Incidence, severity, aetiology and prevention of sports injuries. A review of concepts

Intrinsic factors associated with exercise-related leg pain in collegiate cross-country runners

OBJECTIVES

This study (1) examined the occurrence of exercise-related leg pain (ERLP) in collegiate cross-country athletes and (2) compared structural factors in runners with and without ERLP history.

STUDY DESIGN

Cross-sectional design comparing 2 groups of cross-country athletes (with and without ERLP history).

SETTING

Intercollegiate athletics.

PARTICIPANTS

A total of 63 athletes (30 males, 33 females) representing 2 cross-country teams consented to participate.

MEASURES

Athlete examination included self-report of ERLP history, active ankle dorsiflexion with knee extended and flexed, navicular drop (ND), and 1st ray length. ND index was calculated by dividing ND by 1st ray length. Athletes on 1 team (n = 32) were followed through 1 season to identify incidence of ERLP over the course of 1 season. Independent t tests were used to compare structural measures of those with and without ERLP history, and chi2 was used to examine frequencies.

RESULTS

Of the 63 athletes, 33 (52%) reported ERLP history; most reported medial leg pain and also bilateral symptoms. No differences in structural measures were found between those with and without ERLP history. Ten of 32 athletes (31%) reported the occurrence of ERLP during the fall season, 8 of whom had a history of ERLP.

CONCLUSIONS

Exercise-related leg pain was a common complaint among these athletes, usually occurring bilaterally and located along the medial leg. Athletes with ERLP history did not have a greater foot pronation as measured by ND, nor was there limited ankle range of motion as compared with those without ERLP history. Further research is needed to identify factors associated with the development of ERLP.

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.

An assessment of the methodological quality of research published in The American Journal of Sports Medicine

BACKGROUND

Evidence-based medicine has become a popular topic in academic medicine during the past several decades and more recently in orthopaedics and sports medicine.

HYPOTHESIS

Articles published in The American Journal of Sports Medicine have shown an improvement in methodological quality in 2001-2003, compared with 1991-1993.

STUDY DESIGN

Systematic review.

METHODS

All articles published in The American Journal of Sports Medicine during the periods 1991-1993 and 2001-2003 were reviewed and classified by type of study. The use of pertinent methodologies such as prospective data collection, randomization, blinding, and controlled studies was noted for each article. The frequency of each article type and the use of evidence-based techniques were compared across study periods.

RESULTS

Case series and descriptive studies decreased during the study period, from 27.4% to 15.3% (P = .00003) and from 11.9% to 5.6% (P = .001), respectively, of articles published. Prospective cohort studies increased from 4.7% to 14.1% (P = .000005), and randomized, prospective clinical trials increased from 2.7% to 5.9% of articles (P = .04). More studies tested an explicit hypothesis (P = .0000002), used prospective data collection (P = .000003), and used blinding (P = .02), and more studies identified a funding source (P = .004).

CONCLUSIONS

Overall, there was a shift toward more prospective and randomized research designs published in The American Journal of Sports Medicine during 2001-2003 compared to 1991-1993, demonstrating an improvement in the methodological quality of published research.

Injuries in female soccer players: a prospective study in the German national league

BACKGROUND

In contrast to the high number of studies about soccer injuries in men, epidemiologic data in high-level female soccer players are scarce.

PURPOSE

Analysis of injury incidence in elite female soccer players.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

There were 165 female soccer players (age, 22.4 +/- 5.0 years) from 9 teams competing in the German national league, who were followed for one complete outdoor season. Their trainers documented the exposure to soccer on a weekly basis for each player, and the team physical therapists reported all injuries with regard to location, type, and circumstances of occurrence. An injury was defined as any physical complaint associated with soccer that limited sports participation for at least 1 day.

RESULTS

There were 241 injuries sustained by 115 players (70%) reported; 39 injuries (16%) were owing to overuse, and 202 injuries (84%) were traumatic. Overall, 42% of the traumatic injuries occurred during training (2.8/1000 hours of training; 95% confidence interval, 2.2-3.4) and 58% during matches (23.3/1000 match hours; 95% confidence interval, 19.1-27.5); 102 of the traumatic injuries were caused by a contact situation, whereas 95 occurred without any contact. Most injuries (80%) were located at the lower extremities, concerning mainly the thigh (n = 44), knee (n = 45), and ankle (n = 43). Ankle sprain (n = 37) was the most often diagnosed injury. There were 51% minor injuries, 36% moderate injuries, and 13% major injuries. Eleven anterior cruciate ligament ruptures were observed during the season.

