Materials and methods

Players were eligible for the study if they were members of any category of rugby club affiliated to the Argentine Rugby Union (UAR). Injuries occurring in rugby games of all categories played during a single weekend (Saturday and Sunday) in different provincial unions of Argentina were prospectively registered.

The study was performed every year from 1991 through to 1997, except for 1996. The weekends were randomly chosen between June and July—that is, the middle of the season. All the information gathered during these six years was subjected to statistical analysis. Ages were grouped into a young category (8–21 years of age) and a senior category (adults above 21).

The UAR has a total of 22 provincial unions. Four of them participated in the study in 1991 (Buenos Aires, Rosario, Santa Fé, and Centre of Buenos Aires), seven in 1992 (Buenos Aires, Rosario, Santa Fé, Córdoba, Cuyo, Misiones, Austral, and Entre Ríos), 10 in 1993 (Buenos Aires, Rosario, Entre Ríos, Tucumán, San Juan, Alto Valle, Oeste, and Chubut), 10 in 1994 (Buenos Aires, Rosario, Entre Ríos, Córdoba, Cuyo, Noreste, Austral, Mar del Plata, Santa Fé, and Centre of Buenos Aires), seven in 1995 (Buenos Aires, Rosario, Entre Ríos, Centre of Buenos Aires, Mar del Plata, Salta, and Formosa), and four in 1997 (Buenos Aires, Rosario, Noreste, and Centre of Buenos Aires).

Despite the fact that an average of only seven (32%) provincial unions took part in the study each year, the sample was considered to be highly representative because the rugby union of Buenos Aires has about half of the players in the country.

A rugby injury was defined as a lesion sustained on the field during a competitive official match, which required either temporary replacement of the player because of an open or bleeding wound (law 3), or permanent substitution for the rest of that game.

Medical coverage of all rugby games has been compulsory in Argentina since 1989, otherwise the match is not allowed to begin and the home team loses points. A diagnosis for all the reported cases was made clinically by the respective doctor assigned to the match.

None of the reported injuries were strategic lesions for time outs or substitutions.

Contingency tables, χ² with Yates correction test, odds ratios (OR), and 95% confidence intervals (CI) were calculated in the statistical analysis (Epi Info Version 6.04a).

Results

We studied 1296 rugby games, which included 38 933 players; 11 680 of these played in the senior categories and 27 253 in the young categories. In total, 924 cases of injury were recorded, with an incidence per weekend ranging from 2.1% to 2.5% and a mean (SD) of 2.4 (0.2)% (95% CI 2.22 to 2.53). The incidence of injury and number of players involved each year were 2.1% and 4054 in 1991, 2.4% and 5757 in 1992, 2.5% and 8137 in 1993, 2.3% and 9374 in 1994, 2.5% and 6142 in 1995, and 2.1% and 5469 in 1997.

Senior players suffered more injuries than younger players (χ² = 39.31; OR = 1.53; 95% CI 1.34 to 1.76; p<0.0001) (table 1).

Table 2 summarises the 22 most common types of injury: pulled muscles of the lower limbs were at the top of the list (11.7%; p<0.0001), followed by ankle ligament distension, closed head trauma without loss of consciousness, knee trauma, and bleeding wound on face.

The incidence of the first nine causes of injury proved to be significantly different on a contingency table with nine degrees of freedom (χ² = 706.49; p<0.0001) (table 2).

When the incidence of injury was evaluated by anatomical region, it was found that most lesions affected the lower limbs (42.6%) (χ² = 311.59; p<0.0001), followed by head and neck (35.1%), upper limbs (15.3%), and trunk (6.8%) (table 3). The knee was the region that sustained the largest number of different kinds of lesions (traumas and ligament distension) (14%).

The top nine causes of injury were compared according to age category (table 4). Senior players had a higher risk of suffering the following injuries: pulled muscles of the lower limbs (OR = 2.99; 95% CI 2.01 to 4.46; p<0.0001); ligament distension of the ankle (OR = 1.69; 95% CI 1.12 to 2.53; p = 0.01); blunt trauma of the knee (OR = 1.69; 95% CI 1.06 to 2.68; p = 0.02), bleeding wound on the face (OR = 3.86; 2.24 to 6.70; p<0.0001), ligament distension of the knee (OR = 2.14; 95% CI 1.16 to 3.96; p = 0.01).

Younger players had a greater risk of suffering either muscular or ligament injuries of the cervical column (OR = 3.0; 95% CI 1.05 to 10.08; p = 0.04) (table 4). No cases of neurological compromise of the spine were reported in this study.

Overall, the forwards proved to have a higher risk of injury than the backs (OR = 1.41; 95% CI 1.23 to 1.61; p<0.0001)(table 1¹). When the incidence of injury was estimated for forwards and backs within divisional categories, the forwards uniformly showed higher values than the backs, with the sole exception of the under 16 category where the share was 50 to 50 (table 5).

