Rugby, specifically rugby union, is one of the most popular sports in the world and is played in more than 150 countries (12). Sports participation in rugby union is second only to soccer (17). Rugby union is tremendously popular in New Zealand, Russia, Australia, France, Ireland, the UK, and several Pacific Island nations including Fiji (23). There were more than three billion television viewers for the 2003 Rugby World Cup (20). Although rugby is not yet formally recognized by the National Collegiate Athletic Association (NCAA), its popularity is increasing, particularly collegiate women's rugby with a growing number of varsity teams (17). According to membership data from USA Rugby, in 2009 there were more than 10,000 female collegiate rugby players in the United States. As the sport continues to grow in the United States, it is important for sports medicine personnel to have a good understanding of the demands and peculiarities of the sport to provide appropriate evidence-based treatment on the sideline.
RUGBY UNION FOOTBALL BASICS
It is believed that the sport of rugby was first created in 1823 by an Englishman named William Webb Ellis who "in a fine disregard for the rules" picked up a soccer ball during a match and ran with it. Today, rugby union football is played by an estimated four million athletes around the world (13). It is one of the only contact-collision sports where the rules for women and men are the same.
The game requires muscular strength and aerobic endurance, as well as anaerobic fitness. It is played in two 40-min halves of continuous play on a 100-m by 70-m "pitch" or field. There is one referee per 30 players. Play is only stopped after a score, if the ball goes out of play, the ball becomes unplayable, or there is a rule violation (6). A player can leave the pitch for 10 min for injury care; however, a substitution may occur during their absence.
The game is one of creation of space and ball possession. The ball can be moved down the field only by kicking or running by an individual, or the ball can be passed to a teammate by way of a lateral or backward toss (21). Any player may catch, kick, or run with the ball; the opposing players try to impede this progress by tackling the ball carrier or blocking a kick. The tackle in rugby is similar to that in grid-iron football, rather than a soccer tackle, and often is made with great force. Points can be scored when a "try," worth five points, occurs by touching the ball down over the opposing team's "in-goal" line. When a try is scored, a "conversion" attempt is made by kicking the ball through the goal posts for two additional points. A "goal," which is worth three points, most commonly is made by a place kick when a penalty is called or during open play by drop-kick (21).
UNIQUE FEATURES OF RUGBY
When the ball has become unplayable, the scrum or scrummage, a very unique feature of the game, can be used to restart the game (Fig. 1). The scrum can be dangerous and result in serious injury, specifically to the cervical spine. The scrum is formed by a three-two-three formation of eight forward players in a crouched position bound by shoulders, hands, and arms. Each team engages with the other and attempts to "hook" the ball back to their teammates to gain possession (21). It has been found that the total forward horizontal forces generated on engagement of the scrum can be from 4400 N in high school players to 8000 N in elite players (18). The force needed to injure the cervical spine in flexion only is 2000 N, thus presenting a significant risk to participants in the scrum, especially if there is collapse of the scrum (6).
Another ball possession technique exclusive to rugby occurs when two or more players contest vigorously for the ball. If the ball is on the ground, a ruck forms; if it is still being carried, a maul forms. The scrum received a lot of attention for many years as the main cause of catastrophic cervical spine injuries, and although these injuries still occur in the scrum, more recent data show a trend toward the tackle as the main cause of these injuries (22). Finally, if the ball goes out of bounds, the line-out is created to contest for the ball possession. During a line out, the forwards on opposing teams form two parallel lines facing each other perpendicular to the sideline. The teams boost their teammates into the air to attempt to contest for the ball midair as it is thrown down the middle of the two lines or tunnel (6). Significant injury also can result from the line out, given that athletes are lifted to and may fall from extreme heights.
Player Positions Define Risk for Injury
Rugby union is played with 15 players per side or in a fast-paced variation of seven players per side. There are eight forwards and seven backs in the majority of rugby union matches. As the sideline physician, it is important to understand the various positions when considering each player's risk of injury. It has been shown that certain positions carry considerable risk - especially in the ball possession contests, such as the tackle, scrum, and line-out.
In general, the forwards are responsible for acquiring and maintaining ball possession. See Figure 2 for general layout of positions on the field. The front row forwards include the loose head prop, tight head prop, and the hooker. The loose head prop and tight head prop help support the hooker between them during the scrum ball contest (21). The hooker is the middle player of the front row and tries to hook the ball backward to teammates during the scrum. Worldwide, this position is most susceptible to spinal injuries given the compromised position in the scrum coupled with the significant compressive force at scrum engagement (25). The second row forwards are the locks who join onto the scrum with their heads interlocked and wedged between the thighs of the props and hooker (21). Finally, the back row is made up of two flankers and the eight man. The flankers, or wing forwards, are located on the outside of the third row in the scrum. Eight man is the middle player of the back row whose job is to push during the scrum and quickly make defensive stops or tackles if needed.
