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Hrysomallis C.,Victoria University of Melbourne
Sports Medicine | Year: 2013

Along with the enjoyment and the other positive benefits of sport participation, there is also the risk of injury that is elevated in contact sport. This review provides a summary of injury incidence in Australian Rules Football (ARF), identifies injury risk factors, assesses the efficacy of interventions to reduce injury risk and makes recommendations for future research. The most common injuries were found to be muscle strains, particularly hamstrings; joint ligament sprains, especially ankle; haematomas and concussion. The most severe joint injury was anterior cruciate ligament rupture. Mouthguards are commonly worn and have been shown to reduce orofacial injury. There is evidence that thigh pads can reduce the incidence of thigh haematomas. There is a reluctance to wear padded headgear and an attempt to assess its effectiveness was unsuccessful due to low compliance. The most readily identified risk factor was a history of that injury. There were conflicting findings as to the influence strength imbalances or deficit has on hamstring injury risk in ARF. Static hamstring flexibility was not related to risk but low hip flexor/quadriceps flexibility increased hamstring injury risk. High lower-limb and high hamstring stiffness were associated with an elevated risk of hamstring injury. Since stiffness can be modulated through strength or flexibility training, this provides an area for future intervention studies. Low postural balance ability was related to a greater risk of ankle injury in ARF, players with poor balance should be targeted for balance training. There are preliminary data signifying a link between deficiencies in hip range of motion and hip adductor strength with groin pain or injury. This provides support for future investigation into the effectiveness of an intervention for high-risk players on groin injury rate. Low cross-sectional area of core-region muscle has been associated with more severe injuries and a motor control exercise intervention that increased core muscle size and function resulted in fewer games missed due to injury. A randomized controlled trial of the effectiveness of eccentric hamstring exercise in decreasing hamstring injury rate in ARF players was unsuccessful due to poor compliance from muscle soreness; a progressive eccentric training intervention for ARF should be given future consideration. Jump and landing training reduced injury risk in junior ARF players and it would be advisable to include this component as part of a neuromuscular training intervention. A multifaceted programme of sport-specific drills for hamstring flexibility while fatigued, sport skills that load the hamstrings and high-intensity interval training to mimic match playing conditions showed some success in reducing the incidence of hamstring injuries in ARF. A countermeasure designed to reduce injury risk is more likely to be adopted by coaches and players if it also has the scope to enhance performance. © Springer International Publishing Switzerland 2013.

Aughey R.J.,Victoria University of Melbourne
International Journal of Sports Physiology and Performance | Year: 2011

Background: Australian football (AF) is a highly intermittent sport, requiring athletes to accelerate hundreds of times with repeated bouts of high-intensity running (HIR). Players aim to be in peak physical condition for finals, with anecdotal evidence of increased speed and pressure of these games. Purpose: However, no data exists on the running demands of finals games, and therefore the aim of this study was to compare the running demands of finals to regular season games with matched players and opponents. Methods: Player movement was recorded by GPS at 5 Hz and expressed per period of the match (rotation), for total distance, high-intensity running (HIR, 4.17-10.00 m·s-1) and maximal accelerations (2.78-10.00 m·s -2). All data was compared for regular season and finals games and the magnitude of effects was analyzed with the effect size (ES) statistic and expressed with confidence intervals. Results: Each of the total distance (11%; ES: 0.78 ± 0.30), high-intensity running distance (9%; ES: 0.29 ± 0.25) and number of maximal accelerations (97%; ES: 1.30 ± 0.20) increased in finals games. The largest percentage increases in maximal accelerations occurred from a commencement velocity of between 3-4 (47%; ES: 0.56 ± 0.21) and 4-5 m·s-1 (51%; ES: 0.72 ± 0.26), and with <19 s between accelerations (53%; ES: 0.63 ± 0.27). Conclusion: Elite AF players nearly double the number of maximal accelerations in finals compared with regular season games. This large increase is superimposed on requirements to cover a greater total distance and spend more time at high velocity during finals games. Players can be effectively conditioned to cope with these increased demands, even during a long competitive season. © 2011 Human Kinetics, Inc.

