Incidence of injury in semi-professional rugby league players

Training loads and incidence of injury during the preseason in professional rugby league players

Research into rugby league has found a significant, positive relationship between training load and injury rates. However, there has been limited research investigating this relationship in the preseason period, and the relationship between training load, and injury among professional rugby league players is yet to be examined. The primary aim of this study was to examine the relationships between training load, various psychological data, and the incidence of injury during preseason training at a professional rugby league club. Thirty-six male professional rugby league players undertook a 14-week training program. Each player's training time, intensity rating, and injury status were recorded after each training session. In addition, players rated their sleep, food, energy, mood, and stress on a scale of 1-10 (with 1 being extremely poor and 10 being excellent) biweekly. Over the entire preseason period, a total of 2,877.9 training hours were recorded for the players, with an overall incidence of injury of 6.9 per 1,000 training hours. Higher training loads during the first half of the preseason corresponded to a higher injury rate in comparison to the second half of the preseason. No significant relationship was found between the preseason weekly injury rate and the weekly load, nor was there a relationship between injury and psychological data. These findings suggest no relationship between training load, psychological data, and injury incidence during the preseason training period in professional rugby league players. However, results suggest that players may have an increased risk of injury during the early preseason period. The findings of this study may be particularly useful in professional rugby league teams to determine when a player is at increased risk of injury, using their training loads and psychological data.

Physical collisions and injury during professional rugby league skills training

This study described the number and intensity of collisions experienced by professional rugby league players during pre-season and in-season skills training sessions using microtechnology (e.g. accelerometers, gyroscopes). Short, medium, and long recovery periods between matches were accounted for and the incidence of collision injuries sustained in the training environment was also assessed. Thirty professional rugby league players (mean±SD age, 23.6±3.8yr) participated in this study. The number and intensity of collisions and the incidence of collision injuries were monitored during 117 skills training sessions. Over the course of the season, an average of 77 collisions occurred per player, per session. The average number of mild, moderate, and heavy collisions performed by each member of the squad per session was 24, 46, and 7, respectively. A total of 37 collision injuries were recorded during training over the season, equating to an injury incidence of 6.4 per 10,000 collisions. Over half (54.1%) of all collision injuries resulted in no loss of training time, and less than 14% of collision injuries resulted in a missed match. The greatest number of collisions occurred during training sessions in the weeks with the longest recovery between matches (10 days). The incidence of collision injuries also peaked during the 10 day between match recovery cycle. These findings demonstrate that while significant physiological demands are placed on rugby league players as a result of the large number and intensity of physical collisions performed in training, these collisions are associated with minimal injury risk.

Match and training injuries in rugby league: a review of published studies

Rugby league is an international collision sport played by junior, amateur, semiprofessional and professional players. The game requires participants to be involved in physically demanding activities such as running, tackling, passing and sprinting, and musculoskeletal injuries are common. A review of injuries in junior and senior rugby league players published in Sports Medicine in 2004 reported that injuries to the head and neck and muscular injuries were common in senior rugby league players, while fractures and injuries to the knee were common in junior players. This current review updates the descriptive data on rugby league epidemiology and adds information for semiprofessional, amateur and junior levels of participation in both match and training environments using studies identified through searches of PubMed, CINHAL, Ovid, MEDLINE, SCOPUS and SportDiscus databases. This review also discusses the issues surrounding the definitions of injury exposure, injury rate, injury severity and classification of injury site and type for rugby league injuries. Studies on the incidence of injuries in rugby league have suffered from inconsistencies in the injury definitions utilized. Some studies on rugby league injuries have utilized a criterion of a missed matchas an injury definition, total injury incidences or a combination of both time-loss and non-time-loss injuries, while other studies have incorporated a medical treatment injury definition. Efforts to establish a standard definition for rugby league injuries have been difficult, especially as some researchers were not in favour of a definition that was all-encompassing and enabled non-time-loss injuries to be recorded. A definition of rugby league injury has been suggested based on agreement by a group of international researchers. The majority of injuries occur in the match environment, with rates typically increasing as the playing level increases. However, professional level injury rates were reportedly less than semiprofessional participation. Only a few studies have reported training injuries in rugby league, where injury rates were reported to be less than match injuries. Approximately 16-30% of all rugby league injuries have been reported as severe, which places demands upon other team members and, if the player returns to playing too early, places them at an increased risk of further injuries. Early research in rugby league identified that ligament and joint injuries were the common injuries, occurring primarily to the knee. More recently, studies have shown a change in anatomical injury sites at all levels of participation. Although the lower limb was the frequent injury region reported previously, the shoulder has now been reported to be the most common injury site. Changes in injury site and type could be used to prompt further research and development of injury reduction programmes to readdress the issue of injuries that occur as a result of participation in rugby league activities. Further research is warranted at all participation levels of rugby league in both the match and training environments to confirm the strongest risk factors for injury.

Treatment of magnetic resonance imaging-documented isolated grade III lateral collateral ligament injuries in National Football League athletes

BACKGROUND

Isolated high-grade tears of the lateral collateral ligament (LCL) of the knee are rare, as most injuries are part of a broader pattern of damage to the posterolateral corner. Limited data exist in the literature about the ideal management of isolated LCL injuries, especially in elite-level athletes.

HYPOTHESIS

Operative and nonoperative treatment of MRI-documented isolated grade III LCL injury can produce equal results in terms of return to play in the National Football League (NFL).

