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1.
Previous work on dynamics of interpersonal interactions in 1 vs. 1 sub-phases of basketball has identified changes in interpersonal distance between an attacker and defender as a potential control parameter for influencing organizational states of attacker-defender dyads. Other studies have reported the constraining effect of relative velocity between an attacker and defender in 1 vs. 1 dyads. To evaluate the relationship between these candidate control parameters, we compared the impact of both interpersonal distance and relative velocity on the pattern-forming dynamics of attacker-defender dyads in the sport of rugby union. Results revealed that when interpersonal distance achieved a critical value of less than 4 m, and relative velocity values increased or were maintained above 1 m x s(-1), a successful outcome (i.e. clean attempt) for an attacker was predicted. Alternatively, when values of relative velocity suddenly decreased below this threshold, at the same critical value of interpersonal distance, a successful outcome for the defender was predicted. Data demonstrated how the coupling of these two potential, nested control parameters moved the dyadic system to phase transitions, characterized as a try or a tackle. Observations suggested that relative velocity increased its influence on the organization of attacker-defender dyads in rugby union over time as spatial proximity to the try line increased.  相似文献   

2.
Abstract

Previous work on dynamics of interpersonal interactions in 1 vs. 1 sub-phases of basketball has identified changes in interpersonal distance between an attacker and defender as a potential control parameter for influencing organizational states of attacker–defender dyads. Other studies have reported the constraining effect of relative velocity between an attacker and defender in 1 vs. 1 dyads. To evaluate the relationship between these candidate control parameters, we compared the impact of both interpersonal distance and relative velocity on the pattern-forming dynamics of attacker–defender dyads in the sport of rugby union. Results revealed that when interpersonal distance achieved a critical value of less than 4 m, and relative velocity values increased or were maintained above 1 m · s?1, a successful outcome (i.e. clean attempt) for an attacker was predicted. Alternatively, when values of relative velocity suddenly decreased below this threshold, at the same critical value of interpersonal distance, a successful outcome for the defender was predicted. Data demonstrated how the coupling of these two potential, nested control parameters moved the dyadic system to phase transitions, characterized as a try or a tackle. Observations suggested that relative velocity increased its influence on the organization of attacker–defender dyads in rugby union over time as spatial proximity to the try line increased.  相似文献   

3.
This study investigated the influence of interpersonal coordination tendencies on performance outcomes of 1-vs-1 sub-phases in youth soccer. Eight male developing soccer players (age: 11.8 ± 0.4 years; training experience: 3.6 ± 1.1 years) performed an in situ simulation of a 1-vs-1 sub-phase of soccer. Data from 82 trials were obtained with motion-analysis techniques, and relative phase used to measure the space-time coordination tendencies of attacker-defender dyads. Approximate entropy (ApEn) was then used to quantify the unpredictability of interpersonal interactions over trials. Results revealed how different modes of interpersonal coordination emerging from attacker-defender dyads influenced the 1-vs-1 performance outcomes. High levels of space-time synchronisation (47%) and unpredictability in interpersonal coordination processes (ApEn: 0.91 ± 0.34) were identified as key features of an attacking player's success. A lead-lag relation attributed to a defending player (34% around -30° values) and a more predictable coordination mode (ApEn: 0.65 ± 0.27, P < 0.001), demonstrated the coordination tendencies underlying the success of defending players in 1-vs-1 sub-phases. These findings revealed how the mutual influence of each player on the behaviour of dyadic systems shaped emergent performance outcomes. More specifically, the findings showed that attacking players should be constrained to exploit the space-time synchrony with defenders in an unpredictable and creative way, while defenders should be encouraged to adopt postures and behaviours that actively constrain the attacker's actions.  相似文献   