CONCLUSION

The results revealed a high injury incidence rate in games as well as a comparably low incidence rate during training. An important finding of this investigation was the frequent occurrence of anterior cruciate ligament ruptures. Preventive measures should thus focus on the high prevalence of anterior cruciate ligament tears, mostly occurring in noncontact situations.

Return to play following muscle strains

OBJECTIVE

To assess return to play strategies following muscle strains with the desired outcomes of decreased competition play lost and minimized risk for recurrent injury.

METHODS

Literature review of previous studies that examine return to play criteria for the commonly seen muscle strain injuries in sport.

RESULTS

There have been no studies directly comparing different return to play approaches. Studies have instead concentrated on recurrence risk factors and prognosis assessment, particularly for hamstring injuries. There is some literature support for risk factors for recurrence such as persisting strength deficits, larger injuries seen on diagnostic imaging, players in high-risk positions or sports, inability to complete functional tasks without pain, and strains of specific high-risk muscles (biceps femoris, central tendon of rectus femoris, medial head of gastrocnemius, adductor longus or magnus).

CONCLUSIONS

There are no consensus guidelines or agreed-upon criteria for safe return to sport following muscle strains that completely eliminate the risk for recurrence and maximize performance. At this time, it may be a sensible strategy to allow earlier return to play in team sports and accept a low to moderate injury recurrence rate. Improved prognostic assessment of muscle strains with injury identification (MRI) and injury assessment (isokinetic testing) may be assist practitioners to lower, but not eliminate, recurrent 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.

Methods for injury surveillance in international cricket

BACKGROUND

The varying methods of cricket injury surveillance projects have made direct comparison of published studies in this field impossible.

METHODS

A consensus regarding definitions and methods to calculate injury rates in cricket was sought between researchers in this field. This was arrived at through a variety of face-to-face meetings, email communication and draft reviews between researchers from six of the major cricket-playing nations.

RESULTS

It is recommended that a cricket injury is defined as any injury or other medical condition that either: (a) prevents a player from being fully available for selection for a major match or (b) during a major match, causes a player to be unable to bat, bowl or keep wicket when required by either the rules or the team's captain. Recommended definitions for injury incidence (for matches, training sessions and seasons) and injury prevalence are also provided. It is proposed that match injury incidence is calculated using a denominator based on a standard time estimated for player exposure in matches, for the purposes of simplicity. This will allow all injury surveillance systems, including those with limited resources, to make calculations according to a standard definition.

CONCLUSION

The consensus statement presented provides a standard which, if followed, allows meaningful comparison of injury surveillance data from different countries and time periods, which will assist in the possible identification of risk factors for injury in cricket.

Impact of social standing on sports injury prevention in a WHO safe community: intervention outcome by household employment contract and type of sport

OBJECTIVES

As physical activity is promoted as part of a healthy lifestyle, sports injuries are becoming an important public health concern in many countries. The objective of this study is to investigate rates of sports injuries before and after implementation of a WHO Safe Community program.

METHODS

Sports injury data were collected pre- and post-implementation from all individuals below 65 years of age during 1 year in the targeted municipality (population 41,000) and in a control municipality (population 26,000). A quasi-experimental design was used and individuals were divided into three categories based on household relationship to the labour market.

RESULTS

There were no differences between socio-economic categories regarding pre-intervention injury rates. No statistically significant post-intervention changes in injury rate were observed in the control area or among any females in either area. In the intervention area, a statistically significant (p = 0.011) decrease in injury rate was observed among male members of households in which the vocationally important member was employed. A statistically significant decrease was observed in injuries sustained in team sports among male members of households in which the vocationally important member was employed (p = 0.001) and among members of households in which the vocationally important member was self employed (p<0.05).

CONCLUSIONS

The study indicates areas for improvement in the civic network based WHO Safe Community model. The results show that females, participants in individual sports, and members of non-vocationally active households were less affected by the interventions. These facts have to be addressed in planning future community based sports injury prevention programmes and their evaluations.

