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Cruz-Ferreira AM, Cruz-Ferreira EM, Silva JD, Ferreira RM, Santiago LM, Taborda-Barata L. Epidemiology of injuries in Portuguese senior male rugby union sevens: a cohort prospective study. PHYSICIAN SPORTSMED 2018; 46:255-261. [PMID: 29451056 DOI: 10.1080/00913847.2018.1441581] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVES To assess the incidence, type and location of injuries sustained during the Portuguese rugby union sevens circuit. To investigate the influence of players' training loads on injury risk. METHODS A prospective cohort study recording time-loss injuries was conducted with all teams competing in the Portuguese national rugby sevens circuit (eight from the top-tier and seven from the second-tier). Main outcome measures included: incidence rate, anatomical location, type, injury incident and severity. Data were also collected regarding players' training loads. Fisher's exact test was used to estimate the relative risk of suffering an injury during the sevens season and training sevens during the fifteens season. RESULTS A total of 27 injuries were recorded corresponding to an incidence rate of 133.9 injuries per 1000 player match-hours. The average severity was 22.22 days. Contact events preceded 81.5% of injuries. Most injuries occurred in the lower limb (66.7%) and were joint/ligament or muscle/tendon injuries (85.1%). The association between injuries and lower volume of training during the sevens season was identified for the second-tier (p = 0.021). For the same level, an inverse relation between training hours and injury severity was also found (p = 0.008). Top-tier players training sevens and fifteens simultaneously during the year presented a significant increase of injury risk (relative risk = 3.2; p = 0.011). CONCLUSIONS Injury incidence in our study is similar to that reported for international sevens, although severity is lower. An association between training loads and the occurrence of injuries was found for both tiers, although with differential results, thus reinforcing the need to customize players' preparation. Further studies at non-elite competitions are needed to gather significant data to accurately formulate future injury prevention protocols or recommend modifications to game laws or competition formats, aiming at players' welfare.
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Cross M, Williams S, Kemp SPT, Fuller C, Taylor A, Brooks J, Trewartha G, Stokes K. Does the Reliability of Reporting in Injury Surveillance Studies Depend on Injury Definition? Orthop J Sports Med 2018; 6:2325967118760536. [PMID: 29581994 PMCID: PMC5862373 DOI: 10.1177/2325967118760536] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Background: Choosing an appropriate definition for injury in injury surveillance studies is essential to ensure a balance among reporting reliability, providing an accurate representation of injury risk, and describing the nature of the clinical demand. Purpose: To provide guidance on the choice of injury definition for injury surveillance studies by comparing within- and between-team variability in injury incidence with >24-hour and >7-day time-loss injury definitions in a large multiteam injury surveillance study. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Injury data were reported for 2248 professional rugby union players from 15 Premiership Rugby clubs over 12 seasons. Within-team percentage coefficient of variation and mean between-team standard deviation (expressed as a percentage coefficient of variation) in injury incidence rates (injuries per 1000 player match hours) were calculated. For both variables, a comparison was made between >24-hour and >7-day injury incidence rates in terms of the magnitude of the observed effects. Results: The overall mean incidence across the population with a >24-hour time-loss injury definition was approximately double the reported incidence with the >7-day definition. There was a 10% higher between-team variation in match injury incidence rates with the >24-hour time-loss definition versus the >7-day definition. Conclusion: There was a likely higher degree of between-team variation in match injury incidence rates with a >24-hour time-loss definition than with a >7-day definition of injury. However, in professional sports settings, it is likely that the benefits of using a more inclusive definition of injury (improved understanding of clinical demand and the appropriate and accurate reporting of injury risk) outweigh the small increase in variation in reporting consistency.