4.
Abstract

This study investigated the influence of interpersonal coordination tendencies on performance outcomes of 1-vs-1 sub-phases in youth soccer. Eight male developing soccer players (age: 11.8 ± 0.4 years; training experience: 3.6 ± 1.1 years) performed an in situ simulation of a 1-vs-1 sub-phase of soccer. Data from 82 trials were obtained with motion-analysis techniques, and relative phase used to measure the space-time coordination tendencies of attacker-defender dyads. Approximate entropy (ApEn) was then used to quantify the unpredictability of interpersonal interactions over trials. Results revealed how different modes of interpersonal coordination emerging from attacker-defender dyads influenced the 1-vs-1 performance outcomes. High levels of space-time synchronisation (47%) and unpredictability in interpersonal coordination processes (ApEn: 0.91 ± 0.34) were identified as key features of an attacking player's success. A lead-lag relation attributed to a defending player (34% around ?30° values) and a more predictable coordination mode (ApEn: 0.65 ± 0.27, P < 0.001), demonstrated the coordination tendencies underlying the success of defending players in 1-vs-1 sub-phases. These findings revealed how the mutual influence of each player on the behaviour of dyadic systems shaped emergent performance outcomes. More specifically, the findings showed that attacking players should be constrained to exploit the space-time synchrony with defenders in an unpredictable and creative way, while defenders should be encouraged to adopt postures and behaviours that actively constrain the attacker's actions.  相似文献   

5.
ABSTRACT

This study examined the relationships between daily cognitive appraisals of organizational events, affective responses, and coping. In addition, a 5-year longitudinal relationship between coping and performance outcomes at the senior professional level was assessed. Using an experience sampling method, professional academy rugby union players (N = 39, Mage = 17.23 years, SD = 0.87) completed daily diary measures of appraisals, affective responses, and coping over 5 weeks of training. Hierarchical linear modeling revealed that daily cognitive appraisals were related to daily affective responses and coping functions enacted by behaviours, after accounting for a series of within (e.g., time, day, week) and between-person (e.g., personality, key decision-makers) differences. Zero-inflated negative binomial regression revealed that coping related to eliciting support was associated with minutes played at the senior professional level five years later. This study extends theoretical knowledge of the within- and between-person relationships that explain organizational stress experiences. The findings suggest that some coping functions enacted by behaviours may be early indicators of future performance outcomes in professional sport.  相似文献   

6.
The aim of this study was to determine whether spatiotemporal interactions between footballers and the ball in 1 vs. 1 sub-phases are influenced by their proximity to the goal area. Twelve participants (age 15.3 ± 0.5 years) performed as attackers and defenders in 1 vs. 1 dyads across three field positions: (a) attacking the goal, (b) in midfield, and (c) advancing away from the goal area. In each position, the dribbler was required to move beyond an immediate defender with the ball towards the opposition goal. Interactions of attacker-defender dyads were filmed with player and ball displacement trajectories digitized using manual tracking software. One-way repeated measures analysis of variance was used to examine differences in mean defender-to-ball distance after this value had stabilized. Maximum attacker-to-ball distance was also compared as a function of proximity-to-goal. Significant differences were observed for defender-to-ball distance between locations (a) and (c) at the moment when the defender-to-ball distance had stabilized (a: 1.69 ± 0.64 m; c: 1.15 ± 0.59 m; P < 0.05). Findings indicate that proximity-to-goal influenced the performance of players, particularly when attacking or advancing away from goal areas, providing implications for training design in football. In this study, the task constraints of football revealed subtly different player interactions than observed in previous studies of dyadic systems in basketball and rugby union.  相似文献   

7.
The need to identify information sources which facilitate a functional coupling of perception and action in representative practice contexts is an important challenge for sport scientists and coaches. The current study investigated the role of visual information in regulating athlete gait behaviours during a locomotor pointing task in cricket. Integration of experiential knowledge of elite coaches and theoretical understanding from previous empirical research led us to investigate whether the presence of an umpire would act as a vertical informational constraint that could constrain the emergent coordination tendencies of cricket bowlers’ run-up patterns. To test this idea, umpire presence was manipulated during run-ups of 10 elite medium-fast bowlers. As hypothesised, removal of the umpire from the performance environment did not result in an inability to regulate gait to intercept a target, however, the absence of this informational constraint resulted in the emergence of different movement patterns in participant run-ups. Significantly lower standard deviation values of heel-to-crease distances were observed in the umpire condition at multiple steps, compared to performance in the no-umpire condition. Manipulation of this informational constraint altered gait regulation of participants, offering a mechanism to understand how perception–action couplings can be varied during performance in locomotor pointing tasks in sport.  相似文献   