Understanding injury mechanisms: a key component of preventing injuries in sport

Anterior cruciate ligament (ACL) injuries are a growing cause of concern, as these injuries can have serious consequences for the athlete with a greatly increased risk of early osteoarthrosis. Using specific training programmes, it may be possible to reduce the incidence of knee and ankle injuries. However, it is not known which programme components are the key to preventing knee and ankle injuries or how the exercises work to reduce injury risk. Our ability to design specific prevention programmes, whether through training or other preventive measures, is currently limited by an incomplete understanding of the causes of injuries. A multifactorial approach should be used to account for all the factors involved-that is, the internal and external risk factors as well as the inciting event (the injury mechanism). Although such models have been presented previously, we emphasise the need to use a comprehensive model, which accounts for the events leading to the injury situation (playing situation, player and opponent behaviour), as well as to include a description of whole body and joint biomechanics at the time of injury.

Methods for epidemiological study of injuries to professional football players: developing the UEFA model

A problem with epidemiological studies of football injuries is the inconsistent manner in which injury is defined and data are collected. Projects have been initiated to study the incidence and causes of injury in football, but there is no uniformly accepted reporting system. In this report, some common pitfalls encountered in the recording of injury are addressed, and practical guidelines for epidemiological studies are provided. An injury reporting system developed for the UEFA Football Safety Project for studies on professional footballers is used as a starting point for a general discussion on injury registration and compared with other existing reporting systems. The recording definition of injury may vary between studies depending on its purpose. A time loss injury definition is practical for all playing levels, and, as a minimum, results on time loss injuries should therefore always be reported separately to allow direct comparisons between studies. There is a need to agree on a uniform sports injury classification system with corresponding diagnostic criteria, as well as standardised return to play criteria after injury.

Research approaches to describe the mechanisms of injuries in sport: limitations and possibilities

A number of different methodological approaches have been used to describe the inciting event for sports injuries. These include interviews of injured athletes, analysis of video recordings of actual injuries, clinical studies (clinical findings of joint damage are studied to understand the injury mechanism, mainly through plain radiography, magnetic resonance imaging, arthroscopy, and computed tomography scans), in vivo studies (ligament strain or forces are measured to understand ligament loading patterns), cadaver studies, mathematical modelling and simulation of injury situations, and measurement/estimation from "close to injury" situations. In rare cases, injuries have even occurred during biomechanical experiments. This review describes each research approach and assesses its strengths and weaknesses in contributing to the understanding and prevention of sports injuries.

Psychological predictors of injury among elite athletes

OBJECTIVES

To establish injury rates among a population of elite athletes, to provide normative data for psychological variables hypothesised to be predictive of sport injuries, and to establish relations between measures of mood, perceived life stress, and injury characteristics as a precursor to introducing a psychological intervention to ameliorate the injury problem.

METHODS

As part of annual screening procedures, athletes at the Queensland Academy of Sport report medical and psychological status. Data from 845 screenings (433 female and 412 male athletes) were reviewed. Population specific tables of normative data were established for the Brunel mood scale and the perceived stress scale.

RESULTS

About 67% of athletes were injured each year, and about 18% were injured at the time of screening. Fifty percent of variance in stress scores could be predicted from mood scores, especially for vigour, depression, and tension. Mood and stress scores collectively had significant utility in predicting injury characteristics. Injury status (current, healed, no injury) was correctly classified with 39% accuracy, and back pain with 48% accuracy. Among a subset of 233 uninjured athletes (116 female and 117 male), five mood dimensions (anger, confusion, fatigue, tension, depression) were significantly related to orthopaedic incidents over the preceding 12 months, with each mood dimension explaining 6-7% of the variance. No sex differences in these relations were found.

CONCLUSIONS

The findings support suggestions that psychological measures have utility in predicting athletic injury, although the relatively modest explained variance highlights the need to also include underlying physiological indicators of allostatic load, such as stress hormones, in predictive models.

Injuries in Swedish elite football--a prospective study on injury definitions, risk for injury and injury pattern during 2001

The purpose of this study was to study the risk for injury and injury pattern in Swedish male elite football and to compare two different injury definitions. A prospective cohort study was conducted during 2001 on all 14 teams (310 players) in the Swedish top division. Injuries and individual exposure were recorded. Injury was defined as time-lost injury (715 injuries) and for comparison as tissue injury (765 injuries). No significant difference in the risk for injury between tissue injuries and time-lost injuries was found during matches (27.2 vs. 25.9 injuries per 1000 match hours, P=0.66) or training sessions (5.7 vs. 5.2 injuries per 1000 training hours, P=0.65). The risk for injury during training was significantly higher during the pre-season compared with the competitive season (P=0.01). Thigh strain was the single most common injury (14%). Knee sprain was the most common major injury (absence >4 weeks). Overuse injuries and re-injuries were frequent and constituted 37% and 22% of all injuries. Re-injuries caused significantly longer absence than their corresponding initial injuries (P=0.02). The risk for re-injury (P=0.02) and overuse injury (P<0.01) was significantly higher during the pre-season compared with the competitive season.

