Monitoring meaningful rugby ratings

The performance of individual rugby players can be quantified using multivariate analysis and modified control chart methodology. Using factor analysis, multivariate data are reduced to five orthogonal factors (key performance indicators). These factors are reduced to a single measure of performance by modifying control chart ideology. By comparing the observed performances with 'unattainable perfection' rather than the average, a statistic that is suitable for monitoring the performance of individual rugby players with control charts is obtained for use by coaches and selectors.     

橄榄球运动损伤特征、影响因素及监控策略研究

橄榄球运动具有团体性项目中最为激烈的对抗性,这导致橄榄球运动员出现运动损伤的风险是显著的,因此如何针对橄榄球运动损伤进行有效预防成为教练员和运动员们所关注的内容。该研究主要基于英语文献,对橄榄球项目的运动损伤特征、影响因素及监控策略进行了梳理与分析,研究表明(1)橄榄球运动员的损伤类型、部位和严重程度具有明显的橄榄球专项特征,依据橄榄球运动员主要损伤类型、部位及严重程度采取针对性的预防措施能够降低球队的伤病风险;(2)橄榄球运动员运动损伤的影响因素主要包括伤病史、比赛与训练负荷、竞技水平、年龄与性别、接触动作、球员位置以及疲劳,依据运动损伤影响因素对训练和比赛过程进行合理控制能够减少运动损伤对球队整体竞技能力的影响;(3)橄榄球运动员的损伤监控策略主要包括运动损伤预筛查、建立运动损伤监测系统以及进行多学科合作参与,通过对橄榄球运动损伤监控策略的应用和探索可以从根源上提高橄榄球队的运动损伤监控效果。     

Elite wheelchair rugby: a quantitative analysis of chair configuration in Australia

Limited recommendations of wheelchair configurations for court sports have been identified in the published literature. To accommodate the wide range of impairments in wheelchair rugby, players are given a point score that reflects their impairment. Players have regularly been grouped as high-, mid-, or low-point players in research, with high-point players having greater levels of muscle function compared with other classifications. This research documented the wheelchair configurations of elite Australian wheelchair rugby players across classification groups. Significant differences (p < 0.05) were found for increased seat height and decreased seat depth for high-point players compared with low- and mid-point groups, respectively. Low-point players displayed reduced wheelchair mass compared with high- and mid-point players, as well as increased frame length. Camber angles showed no significant differences across the classification groups. The incorporation of anthropometric measures, such as the elbow angle at the top dead center, was also investigated. While elbow angle showed no significant differences, seat height-to-total arm length ratio was higher for high-point players. Participants also completed surveys detailing their perception of the effect of altering wheelchair configurations. It is suggested that wheelchair configurations should consider an individual’s anthropometrics, impairment, training history, and court role to promote optimal performance, with predictive modeling having the potential to reduce the associated time and cost.     

Science of rugby league football: a review

The purpose of this paper is to provide a comprehensive review of the science of rugby league football at all levels of competition (i.e. junior, amateur, semi-professional, professional), with special reference to all discipline-specific scientific research performed in rugby league (i.e. physiological, psychological, injury epidemiology, strength and conditioning, performance analysis). Rugby league football is played at junior and senior levels in several countries worldwide. A rugby league team consists of 13 players (6 forwards and 7 backs). The game is played over two 30 - 40 min halves (depending on the standard of competition) separated by a 10 min rest interval. Several studies have documented the physiological capacities and injury rates of rugby league players. More recently, studies have investigated the physiological demands of competition. Interestingly, the physiological capacities of players, the incidence of injury and the physiological demands of competition all increase as the playing standard is increased. Mean blood lactate concentrations of 5.2, 7.2 and 9.1 mmol . l(-1) have been reported during competition for amateur, semi-professional and professional rugby league players respectively. Mean heart rates of 152 beats . min(-1) (78% of maximal heart rate), 166 beats . min(-1) (84% of maximal heart rate) and 172 beats . min(-1) (93% of maximal heart rate) have been recorded for amateur, semi-professional and junior elite rugby league players respectively. Skill-based conditioning games have been used to develop the skill and fitness of rugby league players, with mean heart rate and blood lactate responses during these activities almost identical to those obtained during competition. In addition, recent studies have shown that most training injuries are sustained in traditional conditioning activities that involve no skill component (i.e. running without the ball), whereas the incidence of injuries while participating in skill-based conditioning games is low. Collaborative research among the various sport science disciplines is required to identify strategies to reduce the incidence of injury and enhance the performance of rugby league players. An understanding of the movement patterns and physiological demands of different positions at all standards of competition would allow the development of strength and conditioning programmes to meet the precise requirements of these positions. Finally, studies investigating the impact of improvements in physiological capacities (including the effect of different strength and conditioning programmes) on rugby league playing performance are warranted.     

