scholarly journals Quantifying Fatigue in the Rugby Codes: The Interplay Between Collision Characteristics and Neuromuscular Performance, Biochemical Measures, and Self-Reported Assessments of Fatigue

2021 ◽  
Vol 12 ◽  
Author(s):  
Mitchell Naughton ◽  
Scott McLean ◽  
Tannath J. Scott ◽  
Dan Weaving ◽  
Colin Solomon
Keyword(s):  
Time Course ◽  
Time Windows ◽  
Rugby League ◽  
Rugby Union ◽  
Primary Role ◽  
Match Play ◽  
Neuromuscular Performance ◽  
Objective Metrics ◽  
The Hours ◽  
Latent Structures

Locomotor and collision actions that rugby players complete during match-play often lead to substantial fatigue, and in turn, delays in recovery. The methods used to quantify post-match fatigue and recovery can be categorised as subjective and objective, with match-related collision characteristics thought to have a primary role in modulating these recovery measures. The aim of this review was to (1) evaluate how post-match recovery has been quantified in the rugby football codes (i.e., rugby league, rugby union, and rugby sevens), (2) to explore the time-course of commonly used measures of fatigue post-match, and (3) to investigate the relationships between game-related collisions and fatigue metrics. The available evidence suggests that upper-, and lower-body neuromuscular performance are negatively affected, and biomarkers of muscular damage and inflammation increase in the hours and days following match-play, with the largest differences being at 12–36 h post-match. The magnitude of such responses varies within and between neuromuscular performance (Δ ≤ 36%, n = 13 studies) and tissue biomarker (Δ ≤ 585%, n = 18 studies) measures, but nevertheless appears strongly related to collision frequency and intensity. Likewise, the increase in perceived soreness in the hours and days post-match strongly correlate to collision characteristics across the rugby football codes. Within these findings, there are specific differences in positional groups and recovery trajectories between the codes which relate to athlete characteristics, and/or locomotor and collision characteristics. Finally, based on these findings, we offer a conceptual model of fatigue which details the multidimensional latent structure of the load to fatigue relationship contextualised to rugby. Research to date has been limited to univariate associations to explore relationships between collision characteristics and recovery, and multivariate methods are necessary and recommended to account for the latent structures of match-play external load and post-match fatigue constructs. Practitioners should be aware of the typical time windows of fatigue recovery and utilise both subjective and objective metrics to holistically quantify post-match recovery in rugby.

scholarly journals The Reliability of Neuromuscular and Perceptual Measures Used to Profile Recovery, and the Time-Course of Such Responses Following Academy Rugby League Match-Play

Sports ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 73
Author(s):  
Hendrickus G. J. Aben ◽  
Samuel P. Hills ◽  
Darren Higgins ◽  
Carlton B. Cooke ◽  
Danielle Davis ◽  
...  
Keyword(s):  
Peak Power ◽  
Time Course ◽  
Intraclass Correlation ◽  
Rugby League ◽  
Flight Time ◽  
Jump Height ◽  
Monitoring Tool ◽  
Match Play ◽  
Acceptable Reliability ◽  
Recovery Monitoring

In professional academy rugby league (RL) players, this two-part study examined; (A) the within- and between-day reliability of isometric mid-thigh pulls (IMTP), countermovement jumps (CMJ), and a wellness questionnaire (n = 11), and (B) profiled the responses with acceptable reliability (no between-trial differences and between-day coefficient of variation (CV) ≤10% and intraclass correlation coefficient (ICC) ≥0.8) for 120 h (baseline: −3, +24, +48, +72, +96, +120 h) following RL match-play (n = 10). In part A, force at 200, and 250 ms, and peak force (PF) demonstrated acceptable within- (CV%: 3.67–8.41%, ICC: 0.89–0.93) and between-day (CV%: 4.34–8.62%, ICC: 0.87–0.92) reliability for IMTP. Most CMJ variables demonstrated acceptable within-day reliability (CV%: 3.03–7.34%, ICC: 0.82–0.98), but only six (i.e., flight-time, PF, peak power (PP), relative PP, velocity at take-off (VTO), jump-height (JH)) showed acceptable between-day reliability (CV%: 2.56–6.79%, ICC: 0.83–0.91). Only total wellness demonstrated acceptable between-day reliability (CV%: 7.05%, ICC: 0.90) from the questionnaire. In part B, reductions of 4.75% and 9.23% (vs. baseline; 2.54 m∙s−1; 0.33 m) occurred at +24 h for CMJ VTO, and JH, respectively. Acceptable reliability was observed in some, but not all, variables and the magnitude and time-course of post-match responses were test and variable specific. Practitioners should therefore be mindful of the influence that the choice of recovery monitoring tool may have upon the practical interpretation of the data.