Methods for injury surveillance in international cricket

BACKGROUND

The varying methods of cricket injury surveillance have made direct comparison of published studies in this field impossible.

METHODS

A consensus regarding definitions and methods to calculate injury rates in cricket was sought between researchers in this field. This was arrived at through a variety of face to face meetings, email communication, and draft reviews between researchers from six of the major cricket playing nations.

RESULTS

It is recommended that a cricket injury is defined as any injury or other medical condition that either (a) prevents a player from being fully available for selection for a major match or (b) during a major match, causes a player to be unable to bat, bowl, or keep wicket when required by either the rules or the team's captain. Recommended definitions for injury incidence (for matches, training sessions, and seasons) and injury prevalence are also provided. It is proposed that match injury incidence is calculated using a denominator based on a standard time estimated for player exposure in matches, for the purposes of simplicity. This will allow all injury surveillance systems, including those with limited resources, to make calculations according to a standard definition.

CONCLUSION

The consensus statement presented provides a standard which, if followed, allows meaningful comparison of injury surveillance data from different countries and time periods, which will assist in the possible identification of risk factors for injury in cricket.

Injury incidence and distribution in elite football--a prospective study of the Danish and the Swedish top divisions

The Danish and Swedish male top football divisions were studied prospectively from January to June 2001. Exposure to football and injury incidence, severity and distribution were compared between the countries. Swedish players had greater exposure to training (171 vs. 123 h per season, P<0.001), whereas exposure to matches did not differ between the countries. There was a higher risk for injury during training in Denmark than in Sweden (11.8 vs. 6.0 per 1000 h, P<0.01), whereas for match play there was no difference (28.2 vs. 26.2 per 1000 h). The risk for incurring a major injury (absence from football more than 4 weeks) was greater in Denmark (1.8 vs. 0.7 per 1000 h, P = 0.002). The distribution of injuries according to type and location was similar in both countries. Of all injuries in Denmark and Sweden, overuse injury accounted for 39% and 38% (NS), and re-injury for 30% and 24% (P = 0.032), respectively. The greater training exposure and the long pre-season period in Sweden may explain some of the reported differences.

Soccer injuries: a review on incidence and prevention

Several investigators have studied the incidence and causes of soccer injuries in male professional players; however, epidemiological data on injuries in female soccer players are limited. From the data presented, it can be estimated that, on average, every elite male soccer player incurs approximately one performance-limiting injury each year. Nine studies on the prevention of soccer injuries were found in the literature. There is some evidence that multi-modal intervention programmes result in a general reduction in injuries. Ankle sprains can be prevented by external ankle supports and proprioceptive/coordination training, especially in athletes with previous ankle sprains. With regard to severe knee injuries, the results of prevention studies are partly inconclusive; however, training of neuromuscular and proprioceptive performance as well as improvement of jumping and landing technique seem to decrease the incidence of anterior cruciate ligament injuries in female athletes. Prevention programmes are likely to be more effective in groups with an increased risk of injury. More methodologically well-designed studies are required to evaluate the effects of specific preventive interventions.

Kinetic Changes with Fatigue and Relationship to Injury in Female Runners

PURPOSE

This research examined how ground reaction forces (GRF) changed with fatigue induced by an exhaustive treadmill run in female runners. A separate retrospective and prospective analysis correlated initial magnitude of GRF and fatigue-induced changes in GRF with lower-extremity injury.

METHODS

Ninety adult female runners had vertical GRF measured before and after an exhaustive treadmill run. Subjects initially were questioned about previous running injuries, and were contacted during the following year and asked to report any additional running injuries.

RESULTS

Fatigue induced by the exhaustive treadmill run resulted in decreased impact peak and loading rates in all runners by an average of 6 and 11%, respectively. The changes in GRF were attributed to altered running cadence, step length, and lower-extremity joint kinematics. It is unclear whether these changes were attempts by the runners to minimize impact forces and protect against injury, or represented a fatigue-induced loss of optimal performance capabilities. An interaction between injury in the previous year and change in impact loading rate with fatigue was observed, suggesting previously injured runners are exposed to relatively higher impact forces over time.

CONCLUSION

Habitual female runners appear to adapt their running style with fatigue, resulting in altered GRF. Changes in GRF with fatigue may be associated with lower-extremity running injuries.