8.
Abstract

Despite increased professionalization of adolescent sport and improved articulation to elite adult participation, the impact of sports such as rugby union among adolescents is under-explored. This study describes psychological stress–recovery responses relative to training loads in 106 male adolescent rugby union players. The results showed that players with the highest training and physical activity volumes during the season demonstrated more favourable recovery–stress states than moderate- and low-volume groups. Stress and under-recovery did not increase with increases in weekly volume when assessed across a season. When assessed more acutely during intensive competition phases, stress and under-recovery increased with increases in participation demands. Despite better psychological stress and recovery profiles of more elite, higher-load players, not all participants demonstrated favourable capacities to deal with stress and recovery processes. Seven participants were in at least two of three categories of highest volume, highest stress, and poorest recovery. Even in the absence of a full understanding of the impact of high-volume, high-stress, poor-recovery participation among adolescent athletes, these markers may be precursors for more deleterious outcomes such as injury, performance decrements, and overtraining. Findings support the efficacy of serially monitoring young athletes.  相似文献   

9.
In this study, we investigated the effects of acute post-exercise alcohol consumption on measures of physical performance, creatine kinase, and immunoendocrine function in the 48 h following a rugby game simulation. Ten male senior rugby union players completed a rugby game simulation after which they consumed either 1 g of alcohol per kilogram of body mass or a non-alcoholic control beverage. Agility, 15 m sprint, countermovement jump, and srummaging performance were assessed pre-simulation and 24 and 48 h post-simulation. White blood cell count, testosterone, cortisol, and creatine kinase were measured before the simulation and 30 min, 12, 24, 36, and 48 h after the simulation. One week after the first trial, participants completed the second simulation after which the other beverage was consumed. The acute consumption of alcohol after a rugby game simulation negatively affected countermovement jump performance in the days following the simulation (P = 0.028). No differences between treatments were observed for the other criterion measures made in this study. In conclusion, after 80 min of a simulated rugby game, the consumption of 1 g of alcohol per kg body mass negatively impacts lower body vertical power output. However, performance of tasks requiring repeated maximal muscular effort is not affected.  相似文献   

10.
Abstract In this study, we examined the effects of relative positioning of attacker-defender dyads to the basket on interpersonal coordination tendencies in basketball. To achieve this aim, four right-hand dominant basketball players performed in a 1 vs. 1 sub-phase, at nine different playing locations relative to the basket (from 0° to 180°, in 20° increments). Performers' movement displacement trajectories were video-recorded and digitized in 162 trials. Results showed that interpersonal coordination tendencies changed according to the scaling of the relative position of performers to the basket. Stable in-phase modes of coordination were observed between performers' longitudinal and lateral displacements (50.47% and 43.02%) on the left side of the court. On the right side of the court, a shift in the dominant mode of coordination was observed to a defender lead-lag of -30°, both for longitudinal and lateral displacements (30.51% and 32.65%). These results suggest how information about dribbler hand dominance and relative position to the basket may have constrained attacker-defender coordination tendencies in 1 vs. 1 sub-phases of basketball.  相似文献   

11.
Abstract

In this study, we examined the effects of relative positioning of attacker–defender dyads to the basket on interpersonal coordination tendencies in basketball. To achieve this aim, four right-hand dominant basketball players performed in a 1 vs. 1 sub-phase, at nine different playing locations relative to the basket (from 0° to 180°, in 20° increments). Performers’ movement displacement trajectories were video-recorded and digitized in 162 trials. Results showed that interpersonal coordination tendencies changed according to the scaling of the relative position of performers to the basket.