scholarly journals Concussion in youth rugby union and rugby league: a systematic review

2015 ◽  
Vol 49 (8) ◽  
pp. 506-510 ◽  
Author(s):  
Graham Kirkwood ◽  
Nikesh Parekh ◽  
Richard Ofori-Asenso ◽  
Allyson M Pollock
Keyword(s):  
Systematic Review ◽  
Rugby League ◽  
Rugby Union

Attitude and behaviour of junior rugby union players towards tackling during training and match play

2012 ◽  
Vol 50 (2) ◽  
pp. 266-284 ◽  
Author(s):  
Sharief Hendricks ◽  
Esme Jordaan ◽  
Michael Lambert
Keyword(s):  
Rugby Union ◽  
Match Play

5 Examination of the relationship between changes in workload and changes in loaded countermovement jump during a rugby union season

2021 ◽  
Vol 55 (16) ◽  
pp. 941.3-942
Author(s):  
Rob Strong ◽  
Daniel West ◽  
Joe Kupsarevic
Keyword(s):  
Peak Power ◽  
Rank Order ◽  
Rugby Union ◽  
Countermovement Jump ◽  
Match Play ◽  
Time To Peak ◽  
Significant Relationships ◽  
Flight Season ◽  
Acute Changes ◽  
The Relationship

BackgroundThe loaded countermovement jump (CMJ) is a variation on the normal CMJ (bodyweight-only), used routinely in sport settings as a measure of neuromuscular fatigue (NMF). Although commonplace, the CMJ variables that are most sensitive to NMF remain somewhat unclear.PurposeThe aim of this study was to examine the relationship between changes in workload and changes in the loaded CMJ; specifically, to determine its suitability for assessment of NMF.MethodsEighteen professional rugby union players performed loaded CMJ tests on seven occasions over the course of thirteen weeks, during an English top-flight season. Eight CMJ variables were measured, assessing different aspects of the CMJ. Workload was measured by GPS total distance and was the sum of the previous week’s data, recorded in on-field training and match-play. Spearman’s rank-order correlations were calculated to identify the relationship between changes in workload and changes in loaded CMJ variables.ResultsNo significant relationships were found between loaded CMJ variables and workload with no lag or workload lagged one week. Significant relationships were found between workload lagged 2 weeks and flight time/contact time (FT-CT; rs=-0.35; p=0.04) and time to peak power (TtPP; rs=0.35; p=0.05).ConclusionThis study suggests loaded CMJ is not a suitable test to monitor acute changes to NMF. However, results also indicate that FT-CT and TtPP, are associated with changes in workload lagged 2-weeks. Therefore, certain CMJ variables may prove useful to help prescribe alterations to athlete training plans following periods of heavy workload.

scholarly journals A Case–Control Study of Tackle-Based Concussion Risk Factors in The National Rugby League

2021 ◽  
Author(s):  
Andrew J Gardner ◽  
Grant Iverson ◽  
Suzi Edwards ◽  
Ross Tucker
Keyword(s):  
Head Injury ◽  
Body Position ◽  
Rugby League ◽  
Rugby Union ◽  
Head Impacts ◽  
Game Activity ◽  
Impact Risk ◽  
Injury Assessment ◽  
Control Study ◽  
Recent Evaluation