Use of dual-task methodology for skill assessment and development: examples from rugby league

We assessed the attentional demands of drawing and passing in rugby league players and investigated the effects of single-task and dual-task training on the acquisition, retention, and transfer of skill in these athletes. In Study 1, high-skilled and lesser-skilled rugby league players performed a standardized 2-on-1 drill under single-task (primary skill in isolation) and dual-task (primary skill while performing a secondary verbal tone recognition task) conditions. No differences were detected in primary task performance between groups, although the performance of the high-skilled players was more resistant to skill decrement under dual-task conditions. In Study 2, high-performance rugby league players were randomly allocated to either a single-task or dual-task training group. Each group underwent 8 weeks of training between the pre- and post-test sessions. While the mean improvement for draw and pass proficiency under dual-task conditions in the dual-task training group was greater than in the single-task training group (10.0% vs. 2.3%), the differences, while providing a moderate effect size (d = 0.57), were not statistically significant. These results suggest that the attentional demands of drawing and passing are reduced in high-skilled rugby league players compared with their lesser-skilled counterparts. In addition, compared with single-task training, dual-task training appears to improve the ability to perform dual-task draw and pass tasks (possibly through an improvement in time-sharing skills). Further studies are required to verify the efficacy of dual-task training as a training stimulus.     

Science of rugby league football: A review

The purpose of this paper is to provide a comprehensive review of the science of rugby league football at all levels of competition (i.e. junior, amateur, semi-professional, professional), with special reference to all discipline-specific scientific research performed in rugby league (i.e. physiological, psychological, injury epidemiology, strength and conditioning, performance analysis). Rugby league football is played at junior and senior levels in several countries worldwide. A rugby league team consists of 13 players (6 forwards and 7 backs). The game is played over two 30?–?40 min halves (depending on the standard of competition) separated by a 10?min rest interval. Several studies have documented the physiological capacities and injury rates of rugby league players. More recently, studies have investigated the physiological demands of competition. Interestingly, the physiological capacities of players, the incidence of injury and the physiological demands of competition all increase as the playing standard is increased. Mean blood lactate concentrations of 5.2, 7.2 and 9.1?mmol?·?l^?1 have been reported during competition for amateur, semi-professional and professional rugby league players respectively. Mean heart rates of 152 beats?·?min^?1 (78% of maximal heart rate), 166 beats?·?min^?1 (84% of maximal heart rate) and 172 beats?·?min^?1 (93% of maximal heart rate) have been recorded for amateur, semi-professional and junior elite rugby league players respectively. Skill-based conditioning games have been used to develop the skill and fitness of rugby league players, with mean heart rate and blood lactate responses during these activities almost identical to those obtained during competition. In addition, recent studies have shown that most training injuries are sustained in traditional conditioning activities that involve no skill component (i.e. running without the ball), whereas the incidence of injuries while participating in skill-based conditioning games is low. Collaborative research among the various sport science disciplines is required to identify strategies to reduce the incidence of injury and enhance the performance of rugby league players. An understanding of the movement patterns and physiological demands of different positions at all standards of competition would allow the development of strength and conditioning programmes to meet the precise requirements of these positions. Finally, studies investigating the impact of improvements in physiological capacities (including the effect of different strength and conditioning programmes) on rugby league playing performance are warranted.     

