Interface pressure, perceptual, and mean arterial pressure responses to different blood flow restriction systems.

This study examined the cuff to limb interface pressure during blood flow restriction (BFR), and the perceptual and mean arterial pressure responses, in different BFR systems. Eighteen participants attended three experimental sessions in a randomised, crossover, counterbalanced design. Participants underwent inflations at 40% and 80% limb occlusive pressure (LOP) at rest and completed 4 sets of unilateral leg press exercise at 30% of one repetition maximum with BFR at 80% LOP. Different BFR systems were used each session: an automatic rapid-inflation (RI), automatic personalized tourniquet (PT) and manual handheld pump and sphygmomanometer (HS) system. Interface pressure was measured using a universal interface device with pressure sensors. Perceived exertion and pain were measured after each set, mean arterial pressure (MAP) was measured pre-, 1-minute post- and 5-minutes post-exercise. Interface pressure was lower than the set pressure in all BFR systems at rest (P < .05). Interface pressure was, on average, 10 ± 8 and 48 ± 36 mm Hg higher than the set pressure in the RI and HS system (P < .01), with no differences observed in the PT system (P > .05), during exercise. Pain and exertion were greater in sets 3 and 4 in the RI and HS system compared to the PT system (P < .05). MAP was higher in the RI and HS system compared to the PT system at 1-minute and 5-minutes post-exercise (P < .05). BFR systems applying higher pressures amplify mean arterial pressure and perceptual responses. Automatic BFR systems appear to regulate pressure effectively within an acceptable range during BFR exercise.

MRI findings in the lumbar spines of asymptomatic elite junior tennis players.

OBJECTIVE: To evaluate the MRI findings in the lumbar spines of asymptomatic elite junior tennis players. MATERIALS AND METHODS: The lumbar spine MRI studies of 98 asymptomatic junior elite tennis players (51 male, 47 female) with a mean age of 18 years (age range 11.2-26.3 years; standard deviation 3.1) was reviewed by two consultant musculoskeletal radiologists using consensus opinion. Images were assessed using accepted classification systems. RESULTS: Four players (4%) had no abnormality. Facet joint arthropathy occurred in 89.7% of the players, being mild in 84.5% of cases. There were 41 synovial cysts in 22.4% of the cohort all occurring in the presence of facet arthropathy. Disc degeneration was noted in 62.2 % of players, being mild in 76.2% of those affected. Disc herniation was noted in 30.6% of players, with 86.1% of these being broad based and 13.9% being focal. There was nerve root compression in 2%. There were 41 pars interarticularis abnormalities in 29.6% of patients, 63.4% of these being grades 1-3. There was grade 1 spondylolisthesis in 5.1% of players. The prevalence of facet joint arthropathy, disc degeneration, disc herniation and pars interarticularis fracture was lower in female players than in male and lower in the under 16-year-olds compared with the over 20-year-olds. CONCLUSION: There is a significant amount of underlying pathology that would normally go undetected in this group of asymptomatic elite athletes. Whilst these findings cannot be detected clinically, their relevance is in facilitating appropriate prehabilitation to prevent loss of playing time and potentially career-ending injuries.

An investigation into the influence of socioeconomic variables on gestational body mass index in pregnant women living in a peri-urban settlement, South Africa.

Maternal and child mortality rates are still unacceptably high in South Africa. The health status of women in peri-urban areas has been influenced by political and socio-economic factors. Examining socio-economic variables (SEV) in a population aids in the explanation of the impact of social structures on an individual. Risk factors can then be established and pregnant women in these higher risk groups can be identified and given additional support during pregnancy. The aim of this study was to investigate the association between SEV and gestational Body Mass Index (GBMI) in a peri-urban settlement, South Africa. This was a sub-study of the Philani Mentor Mothers' Study (2009-2010). Maternal anthropometry and SEV were obtained from 1,145 participants. Multinomial regression was used to analyse the data. Household income was the only SEV that was significantly associated with GBMI. The odds of being underweight rather than normal weight during pregnancy increase by a factor of 2.145 (P < 0.05) for those who had a household income lower than R2000 per month. All other SEV were not significant. Logistic regression was therefore not carried out. Women who had a lower income were at risk of having a lower GBMI during pregnancy. This can lead to adverse birth outcomes such as premature birth, low birth weight, height and head circumference. Public health policy needs to be developed to include optimal nutrition health promotion strategies targeting women with a low income ante and post-natally. Once implemented, they need to be evaluated to assess the impact on maternal and child mortality.

