John H. M. Brooks

Incidence, Risk, and Prevention of Hamstring Muscle Injuries in Professional Rugby Union

Background The incidence of hamstring muscle injuries in professional rugby union is high, but evidence-based information on risk factors and injury-prevention strategies in this sport is limited. Purpose To define the incidence, severity, and risk factors associated with hamstring muscle injuries in professional rugby union and to determine whether the use of hamstring strengthening and stretching exercises reduces the incidence and severity of these injuries. Study Design Cohort study (prevention); Level of evidence, 3. Methods Team clinicians reported all hamstring muscle injuries on a weekly basis and provided details of the location, diagnosis, severity, and mechanism of each injury; loss of time from training and match play was used as the definition of an injury. Players’ match and training exposures were recorded on a weekly basis. Results The incidence of hamstring muscle injuries was 0.27 per 1000 player training hours and 5.6 per 1000 player match hours. Injuries, on average, resulted in 17 days of lost time, with recurrent injuries (23%) significantly more severe (25 days lost) than new injuries (14 days lost). Second-row forwards sustained the fewest (2.4 injuries/1000 player hours) and the least severe (7 days lost) match injuries. Running activities accounted for 68% of hamstring muscle injuries, but injuries resulting from kicking were the most severe (36 days lost). Players undertaking Nordic hamstring exercises in addition to conventional stretching and strengthening exercises had lower incidences and severities of injury during training and competition. Conclusion The Nordic hamstring strengthening exercise may reduce the incidence and severity of hamstring muscle injuries sustained during training and competition.

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 “prehabilitation” strategies in an effort to minimize the risk of shoulder dislocation/instability.

Contact events in rugby union and their propensity to cause injury

Objective: The objective of this study was to determine the incidence of contact events in professional rugby union matches and to assess their propensity to cause injury. Design: The study was a two-season (2003/2004 and 2005/2006) prospective cohort design. It included 645 professional rugby union players from 13 English Premiership rugby union clubs. The main outcome measures were: incidence of match contact events (events per game); incidence (injuries per 1000 player-hours and per 1000 contact events), risk (days lost per 1000 player-hours and per 1000 contact events) and diagnosis of injury; referee’s decision. Risk factors were player–player contact, position on pitch and period of play. Results: Tackles (221.0 events/game) and rucks (142.5 events/game) were the most common events and mauls (13.6%) and scrums (12.6%) the most penalised. Tackles (701.6 days/1000 player-hours) were responsible for the greatest loss of time but scrums (213.2 days lost/1000 events) and collisions (199.8 days lost/1000 events) presented the highest risk per event. Conclusions: Tackles were the game event responsible for the highest number of injuries and the greatest loss of time in rugby union because they were by far the most common contact event. Collisions were 70% more likely to result in an injury than a tackle and scrums carried a 60% greater risk of injury than a tackle. The relative propensities for contact events to cause injury were rated as: lineout – very low; ruck – low; maul and tackle – average; collision and scrum – high.

The influence of methodological issues on the results and conclusions from epidemiological studies of sports injuries : Illustrative examples

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.

Injury risks associated with tackling in rugby union

Objective To examine factors associated with tackles in rugby union and to assess their impact on the risk of injury. Design Two-season (2003/2004 and 2005/2006) prospective cohort design with video analysis. Setting 13 English Premiership clubs. Participants 645 players. Main outcome measure RR (95% CI) calculated by comparing the frequency of occurrence of risk factors in a cohort of players injured during tackles with their frequency of occurrence in tackles in general play. Risk factors Playing position; player’s speed, impact force, head position, head/neck flexion and body region struck in the tackle; sequence, direction and type of tackle; and location and type of injury. Results High-speed going into the tackle, high impact force, collisions and contact with a player’s head/neck were identified as significant (p<0.01) risk factors for ball carriers (BCs) and tacklers. Midfield backs were significantly (p<0.01) more prone to injury when tackling than other players. Relatively few tacklers were penalised by referees for collision tackles (general play: 2.0%; injured players: 3.3%) and tackles above the line of the shoulder (general play: 5.9%; injured players: 16.7%). Conclusions Advice in national and international injury prevention programmes for reducing the risk of injury in tackles is strongly supported by the results obtained from this study. These programmes should be reviewed, however, to provide specific advice for each type of tackle. Stricter implementation of the Laws of Rugby relating to collisions and tackles above the line of the shoulder may reduce the number of head/neck injuries sustained by BCs.