Use of dual-task methodology for skill assessment and development: Examples from rugby league

Abstract

We assessed the attentional demands of drawing and passing in rugby league players and investigated the effects of single-task and dual-task training on the acquisition, retention, and transfer of skill in these athletes. In Study 1, high-skilled and lesser-skilled rugby league players performed a standardized 2-on-1 drill under single-task (primary skill in isolation) and dual-task (primary skill while performing a secondary verbal tone recognition task) conditions. No differences were detected in primary task performance between groups, although the performance of the high-skilled players was more resistant to skill decrement under dual-task conditions. In Study 2, high-performance rugby league players were randomly allocated to either a single-task or dual-task training group. Each group underwent 8 weeks of training between the pre- and post-test sessions. While the mean improvement for draw and pass proficiency under dual-task conditions in the dual-task training group was greater than in the single-task training group (10.0% vs. 2.3%), the differences, while providing a moderate effect size (d = 0.57), were not statistically significant. These results suggest that the attentional demands of drawing and passing are reduced in high-skilled rugby league players compared with their lesser-skilled counterparts. In addition, compared with single-task training, dual-task training appears to improve the ability to perform dual-task draw and pass tasks (possibly through an improvement in time-sharing skills). Further studies are required to verify the efficacy of dual-task training as a training stimulus.     

The development of position-specific performance indicators in professional rugby union

The aim of this study was to construct a valid and reliable methodology for the analysis of performance profiles of individual playing positions within rugby union. Twenty-two matches were sampled from the domestic season of a professional male rugby union team. Key performance indicators for individual positions were developed and notated using a computerized behavioural analysis system. Performance profiles of playing positions containing data from one or more individuals were then constructed to compare intra-positional differences. Significant differences (chi-square) were observed between individuals within all the tested playing positions for the principal performance indicators (passing, carrying and tackling for the forward positions, and passing, carrying, tackling and kicking for the backs). For example, the difference between the two outside-halves in the study (P < 0.001) was illustrated by one of the players having a median of 6 successful carries for the season (95% confidence limits of 13 and 3), whereas the other had a median of 2 successful carries (95% confidence limits of 5 and 1). The findings suggest that while general positional performance profiles appear to exist, intra-positional differences may occur due to variations in an individual's style of play, the decision-making demands of the position and the effects of potential confounding variables. Multiple profiles may therefore be necessary for some playing positions to account for variation in factors such as playing conditions and the strength of the opposition.     

高住低训对国家男子橄榄球运动员体能的影响

研究高住低训(HiLo)提高橄榄球运动员体能的效果。将14名国家男子橄榄球队运动员随机分成HiLo组(n=8)和LoLo组(n=6),进行为期4周的实验。HiLo组每晚在O2浓度为14.7%的实验室居住10h。每周除正常训练外,还有3次30min在O2浓度为15.4%、强度为个体72%V.O2max的功率自行车运动。LoLo组的训练方案与HiLo组相同,但没有低氧居住和低氧运动。每周3次的30min功率自行车运动在常氧环境下进行,强度为个体80%V.O2max。结果表明,HiLo可以显著提高运动员有氧耐力,12min跑成绩明显提高;对4种距离折返跑时间、球门折返跑等无氧能力的提高也有一定帮助;对Hb等血象指标的提高没有显著作用,但可以保持运动员正常的Hb水平。     

The development of position-specific performance indicators in professional rugby union

The aim of this study was to construct a valid and reliable methodology for the analysis of performance profiles of individual playing positions within rugby union. Twenty-two matches were sampled from the domestic season of a professional male rugby union team. Key performance indicators for individual positions were developed and notated using a computerized behavioural analysis system. Performance profiles of playing positions containing data from one or more individuals were then constructed to compare intra-positional differences. Significant differences (chi-square) were observed between individuals within all the tested playing positions for the principal performance indicators (passing, carrying and tackling for the forward positions, and passing, carrying, tackling and kicking for the backs). For example, the difference between the two outside-halves in the study (P?<?0.001) was illustrated by one of the players having a median of 6 successful carries for the season (95% confidence limits of 13 and 3), whereas the other had a median of 2 successful carries (95% confidence limits of 5 and 1). The findings suggest that while general positional performance profiles appear to exist, intra-positional differences may occur due to variations in an individual's style of play, the decision-making demands of the position and the effects of potential confounding variables. Multiple profiles may therefore be necessary for some playing positions to account for variation in factors such as playing conditions and the strength of the opposition.     