A prospective study of injury and activity profile in elite soccer referees and assistant referees.

Injuries to soccer players have been extensively examined, but not the injury experience of referees and assistant referees. This study aimed to determine the injury incidence and activity profile of soccer match officials. A 12 month prospective cohort study was used to collect activity and injury data of 31 participants who reported their training and match exposure and their injury incidence by means of weekly online questionnaire. Study participants spent a mean of 2632 hrs training and 1704 hrs officiating over the 12 month study period. Thirty eight injuries were recorded, (8.8 injuries/1000 hr of training (CI 6.2 to 12.0) and 16.4 injuries/1000 hr for match officiating (CI 10.9 to 23.8)), (Risk Ratio 4.3, 2.1 to 8.9). Fifty five percent (CI 40 to 70%) of the injuries were to muscles, and 76% (CI 61 to 87%) were to the lower leg. Overuse injuries represented 61% (CI 45 to 74%) of all cases. Findings showed that the injury frequency rate associated with soccer referees is higher than that in a number of other non contact sports. The injury incidence associated with training for soccer referees is higher than that associated with training for soccer players. Further prospective studies are merited to examine effectiveness and availability of injury management programmes to establish the welfare of this population.

A 12-month prospective cohort study of injury in international rowers.

OBJECTIVE: In this study, the injury incidence and association with type and volume of training in international rowers were described. DESIGN: A prospective cohort design was used over a 12-month period. PATIENTS: 20 international rowers who were competing as part of the Irish Amateur Rowing Union squad system. METHODS: The rowers were interviewed monthly, and data were collected regarding their training and competition exposure as well as their injury experience. RESULTS: A mean injury rate of 3.67 per 1000 exposure hours was reported with a total of 44 injuries reported in a 12-month period. The mean number of injuries sustained per athlete was 2.2 (1.24) over the 12-month period. The area where the greatest number of injuries were reported was the lumbar spine (31.82% of total injuries, 95% CI 20 to 50) (fig 2) followed by the knee (15.91% of total injuries, 95% CI 10 to 30) and the cervical spine (11.36% of total injuries, 95% CI 5 to 24). Half of the injuries (22 injuries, 50% of total reported injuries) were to the spine (chi(2) = 30.8, df = 9, p = 0.0003). Ergometer training load was the most significantly associated with injury risk (r = 0.68, p = 0.01). CONCLUSION: International rowers are at higher risk of injury than most non-contact sports and some contact sports. The high risk of lumbar spine injury and the significant association of high volume of ergometer training merit further research to reduce time and competition lost to injury.

Epidemiological studies of injuries in rugby league: suggestions for definitions, data collection and reporting methods.

Studies on rugby league injuries use a variety of definitions and methodologies. Consequently, comparisons of published studies are difficult. Researchers with an interest in understanding the epidemiology of rugby league injury participated in a majority agreement process. This paper provides suggestions for the definitions, data collection and reporting methods for future studies of rugby league injuries. The proposed methods and definitions were developed through the use of a majority agreement process on draft versions by all authors. Recommended definitions for injury incidence, recurrence, severity and match exposure are provided as well as injury site, type, diagnosis and causation. Suggestions for match and training injury incidence calculations are also provided for the purposes of comparison. This paper provides standard definitions that, if utilised, will enable meaningful comparison of future rugby league injury surveillance data from different countries and playing levels.

Female rugby union injuries in New Zealand: A review of five years (2013-2017) of Accident Compensation Corporation moderate to severe claims and costs.