Stable in-phase modes of coordination were observed between performers’ longitudinal and lateral displacements (50.47% and 43.02%) on the left side of the court. On the right side of the court, a shift in the dominant mode of coordination was observed to a defender lead-lag of ?30°, both for longitudinal and lateral displacements (30.51% and 32.65%). These results suggest how information about dribbler hand dominance and relative position to the basket may have constrained attacker–defender coordination tendencies in 1 vs. 1 sub-phases of basketball.  相似文献   

12.
This study examined the consistency of pre-performance routines in international rugby union goal kickers on kicks of varying difficulty and under different amounts of situational pressure. Concentration times and physical preparation times were calculated from video recordings of the 572 place kicks taken during the 1999 Rugby Union World Cup. In contrast to the view that performers should seek consistent pre-performance routine times, the results revealed a strong positive relationship between kick difficulty and concentration time. Analysis of the effect of situational pressure, determined by the difference in score before the kick, revealed that players tended to have longer concentration times and shorter physical preparation times when the scores were close. There were no differences between the best and worst kickers in the tournament on routine time, consistency or rhythmicity. The view that increasing the temporal consistency of a routine will result in improved performance is challenged.  相似文献   

13.
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.  相似文献   

14.
Abstract

This study examined the consistency of pre-performance routines in international rugby union goal kickers on kicks of varying difficulty and under different amounts of situational pressure. Concentration times and physical preparation times were calculated from video recordings of the 572 place kicks taken during the 1999 Rugby Union World Cup. In contrast to the view that performers should seek consistent pre-performance routine times, the results revealed a strong positive relationship between kick difficulty and concentration time. Analysis of the effect of situational pressure, determined by the difference in score before the kick, revealed that players tended to have longer concentration times and shorter physical preparation times when the scores were close. There were no differences between the best and worst kickers in the tournament on routine time, consistency or rhythmicity. The view that increasing the temporal consistency of a routine will result in improved performance is challenged.  相似文献   

15.
Abstract

Evasive change-of-direction manoeuvres (agility skills) are a fundamental ability in rugby union. In this study, we explored the attributes of agility skill execution as they relate to effective attacking strategies in rugby union. Seven Super 14 games were coded using variables that assessed team patterns and individual movement characteristics during attacking ball carries. The results indicated that tackle-breaks are a key determinant of try-scoring ability and team success in rugby union. The ability of the attacking ball carrier to receive the ball at high speed with at least two body lengths from the defence line against an isolated defender promoted tackle-breaks. Furthermore, the execution of a side-step evasive manoeuvre at a change of direction angle of 20–60° and a distance of one to two body lengths from the defence, and then straightening the running line following the initial direction change at an angle of 20–60°, was associated with tackle-breaks. This study provides critical insight regarding the attributes of agility skill execution that are associated with effective ball carries in rugby union.  相似文献   

16.
Abstract

The aim of this study was to determine the physical demands of women’s rugby union match play using time–motion analysis and heart rate (HR) response. Thirty-eight premier club level female rugby players, ages 18–34 years were videotaped and HRs monitored for a full match. Performances were coded into 12 different movement categories: 5 speeds of locomotion (standing, walking, jogging, striding, sprinting), 4 forms of intensive non-running exertion (ruck/maul/tackle, pack down, scrum, lift) and 3 discrete activities (kick, jump, open field tackle). The main results revealed that backs spend significantly more time sprinting and walking whereas forwards spend more time in intensive non-running exertion and jogging. Forwards also had a significantly higher total work frequency compared to the backs, but a higher total rest frequency compared to the backs. In terms of HR responses, forwards displayed higher mean HRs throughout the match and more time above 80% of their maximum HR than backs. In summary, women’s rugby union is characterised by intermittent bursts of high-intensity activity, where forwards and backs have similar anaerobic energy demands, but different specific match demands.  相似文献   