The backs typically are responsible for both advancing the ball downfield as well as defending against the opposing team's advance. The scrumhalf and flyhalf are the links between the scrum and backline and must defend around the base of the scrum. The inside and outside centers are integral in both offense and defense. The wings and fullback provide speed and are the last line of defense. Risks to the backline are primarily at the tackles, which occur frequently and at speeds generating significant force. Technique of the tackle is critically important in preventing injury.
According to the Rugby World Cup injury surveillance project in 2003, which followed professional rugby players through the tournament, the flanker and eight man were two of the most injured playing positions (1). However, in a large epidemiologic study of professional rugby union teams in England from the 2002-2003 and 2003-2004 seasons, it was the hookers and outside centers who were at greatest risk for overall match injuries in terms of incidence and severity of injury (2).
The overall incidence of injury during professional rugby union matches as outlined by Brooks et al. was documented as 91 injuries per 1000 player-hours. This is higher than the incidence of injury reported for soccer and ice hockey (2). Previous studies of injury in Soccer World Cup matches showed injury rates of only 71 per 1000 player-hours (1). The goal of epidemiologic data collection in rugby union is to better understand the incidence, nature, severity, and risk factors for injury to allow for implementation of programs to decrease the likelihood of injury (2).
Comparison of injury incidence has been challenging in the rugby literature given significant differences in injury definition, and lack of injury surveillance databases for each gender, country, and level of play. Further complicating analysis is the fact that each level of play has different age cut-offs in each age group and different terms for the level of play in a given country. General age groups can be broken down into youth or school rugby, followed by collegiate, club, and elite or professional. Most injuries occur during contact (2); however, training injury patterns are important to study as the majority of the player's time is spent in training.
HEAD AND NECK INJURIES
The head consistently has been shown to be one of the most commonly injured body parts in rugby (1,16-18). Concussions are a fairly frequent injury at all levels of play, but the incidence of concussion varies widely. Accurate diagnosis and treatment of concussion in rugby union presents several unique challenges to the sideline clinician. First, the clinician only has 10 min to make a decision about a permanent substitution for the player during the match. Second, it has been suggested that there is underreporting of injury either because of lack of knowledge of symptoms of concussion or delayed diagnosis. This is thought to be caused in part by underreporting of injury surmised to be related to the strict criteria outlined by the International Rugby Board (iRB) for players who sustain a concussion. Players who sustain a concussion cannot return to play for 3 wk unless they are symptom-free and evaluated by a neurologic specialist (16). As noted in the study by Kemp et al., few high-level athletes require the 3-wk rest period, and more than 48% of professional rugby players with concussion were able to return to play within a week (16).
As noted, the front row forwards are at risk for catastrophic injury during the scrum. Most cervical spine trauma in rugby is caused by hyperflexion of the neck, with and without rotation. These injuries frequently are caused when an axial force is applied to the vertex of the head and results in a fracture or dislocation (25). Injuries also can be sustained from hyperextension that can lead to narrowing of the spinal cord (25). These injuries can occur more frequently if the scrum collapses, driving the front row players forward into the ground with their necks flexed (Fig. 1). Cervical spine injuries in front row forwards still occur with great frequency during scrummaging; however, there has been a trend toward more cervical spine injuries being sustained during the tackle (7,22).
Early reports on spinal injuries suggested that youth participants were at the greatest risk of spinal injuries. This was thought to be due to skeletal and ligamentous immaturity; however, more recent data suggest that older players and elite players have a higher risk of these injuries (22,25). Because of concerning trends in spinal injuries, the rules for scrum engagement were changed for under-19 players in the late 1980s and early 1990s (22). There is general agreement that this has resulted in a decline in catastrophic cervical spinal injuries, although data are somewhat unclear (7). There has been some evidence that there are national differences to injury patterns in terms of cause of injuries, for example scrum versus tackle (25). The incidence for any spinal injury was found to be significantly higher in forwards versus backs in professional rugby union, with the incidence in forwards more than twice the incidence in backs (7). At the club level, however, more spinal injuries occurred during the tackle than with the scrum. Most front row forwards still sustained spinal injuries during scrummaging (7).
FRACTURES AND DISLOCATIONS
Shoulder injuries, specifically anterior glenohumeral dislocation and instability, caused the greatest proportion of days absent from sport than any other part of the body except the knee in professional rugby players (11). Proximal interphalangeal joint dislocations also are common (6). Elbow and ankle dislocations also can occur but are less common. Severity of recurrent injuries was higher than first injuries. The vast majority occurred during contact, specifically tackling (11). Fractures accounted for 18%-27% of all injuries at the youth level and, as expected, represent a large proportion of lost time due to injury (18). There also appears to be an increasing risk of fracture with age (18).