OBJECTIVES: To provide epidemiological data and related costs for moderate-to-serious and serious injury claims for women's rugby union in New Zealand. DESIGN: A retrospective analytical review of injury entitlement claims for women's rugby from 2013 to 2017. METHODS: Data were analysed by year of competition, age, body site and injury type for total and moderate-to-severe (MSC) Accident Compensation Corporation (ACC) claims and costs. RESULTS: Over 2013 to 2017 there were 26,070 total claims for female rugby union costing $18,440,812 [AD$16,956,998]. The 15-19-year age group recorded 40% (n=1,009) of the total female rugby union Moderate-to-serious and serious (MSC) claims and 41% ($5,419,157 [AD$4,983,112]) of the total female rugby union MSC costs. The knee was the most commonly recorded injury site accounting for 40.3% (n=1,007) of MSC claims and 46.9% ($6,229,714 [AD$5,728732]) of MSC costs with an average cost of $1,245,943 ±$217,796 [AD$595,351 ±AD$104,070] per-year for female rugby union. CONCLUSIONS: This is the first study to report the nature and related costs for moderate-to-serious and serious injury claims for women's rugby union in New Zealand. A total of 26,070 injury claims were lodged over the duration of the study but only 9.6% (n=2,501) of these were classified as MSC injury entitlement claims. Participants 25 years and older accounted for 31% of the female rugby union player claims. Females in the over 35-year age groups compete against younger participants which may account for the higher mean cost per-claim seen as the age groups increase in years until they retire from the game.

A 6-month prospective study of injury in Gaelic football.

OBJECTIVE: To describe the injury incidence in Gaelic football. METHODS: A total of 83 players from three counties were interviewed monthly about their injury experience, during the 6 months of the playing season. RESULTS: The injury rate was 13.5/1000 h exposure to Gaelic football (95% CI, 10.9 to 16.6). There were nearly twice as many injuries during matches (64.4%, 95% CI, 54.1 to 73.6) as in training (35.6%, 95% CI, 26.4 to 49.5). The ankle was found to be the most commonly injured site (13.3%, 95% CI, 7.8 to 21.9). The musculotendinous unit accounted for nearly 1/3 of all injuries (31.1%). The tackle accounted for 27.8% of the injuries sustained (tackler 10%, 95% CI, 5.4 to 17.9; player being tackled 17.9%, 95% CI, 11.2 to 26.9). Of total match injuries, 56.9% (95% CI, 46.1 to 67.1) were experienced in the second half as opposed to 39.7% (95% CI, 29.8 to 50.5) in the first half. CONCLUSIONS: Gaelic footballers are under considerable risk of injury. Greater efforts must be made to reduce this risk so that players miss less time from sport due to injury. Risk factors for injury in Gaelic football must now be investigated so that specific interventions may be established to reduce them.

The Influence of Head Impact Threshold for Reporting Data in Contact and Collision Sports: Systematic Review and Original Data Analysis.

BACKGROUND: Head impacts and resulting head accelerations cause concussive injuries. There is no standard for reporting head impact data in sports to enable comparison between studies. OBJECTIVE: The aim was to outline methods for reporting head impact acceleration data in sport and the effect of the acceleration thresholds on the number of impacts reported. METHODS: A systematic review of accelerometer systems utilised to report head impact data in sport was conducted. The effect of using different thresholds on a set of impact data from 38 amateur senior rugby players in New Zealand over a competition season was calculated. RESULTS: Of the 52 studies identified, 42% reported impacts using a >10-g threshold, where g is the acceleration of gravity. Studies reported descriptive statistics as mean ± standard deviation, median, 25th to 75th interquartile range, and 95th percentile. Application of the varied impact thresholds to the New Zealand data set resulted in 20,687 impacts of >10 g, 11,459 (45% less) impacts of >15 g, and 4024 (81% less) impacts of >30 g. DISCUSSION: Linear and angular raw data were most frequently reported. Metrics combining raw data may be more useful; however, validity of the metrics has not been adequately addressed for sport. Differing data collection methods and descriptive statistics for reporting head impacts in sports limit inter-study comparisons. Consensus on data analysis methods for sports impact assessment is needed, including thresholds. Based on the available data, the 10-g threshold is the most commonly reported impact threshold and should be reported as the median with 25th and 75th interquartile ranges as the data are non-normally distributed. Validation studies are required to determine the best threshold and metrics for impact acceleration data collection in sport. CONCLUSION: Until in-field validation studies are completed, it is recommended that head impact data should be reported as median and interquartile ranges using the 10-g impact threshold.