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Viviers PL, Viljoen JT, Derman W. A Review of a Decade of Rugby Union Injury Epidemiology: 2007-2017. Sports Health 2018; 10:223-227. [PMID: 29442612 PMCID: PMC5958454 DOI: 10.1177/1941738118757178] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Context: Rugby union is the most widely played team collision sport globally. As with
other contact sports, there is substantial risk of injury. To date, the
majority of studies on injury epidemiology have focused on elite male
cohorts, which inherently prevents extrapolation of research findings to
other groups within the player continuum. This review aims to describe
emerging injury trends across the spectrum of various rugby union
subpopulations and to highlight gaps that may influence future injury
prevention tactics. Evidence Acquisition: Relevant articles published from 2007 to 2017 were obtained by searching
MEDLINE, PubMed, and SPORT Discus. Studies on 15-a-side rugby union,
implemented according to the 2007 consensus statement on injury definitions
and data collection procedures for injuries in rugby union, were used. Study Design: Clinical review. Level of Evidence: Level 3. Results: Match injuries occur more frequently than training injuries. Injury rates
increase consistently according to age and level of play. Severity of injury
often is greater among lower levels of the game, and sex-specific
differences relating to injury patterns and incidence rates exist. Conclusion: To date, a paucity of injury surveillance data exists for women and players
of both sexes at all levels of community rugby union. Furthermore, the
incidence of injuries and illnesses are poorly reported in epidemiological
studies. Despite methodological differences, injury trends remain consistent
throughout all levels of play.
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Fornasier-Santos C, Millet GP, Woorons X. Repeated-sprint training in hypoxia induced by voluntary hypoventilation improves running repeated-sprint ability in rugby players. Eur J Sport Sci 2018; 18:504-512. [PMID: 29400616 DOI: 10.1080/17461391.2018.1431312] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE The goal of this study was to determine the effects of repeated-sprint training in hypoxia induced by voluntary hypoventilation at low lung volume (VHL) on running repeated-sprint ability (RSA) in team-sport players. METHODS Twenty-one highly trained rugby players performed, over a 4-week period, seven sessions of repeated 40-m sprints either with VHL (RSH-VHL, n = 11) or with normal breathing (RSN, n = 10). Before (Pre-) and after training (Post-), performance was assessed with an RSA test (40-m all-out sprints with a departure every 30 s) until task failure (85% of the reference velocity assessed in an isolated sprint). RESULTS The number of sprints completed during the RSA test was significantly increased after the training period in RSH-VHL (9.1 ± 2.8 vs. 14.9 ± 5.3; +64%; p < .01) but not in RSN (9.8 ± 2.8 vs. 10.4 ± 4.7; +6%; p = .74). Maximal velocity was not different between Pre- and Post- in both groups whereas the mean velocity decreased in RSN and remained unchanged in RSH-VHL. The mean SpO2 recorded over an entire training session was lower in RSH-VHL than in RSN (90.1 ± 1.4 vs. 95.5 ± 0.5%, p < .01). CONCLUSION RSH-VHL appears to be an effective strategy to produce a hypoxic stress and to improve running RSA in team-sport players.
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Gallo V, McElvenny D, Hobbs C, Davoren D, Morris H, Crutch S, Zetterberg H, Fox NC, Kemp S, Cross M, Arden NK, Davies MAM, Malaspina A, Pearce N. BRain health and healthy AgeINg in retired rugby union players, the BRAIN Study: study protocol for an observational study in the UK. BMJ Open 2017; 7:e017990. [PMID: 29282262 PMCID: PMC5770902 DOI: 10.1136/bmjopen-2017-017990] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 10/20/2017] [Accepted: 10/23/2017] [Indexed: 12/14/2022] Open
Abstract
INTRODUCTION Relatively little is known about the long-term health of former elite rugby players, or former sportspeople more generally. As well as the potential benefits of being former elite sportspersons, there may be potential health risks from exposures occurring during an individual's playing career, as well as following retirement. Each contact sport has vastly different playing dynamics, therefore exposing its players to different types of potential traumas. Current evidence suggests that these are not necessarily comparable in terms of pathophysiology, and their potential long-term adverse effects might also differ. There is currently limited but increasing evidence that poorer age-related and neurological health exists among former professional sportsmen exposed to repetitive concussions; however the evidence is limited on rugby union players, specifically. METHODS AND ANALYSIS We present the protocol for a cross-sectional study to assess the association between self-reported history of concussion during a playing career, and subsequent measures of healthy ageing and neurological and cognitive impairment. We are recruiting a sample of approximately 200 retired rugby players (former Oxford and Cambridge University rugby players and members of the England Rugby International Club) aged 50 years or more, and collecting a number of general and neurological health-related outcome measures though validated assessments. Biomarkers of neurodegeneration (neurofilaments and tau) will be also be measured. Although the study is focusing on rugby union players specifically, the general study design and the methods for assessing neurological health are likely to be relevant to other studies of former elite sportspersons. ETHICS AND DISSEMINATION The study has been approved by the Ethical Committee of London School of Hygiene and Tropical Medicine (reference: 11634-2). It is intended that results of this study will be published in peer-reviewed medical journals, communicated to participants, the general public and all relevant stakeholders.
