Epidemiology of cervical spine abnormalities in asymptomatic adult professional rugby union players using static and dynamic MRI protocols: 2002 to 2006.

OBJECTIVE: In this study, the prevalence of abnormalities in the cervical spine of asymptomatic professional rugby players using both static and dynamic magnetic resonance imaging (MRI) in order to improve the detection of abnormalities and prevention of related injuries was investigated. DESIGN: Prospective observational study. SETTING: French professional rugby union clubs, between 2002 and 2006. PARTICIPANTS: 206 elite male adult players. INTERVENTION: Static sagittal T2 and axial T2* fast spin echo (FSE), and dynamic sagittal single-shot FSE weighted MRI scans of the C2-C7 region were examined for the presence of abnormalities. Participants' spines were in supine neutral position for the static protocol but were allowed complete flexibility in a sagittal plane for the dynamic protocol. MAIN OUTCOME MEASUREMENTS: The medulla-to-canal ratio (MCR) was measured at every vertebral disc level for both MRI methods. When observed, anatomical abnormalities were categorised. RESULTS: Anatomical abnormalities mainly consisted of degenerative discopathy and were most frequently observed in players aged>21 years, as well as in players whose MCR was abnormally high based on medical expertise. Most MCRs that were initially assessed as intermediate with static MRI were subsequently assessed as abnormal with dynamic MRI assessment. CONCLUSIONS: Since dynamic MRI is more accurate than static techniques in examining the cervical spine, it contributes substantially to identifying the risk of spinal injuries in professional rugby players, and when used in association with clinical assessment, it can assist in preventing spinal injury.

An evaluation of mouthguard requirements and dental injuries in New Zealand rugby union.

OBJECTIVES: To document the effects of compulsory mouthguard wearing on rugby related dental injury claims made to ACC, the administrator of New Zealand's accident compensation scheme. METHODS: An ecological study was conducted. Estimates of mouthguard wearing rates were available from prospective studies conducted in 1993, 2002, and 2003. Rugby related dental injury claims were available for the period 1995-2003. Player numbers were available from 1998. Mouthguard wearing was made compulsory during match play for rugby players at under 19 level and below at the beginning of the 1997 season, and for all grades of domestic rugby at the beginning of the 1998 season. Greater powers of enforcement were provided to referees at the beginning of the 2003 season. RESULTS: The self reported rate of mouthguard use was 67% of player-weeks in 1993 and 93% in 2003. A total of 2644 claims was reported in 1995. There was a 43% (90% confidence interval 39% to 46%) reduction in dental claims from 1995 to 2003. On the reasonable assumption that the number of players and player-matches remained constant throughout the study period, the relative rate of injury claims for non-wearers versus wearers was 4.6 (90% confidence interval 3.8 to 5.6). The cumulative savings in claim costs compared with the cost per year if claim numbers had remained constant from 1995 is 1.87 million NZD. CONCLUSION: Although ecological studies have acknowledged weaknesses, the findings provide evidence that mouthguard use is a simple and effective injury prevention strategy for rugby players. The use of mouthguards for all players in both matches and contact practice situations is strongly recommended.

The New Zealand Rugby Injury and Performance Project: alcohol use patterns within a cohort of rugby players.

Although heavy drinking has traditionally been associated with rugby, the drinking patterns of New Zealand rugby players have not been examined. Three hundred and forty-eight rugby players (257 males and 91 females), completed the Alcohol Use Disorders Identification Test (AUDIT) at the beginning of the 1993 rugby season. The mean AUDIT scores were 11.2 (SD = 5.1) for the males and 8.7 (4.1) for the females: a cut-off of 8.0 has been recommended by the developers of the instrument for identifying alcohol use disorders. The consumption of large quantities of alcohol, and a high frequency of heavy drinking sessions were the norm for this group. Sixty-one per cent of males and 38% of females consumed six or more drinks in a session at least weekly: typically, men drank 10 or more drinks in a session and women 5-6 drinks. The patterns of drinking exhibited by the cohort give cause for concern regarding the health risks associated with such behaviour.

Use of protective equipment in a cohort of rugby players.