Use of the King-Devick test for sideline concussion screening in junior rugby league.

AIM: To determine whether the King-Devick (K-D) test used as a sideline test in junior rugby league players over 12 matches in a domestic competition season could identify witnessed and incidentally identified episodes of concussion. METHODS: A prospective observational cohort study of a club level junior rugby league team (n=19) during the 2014 New Zealand competition season involved every player completing two pre-competition season baseline trials of the K-D test. Players removed from match participation, or who reported any signs or symptoms of concussion were assessed on the sideline with the K-D test and referred for further medical assessment. Players with a pre- to post-match K-D test difference >3s were referred for physician evaluation. RESULTS: The baseline test-retest reliability of the K-D test was high (rs=0.86; p<0.0001). Seven concussions were medically identified in six players who recorded pre- to post-match K-D test times greater than 3s (mean change of 7.4s). Post-season testing of players demonstrated improvement of K-D time scores consistent with learning effects of using the K-D test (67.7s vs. 62.2s). DISCUSSION: Although no witnessed concussions occurred during rugby play, six players recorded pre- to post-match changes with a mean delay of 4s resulting in seven concussions being subsequently confirmed post-match by health practitioners. All players were medically managed for a return to sports participation. CONCLUSION: The K-D test was quickly and easily administered making it a practical sideline tool as part of the continuum of concussion assessment tools for junior rugby league players.

The King-Devick test was useful in management of concussion in amateur rugby union and rugby league in New Zealand.

AIM: To use the King-Devick (K-D) test in senior amateur rugby union and rugby league players over a domestic competition season to see if it could identify witnessed and unwitnessed episodes of concussion that occurred from participation in competition matches over three years. METHODS: A prospective observational cohort study was conducted on a club level senior amateur rugby union team (n=36 players in 2012 and 35 players in 2013) and a rugby league team (n=33 players in 2014) during competition seasons in New Zealand. All 104 players completed two trials 10min apart of the K-D at the beginning of their competition season. Concussions (witnessed or unwitnessed) were only recorded if they were formally diagnosed by a health practitioner. RESULTS: A total of 52 (8 witnessed; 44 unwitnessed) concussive events were identified over the duration of the study resulting in a concussion injury incidence of 44 (95% CI: 32 to 56) per 1000 match participation hours. There was a six-fold difference between witnessed and unwitnessed concussions recorded. There were observable learning effects observed between the first and the second K-D test baseline testing (50 vs. 45s; z=-8.81; p<0.001). For every 1 point reduction in each of the post-injury SAC components there was a corresponding increase (worsening) of K-D test times post-match for changes in orientation (2.9s), immediate memory (1.8s) concentration (2.8s), delayed recall (2.0s) and SAC total score (1.7s). DISCUSSION: The rate of undetected concussion was higher than detected concussions by using the K-D test routinely following matches. Worsening of the K-D test post-match was associated with reduction in components of the SAC. The appeal of the K-D test is in the rapid, easy manner of its administration and the reliable, objective results it provides to the administrator. The K-D test helped identify cognitive impairment in players without clinically observable symptoms.

An operational model to investigate contact sports injuries.