Hearts in the fire, heads in the fridge: a qualitative investigation into the temporal patterning of the precompetitive psychological response in elite performers

Retrospective perceptions and causal beliefs regarding the temporal patterning of precompetitive psychological responses were examined in 12 elite rugby union players. Composite sequence analysis resulted in a series of temporal networks to describe participants' cognitive, affective, and behavioural responses in a time-to-event paradigm. Match-related cognitions remained stable in the lead up to competition, while perceptions of physical symptoms peaked at the onset of performance. Affective responses were associated with feelings of anxiety and tension in the early temporal phases but excitement, confidence, and efficacy in team-mates directly before competition. Behavioural themes described activities associated with technical and physical preparation, familiarization with environmental conditions, and strategies to control activation states early on or directly before competition. The findings highlight the idiosyncratic and dynamic nature of the temporal patterning of precompetitive responses and the influence that perceptions of the team have upon individual preparation for performance. Implications are discussed in the context of the type and timing of intervention for developing individual and team preparatory routines.     

A 12-month prospective cohort study of symptoms of common mental disorders among professional rugby players

The primary aims were to determine the 12-month incidence (and comorbidity) of symptoms of common mental disorders (CMD) among male professional rugby players and to explore their association with potential stressors. A secondary aim was to explore the view of male professional rugby players about the consequences of symptoms of CMD and related medical support/needs. An observational prospective cohort study with three measurements over a 12-month period was conducted among male professional rugby players from several countries. Symptoms of CMD (distress, anxiety/depression, sleep disturbance, eating disorders and adverse alcohol use) and stressors (adverse life events, rugby career dissatisfaction) were assessed through validated questionnaires. A total of 595 players (mean age of 26 years; mean career duration of 6 years) were enrolled, of which 333 completed the follow-up period. The incidence of symptoms of CMD were: 11% for distress, 28% for anxiety/depression, 12% for sleep disturbance, 11% for eating disorders and 22% for adverse alcohol use (13% for two simultaneous symptoms of CMD). Professional rugby players reporting recent adverse life events or career dissatisfaction were more likely to report symptoms of CMD but statistically significant associations were not found. Around 95% of the participants stated that symptoms of CMD can negatively influence rugby performances, while 46% mentioned that specific support measures for players were not available in professional rugby. Supportive and preventive measures directed towards symptoms of CMD should be developed to improve not only awareness and psychological resilience of rugby players but also their rugby performance and quality-of-life.     

Effects of latissimus dorsi length on shoulder flexion in canoeists,swimmers, rugby players,and controls

BackgroundShoulder flexion requires an optimal length of the latissimus dorsi muscle in order to allow full lateral rotation of the humerus and upward scapular rotation. If shoulder flexion (in an externally rotated position) is restricted, this may predispose the individual to shoulder pathology. Sports such as swimming and canoeing have increased shoulder injuries and require high levels of latissimus dorsi muscle activity, which may create muscle hypertrophy and increased stiffness, resulting in a loss of muscle length. The objective of this study was to investigate if differences are present in shoulder flexion in internally and externally rotated positions across different sports (swimming, canoeing, and rugby) and a non-sporting control group.MethodsOne hundred subjects (40 physically active controls, 25 professional Rugby Union players, 20 elite, national-level canoeists (slalom), and 15 elite, national-level swimmers) participated in this study. Shoulder flexion range of motion was measured using a standard goniometer, with the arm elevated in either full external or internal rotation.ResultsA significant difference in shoulder flexion range was observed between canoeists and swimmers, canoeists and controls, rugby players and canoeists, rugby players and swimmers, and controls and swimmers in the external rotation position (p < 0.017), but not between controls and rugby players (p = 0.12). For the internal rotation position, swimmers significantly differed from canoeists, rugby players, and controls (p < 0.017), but there were no significant differences between rugby players, canoeists, and controls (p > 0.07).ConclusionThis study found that the length of the latissimus dorsi differs between sports and controls in accordance with the specific physical demands of their sport.     

Coaches’ perceptions of decision making in rugby union

ABSTRACT

Background: In team games situations, the ability to make fast and accurate decisions is crucial to performance. As such, effective decision making, characterised by the consistent and efficient ability to choose the right course of action at the right moment, is a key component of match performance in team sports such as rugby union. Previous research has identified pedagogical approaches to enhance decision making. However, there is dearth in research to investigate how coaches evaluate tactical decision making and subsequently develop context specific ‘on’ and ‘off-field’ coaching practices to improve it. Further, the value coaches place on decision making is under explored.