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The NFL Injury Surveillance System was used to identify all players with lateral ligament injuries of the knee from 1994 to 2004. In addition, the medical staffs of all NFL clubs were surveyed about injuries during the same period. Nine players with MRI-documented isolated grade III LCL injuries were identified through this process. The medical staff for each respective player then completed a data questionnaire. Statistics were analyzed using 1-way analysis of variance.

RESULTS

Four players underwent direct surgical repair of their injuries; they missed an average of 14.5 weeks of play and did not return within the same season. Five players were managed nonoperatively and missed an average of 2.0 weeks (P = .0001). Four of the 5 players in the nonoperative group returned within the same season at an average of 10 days; 1 missed the rest of the season. All 9 players were able to return to play the following season, and played for an average total of 2.8 (operative) and 4.4 (nonoperative) additional seasons (P = .253).

CONCLUSION

Nonoperative management of MRI-documented isolated grade III lateral collateral ligament injuries in NFL athletes results in more rapid return to play without subjecting the player to the risks of surgery, while achieving an equal likelihood of return to play at the professional level.

Injuries in amateur rugby league matches in New Zealand: a comparison between a division 1 and a division 2 premier grade team

OBJECTIVE

To investigate the incidence, site, nature, and severity of injuries in amateur rugby league in New Zealand at 2 different participation levels.

DESIGN

A nonconcurrent observational prospective cohort study design.

SETTING

Rugby league match environment over the 2006 (division 2) and 2008 (division 1) competition seasons.

PARTICIPANTS

Members of the rugby league team participating in match activities.

ASSESSMENT OF RISK FACTORS

For each injury, it was recorded in which division it occurred; how many games, if any, were subsequently missed; and the type, site, and severity of injury.

MAIN OUTCOME MEASURES

Injuries were reported as rate per 1000 hours, also broken down into severity according to the number of games missed.

RESULTS

Over the duration of the study periods, there was a combined total of 372 (division 1: 166 and division 2: 206) injuries recorded. The combined injury rate was 405 per 1000 playing hours (division 1: 266 per 1000 playing hours and division 2: 700 per 1000 playing hours).

CONCLUSIONS

The total injury incidence was higher than those previously reported for amateur and professional rugby league competitions. The incidence of missed match injuries for this study is also higher than missed match injuries reported for amateur, semiprofessional, and professional level competitions. The results of this study suggest that division 2 participants may have a lower fitness and skill level than division 1 participants. Further multidistrict prospective studies on the incidence of injuries in amateur rugby league competitions in New Zealand would enable further clarification on the actual total and missed match injury incidence and the incidence of tackle-related injuries in amateur competitions throughout New Zealand.

Electromyographic analysis of selected shoulder muscles during a rugby football tackle

Background

Epidemiological studies have shown that the incidence of shoulder injuries is increasing in rugby and the majority are related to the contact/tackle phase of play. However, no data currently exists that describes preparatory muscle activity during tackle. This information could aid in guiding training and rehabilitation, if available. The purpose of the study was to assess the sequence of onset of EMG activity of selected scapulohumeral muscles during rugby tackle. 15 healthy professional rugby players participated in the study. Surface EMG activity was assessed for timing of onset relative to time of impact during a modified tackle activity in pectorialis major, biceps brachii, latissimus dorsi, serratus anterior and infraspinatus muscles.

Results

Onset of activity occurred in all muscles prior to impact. Factorial ANOVA showed significant differences between muscles in activation timing (p = 0.0001), paired t-tests revealed that serratus anterior was activated prior to all other muscles tested (p < 0.04, for all comparisons), with comparison between all other muscles showing no significant differences (p > 0.05), except pectorialis major on all comparisons showed significantly later activation timing than all other muscles (p < 0.001).

Conclusion

Muscle activation timing may if not properly balanced around the shoulder girdle expose the glenohumeral joint to excessive load and stress. This paper demonstrates a simple method which sets out some preliminary normative data in healthy players. Further studies relating these data to injured players are required.

Effects of field location, time in competition, and phase of play on injury severity in high school football

This study evaluated the effects of competitive intensity, represented by the variables time in competition, phase of play, and field location, on injury severity in U.S. high school football. The injury rate was higher in competition than practice (RR = 4.75, 95% CI: 4.34-5.20). Mild and moderate injuries were frequently lower leg/foot/ankle sprains/strains and concussions. Severe injuries were frequently knee Sprains/strains and arm fractures. Severe injuries composed a greater proportion of injuries sustained during the beginning and middle of competition compared with injuries sustained during the end/overtime (IPR = 1.83, 95% CI: 1.25-2.69). Compared with injuries sustained during general play, a greater proportion of kickoff/punt injuries were severe (IPR = 1.69, 95% CI: 1.07-2.68) or were concussions (IPR = 1.86, 95% CI: 1.05-3.30). Identifying factors contributing to severe injury is a crucial first step toward developing targeted evidence-based interventions aimed at reducing the incidence of severe injuries among the millions of high school football players.