The most commonly injured player of the team was the flanker with 14.9% each, while the fullback (11.1%) was mostly affected among the backs. The incidence of injury by player position was also different when analysed on a contingency table with nine degrees of freedom (p<0.01) (table 5).

A comparison of senior and younger players with regard to the incidence of injury by player position showed that senior players in the second row (p<0.0001), at fly half (p<0.01), fullback (p = 0.02), and number 8 (p = 0.03) had a statistically higher risk of injury than their younger counterparts. No difference in the risk of injury was found between senior players and younger players with regard to the rest of the positions (table 6).

Table 7 describes the different phases of play leading to injuries in general and within divisional categories. Loose play was the main cause of injury in all categories with a total of 33%, and foul play was the least common cause in all categories. No injuries occurred in lineouts.

The number of injuries suffered during the second half (54%) was higher than in first (46%) (p = 0.01) (table 1).

No deaths were recorded during the study.

Discussion

Injuries are an important cause of morbidity among rugby players.^1–7 A team is estimated to play an average of 22 matches a year in Argentina. Therefore the incidence of injury by the end of the season would rise to 50.6%. The UAR has about 48 000 players, and if one injury occurred per player, there would be 24 188 injured players by the end of the season.

The trends of injury have been fairly stable throughout the years, ranging from 2.5% in both 1993 and 1995 to 2.1% in 1991 and 1997.

Although these figures are inaccurate because 26% of injuries sustained in rugby are iterative,^8,9 they give a rough picture of the situation.

Our data probably underestimate the true incidence of injury for three reasons. Firstly, it can be assumed that 15–17% of injuries occur during training sessions.^4,8–10 Secondly, Garraway and Macleod⁹ observed a peak of incidence at the beginning of the season. Other authors reported two peaks, one at the beginning and another after the mid-season break.^8,10 Despite the fact that the weekends in this study were randomly chosen in the middle of the season, it is not known whether they corresponded to peaks or not. Thirdly, there are several slowly developing joint degenerative lesions resulting from overweight and chronic joint use.⁹

As regards the anatomical distribution of the injuries found in this study, other authors have also noticed that lower limbs, particularly the knee, are mostly affected (table 3).^1–10

It is especially worrisome that younger players proved to have a three times higher risk of muscular or ligament injuries of the cervical column than senior players (table 4). The design of this study does not allow us to retrieve unusual causes of injury in rugby, such as injuries with neurological damage of the spine. However, this observation agrees with a previous study carried out from 1977 to 1997 in which young hookers had a significantly higher risk of suffering disabling injuries to the cervical spine than seniors in Argentine rugby.¹¹

The greater incidence of lesions among senior players confirms that more playing experience does not necessarily reduce the risk of injury,^8–10,12,13 and it may be linked to their more aggressive attitude to the game. Clear evidence of this is the fact that a senior player is almost four times more likely to receive a “bleeding wound on the face” than a younger player (OR = 3.86; 95% CI 2.24 to 6.70; p<0.0001) (table 4).

We found that forwards have a higher risk of injury than the backs (OR = 1.41; 95% CI 1.23 to 1.61; p<0.0001); however, results from different studies are contradictory on this point (tables 1 and 8).

Flankers received the predominant number of injuries, both overall and within each divisional category (table 5). However, table 8 shows great variability in the incidence of injury by position according to different authors. Stokes et al⁸ also found that flankers were injured most often.

Speed, tackle, and counterattack are key tactical features in modern rugby, so it is no wonder that the most common mechanism of injury was the loose play (table 7). However, most catastrophic injuries, such as disabling lesions of the cervical spine, are particularly related to the scrum in Argentina.¹¹

A lower incidence of injuries caused by foul play (1.9%) (table 7) was found than in other countries such as England (between 12% and 31%)⁶ and South Africa (less than 5%).¹⁰

The fact that the greatest percentage of injuries were sustained during the second half (p = 0.01) (table 1) may be related to muscle fatigue and slower reaction time,⁶ which could be prevented by improvement in physical fitness.

A minor number of severe injuries have been reported to result from congenital predisposition^16–19; however, different authors agree that most lesions are preventable.⁵ Gum shields,^20–23 knee braces,^24–27 grease, shoulder pads, and soft helmets may be of help.

A worrisome number of injuries occur in Argentine rugby players, and the true values are undoubtedly higher than found in this study. Measures should be taken to reduce them, placing rigorous emphasis on events related to the high risk positions and situations.

Continuous epidemiological investigation and information on injury mechanisms and their associated risks, as well as permanent updating of rugby rules, are still the basic means of making rugby a safer game.^28–30