PURPOSE: To describe the level of usage of protective devices and equipment in a cohort of New Zealand rugby players. METHODS: Male and female players (N = 327) from a range of competitive grades were followed over the course of the season. Participants were interviewed weekly about their participation in rugby and use of protective equipment. The main outcome measure was percentage of all player-weeks of follow-up for which each equipment item was used. RESULTS: Mouthguards, the most commonly used equipment item, were worn for 64.9% of player-weeks. Mouthguard usage ranged from 55.0% of player-weeks in Schoolgirls grade to 72.9% of player-weeks in Senior A competition. The next most common item was taping of body joints (23.7% of player-weeks). The sites most commonly taped were the ankle, knee, and hand. Overall usage for the other protective equipment items studied (shin guards, padded headgear, head tape, support sleeves, and grease) was below 15%. In general, forwards had higher usage of protective equipment than backs, and male players had higher usage than female players. The most common self-reported reasons for using protective equipment were to prevent injury and because of a past injury. Players exhibited considerable week-to-week variation in their usage of protective equipment. CONCLUSIONS: In general, equipment usage was highest in those at greatest risk of injury, namely, forwards, male players, and the senior grades. The high voluntary use of mouthguards is encouraging and indicative of a base of player support for their role in this sport.

The nature and circumstances of tackle injuries in rugby union.

This study describes the nature and circumstances of injury occurring in rugby union tackles (33% of 569 injury events) using data from the Rugby Injury and Performance Project (RIPP) and provides supplementary information on the nature of tackles involving injury from analysis of videotape of tackle injury events. The most common tackle injuries in the RIPP data were sprains/strains (41%) followed by haematomas/bruising (26%). The most frequently injured body sites were the head/neck/face (22%) and the knee (17%). The ball carrier and tackler were injured in tackles in similar proportions in both RIPP and New Zealand Rugby Football Union (NZRFU) video tackle incidents. Both players were most often in motion in the tackle at the time of injury with approximately 70% of injuries occurring when the injured player was running or diving/falling to the ground. Tackle injury was most often caused by impact with another player rather than impact with the ground. The use of protective padding may reduce the risk of impact injury. The majority of tackle injuries were associated with stopping tackles to the trunk which were from the front (63%), rather than from the side or behind. Thus consideration should be given to coaching strategies or to rule changes which reduce the likelihood or prohibit front-on tackles.

Temporal patterns of injury during a rugby season.

The aim of this study was to describe temporal patterns in the frequency, nature and circumstances of injuries occurring among a cohort of 356 rugby players during a club rugby season in New Zealand. It was found that the rate of injury in games decreased significantly over time in both males and females. The reduction in injury rate over the season was more pronounced in some grades, but no differences were found when examined by gender. playing position, age, ethnicity or by health and fitness types. Trends in injury rate were consistent over the rugby season and did not appear to be the result of a bias involving under-reporting of end-of-season injuries. The types and severity of injury remained relatively constant, but the proportion of injuries occurring in back play fell significantly over the season and injuries were more likely to occur in the trunk body region as the season progressed. This study supported the hypothesis that higher rates of injury occur at the start of the rugby season and decrease over the course of the season. This reduction is consistent over time and across player types, and is not attributable either to decreasing injury severity or to increasing player fitness.

Consensus statement on injury definitions and data collection procedures for studies of injuries in rugby union.

Wide variations in the definitions and methodologies used for studies of injuries in rugby union have created inconsistencies in reported data and made interstudy comparisons of results difficult. The International Rugby Board established a Rugby Injury Consensus Group (RICG) to agree on appropriate definitions and methodologies to standardize the recording of injuries and reporting of studies in rugby union. The RICG reviewed the consensus definitions and methodologies previously published for football (soccer) at a meeting in Dublin to assess their suitability for and application to rugby union. Following this meeting, iterative draft statements were prepared and circulated to members of the RICG for comment; a follow-up meeting was arranged in Dublin at which time all definitions and procedures were finalized. At this stage, all authors confirmed their agreement with the consensus statement. The agreed-on document was presented to and approved by the International Rugby Board Council. Agreement was reached on definitions for injury, recurrent injury, nonfatal catastrophic injury, and training and match exposures together with criteria for classifying injuries in terms of severity, location, type, diagnosis, and causation. The definitions and methodology presented in this consensus statement for rugby union are similar to those proposed for football. Adoption of the proposals presented in this consensus statement should ensure that more consistent and comparable results will be obtained from studies of injuries within rugby union.

Force production in the rugby union scrum.