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Martín A, Sfer AM, D'Urso Villar MA, Barraza JF. Position Affects Performance in Multiple-Object Tracking in Rugby Union Players. Front Psychol 2017; 8:1494. [PMID: 28951725 PMCID: PMC5599788 DOI: 10.3389/fpsyg.2017.01494] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 08/18/2017] [Indexed: 11/13/2022] Open
Abstract
We report an experiment that examines the performance of rugby union players and a control group composed of graduate student with no sport experience, in a multiple-object tracking task. It compares the ability of 86 high level rugby union players grouped as Backs and Forwards and the control group, to track a subset of randomly moving targets amongst the same number of distractors. Several difficulties were included in the experimental design in order to evaluate possible interactions between the relevant variables. Results show that the performance of the Backs is better than that of the other groups, but the occurrence of interactions precludes an isolated groups analysis. We interpret the results within the framework of visual attention and discuss both, the implications of our results and the practical consequences.
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Roberts SP, Trewartha G, England M, Goodison W, Stokes KA. Concussions and Head Injuries in English Community Rugby Union Match Play. Am J Sports Med 2017; 45:480-487. [PMID: 28146395 DOI: 10.1177/0363546516668296] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Previous research has described general injury patterns in community-level rugby union, but specific information on time-loss head injuries has not been reported. PURPOSE To establish the incidence and nature of significant time-loss head injuries in English community rugby match play, and to identify the injury risk for specific contact events. STUDY DESIGN Descriptive epidemiology study. METHODS Over 6 seasons, injury information was collected from 46 (2009-2010), 67 (2010-2011), 76 (2011-2012), 50 (2012-2013), 67 (2013-2014), and 58 (2014-2015) English community rugby clubs (Rugby Football Union levels 3-9) over a total of 175,940 hours of player match exposure. Club injury management staff reported information for all head injuries sustained during match play whereby the player was absent for 8 days or greater. Clubs were subdivided into semiprofessional (mean player age, 24.6 ± 4.7 years), amateur (24.9 ± 5.1 years), and recreational (25.6 ± 6.1 years) playing levels. Contact events from a sample of 30 matches filmed over seasons 2009-2010, 2010-2011, and 2011-2012 provided mean values for the frequency of contact events. RESULTS The overall incidence for time-loss head injuries was 2.43 injuries per 1000 player match hours, with a higher incidence for the amateur (2.78; 95% CI, 2.37-3.20) compared with recreational (2.20; 95% CI, 1.86-2.53) ( P = .032) playing level but not different to the semiprofessional (2.31; 95% CI, 1.83-2.79) playing level. Concussion was the most common time-loss head injury, with 1.46 per 1000 player match hours. The tackle event was associated with 64% of all head injuries and 74% of all concussions. There was also a higher risk of injuries per tackle (0.33 per 1000 events; 95% CI, 0.30-0.37) compared with all other contact events. CONCLUSION Concussion was the most common head injury diagnosis, although it is likely that this injury was underreported. Continuing education programs for medical staff and players are essential for the improved identification and management of these injuries. With the majority of head injuries occurring during a tackle, an improved technique in this contact event through coach and player education may be effective in reducing these injuries.
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King D, Hume P, Gissane C, Clark T. Head impacts in a junior rugby league team measured with a wireless head impact sensor: an exploratory analysis. J Neurosurg Pediatr 2017; 19:13-23. [PMID: 27791705 DOI: 10.3171/2016.7.peds1684] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE The aim of this study was to investigate the frequency, magnitude, and distribution of head impacts sustained by players in a junior rugby league over a season of matches. METHODS The authors performed a prospective cohort analysis of impact magnitude, frequency, and distribution on data collected with instrumented XPatches worn behind the ear of players in an "under-11" junior rugby league team (players under 11 years old). RESULTS A total of 1977 impacts were recorded. Over the course of the study, players sustained an average of 116 impacts (average of 13 impacts per player per match). The measured linear acceleration ranged from 10g to 123g (mean 22g, median 16g, and 95th percentile 57g). The rotational acceleration ranged from 89 rad/sec2 to 22,928 rad/sec2 (mean 4041 rad/sec2, median 2773 rad/sec2, and 95th percentile 11,384 rad/sec2). CONCLUSIONS The level of impact severity based on the magnitude of impacts for linear and rotational accelerations recorded was similar to the impacts reported in studies of American junior and high school football, collegiate football, and youth ice hockey players, but the players in the rugby league cohort were younger, had less body mass, and played at a slower speed than the American players. Junior rugby league players are required to tackle the player to the ground and use a different tackle technique than that used in American football, likely increasing the rotational accelerations recorded at the head.