PURPOSE: A cyclical operational model is proposed to examine the interrelationship of a number of factors that are involved in sports injury epidemiology. In sports injury research, investigations often attempt to identify a unique risk factor that distinguishes an injured player. However, a wide variety of factors can contribute to a sports injury occurring, and an understanding of the cause of injury is important to advance knowledge. METHODS: The proposed model identifies a healthy/fit player initially, although the player may exhibit a number of intrinsic risk factors for sports injury. Before exposure to extrinsic risk factors, there is the opportunity for implementation of prevention strategies by coaching personnel and the sports medicine team. These strategies might include, among others, appropriate warm-up, adequate hydration, wearing protective equipment, and prophylactic taping. Additionally, preventative screening could take place to assess the various intrinsic and extrinsic risk factors that could lead to sports injury. DISCUSSION: Two examples of how the operational model relates to contact sports injury cases are presented. Participating in sport inevitably exposes the player to external risk factors that predispose toward injury. The treatment of the injured player aims to restore the player to preinjury playing status and to prevent the injury from becoming chronic. CONCLUSIONS: It is suggested that the application of this proposed cyclical model may lead to greater success in understanding the multifaceted nature of sports injuries and furthermore help minimize injury risk and support the rehabilitation of injured contact sports participants.

Fluid replacement needs of well-trained male and female athletes during indoor and outdoor steady state running.

Twelve male and six female well-trained middle distance athletes performed a series of six one hour runs at 75% VO2 peak pace under similar environmental states indoors (treadmill) and outdoors (track). Running was undertaken in control (C, no fluid), followed by water (W) and sports drink (SD) treatments, with each run separated by a one week interval. Both fluid treatments were supplied in volumes equivalent to individual body mass (fluid) losses incurred in the respective indoor and outdoor C treatments. Haemodynamic (plasma volume), physiological (heart rate and body temperature) and blood chemistry (blood lactate and glucose) measures were analysed as pre to post run changes (delta values). During the respective indoor and outdoor C treatments, males demonstrated approximately a twofold change in body mass (fluid) losses (delta 1.81 +/- 0.10 kg and 2.06 +/- 0.13 kg) compared with females (delta 0.93 +/- 0.11 kg and 1.32 +/- 0.12 kg) (all p<0.05). These losses resulted in almost a twofold fluid replacement need relative to body mass during the running phases of respective indoor and outdoor W and SD treatments in males compared with females (all p<0.05). Both W and SD treatments were effective in minimising the pre to post run disturbances in plasma volume, heart rate, body temperature and blood lactate, while SD treatment resulted in enhanced blood glucose changes. The results suggest gender specific differences in fluid replacement needs during steady state running, which need to be incorporated into fluid replacement strategies to compensate for the demands of training and competition in middle distance athletic events.

Nursing evaluation: purposes, achievements and opportunities.

Evaluation has become a powerful, specialized discipline in recent decades, with its own sophisticated conceptual and technical apparatus. Evaluation of nursing has benefited strongly from these developments, as examples of cogent, recent evaluations demonstrate. Evaluation is already proving an indispensable practical tool for raising the quality of health care, and for advancing professional nursing standards. Nonetheless, there is room for further improvement. Neglected areas of nursing should be brought under the spotlight of evaluation, conceptual and methodological rigour should be strengthened, and training in research skills should be extended.

The prevalence of patellar tendinopathy in elite academy rugby: a clinical and imaging study.