Recent Trends in Rugby Union Injuries

Rugby union has changed in recent years because of several rule modifications and the 1995 advent of professionalism. Trends in rugby union injury epidemiology include: higher incidence of injury than other team sports, an apparent increase in injury risk in professional and amateur games since the advent of professionalism, reduction in injury incidence with decreasing age and competitive level, significantly higher incidence of injuries during matches compared with training, and a high proportion of tackle injuries. The commonest high-risk injury sites are the shoulder, knee, thigh, ankle, and head. Although injury research publications have increased since 1995, studies investigating risk factors for specific high-risk injuries (including nonfatal catastrophic injury) and to assess the effects of discrete prevention strategies need prioritizing.

The Epidemiology of Head Injuries in English Professional Rugby Union

Objectives:To undertake a detailed epidemiological study of head injuries sustained by professional rugby union players in order to define their incidence, nature, severity, and causes. Design:A 3-season prospective cohort design. Setting:13 English Premiership rugby union clubs. Participants:757 male rugby union players. Main Outcome Measures:Anatomical location, diagnosis, severity (number of days unavailable for training and match play), injury incident, and incidence of match and training injuries (injuries/1000 player-hours). Risk Factors:Playing position, use of headgear, and activity. Results:The overall incidence of match head injury was 6.6 injuries/1000 player-hours, and each injury resulted, on average, in 14 days lost-time. The overall incidence of match concussions was 4.1 injuries/1000 player-hours resulting, on average, in 13 days lost-time. Concussion was the third most common match injury for all players. A large proportion of the players (48%) were able to return to play safely within 7 days. Match concussions were most commonly associated with tackling head-on (28%), collisions (20%), and being tackled head-on (19%). The midfield backs were the playing position at the greatest risk of sustaining a concussion. Only 42% of players were removed from the field of play immediately after a concussion. Foul play was reported by the player to be associated with match head injury in 17% of cases. Mouthguard and headgear usage was associated with a reduced incidence of concussive injury. The overall incidence of training head injury was 0.05 injuries/1000 player-hours, and the overall incidence of training concussions was 0.02 injuries/1000 player-hours. Conclusions:The results showed that rugby union players were exposed to a high risk of noncatastrophic head injury and concussion, particularly whilst tackling and being tackled head-on. In all, 48% of players sustaining a concussion were able to return to play in less than 7 days. The clinical challenge when assessing the potentially concussed player during a game is compounded by the current regulations regarding the permanent replacement of injured players. Injury prevention strategies should be focussed on minimizing the risk and force of direct contact to the head in the tackle.