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Whitaker L, Backhouse S. Doping in sport: an analysis of sanctioned UK rugby union players between 2009 and 2015. J Sports Sci 2016; 35:1607-1613. [PMID: 27578446 DOI: 10.1080/02640414.2016.1226509] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
To inform anti-doping policy and practice, it is important to understand the complexities of doping. The purpose of this study was to collate and systematically examine the reasoned decisions published by UK Anti-Doping for doping sanctions in rugby union in the UK since the introduction of the 2009 World Anti-Doping Code. Case files were content analysed to extract demographic information and details relating to the anti-doping rule violation (ADRV), including individuals' explanations for how/why the ADRV occurred. Between 2009 and 2015, 49 rugby union players and one coach from across the UK were sanctioned. Over 50% of the cases involved players under the age of 25, competing at sub-elite levels. Reasons in defence of the ADRV focused on functional use and lifestyle factors rather than performance enhancement. An a priori assessment of the "need", "risk" and "consequence" of using a substance was not commonplace; further strengthening calls for increasing the reach of anti-doping education. The findings also deconstruct the view that "doped" athletes are the same. Consequently, deepening understanding of the social and cultural conditions that encourage doping remains a priority.
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King DA, Hume PA, Gissane C, Clark TN. Similar head impact acceleration measured using instrumented ear patches in a junior rugby union team during matches in comparison with other sports. J Neurosurg Pediatr 2016; 18:65-72. [PMID: 26942267 DOI: 10.3171/2015.12.peds15605] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Direct impact with the head and the inertial loading of the head have been postulated as major mechanisms of head-related injuries, such as concussion. METHODS This descriptive observational study was conducted to quantify the head impact acceleration characteristics in under-9-year-old junior rugby union players in New Zealand. The impact magnitude, frequency, and location were collected with a wireless head impact sensor that was worn by 14 junior rugby players who participated in 4 matches. RESULTS A total of 721 impacts > 10g were recorded. The median (interquartile range [IQR]) number of impacts per player was 46 (IQR 37-58), resulting in 10 (IQR 4-18) impacts to the head per player per match. The median impact magnitudes recorded were 15g (IQR 12g-21g) for linear acceleration and 2296 rad/sec(2) (IQR 1352-4152 rad/sec(2)) for rotational acceleration. CONCLUSIONS There were 121 impacts (16.8%) above the rotational injury risk limit and 1 (0.1%) impact above the linear injury risk limit. The acceleration magnitude and number of head impacts in junior rugby union players were higher than those previously reported in similar age-group sports participants. The median linear acceleration for the under-9-year-old rugby players were similar to 7- to 8-year-old American football players, but lower than 9- to 12-year-old youth American football players. The median rotational accelerations measured were higher than the median and 95th percentiles in youth, high school, and collegiate American football players.
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Fraas MR, Burchiel J. A systematic review of education programmes to prevent concussion in rugby union. Eur J Sport Sci 2016; 16:1212-8. [PMID: 27063067 DOI: 10.1080/17461391.2016.1170207] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
BACKGROUND There is a high incidence of concussion sustained by athletes participating in rugby union, many of which go unreported. A lack of sufficient knowledge about concussion injuries may explain athletes' failure to report. Several rugby union-playing countries have developed injury education and prevention programmes to address this issue. OBJECTIVE The aim of the current review was to systematically assess the content and level of evidence on concussion education/prevention programmes in rugby union and to make recommendations for the quality, strength, and consistency of this evidence. METHODS We searched PubMed, PsycInfo, MEDLINE, SPORTDiscuss, Webofscience, and conducted a manual search for articles. RESULTS Ten articles were included for review. Of these, six focused on the BokSmart injury prevention programme in South Africa, two focused on the RugbySmart injury prevention programme in New Zealand, one was an analysis of prevention programmes, and one was a systematic review of rugby injury prevention strategies. CONCLUSIONS Despite the initiative to develop concussion education and prevention programmes, there is little evidence to support the effectiveness of such programmes. There is evidence to support education of coaches and referees. In addition, there is scant evidence to suggest that education and rule changes may have the benefit of changing athlete behaviours resulting in a reduction in catastrophic injury.