Use of discretionary protective equipment and rate of lower extremity injury in high school athletes

Use of protective equipment is an important sports injury prevention strategy, yet use of protective equipment by high school athletes has seldom been studied. The authors analyzed data from a 3-year (1996-1999), stratified, two-stage cluster sample of athletes from 12 organized sports in 100 North Carolina high schools (n = 19,728 athlete-seasons). Information on each athlete's use of protective equipment and prior injury was collected during the preseason. Prospective information on injuries and weekly participation in games and practices was collected during the playing season. Use of lower extremity discretionary protective equipment tended to decrease the overall rate of lower extremity injury (rate ratio (RR) = 0.91, 95% confidence interval (CI): 0.72, 1.15). However, this slight protective effect was entirely due to kneepad use (for knee injury, RR = 0.44, 95% CI: 0.27, 0.74). Knee brace use and ankle brace use were associated with increased rates of knee injury (RR = 1.61, 95% CI: 1.08, 2.41) and ankle injury (RR = 1.74, 95% CI: 1.11, 2.72), respectively. This could be due to slippage of the brace during use, increased fatigue due to the energy cost of wearing a brace, or bias in the study. Further investigation into the effects of brace use is warranted.

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.

A congested football calendar and the wellbeing of players: correlation between match exposure of European footballers before the World Cup 2002 and their injuries and performances during that World Cup

OBJECTIVES

To investigate the correlation between exposure of footballers in European clubs to match play in the months before the World Cup 2002 and their injuries and performances during that World Cup.

METHODS

The team doctors at 11 of the best football clubs in Europe prospectively recorded players' exposure and injuries during the 2001-2002 season (July 2001-May 2002). Sixty five players participated in the World Cup in Korea/Japan (June 2002). During the World Cup, the clubs reported injuries sustained by these players, and their performance was evaluated by three international experts.

RESULTS

The number of team matches during the season varied between 40 and 76 for the different countries involved. The individual player had a mean of 36 matches during the season. Top players played more matches, especially during the final period of the season. Players who participated in the World Cup played more matches during the season than those who did not (46 v 33 matches). World Cup players did not show any increased risk of injury during the season. About 29% incurred injuries during the World Cup, and 32% performed below their normal standard. The players who underperformed had played more matches during the 10 weeks before the World Cup than those who performed better than expected (12.5 v 9, p<0.05). Twenty three (60%) of the 38 players who had played more than one match a week before the World Cup incurred injuries or underperformed during the World Cup.

CONCLUSIONS

There is considerable variation in the number of matches played per season in European professional football leagues. Top level players are obliged to play many matches especially during the final period of the season.

A one season prospective cohort study of volleyball injuries

OBJECTIVE

To estimate the overall incidence of acute and overuse volleyball injuries, and to describe factors associated with ankle sprains.

METHODS

486 players from the second and third Dutch national volleyball divisions participated in the study and were followed prospectively during a whole season. Three measurements were made during the season (baseline, follow up 1, and follow up 2), where all players completed a questionnaire on demographic variables (only at baseline), sports participation, use of preventive measures, and previous injuries. Volleyball exposure during training and matches was recorded for each individual player by the coach on a weekly exposure form. In case of injury the coach provided the injured player with an injury registration form, which had to be completed within one week after the onset of injury.

RESULTS

100 injuries were reported, resulting in an overall injury incidence of 2.6 injuries/1000 hours. The incidence of acute injuries was 2.0/1000 hours. Ankle sprains (n = 41) accounted for most of the acute injuries, and 31 (75%) of all players with an ankle sprain reported a previous ankle sprain. Twenty five overuse injuries were reported. The overall incidence of overuse injuries was 0.6/1000 hours; the back and the shoulder were the most common sites.

CONCLUSIONS

Ankle sprain is the most common injury in volleyball, accounting for 41% of all volleyball related injuries. Previous injury seems to be an important risk factor for an ankle sprain. Injury prevention programmes should focus on ankle sprains and concentrate on players with previous ankle sprains.

The Football Association medical research programme: an audit of injuries in academy youth football

OBJECTIVES

To undertake a prospective epidemiological study of the injuries sustained in English youth academy football over two competitive seasons.

METHODS

Player injuries were annotated by medical staff at 38 English football club youth academies. A specific injury audit questionnaire was used together with a weekly return form that documented each club's current injury status.

