus, SPORTDiscus, CINAHL, PsycINFO, Cochrane Library, OpenGrey, and two clinical trial registries were searched (until March 30, 2022) using descriptors for subconcussive head impacts, biomarkers, and contact sports. Included studies were assessed for risk of bias and quality.

RESULTS

Seventy-nine research publications were included in the review. Forty-nine studies assessed the acute effects, 23 semi-acute and 26 long-term effects of RSHI exposure. The most studied sports were American football, boxing, and soccer, and the most investigated markers were (in descending order): S100 calcium-binding protein beta (S100B), tau, neurofilament light (NfL), glial fibrillary acidic protein (GFAP), neuron-specific enolase (NSE), brain-derived neurotrophic factor (BDNF), phosphorylated tau (p-tau), ubiquitin C-terminal hydrolase L1 (UCH-L1), and hormones. High or moderate bias was found in most studies, and marker-specific conclusions were subject to heterogeneous and limited evidence. Although the evidence is weak, some biofluid markers-such as NfL-appeared to show promise. More markedly, S100B was found to be problematic when evaluating the effects of RSHI in sport.

CONCLUSION

Considering the limitations of the evidence base revealed by this first review dedicated to systematically scoping the evidence of biofluid marker levels following RSHI exposure, the field is evidently still in its infancy. As a result, any recommendation and application is premature. Although some markers show promise for the assessment of brain health following RSHI exposure, future large standardized and better-controlled studies are needed to determine biofluid markers' utility.

Incidence of concussion in men's Super League, Championship, and Academy rugby league matches between 2016 and 2022

OBJECTIVES

To quantify the incidence of concussion and compare between playing levels in male rugby league.

DESIGN

Retrospective cohort.

METHODS

Between 2016 and 2022, medically diagnosed concussions in Super League, Championship, and Academy competitions were reported to the Rugby Football League via club medical staff. Anonymised data were analysed using generalised linear mixed-effects models by season, month, and between competitions.

RESULTS

Overall, 1403 concussions were identified from 104,209 player-match hours. Concussion incidence for Super League, Championship, and Academy was 15.5, 10.5, and 14.3 per 1000 player-match hours, respectively. Championship concussion incidence was significantly lower than the Super League (p < 0.001) and Academy (p < 0.001). No significant differences were identified between years for Super League (range: 13.3 to 18.8 per 1000 player-match hours) and Championship (range: 8.4 to 12.1 per 1000 player-match hours). In Academy (range: 9.6 to 20.5 per 1000 player-match hours), concussion incidence was significantly greater in 2021 compared to earlier years (2016, p = 0.01 and 2017, p = 0.03). No significant differences were identified between months for any competition.

CONCLUSIONS

The incidence of concussion is greater in Super League and Academy compared to the Championship. Academy concussion incidence has increased over time. Different factors between and within competitions, such as changes to medical standards and knowledge, could have influenced the identification and diagnosis of concussion.

Students' Perceptions About Inclusive and Orthodox Masculinities in Contact Sports at a South African University

In light of recent studies on the changing views on masculinity, this quantitative study aimed to determine the attitudes of South African undergraduate students toward the display of the tenets associated with orthodox and inclusive masculinities in contact sport, and to determine to what extent these attitudes were predicted by students' gender, race, religiosity, and attitudes toward the importance of primary gender-role sport socialization and homosexuality. Findings, which originated from the data collected through the use of 200 structured interviews, indicated that male and female students endorsed displays of a 'softening' in masculinities in sport, and were slightly opposed toward displays of 'harder' masculinities, a trend that was strongest among women. The more importance these students' ascribed to primary gender-role sports socialization, the more likely they were to support the display of orthodox masculinities in sport, and the less likely they were to endorse inclusive masculinities, with the converse being true for those who were more accepting of homosexuality. The study contributes to current theorization in a twofold way: Firstly, by problematizing a simplistic differentiation between orthodox and inclusive masculine typologies in favor of ascribing to theorization that indicates how the attitudes among students of the said South African university campus arguably attest to the concurrent existence of 'multiple dominant masculinities.' In-keeping with this, the findings arguably echo the Andersonian emphasis on the co-existence of declining levels of homohysteria among younger persons and the continuing prevalence of homophobia among some students on university campuses.

Development of a rugby shoulder function (RSF) questionnaire: An online Delphi study

OBJECTIVE

Develop a questionnaire to monitor symptoms of player perceived shoulder function/dysfunction.

DESIGN

3-Stage Online Delphi Study.

METHODS

Participants: surgeons, sports and exercise medics, academic researchers, strength and conditioning coaches, therapists and athletes split by level of expertise/experience. Stage-1: experts (n = 12) rated constructs/items from the steering group and made changes/proposed additional constructs/items. Stage-2: experts rated/amended new constructs/items from stage-1. Stage-3: experienced professionals (n = 25) rated/ranked constructs/items from stage 2. Consensus thresholds were defined per stage (≥50% agreement/4-5 rating on 1-5 Likert scale (stages 1-2), ≥68% agreement, and items ranked for perceived importance (stage-3)).