A comparison of fitness and skill among playing positions in sub-elite rugby league players

In rugby league, individual playing positions require a wide range of physical performance qualities and offensive and defensive skills. This study investigated the physical performance, anthropometric, and skill characteristics of specific playing positions in sub-elite rugby league players. Ninety-eight sub-elite rugby league players (mean+/-S.D. age, 22.5+/-4.9 years) participated in this study. Players underwent measurements of anthropometry (height, body mass, and sum of four skinfolds), muscular power (vertical jump), speed (10m, 20m, and 40m sprint), change of direction speed (L run), and maximal aerobic power (multistage fitness test). In addition, two expert coaches independently assessed the skill of players using standardised technical criteria. Hit-up forwards were heavier and had greater skinfold thickness than the adjustables and outside backs positional groups. Furthermore, hit-up forwards had significantly (p<0.05) slower change of direction speed than outside backs, and slower 20m and 40m speed than both the adjustables and outside backs positional groups. Hit-up forwards had a significantly greater (p<0.05) ability to 'hit and spin' than both adjustables and outside backs. The evasion skills (i.e. ability to beat a player and 2 versus 1 ability) of adjustables and outside backs were significantly greater (p<0.05) than hit-up forwards. Adjustables had significantly greater (p<0.05) skills under physiological game stress than hit-up forwards and better catching, ball carrying, and basic passing skills than the hit-up forwards and outside backs. These findings demonstrate that the physical performance, anthropometric, and skill qualities of sub-elite rugby league players vary according to playing position.

Incidence of injury in junior rugby league players over four competitive seasons

While several studies have documented the incidence of injury in senior rugby league players, information on the injury rates of junior rugby league players is limited. In addition, all of the injury surveillance studies performed on junior rugby league players have been performed over a limited time frame (typically one season). The purpose of this study was to document the incidence of injury in junior rugby league players over four competitive seasons. Injury data were collected from 84 matches. An injury was defined as one that occurred in a match and resulted in the player missing a subsequent match. The overall incidence of injury was 56.8 (95% CI, 42.6-70.9) per 1000 playing hours. The majority of injuries were sustained to the shoulder (15.6 [95% CI, 8.2-23.0] per 1000 playing hours). Sprains were the most common type of injury (24.7 [95% CI, 15.4-34.1] per 1000 playing hours). Injuries were most commonly sustained while being tackled (19.2 [95% CI, 11.0-27.5] per 1000 playing hours) and while tackling (10.1 [95% CI, 4.1-16.0] per 1000 playing hours). While there was a tendency towards differing injury rates over the four competitive seasons (chi(2)=6.3, d.f.=3), the differences were not statistically significant (p=0.10). These findings demonstrate that the incidence of junior rugby league injuries is similar to previously reported for senior competitors. A long-term collaborative effort to reduce the incidence of injury in junior rugby league players is warranted.

Applied physiology of rugby league

Rugby league football is played in several countries worldwide. A rugby league team consists of 13 players (6 forwards and 7 backs), with matches played over two 40-minute halves separated by a 10-minute rest interval. Several studies have documented the physiological capacities of rugby league players and the physiological demands of competition, with the physiological capacities of players and the physiological demands of competition increasing as the playing level is increased. However, there is also evidence to suggest that the physiological capacities of players may deteriorate as the season progresses, with reductions in muscular power and maximal aerobic power and increases in skinfold thickness occurring towards the end of the rugby league season, when training loads are lowest and match loads and injury rates are at their highest. Player fatigue and playing intensity have been suggested to contribute to injuries in rugby league, with a recent study reporting a significant correlation (r=0.74) between match injury rates and playing intensity in semi-professional rugby league players. Studies have also reported a higher risk of injury in players with low 10-m and 40-m speed, while players with a low maximal aerobic power had a greater risk of sustaining a contact injury. Furthermore, players who completed <18 weeks of training prior to sustaining their initial injury were at greater risk of sustaining a subsequent injury. These findings provide some explanation for the high incidence of fatigue-related injuries in rugby league players and highlight the importance of speed and endurance training to reduce the incidence of injury in rugby league players. To date, most, but not all, studies have investigated the movement patterns and physiological demands of rugby league competition, with little emphasis on how training activities simulate the competition environment. An understanding of the movement patterns and physiological demands of specific individual positions during training and competition would allow the development of strength and conditioning programmes to meet the specific requirements of these positions. In addition, further research is required to provide information on the repeated effort demands of rugby league. A test that assesses repeated effort performance and employs distances, tackles and intensities specific to rugby league, while also simulating work-to-rest ratios similar to rugby league competition, is warranted.

Incidência de lesões na prática do rúgbi amador no Brasil

Este estudo visou verificar a incidência de lesões traumáticas na prática esportiva do rúgbi amador no Brasil. A amostra constituiu-se de 42 praticantes amadores de duas equipes de rúgbi de São Paulo, do sexo masculino, com idade entre 18 e 30 anos. Foi aplicado a cada jogador um questionário em forma de entrevista para verificar a ocorrência de lesões após cada jogo de rúgbi disputado pela respectiva equipe durante cinco meses de 2006. Lesão foi definida como alguma dor ou dano físico sofrido por um jogador durante o treino e durante ou imediatamente após uma partida de rúgbi. Os dados das respostas dos jogadores foram analisados estatisticamente, com nível de significância estabelecido em p£0,05. A incidência total de lesões foi de 574,16 por 1.000 horas de jogo. Houve predomínio de lesões nos membros inferiores em ambas as equipes. A manobra conhecida como tackle foi a maior causa de lesões. O segundo tempo foi o período do jogo em que a maioria das lesões ocorreu. Atacantes foram mais freqüentemente lesionados quando comparados aos defensores. A incidência de lesões traumáticas no rúgbi amador no Brasil mostrou-se extremamente alta, caracterizando uma importante diferença quando comparada à incidência de lesões em outros estudos feitos em países onde o rúgbi é um esporte mais popular.