OBJECTIVES: Patellar tendinopathy (PT) is a challenging condition with variable outcomes. It is not commonly reported in rugby. This study was undertaken to evaluate the prevalence of PT in elite academy rugby. DESIGN: Cross-sectional study. METHODS: Members of the rugby academies in Ireland were evaluated using blinded, standardised clinical examination, self reported questionnaires and ultrasound. Anthropometrics were examined, body mass and fat% were measured by bio-impedance. The Cincinnati Sports Activity Scale, established activity levels. The VISA-P scale evaluated symptoms. Ultrasound examination established tendon thickness, echogenicity and homogeneity including focal areas of tendinopathy in both transverse and longitudinal planes. Studies were reviewed and graded by two musculoskeletal radiologists. Statistical analysis was performed using PASW 18 and CIA software. Significance was set at p<.05. RESULTS: Thirty individuals (36.1%) had US abnormalities identified with 38 abnormal tendons. The abnormalities seen were microcalculi (44.7%; N=17), thickened tendons ± large areas of cystic degenerative change (26.3%) and macrocalculi or large hypoechoic areas (28.9%; N=11). Eleven individuals (13.3%) fulfilled the clinical diagnosis of PT based on clinical examination. Combining both US and clinical the prevalence of PT in this cohort was 9.6% (N=8). There was a statistically significant difference between the prevalence of patellar tendinopathy based upon US findings (p=.027) and the combination of both clinical examination and US (p=.044) in different training academies. CONCLUSIONS: This work shows that PT is a relatively common injury in elite academy rugby players and that training practices may contribute to its development.

An investigation into utilising gestational body mass index as a screening tool for adverse birth outcomes and maternal morbidities in a group of pregnant women in Khayelitsha.

OBJECTIVE: The aim of this study was to investigate the ability of the gestational body mass index (BMI) method to screen for adverse birth outcomes and maternal morbidities. DESIGN: This was a substudy of a randomised controlled trial, the Philani Mentor Mothers' study. SETTING AND SUBJECTS: The Philani Mentor Mothers' study took place in a peri-urban settlement, Khayelitsha, between 2009 and 2010. Pregnant women living in the area in 2009-2010 were recruited for the study. OUTCOME MEASURES: Maternal anthropometry (height and weight) and gestational weeks were obtained at baseline to calculate the gestational BMI, which is maternal BMI adjusted for gestational age. Participants were classified into four gestational BMI categories: underweight, normal, overweight and obese. Birth outcomes and maternal morbidities were obtained from clinic cards after the births. RESULTS: Pregnant women were recruited into the study (n = 1 058). Significant differences were found between the different gestational BMI categories and the following birth outcomes: maternal (p-value = 0.019), infant hospital stay (p-value = 0.03), infants staying for over 24 hours in hospital (p-value = 0.001), delivery mode (p-value = 0.001), birthweight (p-value = 0.006), birth length (p-value = 0.007), birth head circumference (p-value = 0.007) and pregnancy-induced hypertension (p-value = 0.001). CONCLUSION: To the best of our knowledge, this is the first study that has used the gestational BMI method in a peri-urban South African pregnant population. Based on the findings that this method is able to identify unfavourable birth outcomes, it is recommended that it is implemented as a pilot study in selected rural, peri-urban and urban primary health clinics, and that its ease and effectiveness as a screening tool is evaluated. Appropriate medical and nutritional advice can then be given to pregnant women to improve both their own and their infants' birth-related outcomes and maternal morbidities.

Injury in rugby league: a four year prospective survey.

OBJECTIVE: To investigate the incidence of injury in English professional rugby league over a period of four playing seasons. METHODS: All injuries that were received by players during match play were recorded. Each injury was classified according to site, type, player position, team playing for, activity at the time of injury, and time off as a result of injury. RESULTS: The overall injury rate was 114 (95% confidence interval 105 to 124) per 1000 playing hours, the most frequent type of injury were muscular injuries [34 (29 to 40) per 1000 playing hours], while the most frequently injured site was the head and neck region [38 (16 to 25) per 1000 playing hours]. Players received the largest percentage of injuries when being tackled [46.3% (41.9 to 50.7)], most injuries required less than one week away from playing and training [70.1% (66.1 to 74.2)], and forwards had a higher injury rate than backs (139 v 93 injuries per 1000 hours). CONCLUSIONS: The high rates of injury in rugby league are undoubtedly due to the high amount of bodily contact in the game. Being tackled has the highest risk of injury, because of being hit forcibly by other players. Forwards suffer higher injury rates than backs, probably because they are involved in a larger number of physical collisions.

Gross efficiency responses to exercise conditioning in adult males of various ages.