RESULTS

Stage-1, all four constructs (a. Activities of daily living, b. Range of motion, c. Strength and conditioning, d. Sports specific training and competition) and 26/42 original items achieved consensus. Twelve items were combined into five items. Four new items were also proposed. Stage-2, the combined items and three of the four new items achieved consensus. Stage-3 the four constructs and 22 items all achieved consensus.

CONCLUSIONS

Following a 3-stage online Delphi process, involving expert and experienced clinicians, practitioners and athletes, a new four construct, 22 item RSF questionnaire has been developed which can be used with rugby players, to monitor perceived shoulder performance and symptoms.

Diffusion Imaging of Sport-related Repetitive Head Impacts-A Systematic Review

Repetitive head impacts (RHI) are commonly observed in athletes participating in contact sports such as American football, ice hockey, and soccer. RHI usually do not result in acute symptoms and are therefore often referred to as subclinical or "subconcussive" head impacts. Epidemiological studies report an association between exposure to RHI and an increased risk for the development of neurodegenerative diseases. Diffusion magnetic resonance imaging (dMRI) has emerged as particularly promising for the detection of subtle alterations in brain microstructure following exposure to sport-related RHI. The purpose of this study was to perform a systematic review of studies investigating the effects of exposure to RHI on brain microstructure using dMRI. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) to determine studies that met inclusion and exclusion criteria across three databases. Seventeen studies were identified and critically evaluated. Results from these studies suggest an association between white matter alterations and RHI exposure in youth and young adult athletes. The most consistent finding across studies was lower or decreased fractional anisotropy (FA), a measure of the directionality of the diffusion of water molecules, associated with greater exposure to sport-related RHI. Whether decreased FA is associated with functional outcome (e.g., cognition) in those exposed to RHI is yet to be determined. This review further identified areas of importance for future research to increase the diagnostic and prognostic value of dMRI in RHI and to improve our understanding of the effects of RHI on brain physiology and microstructure.

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.

Collision avoidance strategies between two athlete walkers: Understanding impaired avoidance behaviours in athletes with a previous concussion

BACKGROUND

Individuals who have sustained a concussion often display associated balance control deficits and visuomotor impairments despite being cleared by a physician to return to sport. Such visuomotor impairments can be highlighted in collision avoidance tasks that involves a mutual adaptation between two walkers. However, studies have yet to challenged athletes with a previous concussion during an everyday collision avoidance task, following return to sport.

RESEARCH QUESTION

Do athletes with a previous concussion display associated behavioural changes during a 90°-collision avoidance task with an approaching pedestrian?

METHODS

Thirteen athletes (ATH; 9 females, 23 ± 4years) and 13 athletes with a previous concussion (CONC; 9 females, 22 ± 3 years, concussion <6 months) walked at a comfortable walking speed along a 12.6 m pathway while avoiding another athlete on a 90º-collision course. Each participant randomly interacted with individuals from the same group 20 times and interacted with individuals from the opposite group 21 times. Minimum predicted distance (mpd) was used to examine collision avoidance behaviours between ATH and CONC groups.

RESULTS

The overall progression of mpd(t) did not differ between groups (p > .05). During the collision avoidance task, previously concussed athletes contributed less when passing second compared to their peers(p < .001). When two previously concussed athletes were on a collision course, there was a greater amount of variability resulting in inappropriate adaptive behaviours.

SIGNIFICANCE

Although successful at avoiding a collision with an approaching athlete, previously concussed athletes exhibit behavioural changes manifesting in riskier behaviours. The current findings suggest that previously concussed athletes possess behavioural changes even after being cleared to returned to sport, which may increase their risk of a subsequent injury when playing.

Training sessions with tackles impair upper-limb neuromuscular function in elite rugby union

The aim of this study was to investigate the response to non-tackle and tackle field-based training on upper- and lower-limb neuromuscular function in elite rugby union players. Nine elite senior elite rugby union players (mean age = 21 ± 2 years; height = 184 ± 7 cm; body mass 91.0 ± 9 kg) were evaluated before and immediately following 17 training sessions. A total of 306 assessments were performed. Data on neuromuscular function of plyometric push-up and countermovement jump were calculated from force signals using inverse dynamics. The change from pre- to post-session was investigated across non-tackle and tackle training using a linear mixed model. Considering upper-limb neuromuscular function, peak concentric power [P = 0.024; ES = 0.33 95%CI (0.04, 0.62)] was significantly lower after tackle compared to non-tackle training. In addition, peak countermovement jump eccentric power was significantly lower after non-tackle compared to tackle training [P = 0.044; ES = -0.4 95%CI (-0.69, -0.1)] in lower-limb neuromuscular function. Overall, the results indicated that the type of training influences upper- and lower-limb neuromuscular function differently immediately after training. Indeed, due to physical contact, the upper-body neuromuscular function increased during tackle training. In contrast, lower-body neuromuscular function emerged only in non-tackle training, due to the greater distance covered during this type of training session. Coaches and practitioners should plan adequate weekly training sessions according to this information.