Training injuries in New Zealand amateur rugby league players

This study investigated the incidence, site, nature and severity of training injuries in a New Zealand amateur rugby league team. The incidence of injuries was prospectively studied in a senior amateur rugby league club over one domestic season. All injuries sustained during training sessions were recorded. Injury data was collected from a total of 77 training sessions. Information recorded included the date, time, site, nature, cause and severity of injury. A total of 66 training injuries were recorded. The total injury incidence was 22.4 per 1000 training hours. Injuries resulting in missed training sessions were 16.9 per 1000 h. The most common injury site was the thigh for both overall injuries and injuries resulting in missed training weeks. The incidence of overexertion injuries peaked immediately prior to the commencement of the competitive season. The high rates of overexertion injuries suggest that an increase in intensity may contribute to training injuries in amateur rugby league players. An understanding of the demands of training, and the effects that injuries have on players is essential for the identification of injury prevention strategies.

The epidemiology of shoulder injuries in English professional rugby union

BACKGROUND

Shoulder injuries constitute a considerable risk to professional rugby union players; however, there is a shortage of detailed epidemiologic information about injuries in this population.

PURPOSE

To describe the incidence, severity, and risk factors associated with shoulder injuries in professional rugby union.

STUDY DESIGN

Descriptive epidemiology study.

METHOD

Medical personnel prospectively reported time-loss injuries in professional rugby union in England, and the shoulder injuries were evaluated.

RESULTS

The incidence of shoulder injuries was significantly lower during training (0.10/1000 player-training hours) compared with matches (8.9/1000 player-match hours). The most common match injury was acromioclavicular joint injury (32%); the most severe was shoulder dislocation and instability (mean severity, 81 days absent), which also caused the greatest proportion of absence (42%) and had the highest rate of recurrence (62%). The majority of match shoulder injuries were sustained in the tackle (65%), and outside backs were the most likely to sustain an injury from tackling (2.4/1000 player-tackles). Injuries sustained during training were significantly more severe (61 days) than were those sustained during match play (27 days), and defensive training sessions carried the highest risk of injury (0.45/1000 player-hours; mean severity, 67 days). A mean of 241 player-days per club per season were lost to shoulder injuries.

CONCLUSION

Results suggest the potential to reduce this injury burden by modifying training activities and implementing "pre-habilitation" strategies in an effort to minimize the risk of shoulder dislocation/instability.

Influence of environmental and ground conditions on injury risk in rugby league

While the theoretical basis for a relationship between ground and environmental conditions and injury in rugby league is compelling, corroborative research is far from substantive. This study investigated the relationship between environmental and ground conditions and injury risk in 156 semi-professional rugby league players. Injuries were prospectively recorded from 157 training sessions and 137 competitive matches played over two consecutive competitive seasons. Daily weather variables (maximum and minimum temperature, relative humidity, and rainfall) were recorded, while ground conditions were subjectively rated as heavy, slippery, firm, or hard. Regression analysis was conducted to examine the independent effects of the environmental variables, ground condition, session type (training, match), and the interaction between ground condition and session type on injury. Higher temperatures, greater humidity, and greater levels of rainfall were all associated (p<.05) with softer ground conditions. A higher 365-day rainfall was associated with fewer injuries. Both the number of injuries and injury rate were higher in matches than in training sessions and when ground conditions were harder. For both number of injuries and injury rate, there was a statistically significant interaction between ground condition and session type, with harder ground conditions resulting in a higher injury rate in matches, but not training sessions. In conclusion, in rugby league, ground conditions do not influence training injuries, however, both harder ground conditions and less rainfall are associated with a greater number of match injuries.

The incidence of anterior cruciate ligament injuries among competitive Alpine skiers: a 25-year investigation

BACKGROUND

Little is known about the evolution of anterior cruciate ligament injury rates among elite alpine skiers.

PURPOSE

To evaluate epidemiologic aspects of anterior cruciate ligament injuries among competitive alpine skiers during the last 25 years.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

Data were collected from elite French national teams (379 athletes: 188 women and 191 men) from 1980 to 2005.

RESULTS

Fifty-three of the female skiers (28.2%) and 52 of the male skiers (27.2%) sustained at least 1 anterior cruciate ligament injury. The overall anterior cruciate ligament injury incidence was 8.5 per 100 skier-seasons. The primary anterior cruciate ligament injury rate was 5.7 per 100 skier-seasons. The prevalence of reinjury (same knee) was 19%. The prevalence of a bilateral injury (injury of the other knee) was 30.5%. At least 1 additional anterior cruciate ligament surgery (mean, 2.4 procedures) was required for 39% of the injured athletes. Men and women were similar with regard to primary anterior cruciate ligament injury rate (P = .21), career remaining after the injury (P = .44), and skiing specialty (P = .5). There were more anterior cruciate ligament injuries (primary, bilateral, re-injuries) among athletes ranking in the world Top 30 (P < .001). Anterior cruciate ligament-injured athletes had a career length of 7.5 years, whereas athletes with no anterior cruciate ligament injury had a career of 4.5 years (P < .001). Finally, injury rates remained constant over time.

