Physiological and metabolic characteristics of elite tug of war athletes.
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OBJECTIVE: To determine the aerobic power (VO(2)MAX), body composition, strength, muscular power, flexibility, and biochemical profile of an elite international squad of tug of war athletes. METHODS: Sixteen male competitors (mean (SEM) age 34 (2) years) were evaluated in a laboratory. For comparative purposes, data were analysed relative to normative data for our centre and to a group of 20 rugby forwards from the Irish international squad. RESULTS: The tug of war participants were lighter (83.6 (3.0) v 104.4 (1.8) kg, p<0.0001) and had less lean body mass (69.4 (2.1) v 86.2 (1.2) kg) than the rugby players and had lower than normal body fat (16.7 (0.9)%); all values are mean (SEM). Aerobic power measured during a treadmill test was 55.8 (1.6) ml/kg/min for the tug of war participants compared with 51.1 (1.4) ml/kg/min for the rugby forwards (p<0.03). A composite measure of strength derived from (sum of dominant and non-dominant grip strength and back strength)/lean body mass yielded a strength/mass ratio that was 32% greater (p<0.0001) for the tug of war group than the rugby group. Dynamic leg power was lower for the tug of war group than the rugby forwards (4659.8 (151.6) v 6198.2 (105) W respectively; p<0.0001). Leg flexibility was 25.4 (2.0) cm for the tug of war group. Back flexibility was 28.6 (1.4) cm which was lower (p<0.02) than the rugby forwards 34.2 (1.5) cm. Whereas blood chemistry and haematology were normal, packed cell volume, haemoglobin concentration, and erythrocyte volume were lower in the tug of war group than in the rugby players (p<0.05). All three haematological measures correlated with muscle mass (packed cell volume, r(2) = 0.37, p<0.0001; haemoglobin concentration, r(2) = 0.13, p<0.05; erythrocyte volume, r(2) = 0.21, p<0.01). CONCLUSIONS: The data indicate that international level tug of war participants have excellent strength and above average endurance relative to body size, but have relatively low explosive leg power and back flexibility. The data provide reference standards for the sport and may be useful for monitoring and evaluating current and future participants. (+info)
Influence of preseason training, fitness, and existing injury on subsequent rugby injury.
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OBJECTIVES: To examine the influence of preseason fitness, existing injury, and preseason rugby training on subsequent injury. METHODS: Players were eligible for the survey if they were a member of a Scottish Rugby Union (SRU) affiliated rugby club in the Border Reivers District of the SRU during the 1997-1998 season. A total of 803 (84%) players from 22 (88%) participating clubs provided details of rugby training, injuries sustained, and physical activity undertaken during the 16 week summer period (26 April to 16 August 1997) and their perceived fitness before the start of the season. Observers at participating clubs reported all injury episodes occurring to club players throughout the 1997-1998 season. RESULTS: One fifth of players did not attend any rugby training during the 16 week summer period; the remainder attended a median of 14 sessions. Throughout the 1997-1998 season, 675 injury episodes occurred to 423 (53%) players during training or in matches. After adjustment for whether players held a professional contract or were amateurs, Cox regression showed a 3.9% relative increase (95% confidence interval (CI) 1.9 to 5.9%) in the risk of injury over the season for each additional preseason training week attended, and a 61% relative increase (95% CI 32 to 97%) for those players who had been injured or were carrying an injury at the end of the previous season. CONCLUSIONS: Injury risk is more likely to be related to rugby training (type of activities undertaken in rugby training, or personalities and characteristics of players undertaking training more frequently) than to overall player fitness. Players who were injured at the end of the previous season were more likely to be injured in the following season. This may be because they do not allow previous injuries to heal sufficiently before returning to the game, or the intensity of their participation may increase their risk of injury. (+info)
Clinical risk factors for hamstring muscle strain injury: a prospective study with correlation of injury by magnetic resonance imaging.
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OBJECTIVE: To prospectively establish risk factors for hamstring muscle strain injury using magnetic resonance imaging (MRI) to define the diagnosis of posterior thigh injury. METHOD: In a prospective cohort study using two elite Australian Rules football clubs, the anthropometric characteristics and past clinical history of 114 athletes were recorded. Players were followed throughout the subsequent season, with posterior thigh injuries being documented. Hamstring intramuscular hyperintensity on T2 weighted MRI was required to meet our criteria for a definite hamstring injury. Statistical associations were sought between anthropometric and previous clinical characteristics and hamstring muscle injury. RESULTS: MRI in 32 players showed either hamstring injury (n = 26) or normal scans (n = 6). An association existed between a hamstring injury and each of the following: increasing age, being aboriginal, past history of an injury to the posterior thigh or knee or osteitis pubis (all p<0.05). These factors were still significant when players with a past history of posterior thigh injury (n = 26) were excluded. Previous back injury was associated with a posterior thigh injury that looked normal on MRI scan, but not with an MRI detected hamstring injury. CONCLUSIONS: Hamstring injuries are common in Australian football, and previous posterior thigh injury is a significant risk factor. Other factors, such as increasing age, being of aboriginal descent, or having a past history of knee injury or osteitis pubis, increase the risk of hamstring strain independently of previous posterior thigh injury. However, as the numbers in this study are small, further research is needed before definitive statements can be made. (+info)
Does rugby headgear prevent concussion? Attitudes of Canadian players and coaches.