RESULTS

A total of 3805 injuries were reported over two complete seasons (June to May) with an average injury rate of 0.40 per player per season. The mean (SD) number of days absent for each injury was 21.9 (33.63), with an average of 2.31 (3.66) games missed per injury. The total amount of time absent through injury equated to about 6% of the player's development time. Players in the higher age groups (17-19 years) were more likely to receive an injury than those in the younger age groups (9-16 years). Injury incidence varied throughout the season, with training injuries peaking in January (p<0.05) and competition injuries peaking in October (p<0.05). Competition injuries accounted for 50.4% of the total, with 36% of these occurring in the last third of each half. Strains (31%) and sprains (20%) were the main injury types, predominantly affecting the lower limb, with a similar proportion of injuries affecting the thigh (19%), ankle (19%), and knee (18%). Growth related conditions, including Sever's disease and Osgood-Schlatter's disease, accounted for 5% of total injuries, peaking in the under 13 age group for Osgood-Schlatter's disease and the under 11 age group for Sever's disease. The rate of re-injury of exactly the same anatomical structure was 3%.

CONCLUSIONS

Footballers are at high risk of injury and there is a need to investigate ways of reducing this risk. Injury incidence at academy level is approximately half that of the professional game. Academy players probably have much less exposure to injury than their full time counterparts. Areas that warrant further attention include the link between musculoskeletal development and the onset of youth related conditions such as Sever's disease and Osgood-Schlatter's disease, the significant number of non-contact injuries that occur in academy football, and the increased rates of injury during preseason training and after the mid season break. This study has highlighted the nature and severity of injuries that occur at academy level, and the third part of the audit process now needs to be undertaken: the implementation of strategies to reduce the number of injuries encountered at this level.

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.

Knee surgery costs in football, floor ball, European team handball and ice hockey

The purpose of this study was first, to identify the health costs of knee surgery related to different sports (football, floor ball, European team handball and ice hockey) among players at competitive level in Stockholm 1997. Information was retrieved from three different databases, one containing information on all players in different sports, another one containing information on all surgery performed at S:t Gorans Hospital, Stockholm, and a third one containing information on all surgery performed in Stockholm. The National Registration Number (NRN) was used to identify the patients. The NRN is a unique personal identifier assigned to all Swedish residents, which allows linkage between different registers and databases. In Stockholm in 1997, 6781 surgical procedures related to the knee were performed at a cost of SEK (Swedish Crowns) 39,026,657. On players in all studied sports, 762 knee surgical procedures were performed on 657 patients in Stockholm at a cost of SEK 4,884,076. At S:t Gorans Hospital, 319 knee surgical procedures were performed on 288 patients, and 293 (92%) of these were directly related to sport participation. It was also found that only 74% of anterior cruciate ligament injuries that resulted in a surgical intervention were reported to the insurance company.

CONCLUSION

The average cost for knee surgery in the studied sports was low. Knee surgery costs for European team handball players were the highest compared with other sports studied.

Incidence of injury in elite junior Rugby Union: a prospective descriptive study

The high incidence of injury in Rugby Union is well documented, particularly at elite levels of competition. This article describes the incidence and nature of all injuries sustained by elite Western Australian junior Rugby Union players during the 26 weeks up to and including the 1997 National Championship campaign. Informed consent was gained for each participant (n = 44) prior to completion of an extensive baseline questionnaire. Exposure and injury data were collected at each training session and game. The injury incidence rate over the 26 week period was 13.26/1000 player hours. Injury data were analysed by phase of play, position, severity and if occurred at games or training. The incidence of injury was significantly associated with the position played (chi2 = 67.49, p value = 0.008) and the phase of play in which the injury occurred (chi2 = 8.07, p value = 0.042). Tackling was the most dangerous phase of play (52% of injuries) and the most common site of injury was the lower limb (37%). Most injuries occurred during games (56%) and the flanker was the position most at risk of injury (12%). Further research is needed to identify the aetiology of injury at all levels of competition and to use these findings to develop effective injury prevention strategies in this sport. Position-specific risk factors should also be investigated, as should the mechanism of injury associated with tackling which is the phase of play in which significantly more injuries occur in rugby.

Incidence, causes, and severity of high school football injuries on FieldTurf versus natural grass: a 5-year prospective study

BACKGROUND

Numerous injuries have been attributed to playing on artificial turf. Recently, FieldTurf was developed to duplicate the playing characteristics of natural grass. No long-term study has been conducted comparing game-related, high school football injuries between the 2 playing surfaces.