CONCLUSION

Anterior cruciate ligament injury rates (primary injury, bilateral injury, reinjury) among national competitive alpine skiers are high and have not declined in the last 25 years. Finding a way to prevent anterior cruciate ligament injury in this population is a very important goal.

For debate: consensus injury definitions in team sports should focus on encompassing all injuries

OBJECTIVE

The purpose of this paper is to highlight the most effective method of collecting injury data by using a definition that encompasses all injuries into the data collection system. The definition provides an accurate picture of injury incidence and also allows filtering of records so that data can be reported in a variety of comparable ways.

DATA SOURCES/SYNTHESIS

A qualitative review of literature in team sports, plus expert opinion, served as the basis for data collection strategies. Articles were retrieved from SportsDiscus and PubMed using the terms "sports injury definition" and "injury definition." These terms were searched for the period 1966 to November 2006.

RESULTS

One of the major results (from this paper) that supports the use of an all-encompassing injury definition is that 70% to 92% of all injuries sustained fall into the transient category--that is, by only recording injuries that result in missed matches, the majority of injuries are missed and therefore injury rates are underreported.

CONCLUSION

An injury definition should be the most encompassing definition that enables a true, global picture of injury incidence to be seen in participation in any team sport.

SLAP tears of the glenoid labrum in contact athletes

OBJECTIVE

To describe the distribution and clinical presentation of labral injuries in rugby players and the time taken for them to return to sports.

DESIGN

Retrospective cohort study.

SETTING

Busy shoulder practice in the North West of England, treating a large number of professional athletes.

PATIENTS

A review of 51 shoulder arthroscopies performed on professional rugby players over a 35 month period. All patients diagnosed with a SLAP lesion at arthroscopy were identified. Eighteen patients had a documented SLAP tear; this group represented our study population.

INTERVENTIONS

Arthroscopic debridement and/or stabilization was carried out for all labral injuries using Panaloc anchors and No. 2 PDS via a 2 portal technique.

MAIN OUTCOME MEASUREMENTS

Classification of injury, Satisfaction, Time to return to play.

RESULTS

The incidence of SLAP tears in our study population was 35%. There were 11 isolated SLAP tears (61%), 3 SLAP tears associated with a Bankart lesion (17%), 2 SLAP tears associated with a posterior labral lesion (11%), and 2 SLAP tears associated with an anterior and posterior labral injuries (11%). Of the 18 SLAP tears, 14 (78%) were type 2, 3 (17%) were type 3, and 1 (5%) was type 4. None of the patients with a SLAP tear presented with symptoms of instability. MR Arthrogram had a 76% sensitivity for detecting SLAP tears. By 6 months postsurgery, 89% of patients were satisfied. Patients with isolated SLAP tears were the quickest to return to sports, at an average of 2.6 months postsurgery.

CONCLUSIONS

SLAP tears are a common injury in rugby players. These can often be diagnosed with MR arthrography. Arthroscopic repair is associated with excellent results and early return to sports.

Incidence of injuries in the New Zealand national rugby league sevens tournament

This study investigated the incidence, site, nature and causes of injuries sustained in the New Zealand national rugby league sevens tournament. A total of 218 players competing in 47 matches were studied. All injuries sustained within the tournament were prospectively recorded. Injuries were categorised according to the severity assessment at the time of the injury. Information obtained included the time, site, nature and cause of the injury. The incidence of injury was 497.6 per 1000 playing hours. More than 40% (216.1 per 1000) of injuries sustained occurred within the lower limbs. The shoulder was the single most commonly injured site (78.6 per 1000). Sprains were the most common injury type (189.9 per 1000). The ball-carrier sustained significantly more (p<0.05) injuries than the tackling player (216.1 per 1000 [43.4%] versus 117.8 per 1000 [23.7%]). There were significantly more injuries on the first day of competition than on the second day of competition (600.4 per 1000 [76.3%] versus 320.9 per 1000 [23.7%]). The findings of higher injury rates on the first day of competition and during the second period of matches suggest that playing intensity and player fatigue may contribute to injuries in rugby league sevens.

Injury in rugby league

It was the purpose of this review to document the range, incidence, location and mechanism of injury occurring in the sport of rugby league. Rugby league is a collision sport played in Europe and the Pacific regions including Australia. The sport is well established and has competitions ranging from junior to elite professional. Due to the contact nature of the game, injury is relatively common. The most common injuries are musculotendinous in nature and afflict the lower limb more frequently than elsewhere. Despite the high incidence of minor (sprains/strains) to moderate musculoskeletal injury (fracture, ligament and joint injury) and minor head injuries such as lacerations, nasal fractures and concussions, rare more serious spinal cord and other injuries causing death have also been recorded. The literature on rugby league injury is small but growing and suffers from a lack of consistent definition of what an injury is, thereby causing variability in the nature and incidence/prevalence of injury. Information is lacking on the injury profiles of different age groups. Importantly, there has been little attempt to establish a coordinated injury surveillance program in rugby league in the junior or professional levels. The implementation of such programs would require a universal definition of injury and a focus on important events and competitions. The implementation could provide important information in the identification and prevention of risk factors for injury.

