Abstract
The data presented in this study covers five years of successive European Super League seasons, 2013 to 2017. Match injury incidence of 57/1000 h in the European Super League was established. The average number of days missed per match injury in the ESL from 2013 to 2017 was 34 days. With an annual salary cap per club of 2.1 million (RFL Operational Rules, 2020), a loss of 15% of a 28-man squad due to injury per round renders circa £315,000 of a clubs aggregated salary cap spend unavailable for selection. The welfare and financial implications of the current findings have a wide reaching social and economic impact both to further the game’s safety policies, inform player preparation but also advise injury prevention strategies. Whilst it’s acknowledged some injury mechanisms are inevitably unavoidable the potential implications of these findings lend themselves to addressing preparative aspects of the RL player from a conditioning perspective to reduce the risk of injury as much as feasible.
Observation of injury severity in ESL showed that minor injuries accounted for 24.2%, moderate injuries accounted for 40.2% and 35.6% accounted for major injuries. In real terms, April is a seasonal hotspot that holds the greatest number of injuries in respect of the greatest match time played, although when standardised /1000 match hours, February appears as the highest risk month for injuries. Hamstring injuries and calf strains were the most common injuries sustained during ESL rugby league training including preseason, with the majority of hamstring stains during matches occurring in the first half of the competitive season.
Once accounting for standardisation of hours played forwards incurred a significantly higher injury incidence rate at 50% than adjustables, 27% and backs 23%; bearing in mind the difference in playing characteristics in that forwards naturally perform more tackle activities than other positions. It also appears that the main contributor to the increase in reporting incidence of concussion from 2016 onwards originates largely from hit-up forwards.
The severity of injuries in the ESL has remained the same over the 2013 to 2017 five year period however the increased incidence of concussion injuries would have led to more training days lost potentially affecting the ability of the player to perform and potentially increasing the risk of sustaining an injury playing with sub optimal fitness. Players are also renowned for missing training sessions but still manage to play a full game, particularly those in the 30 to 35 age category who have the highest incidence of injury per age group.
A pattern was observed that suggests as match time increases the rate of injury follows suit. There is an observed increase injury occurrence in the second quarter of each match half compared to the first quarter. The final 20-min of the match was evidently higher than any other period for sustaining injury. Player fatigue may influence this incidence of injuries suggesting that changes in training and playing intensity may influence the incidence of injury. There is a need for further investigation into player specific recovery strategies in order to reduce injury in the fourth quarter and decrease levels of injury in the second quarter of each half. This is out of the scope of the present study but warrants further research.
Recurrent match-injuries occurred at an average rate of 7.7 injuries/1000 h, in comparison to the severity of new injuries recurrent match injuries have the potential to cause greater time loss; on average two weeks more. Further, ‘Late-recurrence’ injuries (2-12-months following return from the initial injury) were revealed to be the most prevalent time frame for recurrent injuries, with on average 3.6/1000 h. The severity of injury between the recurrence categories showed little variation. Injuries most likely to become recurrent are those of concussion and hamstring strain. The average time loss from concussion diagnosis to return to full training and match availability was 13-days. Following comparison of average time loss from first concussion and recurrent concussion there is an increase in severity of approximately 5-days, no recurrence 11.6-days, recurrence 16.2-days.
The current consensus suggests that in rugby league, specifically the ESL and Championship, concussions managed correctly, that are fully resolved, don’t have detrimental effects on future concussions the present result would question this. The majority of professional players may have played ten or more years of academy, scholar, and junior rugby league, and may play in other leagues such as national squads. This means the actual number of repeated concussions sustained by individual players during their lifetime may be much higher than the figure reported in this study.
It is important to note that even when polices are implemented it can take time to have an effect following the implementation of concussion reporting laws, it took both the 2014 and 2015 seasons before the new requirements were being more fully adhered to. Further despite the high incidence of hamstring injuries reported in 2013, in 2015 this remained unchanged questioning what effect reporting of research findings has on injury prevention. There remains a gap of translating research into practise from governing bodies to other stakeholders such as clinicians, coaches, athletes and strength and conditioners.
Despite their importance variations of injury definition and methods of calculating incidence mean that often it can be difficult to make valid interpretations, comparisons and standardisation within professional rugby league and to other sports. Agreement is urgently needed to address serious clinical questions such as the rise in concussion and repeated concussion injury incidence and the increased severity following further concussion injury.
Further studies are needed investigating risk factors for injuries in elite rugby league, particularly concussion and hamstring injury and the recurrence rates specific to playing positions and in relation to individual physiological characteristics. Future research should consider both player exposure time and number of collisions, any measurement of time regarding match and training exposure must be recorded specifically for each player. Data capture on all training exposure for each individual player should audit specific individual training activities not just training load. It is also recommended that ‘time loss’ from training time as result of injuries sustained from match play be identified separately from ‘time loss’ as a result of injuries that occur whilst participating in training activity. Recording all injuries that occur as a result of exposure to the training environment may assist in clarifying more severe injury events in subsequent training and or match environments.
With the advent of Covid-19 aspects of the game changed during the 2020 season, all these changes should be investigated with comparisons made to the current study this it may provide insightful information into aspects of performance and injury that were previously unavailable.
The welfare and financial implications of the current findings are wide reaching both to further the game’s safety policies, inform player preparation but also advise injury prevention strategies.