HYPOTHESIS

High school athletes would not experience any difference in the incidence, causes, and severity of game-related injuries between FieldTurf and natural grass.

STUDY DESIGN

Prospective cohort study.

METHODS

A total of 8 high schools were evaluated over 5 competitive seasons for injury incidence, injury category, time of injury, injury time loss, player position, injury mechanism, primary type of injury, grade and anatomical location of injury, type of tissue injured, head and knee trauma, and environmental factors.

RESULTS

Findings per 10 team games indicated total injury incidence rates of 15.2 (95% confidence interval, 13.7-16.4) versus 13.9 (95% confidence interval, 11.9-15.6). Minor injury incidence rates of 12.1 (95% confidence interval, 10.5-13.6) versus 10.7 (95% confidence interval, 8.7-12.7), substantial injury incidence rates of 1.9 (95% confidence interval, 1.4-2.6) versus 1.3 (95% confidence interval, 0.8-2.1), and severe injury incidence rates of 1.1 (95% confidence interval, 0.7-1.7) versus 1.9 (95% confidence interval 1.2-2.8) were documented on FieldTurf versus natural grass, respectively. Multivariate analyses indicated significant playing surface effects by injury time loss, injury mechanism, anatomical location of injury, and type of tissue injured. Higher incidences of 0-day time loss injuries, noncontact injuries, surface/epidermal injuries, muscle-related trauma, and injuries during higher temperatures were reported on FieldTurf. Higher incidences of 1- to 2-day time loss injuries, 22+ days time loss injuries, head and neural trauma, and ligament injuries were reported on natural grass.

CONCLUSIONS

Although similarities existed between FieldTurf and natural grass over a 5-year period of competitive play, both surfaces also exhibited unique injury patterns that warrant further investigation.

Looking for the evidence: a systematic review of prevention strategies addressing sport and recreational injury among children and youth

OBJECTIVES

To examine evidence on the effectiveness of current injury prevention strategies in selected sport and recreational activities, determine the applicability of the evidence to children and youth and discuss the implications related to policy, programming and future research.

METHODS

Research questions and relevance criteria were developed a priori. Potentially relevant studies were located through electronic and hand searches. Two independent assessors assessed articles for first relevance and then quality. Relevant articles were abstracted and synthesised for activities that had three or more relevant articles.

RESULTS

A total of 21,499 articles identified through database and manual searching yielding 117 that met inclusion criteria. The majority of the studies (93 or 89%) involved eight activities: baseball, basketball, cycling, football, ice hockey, rugby, alpine skiing and soccer. Children and youth were identified as the specific target group in 45% of the studies and another 12% included children in their sample. Studies addressed a range of intervention strategies and varied on quality of evidence.

CONCLUSIONS

Surprisingly few well-designed and controlled studies investigating strategies to prevent injuries were found and an even smaller number evaluated strategies to reduce injury in children and youth. As governments in developed countries continue to focus on increasing physical activity among children and youth, thought must be given to the issue of risk of injury and the relative lack of evidence of effective preventive measures.

Spinal injuries in rugby union, 1970–2003: lessons and responsibilities

There was an increase in the frequency of rugby union spinal injuries worldwide during the 1970s and early 1980s. The United Kingdom and Australia have since had some success in reducing this increase in spinal injuries. These changes were the result of actions by rugby union authorities in response to recommendations by medical advisors; legal action by injured players has also played a part. The frequency of spinal injuries has not decreased in New Zealand (up to 2000) and South Africa (up to 1997). Rugby union authorities' responsibilities should include establishing and maintaining national and international spinal injury registers to forge closer working relationships with medical researchers. Such registers would provide up-to-date information for enhancing and developing preventive measures. There has been no specific publicly available record of the incidence of rugby union spinal injuries in Australia since 1996, so it is uncertain whether the safety measures introduced so far have had a lasting impact.

Risk for injury when playing in a national football team

The Swedish male senior national football team was followed prospectively between 1991 and 1997. During these 6 years, the team played 73 official matches and had three training camps. The senior author (J. E.) attended 57 of these matches and the three training camps and these matches and training camps, are included in the present study. Exposure to football was recorded individually for each player. The team physician examined all injuries. Total exposure was 7245 h (6235 training and 1010 match hours) and there were 71 injuries (40 training and 31 match injuries). Five (16%) of the match injuries were major, with more than 4 weeks of absence from football. The injury incidence during training was 6.5/1000 h and the injury risk during matchplay was 30.3/1000 h. A significantly higher injury incidence was found for matches lost compared to matches won or drawn (52.5 vs. 22.7/1000 h, P=0.026). No statistically significant difference for injury was found between competitive matches and friendly matches. No difference was found between home and away matches or matches on neutral ground. The risk for injury when playing in a national team compares with previously reported figures for professional football at a high level.