The Influence of Methodological Issues on the Results and Conclusions from Epidemiological Studies of Sports Injuries

Data obtained from epidemiological studies of sports injuries are an essential requirement for developing injury prevention, treatment and rehabilitation strategies. Although many authors have discussed the strengths and weaknesses of research methods employed in epidemiology, the potential effects that variations in research design and methods of analysis can have on study conclusions have not been clearly illustrated. This article addresses a number of methodological issues and illustrates their potential effects using examples based on injury data obtained from a single, large epidemiological study in professional rugby union. The examples demonstrate that conflicting conclusions can be reached depending on how the data are collected and analysed. The pivotal roles played by injury definition (loss-of-time, missed matches, diagnostic assessment and surgery), recurrent injury definition (clinical judgement and same injury/same location/same season), method of reporting injuries (number, proportions and incidence) and method of calculating incidence (injuries per 1000 player-hours, per 1000 athlete-exposures and per 1000 matches) are highlighted and illustrated. Other examples show that if training and match injuries are combined, the incidence of injury is more likely to reflect the incidence of training injuries but the distributions of injuries are more likely to reflect the distributions of match injuries. An example is presented that demonstrates that the identification of injuries causing the greatest concern within a sport depends on whether the assessment is based on injury incidence, severity or risk. Finally, examples are presented to show that the relationships identified between sports injuries and risk factors may be dependent on whether case-control or cohort study designs are used. Although there are no simple solutions available to resolve the issues raised, the discussion demonstrates the importance, at least within a sport, of reaching consensus agreements on acceptable study designs and methods of data analysis in sports epidemiology.

Epidemiology of injuries in English professional rugby union: part 2 training Injuries

OBJECTIVES

To undertake a detailed epidemiological study of training injuries sustained by professional rugby union players in order to define their incidence, nature, severity, and causes.

METHODS

A two season prospective design was used to study training injuries associated with 502 rugby union players at 11 English Premiership clubs. Team clinicians reported all training injuries on a weekly basis and provided details of the location, diagnosis, severity, and mechanism of each injury. Training exposures for individual players were recorded on a weekly basis. Loss of time from training and match play was used as the definition of an injury.

RESULTS

The overall incidence of injury was 2.0 per 1000 player-hours, and each injury resulted on average in 24 days lost time. Recurrences, which accounted for 19% of injuries, were more severe (35 days) than new injuries (21 days). Twenty two per cent of all training occurred during the preseason but 34% of all injuries were sustained in this period. Hamstring, calf, hip flexor/quadriceps, and adductor muscle injuries were the most common for backs, whereas hamstring, lateral ankle ligament, and lumbar disc/nerve root injuries predominated for forwards. Lumbar disc/nerve root, shoulder dislocation/instability, and hamstring muscle injuries for forwards and hamstring muscle and anterior cruciate ligament injuries for backs caused the greatest number of days absence. Running was the predominant cause of injury for both forwards and backs, although the overall incidence and severity of injuries sustained during skills training were significantly greater than those sustained during conditioning training.

CONCLUSIONS

On average, a club will have 5% of their players unavailable for selection as a consequence of training injuries.

Epidemiology of injuries in English professional rugby union: part 1 match injuries

OBJECTIVES

To undertake a detailed, large scale epidemiological study of match injuries sustained by professional rugby union players in order to define their incidence, nature, severity, and causes.

METHODS

A two season prospective design was used to study match injuries associated with 546 rugby union players at 12 English Premiership clubs. Team clinicians reported all match injuries on a weekly basis and provided details of the location, diagnosis, severity, and mechanism of each injury. Match exposures for individual players were recorded on a weekly basis. Loss of time from training and match play was used as the definition of an injury.

RESULTS

The overall incidence of injury was 91 injuries/1000 player-hours, and each injury resulted on average in 18 days lost time. Recurrences, which accounted for 18% of injuries, were significantly more severe (27 days) than new injuries (16 days). Thigh haematomas were the most common injury for forwards and backs, but anterior cruciate ligament injuries for forwards and hamstring injuries for backs caused the greatest number of days absence. Contact mechanisms accounted for 72% of injuries, but foul play was only implicated in 6% of injuries. The ruck and maul elements of the game caused most injuries to forwards, and being tackled caused most injuries to backs. The hooker and outside centre were the playing positions at greatest risk of injury.

CONCLUSIONS

On average, a club will have 18% of their players unavailable for selection as a consequence of match injuries.

