Space–time coordination dynamics in basketball: Part 2. The interaction between the two teams     

Jérôme Bourbousson  Carole Sève  Tim McGarry 《Journal of sports sciences》2013,31(3):349-358

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Severity and cost of injuries in amateur rugby league: A case study     

Tim J. Gabbett 《Journal of sports sciences》2013,31(5):341-347

The aim of this study was to determine the severity and cost of injuries in amateur rugby league. Seventy-two amateur rugby league players aged 28 - 6 years (mean - s) were surveyed at the end of a competitive season. An injury was defined as any pain, disability or injury that occurred as a result of a competition game which caused the player to miss subsequent games. Injuries were classified as minor (one game missed), moderate (two to four games missed) and major (five or more games missed). Of the 72 questionnaires distributed, 34 (47.2%) were returned. Twenty respondents (58.8%) sustained an injury that resulted in one or more missed games. Eight injured players (40.0%) missed five or more training sessions, six of whom (30%) missed five or more games as a result of the injury. The median time lost from employment or study for all injured players was 2 days per playing injury. The respective median direct (e.g. medical expenses) and indirect (e.g. wages lost) costs associated with the injury were 28.29 and 77.04 per playing injury. A considerable proportion of injuries sustained in the present sample of amateur rugby league players were major, resulting in a loss of training, playing and employment or study time, and these injuries were associated with significant direct and indirect economic costs. Further studies, using a larger sample, would complement the present findings in establishing the severity and cost of amateur rugby league injuries. These results suggest that prevention strategies are required to reduce the severity and cost of amateur rugby league injuries.  相似文献   

Influence of training and match intensity on injuries in rugby league     

Tim J Gabbett 《Journal of sports sciences》2013,31(5):409-417

The aim of this study was to examine the influence of perceived intensity, duration and load of matches and training on the incidence of injury in rugby league players. The incidence of injury was prospectively studied in 79 semi-professional rugby league players during the 2001 season. All injuries sustained during matches and training sessions were recorded. Training sessions were conducted from December to September, with matches played from February to September. The intensity of individual training sessions and matches was estimated using a modified rating of perceived exertion scale. Training load was calculated by multiplying the training intensity by the duration of the training session. The match load was calculated by multiplying the match intensity by the time each player participated in the match. Training load increased from December (278.3 [95% confidence interval, CI 262.2 to 294.5] units) to February (385.5 [95% CI 362.4 to 408.5] units), followed by a decline until September (98.4 [95% CI 76.5 to 120.4] units). Match load increased from February (204.0 [95% CI 186.2 to 221.8] units) to September (356.8 [95% CI 302.5 to 411.1] units). More training injuries were sustained in the first half of the season (first vs second: 69.2% vs 30.8%, P?<0.001), whereas match injuries occurred more frequently in the latter stages of the season (53.6% vs 46.4%, P?<0.001). A significant relationship (P?<0.05) was observed between changes in training injury incidence and changes in training intensity (r?=?0.83), training duration (r?=?0.79) and training load (r?=?0.86). In addition, changes in the incidence of match injuries were significantly correlated (P?<0.05) with changes in match intensity (r?=?0.74), match duration (r?=?0.86) and match load (r?=?0.86). These findings suggest that as the intensity, duration and load of rugby league training sessions and matches is increased, the incidence of injury is also increased.  相似文献   

Worldwide variation in the performance of children and adolescents: An analysis of 109 studies of the 20-m shuttle run test in 37 countries     

Tim Olds  Grant Tomkinson  Luc Léger  Georges Cazorla 《Journal of sports sciences》2013,31(10):1025-1038

Abstract

This study is a meta-analysis of 109 reports of the performance of children and adolescents on the 20-m shuttle run test (20-mSRT). The studies were performed in 37 countries and included data on 418,026 children, tested between 1981 and 2003. Results were expressed as running speed (km · h^?1) at the final completed stage of the 20-mSRT. Raw data were combined with pseudodata using Monte Carlo simulation. The 20-mSRT performances were expressed as z-scores relative to all children of the same age and sex from all countries. An overall “performance index” was derived for each country as the average of the age- and sex-specific z-scores for all children from that country. Factorial analysis of variance was used to compare scores among countries and regions, and between boys and girls of the same age. There was wide and significant (P < 0.0001) global variability in the performance of children. The best performing children were from the Northern European countries Estonia, Iceland, Lithuania, and Finland (0.6 – 0.9 standard deviations above the global average). The worst performing children were from Singapore, Brazil, USA, Italy, Portugal, and Greece (0.4 – 0.9 standard deviations below the global average). There is evidence that performance was negatively related to being overweight, as well as to a country's average temperature.  相似文献   

A tribute to Professor Thomas Reilly (1941–2009)     

Tim Cable  Frank Sanderson  Alan Nevill 《Journal of sports sciences》2013,31(11):1107-1108