In this study, we examined the relationship between anthropometric, strength and power characteristics of rugby forwards, their body position when scrummaging, and their ability to apply force when scrummaging. Force applied to an instrumented scrum machine was measured for 56 players, both individually and as scrum packs. Measurements of body position for individuals were made by digitizing videotape records of the trials. Forty players subsequently had their anthropometry assessed and completed several strength and power tests. Body mass, each component of somatotype, maximal anaerobic power developed on a cycle ergometer, and isokinetic knee extension strength correlated significantly with individual scrummaging force. A regression model (P < 0.001) including body mass, mesomorphy, maximal anaerobic power and hip angle while in the scrummaging position accounted for 45% of the variance in individual scrummaging force. The packs that produced the largest scrummaging forces were, in general, characterized by a greater pack force to sum of individual force ratio than the packs producing lower forces. Our results emphasize the need for a scrum pack to develop technique and coordination as a unit to maximize scrummaging force.

The New Zealand rugby injury and performance project. IV. Anthropometric and physical performance comparisons between positional categories of senior A rugby players.

OBJECTIVE: To describe the anthropometric and physical performance characteristics of a sample of senior A club rugby players and to highlight differences between the positional categories of the players within the forwards and backs. METHODS: 94 senior A male rugby players were assessed on a number of anthropometric and physical performance assessments. The forwards were categorised into props, hookers, locks, and loose forwards. Backs were categorised into inside, midfield, and outside backs. Categories within the forwards were compared with each other, as were the categories within the backs. RESULTS: The anthropometric characteristics of forwards differed significantly between positional categories. Front row forwards (props and hookers) possessed highly endo-mesomorphic somatotypes, and typically rated very low for ectomorphy. Props possessed greater body mass than hookers. Locks and loose forwards were taller than the front row forwards. In terms of physical performance fewer differences were observed. Hookers performed better than props on an aerobic assessment. Locks and loose forwards were faster than the front row forwards on a 30 m sprint from a running start. The inside backs were shorter and lighter than the midfield and outside backs. CONCLUSIONS: The combination of anthropometric characteristics and physical performance attributes observed allows players to best meet the demands imposed on them by their position.

The New Zealand rugby injury and performance project. VI. A prospective cohort study of risk factors for injury in rugby union football.

OBJECTIVES: Although the nature of rugby injury has been well documented, little is known about key risk factors. A prospective cohort study was undertaken to examine the association between potential risk factors and injury risk, measured both as an injury incidence rate and as a proportion of the playing season missed. The latter measure incorporates a measure of injury severity. METHODS: A cohort of 258 male players (mean (SD) age 20.6 (3.7) years) were followed through a full competitive season. At a preseason assessment, basic characteristics, health and lifestyle patterns, playing experience, injury experience, training patterns, and anthropometric characteristics were recorded, and then a battery of fitness tests were carried out. RESULTS: A multiple regression model identified grade and previous injury experience as risk factors for in season injury, measured as an injury incidence rate. A second model identified previous injury experience, hours of strenuous physical activity a week, playing position, cigarette smoking status, body mass index, years of rugby participation, stress, aerobic and anaerobic performance, and number of push ups as risk factors for in season injury, measured as proportion of season missed. CONCLUSIONS: The findings emphasise the importance of previous injury as a predictor of injury incidence and of missing play. They also show the importance of considering both the incidence rate and severity of injury when identifying risk factors for injury in sport.

The New Zealand rugby injury and performance project. III. Anthropometric and physical performance characteristics of players.

OBJECTIVE: To investigate the anthropometric and physical performance characteristics of New Zealand rugby players of different ages and both sexes. METHODS: 356 rugby players (264 male, 92 female) took part in the study during a single season. Playing grade ranged from schoolboys and schoolgirls to senior men and women. Assessment of height, weight, neck circumference, and somatotype was performed before the competitive rugby season. A battery of six physical performance assessments was completed after the anthropometry. Analysis of variance was used to examine differences in these variables between field positions and grades. RESULTS: Significant differences between forwards and backs on anthropometric and physical performance variables were apparent at all grades assessed. In terms of anthropometric characteristics, forwards of a given grade were generally taller, possessed greater body mass, and were more endomorphic and less ectomorphic than backs of the same grade. The backs tended to perform better on physical performance measures than forwards, being more aerobically fit, faster, more agile, and possessing a higher degree of muscular endurance. Differences in anthropometry and physical performance attributes were also apparent between players from the various grades. The players at higher levels were generally larger, and performed better on tests of physical performance than the players at lower levels. These differences were found in both sexes. CONCLUSIONS: The greater body mass of the forwards allows them to obtain greater momentum than the backs when sprinting. The ability to obtain greater momentum is important in the body contact phases of the game. Forwards may compromise their aerobic fitness and speed to some extent in order to maintain a high body mass. The anthropometric and physical performance characteristics of players appear to reflect the demands placed on them by the sport.