Abstract Background The tackle is the in-game activity carrying the greatest risk for concussion in Rugby. A recent evaluation of tackle characteristics in Rugby Union precipitated a rule modification to reduce head impact risk during tackles. This study aims to replicate the work conducted in Rugby Union by examining the association between tackle characteristics and head injury events in professional Rugby League. Methods We reviewed and coded 446 tackles resulting in a head injury assessment (HIA) and 5,694 tackles that did not result in a head injury from two National Rugby League (NRL) seasons. Tackle height, body position of players, and contact area on an opponent’s body were evaluated, with the propensity of each situation to cause an HIA calculated as HIAs per 1000 events. Results The propensity for tacklers to sustain a head injury was 0.99 HIAs per 1000 tackles, 1.74-fold greater than for the ball carrier (0.57 HIAs per 1,000 tackles). There was a 3.2-fold higher risk for an HIA when the tackler was upright compared to bent-at-the-waist. The greatest risk of a tackler HIA occurred when head contact was very low (knee, boot) or high (head and elbow). HIAs were most common following head-to-head impacts. The lowest propensity for tackler HIA was found when the tackler’s head was in proximity with the ball carrier’s torso. Conclusions The result of this study replicated the findings in professional rugby union. This has implications for the injury prevention initiatives implemented to reduce HIA risk because the majority of injuries are sustained by the player initiating the action.

scholarly journals The Physical Characteristics of Specific Phases of Play During Rugby Union Match Play

2018 ◽  
Vol 13 (10) ◽  
pp. 1331-1336 ◽  
Author(s):  
Dale B. Read ◽  
Ben Jones ◽  
Sean Williams ◽  
Padraic J. Phibbs ◽  
Josh D. Darrall-Jones ◽  
...  
Keyword(s):  
Rugby Union ◽  
Physical Characteristics ◽  
Effect Sizes ◽  
Relative Distance ◽  
Linear Mixed Effects Model ◽  
Match Play ◽  
Linear Mixed Effects ◽  
Video Footage ◽  
Dependent Variables ◽  
Attack And Defense

Purpose: To quantify the frequencies and timings of rugby union match-play phases (ie, attacking, defending, ball in play [BIP], and ball out of play [BOP]) and then compare the physical characteristics of attacking, defending, and BOP between forwards and backs. Methods: Data were analyzed from 59 male rugby union academy players (259 observations). Each player wore a microtechnology device (OptimEye S5; Catapult, Melbourne, Australia) with video footage analyzed for phase timings and frequencies. Dependent variables were analyzed using a linear mixed-effects model and assessed with magnitude-based inferences and Cohen d effect sizes (ES). Results: Attack, defense, BIP, and BOP times were 12.7 (3.1), 14.7 (2.5), 27.4 (2.9), and 47.4 (4.1) min, respectively. Mean attack (26 [17] s), defense (26 [18] s), and BIP (33 [24] s) phases were shorter than BOP phases (59 [33] s). The relative distance in attacking phases was similar (112.2 [48.4] vs 114.6 [52.3] m·min−1, ES = 0.00 ± 0.23) between forwards and backs but greater in forwards (114.5 [52.7] vs 109.0 [54.8] m·min−1, ES = 0.32 ± 0.23) during defense and greater in backs during BOP (ES = −0.66 ± 0.23). Conclusions: Total time in attack, defense, and therefore BIP was less than BOP. Relative distance was greater in forwards during defense, whereas it was greater in backs during BOP and similar between positions during attack. Players should be exposed to training intensities from in-play phases (ie, attack and defense) rather than whole-match data and practice technical skills during these intensities.

The Unfolding of Cognitive Effort During Sentence Processing: Pupillometric Evidence From People With and Without Aphasia

2021 ◽  
pp. 1-18
Author(s):  
Laura Roche Chapman ◽  
Brooke Hallowell
Keyword(s):  
Language Processing ◽  
Sentence Processing ◽  
Time Course ◽  
Time Windows ◽  
Cognitive Effort ◽  
Task Engagement ◽  
The Body ◽  
Group Differences ◽  
Language Deficits ◽  
Pupillary Responses

Purpose: Arousal and cognitive effort are relevant yet often overlooked components of attention during language processing. Pupillometry can be used to provide a psychophysiological index of arousal and cognitive effort. Given that much is unknown regarding the relationship between cognition and language deficits seen in people with aphasia (PWA), pupillometry may be uniquely suited to explore those relationships. The purpose of this study was to examine arousal and the time course of the allocation of cognitive effort related to sentence processing in people with and without aphasia. Method: Nineteen PWA and age- and education-matched control participants listened to relatively easy (subject-relative) and relatively difficult (object-relative) sentences and were required to answer occasional comprehension questions. Tonic and phasic pupillary responses were used to index arousal and the unfolding of cognitive effort, respectively, while sentences were processed. Group differences in tonic and phasic responses were examined. Results: Group differences were observed for both tonic and phasic responses. PWA exhibited greater overall arousal throughout the task compared with controls, as evidenced by larger tonic pupil responses. Controls exhibited more effort (greater phasic responses) for difficult compared with easy sentences; PWA did not. Group differences in phasic responses were apparent during end-of-sentence and postsentence time windows. Conclusions: Results indicate that the attentional state of PWA in this study was not consistently supportive of adequate task engagement. PWA in our sample may have relatively limited attentional capacity or may have challenges with allocating existing capacity in ways that support adequate task engagement and performance. This work adds to the body of evidence supporting the validity of pupillometric tasks for the study of aphasia and contributes to a better understanding of the nature of language deficits in aphasia. Supplemental Material https://doi.org/10.23641/asha.16959376