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

Dr Tim Gabbett  Matthew Wake  Bruce Abernethy 《Journal of sports sciences》2013,31(1):7-18

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.  相似文献   

Validating the multimedia activity recall for children and adolescents in a large New Zealand sample     

Ralph Maddison  Louise S. Foley  Tim S. Olds  Kate Ridley  Yannan Jiang 《Journal of sports sciences》2013,31(5):470-478

Abstract

The aim of the study was to validate the self-report Multimedia Activity Recall for Children and Adolescents (MARCA) against accelerometry for the assessment of physical activity in New Zealand children. Participants (n = 716, 10–18 years) recalled 3–4 days of activity using the MARCA and underwent a partially overlapping 7-day accelerometry protocol during a national survey. Spearman correlation coefficients (ρ) assessed the association between accelerometer-derived counts per minute and MARCA-derived physical activity level and time in locomotion. Both data sources estimated time spent in light and moderate–vigorous physical activity. Association and agreement between methods for light physical activity and moderate–vigorous physical activity was assessed using correlations and Bland–Altman plots respectively, and paired t-tests conducted. Accelerometer-derived activity counts were moderately correlated with both MARCA-derived physical activity level and locomotion (ρ = 0.38, P < 0.0001). The correlation between methods was –0.14 for light physical activity and 0.28 for moderate–vigorous physical activity (P < 0.0001). The MARCA overestimated moderate–vigorous physical activity compared with accelerometry (120 min, P < 0.0001), which increased as moderate–vigorous physical activity time increased. Some sex and ethnicity (Māori [indigenous] versus non-Māori) differences were observed. Overall, the MARCA indicated moderate validity for assessment of physical activity level, locomotion and moderate–vigorous physical activity and poor validity for assessment of light physical activity. This was comparable to other self-report tools. The MARCA has utility for future large-scale research.  相似文献   

Biomechanical Effects of Fatigue on 10,000 Meter Running Technique     

Bruce Elliot  Tim Ackland 《Research quarterly for exercise and sport》2013,84(2):160-166

Abstract

A study of the effect of fatigue on the mechanical characteristics of running during a 10,000 meter race was undertaken using high speed cinematography and a computer analysis technique. Eight highly skilled male subjects were filmed at four intervals throughout the event. An analysis of variance for trends was conducted for each of the dependent variables indicating the adjustments made by the runners that accompanied fatigue over the four stages of the event. Runners countered fatigue by changing sections of their total gait pattern (stride length, stride rate, segmental body positions) and reducing running velocity. Toward the end of the race the runners became less competent in the positioning of the foot and leg at foot-strike, which increased the potential for a retarding effect. A more extended lower limb increased the energy requirements of the recovery phase during the latter stages of the race. Fatigue caused these highly skilled runners to systematically alter their technique throughout the race. These adjustments, however, were not excessive.  相似文献   

There Is an “I” in TEAM     

Tim Woodman  Ross Roberts  Lew Hardy  Nichola Callow  Catherine H. Rogers 《Research quarterly for exercise and sport》2013,84(2):285-290

Abstract

We investigated narcissism as a moderator of social loafing on a physical performance task. High and low narcissistic individuals twice performed a cycling task in same-sex teams of three: once when identifiability was low; and once when identifiability was high. A significant interaction between narcissism and identifiability was revealed, F(1, 40) = 4.09, p < .05, η² = .09 for performance. Follow-up tests indicated that high narcissists' performance significantly increased with greater identifiability, whereas low narcissists displayed no such performance differences. Results suggested that this effect was due to an increase in narcissists' on-task effort (ratings of perceived exertion and heart rate) when they knew that their performance was to be identified.  相似文献   

Modifying Equipment in Early Skill Development: A Tennis Perspective     

Tim Buszard  Damian Farrow  Machar Reid  Rich S. W. Masters 《Research quarterly for exercise and sport》2013,84(2):218-225

Purpose: The International Tennis Federation recently launched a worldwide campaign advocating the use of equipment scaling for children learning to play tennis. The aim of this study was to investigate the influence that varying racquet sizes and ball compressions had on children's ability to play a forehand groundstroke. Method: This was a quantitative repeated-measures design experiment. Children were required to perform a forehand hitting task using each of 9 combinations of tennis racquets and balls (i.e., 3 racquet sizes × 3 ball compressions). Children's hitting performance was measured using a points system. The aim for the children was to score as many points as possible. Hitting technique was measured via video replay. Results: Hitting performance was best when the smallest racquet combined with the ball with the least compression was used. The ball with the least compression also promoted 2 technique benefits: swinging the racquet from low to high and striking the ball in front and to the side of the body. Conclusions: This study demonstrated the benefits for young children playing with scaled racquets and low-compression balls. The findings are discussed with regards to their relevance to theories of skill acquisition.  相似文献