Aughey R.J.,Victoria University of Melbourne
International Journal of Sports Physiology and Performance | Year: 2011

Global positioning system (GPS) technology was made possible after the invention of the atomic clock. The first suggestion that GPS could be used to assess the physical activity of humans followed some 40 y later. There was a rapid uptake of GPS technology, with the literature concentrating on validation studies and the measurement of steady-state movement. The first attempts were made to validate GPS for field sport applications in 2006. While GPS has been validated for applications for team sports, some doubts continue to exist on the appropriateness of GPS for measuring short high-velocity movements. Thus, GPS has been applied extensively in Australian football, cricket, hockey, rugby union and league, and soccer. There is extensive information on the activity profile of athletes from field sports in the literature stemming from GPS, and this includes total distance covered by players and distance in velocity bands. Global positioning systems have also been applied to detect fatigue in matches, identify periods of most intense play, different activity profiles by position, competition level, and sport. More recent research has integrated GPS data with the physical capacity or fitness test score of athletes, game-specific tasks, or tactical or strategic information. The future of GPS analysis will involve further miniaturization of devices, longer battery life, and integration of other inertial sensor data to more effectively quantify the effort of athletes. © 2011 Human Kinetics, Inc.

Hrysomallis C.,Victoria University of Melbourne
Sports Medicine | Year: 2011

The relationship between balance ability and sport injury risk has been established in many cases, but the relationship between balance ability and athletic performance is less clear. This review compares the balance ability of athletes from different sports, determines if there is a difference in balance ability of athletes at different levels of competition within the same sport, determines the relationship of balance ability with performance measures and examines the influence of balance training on sport performance or motor skills.Based on the available data from cross-sectional studies, gymnasts tended to have the best balance ability, followed by soccer players, swimmers, active control subjects and then basketball players. Surprisingly, no studies were found that compared the balance ability of rifle shooters with other athletes. There were some sports, such as rifle shooting, soccer and golf, where elite athletes were found to have superior balance ability compared with their less proficient counterparts, but this was not found to be the case for alpine skiing, surfing and judo. Balance ability was shown to be significantly related to rifle shooting accuracy, archery shooting accuracy, ice hockey maximum skating speed and simulated luge start speed, but not for baseball pitching accuracy or snowboarding ranking points. Prospective studies have shown that the addition of a balance training component to the activities of recreationally active subjects or physical education students has resulted in improvements in vertical jump, agility, shuttle run and downhill slalom skiing. A proposed mechanism for the enhancement in motor skills from balance training is an increase in the rate of force development. There are limited data on the influence of balance training on motor skills of elite athletes. When the effectiveness of balance training was compared with resistance training, it was found that resistance training produced superior performance results for jump height and sprint time.Balance ability was related to competition level for some sports, with the more proficient athletes displaying greater balance ability. There were significant relationships between balance ability and a number of performance measures. Evidence from prospective studies supports the notion that balance training can be a worthwhile adjunct to the usual training of non-elite athletes to enhance certain motor skills, but not in place of other conditioning such as resistance training. More research is required to determine the influence of balance training on the motor skills of elite athletes. © 2011 Adis Data Information BV. All rights reserved.

Liddle B.,Victoria University of Melbourne
Environmental Modelling and Software | Year: 2013

This paper analyzes urban population's and affluence's (GDP per capita's) influence on environmental impact in developed and developing countries by taking as its starting point the STIRPAT framework. In addition to considering environmental impacts particularly influenced by population and affluence (carbon emissions from transport and residential electricity consumption), the paper determines whether and, if so, how those environmental impact relationships vary across development levels by analyzing panels consisting of poor, middle, and rich countries. The development-based panels approach is an improvement on the GDP per capita polynomial model used in the Environmental Kuznets curve and other literature for several reasons: (i) it allows one to determine whether the elasticity of all variables considered varies according to development; (ii) it is arguably a more accurate description of the development process; (iii) it avoids potentially spurious regressions involving nonlinear transformations of nonstationary variables (GDP per capita squared); and (iv) unlike the polynomial model, it allows for the possibility that elasticities are significantly different across development levels but still positive-precisely the relationship expected for the environmental impacts considered here. Whether or not the elasticity for affluence was greater than that for population was a function of both the choice of dependent variable and the makeup of the panel (all countries, poor, middle, or rich). Furthermore, the estimated elasticities varied, in a nonlinear fashion, according to the development process: U-shaped, inverted U-shaped, and monotonic patterns were revealed, again, depending on the dependent variable. © 2012 Elsevier Ltd.

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