Science of rugby league football: A review

The purpose of this paper is to provide a comprehensive review of the science of rugby league football at all levels of competition (i.e. junior, amateur, semi-professional, professional), with special reference to all discipline-specific scientific research performed in rugby league (i.e. physiological, psychological, injury epidemiology, strength and conditioning, performance analysis). Rugby league football is played at junior and senior levels in several countries worldwide. A rugby league team consists of 13 players (6 forwards and 7 backs). The game is played over two 30 - 40 min halves (depending on the standard of competition) separated by a 10 min rest interval. Several studies have documented the physiological capacities and injury rates of rugby league players. More recently, studies have investigated the physiological demands of competition. Interestingly, the physiological capacities of players, the incidence of injury and the physiological demands of competition all increase as the playing standard is increased. Mean blood lactate concentrations of 5.2, 7.2 and 9.1 mmol . l(-1) have been reported during competition for amateur, semi-professional and professional rugby league players respectively. Mean heart rates of 152 beats . min(-1) (78% of maximal heart rate), 166 beats . min(-1) (84% of maximal heart rate) and 172 beats . min(-1) (93% of maximal heart rate) have been recorded for amateur, semi-professional and junior elite rugby league players respectively. Skill-based conditioning games have been used to develop the skill and fitness of rugby league players, with mean heart rate and blood lactate responses during these activities almost identical to those obtained during competition. In addition, recent studies have shown that most training injuries are sustained in traditional conditioning activities that involve no skill component (i.e. running without the ball), whereas the incidence of injuries while participating in skill-based conditioning games is low. Collaborative research among the various sport science disciplines is required to identify strategies to reduce the incidence of injury and enhance the performance of rugby league players. An understanding of the movement patterns and physiological demands of different positions at all standards of competition would allow the development of strength and conditioning programmes to meet the precise requirements of these positions. Finally, studies investigating the impact of improvements in physiological capacities (including the effect of different strength and conditioning programmes) on rugby league playing performance are warranted.

Assessment of functional capacity of the musculoskeletal system in the context of work, daily living, and sport: a systematic review

The aim of this systematic review was to survey methods to assess the functional capacity of the musculoskeletal system within the context of work, daily activities, and sport. The following key words and synonyms were used: functional physical assessment, healthy/disabled subjects, and instruments. After applying the inclusion criteria on 697 potential studies and a methodological quality appraisal, 34 studies were included. A level of reliability > 0.80 and of > 0.60 resp 0.75 and 0.90, dependent of type of validity, was considered high. Four questionnaires (the Oswestry Disability Index, the Pain Disability Index, the Roland-Morris Disability Questionnaire, and the Upper Extremity Functional Scale) have high levels on both validity and reliability. None of the functional tests had a high level of both reliability and validity. A combination of a questionnaire and a functional test would seem to be the best instrument to assess functional capacity of the musculoskeletal system, but need further examined.

The management of hamstring injury—Part 1: Issues in diagnosis

Hamstring injuries are the most prevalent muscle injury in sports involving rapid acceleration and maximum speed running. Injury typically occurs in an acute manner through an eccentric mechanism at the terminal stages of the swing phase of gait. Biceps femoris is most commonly injured. Re-injury rates are high and management is a challenge given the complex multi-factorial aetiology. The high rates of hamstring injury and re-injury may result from a lack of high-quality research into the aetiological factors underlying injury. Re-injury may also result from inaccuracy in diagnosis that results from the potential multi-factorial causes of these conditions. Inaccuracy in diagnosis could lead to multiple potential diagnoses that may result in the implementation of variable management protocols. Whilst potentially useful, such variability may also lead to the implementation of sub-optimal management strategies. Previous hamstring injury is the most recognized risk factor for injury, which indicates that future research should be directed at preventative measures. Much anecdotal and indirect evidence exists to suggest that several non-local factors contribute to injury, which may be addressed through the application of manual therapy. However, this connection has been neglected in previous research and literature. This paper will explore and speculate on this potential connection and offer some new contributive factors for hamstring injury management. This first paper of a two part series on hamstring injury will explore diagnostic issues relevant to hamstring injury and the second will investigate various established and speculative management approaches.

Risk factors for injury in subelite rugby league players

BACKGROUND

Although player fatigue and playing intensity have been suggested to contribute to injuries in rugby league players, no study has confirmed if the level of physical fitness is a risk factor for injury in rugby league players. The aim of this study was to identify risk factors for injury in subelite rugby league players.

HYPOTHESIS

Low physical fitness levels are risk factors for injury in subelite rugby league players.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

One hundred fifty-three players from a subelite rugby league club underwent preseason measurements of muscular power (vertical jump), speed (10- and 40-m sprint), and maximal aerobic power (multistage fitness test) over 4 competitive seasons. All injuries sustained by players were prospectively recorded over the 4 competitive seasons.

RESULTS

The risk of injury was greater in players with low 10- and 40-m speed. Players with a low maximal aerobic power had a greater risk of sustaining a contact injury. In addition, players who completed less than 18 weeks of training before sustaining their initial injuries were at greater risk of sustaining a subsequent injury.

CONCLUSIONS

Subelite rugby league players with low speed and maximal aerobic power are at an increased risk of injury. In addition, players who complete less than 18 weeks of training before sustaining an initial injury are at greater risk of sustaining a subsequent injury. These findings highlight the importance of speed and endurance training to reduce the incidence of injury in subelite rugby league players.

