Injury risk grows for elite AFL players
Under
current rules, elite athletes in the Australian Football League run the
risk of higher rates of serious player collisions because of the ever
increasing speed of the modern game, according to UniSA research.
Studies on the physics of AFL football show that player speed has increased by about 1.5 per cent each year since 1998, according to Dr Kevin Norton, Professor of Exercise Science at UniSA’s School of Health Sciences.
Professor Norton’s research, in close association with Adelaide Crows’ coach, Neil Craig, shows that the game has become more physical, the colliding players are much taller and heavier, and their collision speeds are greater.
“An average player can expect about 600 serious collisions throughout a four year career. These collisions may not stand out as much as those of past years due to the improved fitness of today’s players, who can absorb greater contact without damage,” Professor Norton said.
A review of the 2003 Wizard Cup football games provided a unique opportunity for researchers to look at how rule changes might affect game and player speeds, the injury potential related to player collisions at high speed, and the structure of the game.
“We found that the number of serious collisions across the Wizard series was well below what we predicted, based on results for home and away AFL games. In fact, it was only half of the number expected.
“The Wizard rules have resulted in longer play periods when compared with AFL games. Because umpires restart faster, players have shorter rest breaks. This means that their average running speed drops and there are fewer very intense two-second sprints per minute. The reduction in ‘top end’ high speeds is almost certainly related to the lower incidence of serious collisions,” Professor Norton said.
“Surprisingly, because of the continuous ‘free-flowing’ nature of the Wizard game, some players and many spectators perceive the game to be faster, but our results show that the game is played at a lower average intensity. The game appears faster because players keep moving, they have short rest times, there is often action in the game, and umpires have the ball less often and for less time.
“In AFL games, especially in finals, the intensity is greater and the ball moves faster but rest periods are more frequent. We also know that the rest periods (before umpires restart play) are longer in finals.
“Our data shows that the AFL games produce about 10 per cent more top end speeds and 20 per cent more walking, while Wizard has more jogging and striding,” Professor Norton said.
In compiling the data, UniSA honours student Brett Burton has been quantifying every training session by tracking Crows players using GPS, looking at various measures that will enable coaches to determine if players are being overtrained and to develop coaching strategies to get players in peak condition without running them down.
UniSA graduates Mark Upton and Paul Haynes, who are now fulltime with the Crows, are also working with Burton on tracking players, honours student Steven Edgecombe is concentrating on Crows fitness programs, and honours student Kirsty Lange has completed a project on training and rehabilitation for AFL players.
“Six years ago when we first started tracking key midfield players, more than two-thirds stayed on the ground for the whole game and when fatigued they were moved to full or back pocket positions to catch their breath. Now more than two-thirds come off the ground regularly. Today’s top midfielders work very hard for ten minutes, and then sprint off the ground and rest, to be replaced by another midfield. After a few minutes, they might go back on the ground, go flat-chat, and come off again.
“Because of that strategy the average speed of the game in the midfield stays high. That is problematic because the high speeds, while they look great, can lead to high impact collisions and high injury rates. This on-off tactic involves a different utilisation of players’ physiological capabilities and is one strategy being used to overcome the problem of overtraining or potential fatigue of players spending so much time training,” Professor Norton said.
Today’s elite AFL athletes train for about 1,000 to 1,200 hours annually, which parallels the training regimes of elite athletes from other sports. Players attend 100 training sessions in the 10 weeks before the official season starts, and train 10-12 times each week, often twice daily for about 20 hours a week during the season.
“I think we’ve reached a stage now where it is very difficult to increase the physical workload that athletes are doing across all sports. We’ve saturated their physiological capabilities. They must have recovery sessions. Many of them sit on the edge of peak performance versus over training and immune suppression and illness, so we’ve got to get that balance right.
“We can’t force the players to do more training but we can train them smarter. A good example is the greater use of technology by the Crows this year. They have devised video games to help players develop skills for playing in tight situations, so that they can make split-second decisions on the best move while surrounded by a cluster of opposition players. And unlike other clubs, the Crows introduced balls right from the start of pre season training with specially designed drills that combined physical conditioning with ball handling skills.”
Professor Norton would like to see a play-on rule introduced after a point or when the ball is out of bounds, or have just 16 players per team to slow the game, eventually, due to player fatigue. “We need to slow the game down by speeding it up.”