Purpose: The aim of this study was to explore coaches’ perceptions of decision making in rugby union. The specific objectives to meet this aim were to: (i) Explore coaches’ perceptions of the value and importance of decision making in rugby union; (ii) Identify coaches’ opinions of the key decision making moments in games and how to evaluate them; and (iii) Investigate coaches’ on and off field methods for improving players’ tactical and strategic decision making.

Participants: Purposive sampling was used to select five male coaches, whose ages ranged from 25 to 41 years, from a regional rugby union club in Wales to participate in the study. Coaching experience ranged from two years to 16 years.

Methods: The interpretative paradigm was used within the study with data collected through semi-structured interviews with academy rugby union coaches. This type of interview gathered rich, detailed and complex accounts of coaches’ opinions of players’ in-game decision making in rugby union in order to inform practice and theory. Inductive and deductive qualitative thematic analysis was used to analyse and interpret the data.

Findings: All five coaches agreed that decision making was a crucial part of the modern game of rugby union. There was some disagreement between them about the players’ autonomy to make their own decisions on the pitch and a general lack of clarity between ‘game plan’, ‘strategy’ and ‘tactics’ amongst the coaches. All the coaches agreed that the process of evaluation of players’ decision making should involve a joint discussion with the players. They also agreed that developing decision making was one of the hardest things to coach. Finally, they used a variety of ‘on’ and ‘off-field’ coaching methods to achieve this including video analysis, questioning and the use of games based scenarios.

Conclusion: This study acquired the coaches’ voice on players’ decision making in rugby union by exploring its perceived importance to them and how they evaluated and attempted to improve it. A clear attempt was made among the coaches to develop a ‘non-judgemental’ atmosphere in the evaluation and improvement of players’ decision making. Future research should consider the use of explicitation interviewing, where the interviewer (coach) aims to get the player into a state of evocation, to relive the key decision making moments in an attempt to improve it.     

Dual-task assessment of a sporting skill: influence of task complexity and relationship with competitive performances

Abstract

We investigated the effect of increases in task complexity on the dual-task draw-and-pass performance of professional rugby league players. Moreover, we determined the relationship between dual-task draw-and-pass proficiency measured in isolation and draw-and-pass performances as they occurred in actual competitive matches. In Study 1, 12 rugby league players performed 2-on-1 and 3-on-2 attacking drills under single (primary skill) and dual-task (primary skill performed in conjunction with secondary-task) conditions. Reductions in draw-and-pass performance occurred when task complexity was increased from the 2-on-1 to the 3-on-2 situation. In Study 2, 58 rugby league players undertook the dual-task draw-and-pass assessment. Players then competed in National Rugby League matches with video footage coded for the number of tries scored and the activities that led to the try. A total of 303 tries were scored with 150 (49.5%) tries scored from a draw-and-pass situation. Significant associations were detected between 2-on-1 dual-task draw-and-pass performance in the isolated test condition and draw-and-pass performances in competition. These studies provide evidence of (i) the greater attentional demands of the skill of drawing-and-passing in elite team sport athletes when more players are involved and (ii) the practical utility of off-field dual-task testing in supplying information predictive of skills performance in competition.     

Relationship between achievement goal orientations and the perceived purposes of playing rugby union for professional and amateur players

The recent professionalization of rugby union makes it an excellent achievement context in which to examine the relationship between achievement goal orientations and the perceived purposes of sport as a function of competitive standard. During the 1996–97 season, 73 professional and 106 amateur rugby players in England completed a series of questionnaires assessing their achievement goal orientations, beliefs about the purposes of rugby and demographic information. The results of a canonical correlation analysis revealed a conceptually coherent relationship between achievement goal orientations and purposes of rugby. Specifically, a high ego/ moderate task orientation was positively related to fitness, aggression and financial remuneration as significant purposes of rugby. Professional players scored higher on those purposes of rugby related to aggression, financial remuneration and fitness, but lower on sportspersonship than amateur players. Professional players also reported higher task and ego goal orientations than amateur players. The findings are discussed in terms of the differences in lifestyle and motivation of professional and amateur rugby union players.     