17.
We compared the visuomotor coordination of tennis players with different levels of expertise (Super-Experts, Experts and Non-Experts) in a visuomotor tracking (VMT) task. Participants were asked to track a moving target which could rebound on the sides of a 2D screen. Results indicated that the VMT task allowed the discrimination of expertise. Multiple regression analysis revealed that performance could be explained by the temporal adaptation of participants to rebounds and the number of movement adaptations. Compared to Non-Experts, the Experts had a shorter perturbation time with higher adaptation and regulation. This corresponds to a better perception–action coupling and the predominant use of a prospective control process. Results also indicate that perception–action coupling capacities are transferable to virtual tasks, and allow us to reveal processes of visuomotor coordination that differentiate experts and novices.  相似文献   

18.
The ability to make fast, accurate decisions is an essential skill for all who play sport. However, measuring this ability has proved difficult for coaches and talent identification practitioners. Pattern recognition (a key factor in decision making) has commonly been measured using pattern recall tasks. This study aimed to understand whether accuracy when recalling rugby union patterns is a valid measure of on-field decision making performance. In Study 1, professional players recalled structured patterns of players from still images (N?=?20) viewed for 5?s. On-field decision-making markers, including coaches’ rankings of decision-making ability, playing position, number of years playing professionally and total number of years playing rugby union, were used as predictor variables of recall accuracy. Results showed that only total number of years playing rugby union was correlated with recall accuracy, suggesting that caution is necessary when adopting these tasks for talent identification purposes. The structured stimuli used in Study 1 were not representative of a true rugby union game, so Study 2 tested novice and expert players on a pattern recall task that included structured, semi-structured and unstructured rugby union patterns. Experts were significantly more accurate than novices when recalling structured and semi-structured patterns; however, there were no differences when recalling unstructured patterns. It was concluded that structured and semi-structured patterns should be used in future studies to test whether pattern recall tasks can be used for talent identification in rugby union.  相似文献   

19.
This study estimated the expected point value for starting possessions in different field locations during rugby league match-play and calculated the mean expected points for each subsequent play during the possession. It also examined the origin of tries scored according to the method of gaining possession. Play-by-play data were taken from all 768 regular-season National Rugby League (NRL) matches during 2010–2013. A probabilistic model estimated the expected point outcome based on the net difference in points scored by a team in possession in a given situation. An iterative method was used to approximate the value of each situation based on actual scoring outcomes. Possessions commencing close to the opposition’s goal-line had the highest expected point equity, which decreased as the location of the possession moved towards the team’s own goal-line. Possessions following an opposition error, penalty or goal-line dropout had the highest likelihood of a try being scored on the set subsequent to their occurrence. In contrast, possessions that follow an opposition completed set or a restart were least likely to result in a try. The expected point values framework from our model has applications for informing playing strategy and assessing individual and team performance in professional rugby league.  相似文献   

20.
Kinesio-tape® has been suggested to increase blood circulation and lymph flow and might influence the muscle's ability to maintain strength during fatigue. Therefore, the aim of this study was to investigate the influence of gluteal Kinesio-tape® on lower limb muscle strength in non-fatigued and fatigued conditions. A total of 10 male rugby union players performed 20-m sprint and vertical jump tests before and after a rugby-specific fatigue protocol. The 20-m sprint time was collected using light gates (SMARTSPEED). A 9-camera motion analysis system (VICON, 100 Hz) and a force plate (Kistler, 1000 Hz) measured the kinematics and kinetics during a counter movement jump and drop-jump. The effect of tape and fatigue on jump height, maximal vertical ground reaction force, reactivity strength index as well as lower limb joint work were analysed via a two-way analysis of variance. The fatigue protocol resulted in significantly decreased performance of sprint time, jump heights and alterations in joint work. No statistical differences were found between the taped and un-taped conditions in non-fatigued and fatigued situation as well as in the interaction with fatigue. Therefore, taping the gluteal muscle does not influence the leg explosive strength after fatiguing in healthy rugby players.  相似文献   

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