Spinal injuries in professional rugby union: a prospective cohort study

Objectives:To determine the incidence, severity, nature, and causes of cervical, thoracic, and lumbar spine injuries sustained during competition and training in professional rugby union. Design:A 2 season prospective cohort design. Setting:Twelve English Premiership rugby union clubs. Participants:Five hundred and forty-six male rugby union players of whom 296 were involved in both seasons. Main Outcome Measures:Location, diagnosis, severity (number of days unavailable for training and matches), and cause of injury: incidence of match and training injuries (injuries/1000 player-hours). Risk Factors:Player age, body mass, stature, playing position, use of headgear, and activity and period of season. Results:The incidences of spinal injuries were 10.90 (9.43 to 12.60) per 1000 player match-hours and 0.37 (0.29 to 0.47) per 1000 player training-hours. No player sustained a catastrophic spinal injury, but 3 players sustained career-ending injuries. Overall, players were more likely to sustain a cervical injury during matches and a lumbar injury during training. Forwards were significantly more likely to sustain a spinal injury than backs during both matches (P < 0.01) and training (P = 0.02). During matches, injuries to the cervical (average: 13 days; P < 0.01) and lumbar (13 days; P < 0.01) spine were more severe than injuries to the thoracic (5 days) spine; during training, injuries to the lumbar spine (26 days) were more severe than injuries to the cervical (13 days; P = 0.10) or thoracic (12 days; P = 0.06) spine. A total of 4037 days were lost to competition and training through spinal injuries with lumbar disc injuries sustained during training accounting for 926 days (23%) and cervical nerve root injuries sustained during matches for 621 days (15%). During matches, more injuries were caused by tackles (37%), and during training more injuries were caused by weight-training (33%). Conclusions:The results showed that rugby union players were exposed to a high risk of noncatastrophic spinal injury during tackling, scrummaging, and weight-training activities; injury prevention strategies, therefore, should be focused on these activities.

Ballet injuries: injury incidence and severity over 1 year.

STUDY DESIGN Prospective, descriptive single-cohort study. OBJECTIVE To assess the incidence and severity of injuries to a professional ballet company over 1 year. METHODS Data for an elite-level ballet company of 52 professional dancers were collected by an in-house medical team using a time-loss injury definition. RESULTS A total of 355 injuries were recorded, with an overall injury incidence of 4.4 injuries per 1000 hours (female, 4.1; male, 4.8; P>.05) and a mean of 6.8 injuries per dancer (female, 6.3; male, 7.3; P>.05). Mean injury severity was 7 days (female, 4; male, 9; P<.05). Most injuries were classified as overuse (64%; female, 68%; male, 60%; P>.05); mean severity of injury was 3 days for females and 9 days for males (P<.05). The percentage of traumatic injuries was 32% for females and 40% for males (P<.05); the corresponding severity was 6 and 10 days, respectively (P<.05). CONCLUSION The relatively high number of injuries reported and the resulting loss of dance time support the need to introduce interventions to reduce the risk of injury in professional dancers.J Orthop Sports Phys Ther 2012;42(9):781-790. Epub 19 July 2012. doi:10.2519/jospt.2012.3893.

Collegiate rugby union injury patterns in New England: a prospective cohort study

Objective: To establish injury profile of collegiate rugby union in the USA Design/setting: 31 men’s and 38 women’s collegiate rugby union teams prospectively recorded injuries during games and practice during the 2005–06 season. Three teams withdrew before data collection. An injury was defined as one: (1) occurring in an organised intercollegiate game or practice; and (2) requiring medical attention during or after the game or practice, or (3) resulting in any restriction of the athletes’ participation for ⩾1 day(s) beyond the day of injury, or in a dental injury. Main outcome measures: In total, 847 injuries (447 in men; 400 in women) during 48 026 practice (24 280 in men; 23 746 in women) and 25 808 game (13 943 in men; 11 865 in women) exposures were recorded. Results: During games, injury rates of 22.5 (95% CI 20.2 to 25.0) and 22.7 (20.2 to 25.5) per 1000 game athletic exposures or 16.9 (15.1 to 18.9) and 17.1 (15.1 to 19.1) per 1000 player game hours were recorded for men and women, respectively. Over half of all match injuries were of major severity (>7 days’ absence) (men 56%; women 51%) and the tackle was the game event most often associated with injury (men 48%; women 53%). Conclusions: Collegiate game injury rates for rugby were lower than rates recorded previously in men’s professional club and international rugby and lower than reported by the National Collegiate Athletic Association Injury Surveillance System for American football, but similar to rates reported for men’s and women’s soccer in 2005–06.