Evaluating postconcussive outcomes after return to play in Australian football

Concussions, defined as complex clinical syndromes precipitated by traumatic forces to the brain, are extremely common injuries sustained in all forms of sports, particularly ones that include high levels of contact. A major matter of debate regarding concussions is the length of time in which concussed athletes should abstain from performing due to a number of possible short- and long-term complications, which include impaired performance, increased risk of injury, prolonged symptoms or even possible symptoms of depression. Many have also suggested that an athlete returning to their respective sport is at the highest risk when returning prematurely. The difficulty in assigning a definitive amount of recovery time for concussed athletes is that there is no single, objective, quantitative criterion to measure the actual process of recovery, and physicians therefore vary in their recommendations for said periods. Australian football has one of the highest rates of concussive brain injury of any team contact sport, recording incidences of 3.9 injuries per 1,000 player hours. Based on the frequency of concussive injuries in the sport, a prospective study was conducted to determine whether a concussed player who returns to play using an individual clinical management strategy is at risk of impaired performance or increased risk of injury or concussion after their return to competition.

All players in the Australian Football League (AFL) were monitored closely for four full seasons. Team doctors evaluated players after each experienced concussion-like symptoms such as confusion, memory disturbance, vertigo or lightheadedness, and if actual concussions were suffered, the players were referred to the study. Players were excluded if they had played no games prior to the concussion, no games after the incident, or if they were suffering from an unrelated non-concussive concurrent injury or illness preventing their return to play. All team doctors, who were not informed of the specific nature of the study, were members of the AFL Medical Officers Association (AFLMOA) and therefore shared a similar approach to diagnosing and managing concussions, which includes monitoring symptom recovery and assessing cognitive skills. Data was gathered for each player for three games prior to and three games after the incident, and control subjects were selected from the pool of non-injured players who matched concussed players in age, size and playing position. A "disposal" is an AFL term that describes any movement of the ball by a player (either by hand or foot), and was therefore used to measure each player's performance.

A total of 199 concussive injuries were observed in 158 players throughout the duration of the study, with some players experiencing concussions more than once. Matching these numbers with the total number of player hours (26,640), the overall incident of concussion was 5.6 per 1,000 hours. Sixty-one injuries were excluded from analysis for various reasons, leaving 138 concussive injuries in 117 players. Of these, based on the methodological analysis from team doctors, 127 (92%) did not miss any games after their injuries (a span of between six and nine days) and 11 missed only one game (8%). After returning to play, 10 players were injured in their first game back, with a rate of 7.25 per 100 games, compared to the control, which rated at 3.25 per 100. No players were concussed again in their first game back. Cognitive tests, taken before and after the concussion, also did not show any notable differences after the incident.

Results show that there was no significant increase in injuries for players with the amount of rest recommended to them by team doctors (6-9 days for most and 12-18 days for the others.) This finding displays support for the notion that a comprehensive clinical approach involving careful monitoring of post-concussive symptoms and the use of cognitive tests is suitable for keeping track of recovery from concussions. The level of performance for concussed players, based on disposal rates, also did not waver much after their return to play from the injury. The incidence of concussion reported (5.6 per 100 player hours) is higher than was previously reported in the AFL, which may have to do with the game evolving to include larger, faster players who are therefore more prone to concussive injuries. Judging by the predominantly positive outcome of the criteria used to determine when players were ready to return to activity, the controlled prospective design used to examine players is proven to be an effective method of analyzing players' readiness to return. The concussion management guidelines used in the AFL show that players can return to play with no measurable impairment in playing performance and no increase in injury rates, and these strategies can therefore be considered a safe and effective method for managing concussed athletes in all contact sports such as the NFL and NHL.

-As reported in the Centre for Health, Exercise and Sports Medicine, University of Melbourne

-By Greg Gargiulo