This study investigated gross efficiency changes in a group of 60 adult males (mean age 39.2 +/- 1.2 years) resulting from endurance training and age-related responses to such training in sub-groups (each n = 20) of younger (30.7 +/- 0.7 years), intermediate (38.3 +/- 0.5 years) and older (48.6 +/- 1.1 years) subjects. Gross efficiency (%) was calculated from work output, oxygen consumption and RER energy equivalents following 10 min standard cycle ergometry exercise at 100 W and 50 rev min-1. Measurements were made at pre-, mid- and post-8 months of training, which involved progressive walking/jogging activities designed to enhance endurance capacity. In the total group, VO2 decreased pre- to post-training from 2.15 +/- 0.02 to 1.93 +/- 0.01 1 min-1 (P less than 0.01). In the sub-groups, both the younger and older subjects showed a significantly reduced VO2, from 2.17 +/- 0.01 to 1.98 +/- 0.04 1 min-1 and 2.05 +/- 0.08 to 1.86 +/- 0.03 1 min-1 respectively (P less than 0.05), but no significant changes were noted at mid-training. In the intermediate age subjects, while there were trends towards a reduced VO2, none was significant. The ANOVA revealed increased mean gross efficiency in the total group from pre- (14.3 +/- 0.1%) to post- (15.5 +/- 0.2%) (P less than 0.05) but not at mid-training (14.8 +/- 0.2%). While similar trends were observed in the sub-groups, gross efficiency increases were not significant, although changes in gross efficiency were reflected in VO2. The findings suggest that during standardized exercise, oxygen cost may be reduced and gross efficiency increased in adult males following endurance training and that such changes may take place over a variety of age ranges.

Injury in summer rugby league football: the experiences of one club.

OBJECTIVE: To investigate whether the movement of the playing season from winter to summer would alter the risk of injury to players taking part in first team European professional rugby league. METHODS: The study design was a historical cohort design comparing winter and summer seasons in first team European rugby league, which recorded injuries received by players during match play. Each injury was classified according to site, type, player position, activity at the time of injury, and time off as a result of injury. RESULTS: The risk of injury when playing summer rugby league was higher than when playing winter rugby league (relative risk = 1.67 (95% confidence interval 1.18 to 2.17)). Both forwards (1.08 (0.28 to 1.88)) and backs (2.36 (2.03 to 2.69)) experienced an increased risk of injury. CONCLUSIONS: Summer rugby may have resulted in a shift of injury risk factors as exhibited by a change in injury patterns. This may be due to playing conditions, but there were also some law changes. Changes in playing style, team tactics, player equipment, fitness preparation, and the reduced preseason break may also have had confounding effects on injury risk.

Health and safety implications of injury in professional rugby league football.

BACKGROUND: Professional sport is characterized by high injury rates but is also covered by health and safety legislation. AIM: To examine the incidence of injury in professional rugby league as defined by the Reporting of Diseases and Dangerous Occurrences Regulations 1995 (RIDDOR 95). METHODS: All injuries received during playing and training to both first-team and 'academy' (<19 years old) players during two playing seasons at one professional club were recorded. The length of time a player was unable to take part in full training and playing was used as a measure of severity. Injuries were classified into minor injuries (0-3 days), over 3 day injuries or major injuries, in which the final two categories corresponded with RIDDOR 95. RESULTS: Thirty-two per cent (95% confidence interval=26-39%) of all injuries received satisfied the RIDDOR 95 criteria. The overall injury rate was 8.5 per 1000 h (7.2-9.9) for the first team and 4.1 per 1000 h (3.2-5.4) for the academy team. During match play the first-team injury rate was 157.7 per 1000 h (133.5-185.1) and 67.7 (51-81.1) for the academy team. Training injury rates were lower, at 0.5 per 1000 h (0.2-1.0) and 0.3 per 1000 h (0.1-0.8), respectively. CONCLUSION: The injury rate for professional rugby league is much higher than reported in other high-risk occupations such as mining and quarrying. The large differences in injury rates between first and academy teams have implications for young players likely to progress to first-team status.