Incidence of injury in junior and senior rugby league players

Rugby league is an international collision sport played at junior, amateur, semi-professional and professional levels. Due to the high numbers of physical collisions and tackles, musculoskeletal injuries are common. A large percentage of injuries result in long-term employment and study limitations, medical costs and loss of income. Review articles addressing the applied physiology of rugby league and common rugby league injuries have been published. However, both of these review articles have focused on the professional rugby league player. This review addresses the extent of the injury problem in rugby league in all levels of competition (i.e. junior, amateur, semi-professional and professional). The incidence of rugby league injuries typically increases as the playing level is increased. The majority of studies have shown that the head and neck is the most common site of match injuries in senior rugby league players, while knee injuries are the most common site of injury in junior rugby league players. Muscular injuries are the most common type of injury sustained by senior rugby league players, while junior rugby league players more commonly sustain fractures. Injuries are most commonly sustained in tackles, by the tackled player. Thigh and calf strains are the most common injuries sustained during rugby league training, while overexertion is the most common cause of training injuries. Player fatigue may influence the incidence of injury, with most sub-elite (amateur and semi-professional) rugby league injuries occurring in the second half of matches or the latter stages of training sessions. The majority of training injuries occur in the early stages of the season, while match injuries occur in the latter stages of the season, suggesting that changes in training and playing intensity may influence the incidence of injury in rugby league. Injury prevention studies are required to reduce the incidence, severity and cost of rugby league injuries. These injury prevention strategies could include coaching on defensive skills, correct tackling technique, correct falling technique and methods to minimise the absorption of impact forces in tackles. Game-specific attacking and defensive drills practised before and during fatigue may also encourage players to make appropriate decisions under fatigued conditions and apply learnt skills during the pressure of competitive matches. Further studies investigating risk factors for injury in junior and senior rugby league players, injuries sustained by specific playing positions and the influence of injuries on playing performance are warranted.

Reductions in pre-season training loads reduce training injury rates in rugby league players

OBJECTIVES

To investigate if reductions in pre-season training loads reduced the incidence of training injuries in rugby league players, and to determine if the reductions in training loads compromised the improvements in physical fitness obtained during the pre-season preparation period.

METHODS

A total of 220 sub-elite rugby league players participated in this 3 year prospective study. Players underwent measurements of speed, muscular power, and maximal aerobic power before and after three 4 month (December to March) pre-season preparation periods (2001-2003). A periodised skills and conditioning program was implemented, with training loads progressively increased in the general preparatory phase of the season (December to February) and reduced slightly in March in preparation for the competitive phase of the season. Training loads were calculated by multiplying the training session intensity by the duration of the training session. Following the initial season (2001), training loads were reduced through reductions in training duration (2002) and training intensity (2003). The incidence of injury was prospectively recorded over the three pre-season periods.

RESULTS

The training loads for the 2002 and 2003 pre-season periods were significantly lower (p<0.001) than those in 2001. The incidence of injury was significantly higher in the 2001 pre-season than the 2002 and 2003 pre-season periods. The increases in maximal aerobic power progressively improved across the three seasons with a 62-88% probability that the 2002 and 2003 pre-season improvements in maximal aerobic power were of greater physiological significance than the 2001 pre-season improvements in maximal aerobic power.

CONCLUSIONS

These findings demonstrate that reductions in pre-season training loads reduce training injury rates in rugby league players and result in greater improvements in maximal aerobic power.

Influence of injuries on team playing performance in Rugby League

All injuries have the potential to impact on individual sporting performance and as a result may influence team playing performance. However, the influence of injuries on team playing performance is unclear. The purpose of this study was to investigate the influence of injuries on team playing performance in Rugby League. All injuries sustained by one semi-professional first grade Rugby League team were prospectively studied during the 2001 competitive season. An injury was defined as any pain or disability suffered by a player during a match. Team playing performance for each match was estimated from the metres gained while in possession of the football, points scored, points conceded, the final points differential and the completion rates of attacking sets of tackles. A total of 294 injuries were recorded. The average metres gained for all matches was 1471 (95% confidence interval, CI: 1383 to 1559) m. The team averaged 42 (95% CI: 32 to 51) points in attack each match and conceded an average of 15 (95% CI: 9 to 21) points in defence. The average completion rate for the season was 65.3 (95% CI: 60.6 to 70.0)%. There was no significant association (p>0.05) between the number of injuries sustained and team-playing performance. These findings suggest that injuries have minimal impact on team-playing performance in Rugby League. Further research on a larger sample (including winning and losing teams), is required to provide a detailed analysis of the influence of injuries on team playing performance in Rugby League.

Influence of training and match intensity on injuries in rugby league

The aim of this study was to examine the influence of perceived intensity, duration and load of matches and training on the incidence of injury in rugby league players. The incidence of injury was prospectively studied in 79 semi-professional rugby league players during the 2001 season. All injuries sustained during matches and training sessions were recorded. Training sessions were conducted from December to September, with matches played from February to September. The intensity of individual training sessions and matches was estimated using a modified rating of perceived exertion scale. Training load was calculated by multiplying the training intensity by the duration of the training session. The match load was calculated by multiplying the match intensity by the time each player participated in the match. Training load increased from December (278.3 [95% confidence interval, CI 262.2 to 294.5] units) to February (385.5 [95% CI 362.4 to 408.5] units), followed by a decline until September (98.4 [95% CI 76.5 to 120.4] units). Match load increased from February (204.0 [95% CI 186.2 to 221.8] units) to September (356.8 [95% CI 302.5 to 411.1] units). More training injuries were sustained in the first half of the season (first vs second: 69.2% vs 30.8%, P < 0.001), whereas match injuries occurred more frequently in the latter stages of the season (53.6% vs 46.4%, P < 0.001). A significant relationship (P < 0.05) was observed between changes in training injury incidence and changes in training intensity (r = 0.83), training duration (r = 0.79) and training load (r = 0.86). In addition, changes in the incidence of match injuries were significantly correlated (P < 0.05) with changes in match intensity (r = 0.74), match duration (r = 0.86) and match load (r = 0.86). These findings suggest that as the intensity, duration and load of rugby league training sessions and matches is increased, the incidence of injury is also increased.