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Shearer DA, Kilduff LP, Finn C, Jones RM, Bracken RM, Mellalieu SD, Owen N, Crewther BT, Cook CJ. Measuring Recovery in Elite Rugby Players: The Brief Assessment of Mood, Endocrine Changes, and Power. RESEARCH QUARTERLY FOR EXERCISE AND SPORT 2015; 86:379-386. [PMID: 26288253 DOI: 10.1080/02701367.2015.1066927] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
PURPOSE There is demand in applied sport settings to measure recovery briefly and accurately. Research indicates mood disturbance as the strongest psychological predictor of mental and physical recovery. The Brief Assessment of Mood (BAM) is a shortened version of the Profile of Mood States that can be completed in less than 30 s. The purpose of this study was to examine the BAM as a quick measure of mood in relation to recovery status in elite rugby players alongside established physiological markers of recovery. METHOD Using elite rugby union players (N = 12), this study examined the utility of BAM as an indicator of mental and physical recovery in elite athletes by exploring pattern change in mood disturbance, energy index, power output, cortisol, and testosterone 36 hr before and 12 hr, 36 hr, and 60 hr after a competitive rugby match. RESULTS Repeated-measures multivariate analysis of variance indicated significant changes in all variables across the 4 time points (p < .05, η(2) range = .20-.48), concurrent with previous study findings. Although visual inspection of the graphs indicated that the pattern of change for mood disturbance and energy index mapped changes in all physiological variables, only a low correlation was observed for power output (r = - .34). CONCLUSIONS Although BAM scores changed significantly over time in accordance with the hypotheses, further testing is required to confirm the utility of the BAM as a measure of recovery. The results indicate that the BAM could be used as 1 indicator of recovery status alongside other measures.
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Cockcroft J, Van Den Heever D. A descriptive study of step alignment and foot positioning relative to the tee by professional rugby union goal-kickers. J Sports Sci 2015; 34:321-9. [PMID: 26023827 DOI: 10.1080/02640414.2015.1050599] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
This study describes foot positioning during the final two steps of the approach to the ball amongst professional rugby goal-kickers. A 3D optical motion capture system was used to test 15 goal-kickers performing 10 goal-kicks. The distance and direction of each step, as well as individual foot contact positions relative to the tee, were measured. The intra- and inter-subject variability was calculated as well as the correlation (Pearson) between the measurements and participant anthropometrics. Inter-subject variability for the final foot position was lowest (placed 0.03 ± 0.07 m behind and 0.33 ± 0.03 m lateral to the tee) and highest for the penultimate step distance (0.666 ± 0.149 m), performed at an angle of 36.1 ± 8.5° external to the final step. The final step length was 1.523 ± 0.124 m, executed at an external angle of 35.5 ± 7.4° to the target line. The intra-subject variability was very low; distances and angles for the 10 kicks varied per participant by 1.6-3.1 cm and 0.7-1.6°, respectively. The results show that even though the participants had variability in their run-up to the tee, final foot position next to the tee was very similar and consistent. Furthermore, the inter- and intra-subject variability could not be attributed to differences in anthropometry. These findings may be useful as normative reference data for coaching, although further work is required to understand the role of other factors such as approach speed and body alignment.