Relationship between achievement goal orientations and the perceived purposes of playing rugby union for professional and amateur players

The recent professionalization of rugby union makes it an excellent achievement context in which to examine the relationship between achievement goal orientations and the perceived purposes of sport as a function of competitive standard. During the 1996-97 season, 73 professional and 106 amateur rugby players in England completed a series of questionnaires assessing their achievement goal orientations, beliefs about the purposes of rugby and demographic information. The results of a canonical correlation analysis revealed a conceptually coherent relationship between achievement goal orientations and purposes of rugby. Specifically, a high ego/moderate task orientation was positively related to fitness, aggression and financial remuneration as significant purposes of rugby. Professional players scored higher on those purposes of rugby related to aggression, financial remuneration and fitness, but lower on sportspersonship than amateur players. Professional players also reported higher task and ego goal orientations than amateur players. The findings are discussed in terms of the differences in lifestyle and motivation of professional and amateur rugby union players.     

Digit ratio (2D:4D) and performance in elite rugby players

The relative length of the second and fourth digits (2D:4D) is a putative marker for prenatal testosterone. Low 2D:4D has been reported to correlate with high performance in sport in general. Here, for the first time, we examine the relationship between 2D:4D and performance in elite rugby players. The 44 players (28 forwards, 16 backs) were drawn from the Ospreys Rugby Union Club and 44 age-matched controls. The measures of performance comprised age-adjusted number of international performances (caps) for Wales, a comparison of coaches' first-choice League team with others, and the number of tries scored by backs in club matches. Compared with controls, players were larger and had lower 2D:4D for the right and left hand. With regard to number of caps, players with low 2D:4D in their right hand and low right 2D:4D compared with their left (right?-?left 2D:4D difference) had high numbers of caps. First-choice players did not differ significantly from second-choice players in their 2D:4D but they did have a lower right?-?left 2D:4D difference than second-choice players. Low right 2D:4D and low right?-?left 2D:4D difference were significantly linked with large numbers of tries. We conclude that low right 2D:4D and low right?-?left 2D:4D difference are predictors of high rugby performance.     

A comparison of physiological and anthropometric characteristics among playing positions in sub-elite rugby league players

This study compared the physiological and anthropometric characteristics of specific playing positions and positional playing groups in sub-elite rugby league players. Altogether, 415 sub-elite rugby league players underwent measurements of standard anthropometry (body mass, height, sum of four skinfolds), muscular power (vertical jump), speed (10-m, 20-m, and 40-m sprint), agility ("L" run), and estimated maximal aerobic power (multi-stage fitness test). Props were significantly heavier and had a greater skinfold thickness than all other playing positions. Centres, fullbacks, and hookers were faster than props over 40 m. When the data were analysed according to positional commonality, props were taller, heavier, had a greater skinfold thickness, were less agile, and were slower over 10 m than all other positional groups. The hookers/halves and outside backs positional groups were significantly faster over 40 m than the backrowers and props positional groups. In addition, the hookers/halves and outside backs positional groups had significantly greater estimated maximal aerobic power than the props positional group. The results of this study demonstrate that few physiological and anthropometric differences exist among individual playing positions in sub-elite rugby league players, although props are taller, heavier, have greater skinfold thickness, slower 10-m and 40-m speed, less agility, and lower estimated maximal aerobic power than other positional groups. These findings provide normative data for sub-elite rugby league players competing in specific individual positions and positional playing groups.     

Injuries in Australian school-level rugby union

There is a high incidence of injuries in rugby union due to the physical nature of the game. In youth rugby union, there are large variations in injury rates reported. Our study investigated the rates of injuries in school-level rugby union players in Australia using the consensus statement for rugby union injuries. Injury surveillance was conducted on 480 rugby players from 1 school in Queensland, Australia. Injury data were collected using paper-based injury recording forms during the 8-week rugby season using a “medical-attention” injury definition. In total, 76 players sustained one or more injuries, with a total of 80 injuries recorded. The overall injury rate was 31.8 injuries/1000 match player hours (95% CI, 25.4–39.4). Concussion had an incidence rate of 6.0/1000 match player hours (95% CI, 3.5–9.6). The incidence of upper limb and lower limb injuries were 9.1 and 9.9/1000 match player hours, respectively (95% CI, 5.9–13.5 and 6.6–14.5). The older age divisions had higher injury rates and most injuries occurred while tackling or being tackled. The injury rates observed in this sample of Australian school rugby union players provides direction for future studies to enable informed decisions relating to development of injury prevention programmes at this level of rugby.