SOFT TISSUE INJURIES
A total of 546 elite rugby athletes were followed over two seasons by Best et al. and found that the incidence of hamstring muscle injuries per 1000 hours was 5.6 in elite rugby players during match play and only 0.27 per 1000 h in training. Risk factors for hamstring injury were previous injury in the prior month and training greater than 12.5 h in the prior week. Hamstring injuries are higher in backs (4). Backs also have a higher number of calf, quadriceps, and hip flexor injuries and these generally occur with training, specifically skills training (3). Injuries to the thighs, knees, and ankles are the most common overall (2). Thigh hematomas are the most frequently seen injuries in matches (2). Medial collateral ligament injury of the knee and lateral ankles sprains were the most common sprains; however, anterior cruciate ligament injuries account for the highest number of days missed from sport (5). The number of anterior cruciate ligament (ACL) injuries sustained by female athletes remains far higher than their male counterparts in sports such as soccer, basketball, and rugby (8). A study by Gwinn et al. showed that female naval midshipman rugby players had an overall relative risk of 2.44 compared with their male counterparts (8).
Many studies report that the most frequently injured site during rugby matches is the head/neck with a predominance of facial lacerations. In junior elite rugby union, which includes players younger than 15 and 16 yr, the head and neck injuries account for 30% of all injuries (20). Many of these injuries are lacerations, which often can be repaired quickly and efficiently by sideline physicians, and the players frequently return to the field immediately afterwards. Even in the setting of short injury treatment and assessment time, sterile technique must be maintained, local anesthetic should be routinely used, and monofilament sutures are recommended (10). Dental injuries can cause substantial cost to patients as well as the health care delivery system, and these injuries are extremely common in rugby union. Consistent mouth guard use, though not yet mandated by the iRB, has been shown to dramatically reduce the number of dental injuries in rugby union players (23).
The goal of increasing epidemiologic injury data in rugby is to attempt to prevent injuries through further identification of risk factors and injury patterns. With this information, coaches and athletes can work on modification of skills or training patterns to lower the risk of injury. In 2001, New Zealand instituted an injury prevention program, called RugbySmart, which is an educational injury prevention program specifically focusing on spinal cord injuries (24). The program required all rugby coaches and officials to become familiar with the educational materials on physical conditioning, safe techniques for ball contest phases of play, and injury management (24). Data were then collected on spinal injuries over the 4-yr period after the program was instituted. The introduction of this program coincided with a reduction in the rate of disabling spinal injuries in the scrum (24).
It is instructive that 6 out of 12 athletes who sustained catastrophic cervical spine injuries resulting in paralysis in a study by Shelly et al. felt that their injuries could have been prevented. Several of the athletes felt that their initial management was inadequate and stated that the first responders had little or no knowledge of acute care management of cervical spine injuries (25). Team physicians and emergency personnel should remain up-to-date and have ongoing practice sessions to be able to care appropriately for an athlete with a possible cervical spine injury.
There appears to be an increasing trend of protective gear use in rugby union, especially among elite players (19). Rugby headgear, or "scrum caps," are believed by many players to decrease their likelihood of sustaining a major head injury (15). This has not held up in the literature, but headgear has been shown to decrease the risk of superficial facial laceration (14). Some authors suggest that headgear can be associated with a decreased likelihood of concussive injury (16); however, most studies have shown that wearing headgear does not lessen the risk of concussion. In fact, one study found that boys wearing headgear might actually have higher rates of concussion, perhaps because of greater reckless play from perceived protection (19). Players may wear soft shoulder pads (iRB-approved only) that cover the clavicles. No effect on shoulder injury incidence has been shown by wearing shoulder pads (11).
A growing body of literature in the field of rugby documenting injury incidence data can be used to develop injury prevention programs worldwide. The rule changes in England that helped "depower" the scrum in under-19 athletes in the 1980s and 1990s appear to be responsible for a reduction in the frequency of spinal injuries in certain countries (9). These changes may not have been realized without supporting epidemiologic data. In addition, there are promising data to suggest that educational interventions, such as the RugbySmart program out of New Zealand, can reduce substantially the rate of the spinal injuries (24).
There have been significant advances in epidemiologic incidence, nature, severity, and causative data for injuries sustained in rugby union football. There is, however, a need for ongoing surveillance and improvement. A paucity of data for women rugby athletes still exists despite the sport's growing popularity in this group. The iRB and other organizations are working on creating guidelines and recommendations for safety in the sport of rugby. Ongoing efforts at injury prevention and possibly even "prehabilitation" regimens during training periods can help protect rugby athletes of today and tomorrow.
The authors thank the staff at USA Rugby for their assistance and for use of their figures.
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