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Owen SM, Venter RE, du Toit S, Kraak WJ. Acceleratory match-play demands of a Super Rugby team over a competitive season. J Sports Sci 2015; 33:2061-9. [PMID: 25846204 DOI: 10.1080/02640414.2015.1028086] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The match-play demands of rugby union have increased over time, and these demands should be quantified so as to provide a basis for optimal player loading during training. The primary aim of this article was to quantify accelerations, decelerations, impacts and aggregated body demands during the first half of match-play in a Super Rugby team. The secondary aim was to determine whether these characteristics are position-specific. Thirty-three players were monitored for 14 matches using global positioning system units with inbuilt microtechnology. Players were grouped according to positional roles and data were analysed for those who completed the entire duration of the first half of a given match. Forwards sustained more (d = 0.44) high-intensity impacts and greater (d = 0.26) aggregated body demands, while backs had more moderate (d = 0.55) and heavy accelerations (d = 0.76), and moderate (d = 0.23) and heavy decelerations (d = 0.54). These differences suggest that conditioning and recovery strategies should reflect the physical demands placed on players in different playing positions. Forwards should be conditioned with a focus on impacts and require longer recovery for the same duration of playing time, whereas conditioning for backs should emphasise rapid accelerations and decelerations.
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Jones MR, West DJ, Crewther BT, Cook CJ, Kilduff LP. Quantifying positional and temporal movement patterns in professional rugby union using global positioning system. Eur J Sport Sci 2015; 15:488-96. [PMID: 25675258 DOI: 10.1080/17461391.2015.1010106] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
This study assessed the positional and temporal movement patterns of professional rugby union players during competition using global positioning system (GPS) units. GPS data were collected from 33 professional rugby players from 13 matches throughout the 2012-2013 season sampling at 10 Hz. Players wore GPS units from which information on distances, velocities, accelerations, exertion index, player load, contacts, sprinting and repeated high-intensity efforts (RHIE) were derived. Data files from players who played over 60 min (n = 112) were separated into five positional groups (tight and loose forwards; half, inside and outside backs) for match analysis. A further comparison of temporal changes in movement patterns was also performed using data files from those who played full games (n = 71). Significant positional differences were found for movement characteristics during performance (P < 0.05). Results demonstrate that inside and outside backs have greatest high-speed running demands; however, RHIE and contact demands are greatest in loose forwards during match play. Temporal analysis of all players displayed significant differences in player load, cruising and striding between halves, with measures of low- and high-intensity movement and acceleration/deceleration significantly declining throughout each half. Our data demonstrate significant positional differences for a number of key movement variables which provide a greater understanding of positional requirements of performance. This in turn may be used to develop progressive position-specific drills that elicit specific adaptations and provide objective measures of preparedness. Knowledge of performance changes may be used when developing drills and should be considered when monitoring and evaluating performance.
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Hendricks S, Karpul D, Lambert M. Momentum and kinetic energy before the tackle in rugby union. J Sports Sci Med 2014; 13:557-563. [PMID: 25177182 PMCID: PMC4126292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 03/24/2014] [Indexed: 06/03/2023]
Abstract
Understanding the physical demands of a tackle in match situations is important for safe and effective training, developing equipment and research. Physical components such as momentum and kinetic energy, and it relationship to tackle outcome is not known. The aim of this study was to compare momenta between ball-carrier and tackler, level of play (elite, university and junior) and position (forwards vs. backs), and describe the relationship between ball-carrier and tackler mass, velocity and momentum and the tackle outcome. Also, report on the ball-carrier and tackler kinetic energy before contact and the estimated magnitude of impact (energy distributed between ball-carrier and tackler upon contact). Velocity over 0.5 seconds before contact was determined using a 2-dimensional scaled version of the field generated from a computer alogorithm. Body masses of players were obtained from their player profiles. Momentum and kinetic energy were subsequently calculated for 60 tackle events. Ball-carriers were heavier than the tacklers (ball-carrier 100 ± 14 kg vs. tackler 93 ± 11 kg, d = 0.52, p = 0.0041, n = 60). Ball-carriers as forwards had a significantly higher momentum than backs (forwards 563 ± 226 Kg(.)m(.)s(-1) n = 31 vs. backs 438 ± 135 Kg(.)m(.)s(-1), d = 0.63, p = 0.0012, n = 29). Tacklers dominated 57% of tackles and ball-carriers dominated 43% of tackles. Despite the ball-carrier having a mass advantage before contact more frequently than the tackler, momentum advantage and tackle dominance between the ball-carrier and tackler was proportionally similar. These findings may reflect a characteristic of the modern game of rugby where efficiently heavier players (particularly forwards) are tactically predetermined to carry the ball in contact. Key PointsFirst study to quantify momentum, kinetic energy, and magnitude of impact in rugby tackles across different levels in matches without a device attached to a player.Physical components alone, of either ball-carrier or tackler, are not good predictors of tackle dominance.The range of magnitudes of impact of injury free tackles observed in this study provides evidence for the physical tolerance of players during the tackle.