The effects of repetitive head impacts on postural control: A systematic review

OBJECTIVES

The purpose of our study was to investigate the association between repetitive head impact (RHI) exposure and postural control.

DESIGN

Systematic review.

METHODS

PubMed, Embase and PsycInfo were searched using a self-developed search term including the keywords balance OR postural control AND repetitive OR sub-concussive head impacts. Twenty-one studies excluding non-peer reviewed studies, secondary studies, cross-sectional studies, animal studies, and studies investigating concussion were included for further analyses. We rated Level of Evidence and quality using the Centre for Evidence-Based Medicine tool, the Quality Assessment for the Systematic Review of Effectiveness, and the Sub-concussion Specific Tool.

RESULTS

All included studies were grouped into Category I and II studies. Category I included trials investigating the effects of controlled soccer heading on postural control (n=8) and Category II studies were cohort studies investigating on-the-field changes between preseason and postseason assessments on postural control measures (n=13). Findings were heterogeneous, with a tendency towards no effects of RHI on clinical postural control measures. Most laboratory studies in Category I used instrumented assessments whereas on-the-field studies in Category II used both instrumented and non-instrumented assessments.

CONCLUSIONS

Due to heterogeneous findings, future studies aiming to investigate the effects of RHI on different athlete populations are needed on other participant cohorts. Furthermore, the combination of objective clinical balance measures may be a promising approach to accurately measure how, and to what degree, postural control may be affected by RHI.

Cerebral blood flow in acute concussion: preliminary ASL findings from the NCAA-DoD CARE consortium

Sport-related concussion (SRC) has become a major health problem, affecting millions of athletes each year. Despite the increasing occurrence and prevalence of SRC, its underlying mechanism and recovery course have yet to be fully elucidated. The National Collegiate Athletic Association-Department of Defense Grand Alliance: Concussion Assessment, Research and Education (CARE) Consortium is a large-scale, multisite study of the natural history of concussion across multiple sports. The Advanced Research Core (ARC) of CARE is focused on the advanced biomarker assessment of a reduced subject cohort. This paper reports findings from two ARC sites to evaluate cerebral blood flow (CBF) changes in acute SRC, as measured using advanced arterial spin labeling (ASL) magnetic resonance imaging (MRI). We compared relative CBF maps assessed in 24 concussed contact sport athletes obtained at 24-48 h after injury to those of a control group of 24 matched contact sport players. Significantly less CBF was detected in several brain regions in concussed athletes, while clinical assessments also indicated clinical symptom and performance impairments in SRC patients. Correlations were found between decreased CBF in acute SRC and clinical assessments, including Balance Error Scoring System total score and Immediate Post-Concussion Assessment and Cognitive Test memory composite and impulse control composite scores, as well as days from injury to asymptomatic. Although using different ASL MRI sequences, our preliminary results from two sites are consistent with previous reports and suggest that advanced ASL MRI methods might be useful for detecting acute neurobiological changes in acute SRC.

Shoulder injury incidence and severity through identification of risk factors in rugby union players

Objective: This study aimed to analyze shoulder injury incidence and severity to reduce players' risk of sustaining injuries and missing playing time.

Methods: Ninety-five South African Premier team rugby Union players (mean: 25 years of age) took part in the study with injury data collected through the use of injury reports.

Results: This study found that approximately two of every five participants sampled incurred a primary shoulder injury with dislocation being the most prevalent. Twenty-one (80.8%) of the participants that experienced a primary shoulder injury also sustained a secondary shoulder injury with rotator cuff tears being most predominant. Only three players were found to have suffered tertiary shoulder injuries. The injuries were mainly related to tackling during training and matches. Twenty players were found to have adhered to a strength and conditioning program prior to their injuries and 14 of the injured participants received or adhered to a prehabilitation program. Eight of the injured players also suffered from recurrent injuries with dislocations being the most common.

Conclusions: Results indicated that specific positions in rugby are at higher risk of shoulder injuries than others and that with the correct preventive measures put in place, the severity of injuries can be reduced.

Significant changes in the skin microbiome mediated by the sport of roller derby

Diverse bacterial communities live on and in human skin. These complex communities vary by skin location on the body, over time, between individuals, and between geographic regions. Culture-based studies have shown that human to human and human to surface contact mediates the dispersal of pathogens, yet little is currently known about the drivers of bacterial community assembly patterns on human skin. We hypothesized that participation in a sport involving skin to skin contact would result in detectable shifts in skin bacterial community composition. We conducted a study during a flat track roller derby tournament, and found that teammates shared distinct skin microbial communities before and after playing against another team, but that opposing teams’ bacterial communities converged during the course of a roller derby bout. Our results are consistent with the hypothesis that the human skin microbiome shifts in composition during activities involving human to human contact, and that contact sports provide an ideal setting in which to evaluate dispersal of microorganisms between people.