scholarly journals Effect of a Simulated Match on Lower Limb Neuromuscular Performance in Youth Footballers—A Two Year Longitudinal Study

2020 ◽  
Vol 17 (22) ◽  
pp. 8579
Author(s):  
Michal Lehnert ◽  
Mark De Ste Croix ◽  
Amr Zaatar ◽  
Patrycja Lipinska ◽  
Petr Stastny
Keyword(s):  
Vastus Lateralis ◽  
Age Groups ◽  
Quadriceps Strength ◽  
Firing Frequency ◽  
Strength Parameters ◽  
Match Play ◽  
Neuromuscular Performance ◽  
Leg Stiffness ◽  
Age Dependent ◽  
Simulated Match

The aim of this study was to explore the effects of simulated soccer match play on neuromuscular performance in adolescent players longitudinally over a two-year period. Eleven players completed all measurements in both years of the study (1st year: age 16.0 ± 0.4 y; stature 178.8 ± 6.4 cm; mass 67.5 ± 7.8 kg; maturity-offset 2.24 ± 0.71 y). There was a significant reduction in hamstring strength after simulated match by the soccer-specific aerobic field test (SAFT90), with four out of eight parameters compromised in U16s (4.7–7.8% decrease) and six in the U17s (3.1–15.4%). In the U17s all of the concentric quadriceps strength parameters were decreased (3.7–8.6%) as well as the vastus lateralis and semitendinosus firing frequency (26.9–35.4%). In both ages leg stiffness decreased (9.2–10.2%) and reactive strength increased pre to post simulated match (U16 8.0%; U17 2.5%). A comparison of changes between age groups did not show any differences. This study demonstrates a decrease in neuromuscular performance post simulated match play in both ages but observed changes were not age dependent.

scholarly journals Tendon and Ligament Injuries in Elite Rugby: The Potential Genetic Influence

Sports ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 138 ◽  
Author(s):  
Jon Brazier ◽  
Mark Antrobus ◽  
Georgina K. Stebbings ◽  
Stephen H. Day ◽  
Shane M. Heffernan ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Rugby League ◽  
Rugby Union ◽  
Individual Variability ◽  
Ligament Injury ◽  
Molecular Characteristics ◽  
Surveillance Systems ◽  
Injury Incidence ◽  
Nucleotide Polymorphisms ◽  
Body Contact

This article reviews tendon and ligament injury incidence and severity within elite rugby union and rugby league. Furthermore, it discusses the biological makeup of tendons and ligaments and how genetic variation may influence this and predisposition to injury. Elite rugby has one of the highest reported injury incidences of any professional sport. This is likely due to a combination of well-established injury surveillance systems and the characteristics of the game, whereby high-impact body contact frequently occurs, in addition to the high intensity, multispeed and multidirectional nature of play. Some of the most severe of all these injuries are tendon and ligament/joint (non-bone), and therefore, potentially the most debilitating to a player and playing squad across a season or World Cup competition. The aetiology of these injuries is highly multi-factorial, with a growing body of evidence suggesting that some of the inter-individual variability in injury susceptibility may be due to genetic variation. However, little effort has been devoted to the study of genetic injury traits within rugby athletes. Due to a growing understanding of the molecular characteristics underpinning the aetiology of injury, investigating genetic variation within elite rugby is a viable and worthy proposition. Therefore, we propose several single nucleotide polymorphisms within candidate genes of interest; COL1A1, COL3A1, COL5A1, MIR608, MMP3, TIMP2, VEGFA, NID1 and COLGALT1 warrant further study within elite rugby and other invasion sports.

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