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OBJECTIVES: To examine the attitudes of players and coaches to the use of protective headgear, particularly with respect to the prevention of concussion. METHODS: A questionnaire designed to assess attitudes to headgear was administered to 63 players from four different Canadian teams, each representing a different level of play (high school, university, community club, national). In addition, coaches from all four levels were questioned about team policies and their personal opinions about the use of headgear to prevent concussion. RESULTS: Although the players tended to believe that the headgear could prevent concussion (62%), the coaches were less convinced (33%). Despite the players' belief that headgear offers protection against concussion, only a minority reported wearing headgear (27%) and few (24%) felt that its use should be made mandatory. Common reasons for not wearing headgear were "its use is not mandatory", "it is uncomfortable", and "it costs too much". CONCLUSION: Although most players in the study believe that rugby headgear may prevent concussion, only a minority reported wearing it. Coaches tended to be less convinced than the players that rugby headgear can prevent concussion. (+info)
Incidence of injury in amateur rugby league sevens.
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OBJECTIVES: To investigate the incidence, site, and nature of injuries sustained in amateur rugby league sevens tournaments. METHODS: A total of 168 players competing in three amateur rugby league sevens tournaments were studied. All injuries sustained during matches were recorded. Information recorded included the name of the injured player and the time, cause, anatomical site, and nature of the injury. RESULTS: The incidence of injury was 283.5 per 1000 playing hours. Some 40% (113.4 per 1000 playing hours) of all injuries sustained were to the lower limb (chi(2) = 5.3, df = 1, p<0.05). Contusions were the most common type of injury (113.4 per 1000 hours, 40%, chi(2) = 9.5, df = 4, p<0.05), with most (198.4 per 1000 hours, 70%, chi(2) = 31.5, df =4, p<0.001) occurring in physical collisions and tackles. An increasing injury incidence was observed over the first (99.2 per 1000 hours), second (198.4 per 1000 hours), third (347.2 per 1000 hours), and fourth (694.4 per 1000 hours) matches played during the tournaments (chi(2) = 9.2, df = 3, p<0.05). CONCLUSIONS: The results of this study suggest that amateur rugby league sevens tournaments, which require players to compete repeatedly on the same day, may hasten the onset of fatigue and predispose to injury. (+info)
Haemodynamics during a complete exercise induced atrioventricular block.
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The case is reported of an athlete who, during an exercise test, had a complete atrioventricular block without symptoms of cardiac output failure. Heart rate, stroke index, cardiac index, and myocardial contractility were monitored during the episode by an impedance cardiograph. The most important findings of this report are the continuous increase in stroke index, which compensated for the lack of heart rate response, and the normal cardiac index values achieved during the exercise. This stroke index response was mainly due to an increase in myocardial contractility. (+info)
Effects of posting self-set goals on collegiate football players' skill execution during practice and games.
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The effects of self-set goals and public posting on athletic performance of 5 collegiate football players was studied. All players were linebackers on a National Association of Intercollegiate Athletics Division II football team. The dependent variables were the percentage of correct occasions when the linebacker (a) positioned himself to cover a specified area on the field during a pass or from the line of scrimmage during a run; (b) moved to the correct position in response to the positioning of the offense; and (c) tackled and stopped the progress of the ball carrier. A multiple baseline design across behaviors showed an immediate increase in the practice performance of the players and a corresponding increase in game performance following introduction of the independent variable. This study extends research using public posting in sport by demonstrating the effects of player-determined goals and public posting of goal attainment. (+info)
Benefits and risks of using local anaesthetic for pain relief to allow early return to play in professional football.
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OBJECTIVE: To investigate the risks and benefits of the use of local anaesthetic in a descriptive case series from three professional football (rugby league and Australian football) teams. METHODS: Cases of local anaesthetic use (both injection and topical routes) and complications over a six year period were recorded. Complications were assessed using clinical presentation and also by recording all cases of surgery, incidences of players missing games or leaving the field through injury, and causes of player retirement. RESULTS: There were 268 injuries for which local anaesthetic was used to allow early return to play. There were 11 minor and six major complications, although none of these were catastrophic or career ending. About 10% of players taking the field did so with the assistance of local anaesthetic. This rate should be considered in isolation and not seen to reflect standard practice by team doctors. CONCLUSIONS: The use of local anaesthetic in professional football may reduce the rates of players missing matches through injury, but there is the risk of worsening the injury, which should be fully explained to players. A procedure should only be used when both the doctor and player consider that the benefits outweigh the risks. (+info)