Second Year Report on the Three Year Rugby Injury Surveillance Project*

*Jointly funded by ARU and NSW Sporting Injuries Committee

 Report authors: John Orchard, Mario Chan, David Garlick, Fiona Long, John Best, and Andrew McIntosh.

Executive Summary of Rugby Injuries Report for 2001 Season

The report presents the results for 2001, the second year of the three year survey period. The survey is co-funded by the Australian Rugby Union and the NSW Sporting Injuries Committee and conducted through the UNSW Sports Medicine Unit.  The key findings are:

HIGHLIGHTS

Methods

The major definitions used for the survey are as follows:

Definition of an injury:

An injury or medical condition that caused a player to miss a match.

Definition of cohort: - that is, the group of players to be followed during the season.  These were taken as the 15 players in the first grade team for Round 1. In 2001, teams were encouraged to add to their cohort any player who played first grade during the regular season thereafter. Some teams accepted this offer and their cohort size increased during the year. Consistency was obtained in that all players only joined the survey by playing a first grade match for that team during the year.

Definition of season:

The season surveyed for each team started at Round 1 of the regular season and continued until the last match (finals were included if the team played in them). In order to equally compare injury rates from teams with seasons of different lengths, a “team season” was defined as 300 player weeks (that is, 15 players being followed for 20 weeks).

Definition of player status for a round:

In any given round, a player in the cohort was recorded as having a ‘status’ of one of the following: (1) playing in first grade (2) playing another type of match (e.g. second grade or representative match) (3) not playing due to an injury (4) not playing due to a team bye (5) not playing due to other reasons (e.g. suspended, personal reasons, retirement). By definition, every player in the selected cohort was playing in first grade during round 1.

Definition of missing data:

Where the status of a player (in the cohort) is unknown for a given round during the season.

Definition of injury recovery:

An injury was considered to be recovered when the player returned to playing a match. Any further episode after return to play was considered a new injury.

Definition of injury onset:

Onset was divided into (1) injuries occurring in first grade matches (2) injuries occurring in other matches (3) injuries occurring at training (4) injuries with a gradual onset (5) injuries occurring outside rugby, including illness.

Injury seasonal incidence.

Injury seasonal incidence was measured in units of injuries per team per season, which has been defined as injuries occurring per 300 player weeks. All injuries were included in the numerator. All players were considered at risk for each week of the survey. The final round for each team was not considered to be exposure time due to the definition of an injury (that it must cause a player to miss a game), as there was no future round for the player to miss.

Injury match incidence.

Injury match incidence was measured in units of injuries per 1000 player hours. Only injuries that occurred in first grade matches were included in the numerator and only players participating in first grade matches in each week were included in the denominator. A match was considered to last 80 minutes for Elite, City and Country matches and 70 minutes for Schools matches. All players were considered to have played the full game (as exact time of participation was not available). The final round for each team was not considered to be exposure time due to the definition of an injury (that it must cause a player to miss a game), as there was no future round for the player to miss.

Injury pre valence

Injury prevalence was defined as matches missed per team per season (or matches missed through injury per 300 player weeks). Matches missed per team per season calculated in this manner can be converted to an injury prevalence percentage rate by dividing by 3 (300/100=3). Therefore, an injury prevalence of 21 matches missed per team per season is the equivalent of 7% of players missing through injury at any given time. This measure is related both to injury incidence and injury severity.

(Note - the match in first grade that each player played each season was not considered as part of exposure time as by definition, players must have played in first grade in the first week that they were part of the cohort).

RESULTS

Missing data

There were 91 player weeks in which the status of the player (whether injured or missing through other reasons) was unreported. This means that 0.8% of all 12339 weeks was unaccounted for (or that 99.2% of all data has been accounted for). There were 5 occasions in which it was definitely known that the player was missing through injury but a diagnosis was not submitted.

Injury frequency

There were 377 injuries for which the diagnosis was known and these caused 890 player games to be missed.  In season 2000, there were 101 injuries and in season 2001 there were 276 injuries. Most of the injuries occurred during first grade matches (246). There were also 80 injuries with an onset at training (or gradual onset), 27 in other grade matches and 17 occurring outside rugby matches or training.

Injury seasonal incidence

There was an average of 9.7 injuries per team (of 15 players) per season (of 20 games), with slightly higher number of injuries for City teams and slightly lower numbers of injuries for country teams. The most common specific injuries were A/C joint sprains, hamstring strains, knee medial ligament injuries and ankle sprains. There was no one particular type of injury that occurred more commonly than an average of 1 per team per season in any group.

School teams had an average of 1 episode of concussion per team per season, which was higher than other grades. This may have reflected a greater tendency for the medical staff of school teams to treat concussion conservatively. Apart from concussion, school players tended to have fewer injuries of other types.

Injury prevalence (the amount of time missing through injury) was 7.3% on average, with City grade teams reporting a higher injury prevalence of 9.2%, and school teams reporting a lower prevalence of 6.4%.

City team players had a higher amount of missed playing time through neck sprains and hamstring strains. School team players had a higher amount of missed playing time through concussion. Country team players had a higher amount of missed playing time through shoulder injuries. Elite players had a higher amount of missed playing time through knee medial ligament sprains.

Schoolboy teams had a higher percentage of playing time missed through head and neck injuries, country teams had a higher percentage of playing time missed through upper limb injuries and elite teams through lower limb injuries.

Progress discussion

The first year of the study was critical for the development of methods that are consistent for all teams and over all years of the study, including the standard definition of an injury.

The second year has enabled a gathering of a large amount of injury incidence and prevalence data from teams at all levels, with an excellent level of compliance across the board.

Several trends are evident that are likely to be highlighted in the final report.  These are

·        Lower seasonal incidence of injuries causing missed games for the elite teams;

·        Higher than average trend for shoulder/arm/elbow injuries in country teams;

·        Schoolboy teams tended to show a lower incidence of hamstring and groin injuries, but a higher incidence of concussion.

Although some trends are already apparent from the two years of data, analytical comparisons between groups will be made at the end of 3 years when the full amount of data is available.

A review of rugby injuries and references are not included at this stage, as this is a progress report. These will be included in the final report at the end of the 2002 season.

Tables

Seasonal injury incidence

Match injury incidence

Injury prevalence