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Higham DG, Hopkins WG, Pyne DB, Anson JM. Performance indicators related to points scoring and winning in international rugby sevens. J Sports Sci Med 2014; 13:358-364. [PMID: 24790490 PMCID: PMC3990890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 01/09/2014] [Indexed: 06/03/2023]
Abstract
Identification of performance indicators related to scoring points and winning is needed to inform tactical approaches to international rugby sevens competition. The aim of this study was to characterize team performance indicators in international rugby sevens and quantify their relationship with a team's points scored and probability of winning. Performance indicators of each team during 196 matches of the 2011/2012 International Rugby Board Sevens World Series were modeled for their linear relationships with points scored and likelihood of winning within (changes in team values from match to match) and between (differences between team values averaged over all matches) teams. Relationships were evaluated as the change and difference in points and probability of winning associated with a two within- and between-team standard deviations increase in performance indicator values. Inferences about relationships were assessed using a smallest meaningful difference of one point and a 10% probability of a team changing the outcome of a close match. All indicators exhibited high within-team match-to-match variability (intraclass correlation coefficients ranged from 0.00 to 0.23). Excluding indicators representing points-scoring actions or events occurring on average less than once per match, 13 of 17 indicators had substantial clear within-team relationships with points scored and/or likelihood of victory. Relationships between teams were generally similar in magnitude but unclear. Tactics that increase points scoring and likelihood of winning should be based on greater ball possession, fewer rucks, mauls, turnovers, penalties and free kicks, and limited passing. Key pointsSuccessful international rugby sevens teams tend to maintain ball possession; more frequently avoid taking the ball into contact; concede fewer turnovers, penalties and free kicks; retain possession in scrums, rucks and mauls; and limit passing the ball.Selected performance indicators may be used to evaluate team performances and plan more effective tactical approaches to competition.There is greater match-to-match variability in performance indicator values within than between international rugby sevens teams.The priorities for a rugby sevens team's technical and tactical preparation should reflect the magnitudes of the relationships between performance indicators, points scoring and the likelihood of winning.
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Sayers MGL. Kinematic analysis of line-out throwing in elite international rugby union. J Sports Sci Med 2011; 10:553-558. [PMID: 24150632 PMCID: PMC3737805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Accepted: 07/21/2011] [Indexed: 06/02/2023]
Abstract
The rugby union line-out is a key aspect of game play and involves players from both teams contesting for the ball after it has been thrown in from the side line. Successful lines-out throws require the ball to be delivered accurately to the hands of a jumping and/or lifted team mate (approximately 3-3.5 m off the ground) over distances of between 5- 18 m. Previous research has suggested considerable inter and intra-individual differences in the throwing techniques of international level players. Accordingly, this project investigated the interrelationships between accuracy and the line-out throwing characteristics of three elite international rugby players, and then analyzed whether these changed for throws over increasing length. Three-dimensional (3D) data were developed from video footage (50 Hz) of three elite international subjects for 30 throws over three distances (6 m, 10 m, and 15 m). Results showed notable differences between subjects in many variables at each of the key throw phases. However, several variables such as the degree of trunk flexion at the end of the backswing and at ball release, coupled with elbow flexion angle at ball release remained constant as throw length increased. All subjects exhibited high levels of consistency in movement patterns across all throw lengths. Findings indicated that these high performance line-out throwers shared several common characteristics that will provide useful guides in the development of training programs. Key pointsA key aspect of this research was the assessment of throwing accuracy using a functional throwing task that mimicked normal performance.Although individual differences in throwing technique occurred, several technical aspects of the throw were common to each of these elite international players.Subjects tended to be extremely consistent in the way they positioned the ball at the end of the backswing, and had very consistent elbow (flexion) and shoulder (flexion and abduction) angles at both the end of the backswing and at ball release.In addition, throwers kept the trunk close to upright during the throw with minimal trunk flexion or extension regardless of throw distance.To throw for longer distances participants tended to increase the involvement of the legs.
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