Development of a new activity score for the evaluation of ankle instability

BACKGROUND

Tegner and Lysholm described their generally acknowledged activity score in 1985. It was originally tested for knee ligament injuries, but for the past 17 years it has been used for other joint evaluations as well. The development of already existing and new kinds of sports, differences between knee and ankle loading, and different injury rates provided reasons for developing an ankle-specific activity score.

HYPOTHESIS

The new score should have a higher reliability, validity, and sensitivity than the Tegner score when evaluating ankle-related activity changes.

STUDY DESIGN

Methodological study.

METHODS

Fifty-three sports, 3 working activities, and 4 general activities were inserted into a 0-to-10 category system based on the rankings of a 7 x 2-point pre-evaluation system, followed by a direct comparison with the Tegner score and reliability, validity, and sensitivity testing on 2 different patient populations.

RESULTS

In direct comparison, there is a strong overall correlation of the 2 activity-scoring systems (r = 0.7565), but the ankle activity score proved to be different from the Tegner score in the higher categories, especially in the top 4 ankle score categories (r = 0.1450). Further tests demonstrated the high reliability (1.00) of the new score. Analysis of variance proved that activity changes measured by the ankle score correspond well to the difference between the patients' subjective results and their Karlsson functional scores (P =.0119). This is not the case when we measure ankle activity changes using the knee-specific Tegner score (P =.0987). Furthermore, ankle score differences spread over a wider range (-1.18 +/- 2.12) than did Tegner score differences (-0.68 +/- 1.29), which demonstrates the higher sensitivity of the new score.

CONCLUSIONS

Based on these results, the new ankle activity score could be a better complement in the complex evaluation of ankle instability.

Injuries in youth amateur soccer and rugby players--comparison of incidence and characteristics

OBJECTIVES

In reviewing the literature on sports injuries, few studies could be found in which exposure related incidences of injury in different types of sport were compared. These studies indicated that ice hockey, handball, basketball, soccer, and rugby are popular team sports with a relatively high risk of injury. The aim of the study was to compare the characteristics and incidence of injuries in male youth amateur soccer and rugby players.

METHODS

This prospective cohort study comprised an initial baseline examination to ascertain the characteristics of the players and their level of performance, and a one season observation period during which a physician visited the team weekly and documented all occurring injuries. Twelve soccer and 10 rugby school teams with male amateur players aged 14-18 years were selected for the study. 145 soccer and 123 rugby players could be followed up over one season.

RESULTS

Comparison of the incidence of soccer and rugby injuries indicated that rugby union football was associated with a significantly higher rate of injury than soccer. The differences were pronounced for contact injuries, injuries of the head, neck, shoulder, and upper extremity, as well as for concussion, fractures, dislocations, and strains. Rugby players incurred 1.5 times more overuse and training injuries in relation to exposure time, and 2.7 times more match injuries than soccer players. Three rugby players but no soccer players had to stop their participation in sport because of severe injury.

CONCLUSION

The incidence of injury in New Zealand school teams playing soccer or rugby union is high, probably in part because of the low ratio of hours spent in training relative to hours spent playing matches. The development and implementation of preventive interventions to reduce the rate and severity of injury is recommended.

Football injuries at Asian tournaments

PURPOSE

To examine the incidences and patterns of injuries that required medical attention among Asian football players.

METHODS

A total of 411 Asian football players at both senior and youth (U-20) elite levels were observed during 50 international matches. Independent injury observers and team doctors determined the occurrence of injuries and recorded the location, type, time, and circumstances of the injuries using a protocol sheet.

RESULTS

The overall injury frequency rate was 45.8 out of 1000 hours. As the tournaments progressed into the knockout stages, the incidence and severity of the injuries increased. The most common sites of injuries were the knees (18.5%), lower legs (17.3%), and ankles (14.2%). Although most injuries were diagnosed as contusions, the more serious injuries were those diagnosed as sprains (especially concerning the knee and ankle) or strains (thigh and back).

CONCLUSIONS

The incidences of injuries to Asian football players were higher than those to European players, but the patterns of the injuries showed no major differences.

CLINICAL RELEVANCE

To develop an injury-prevention program, more solid and comprehensive data need to be collected to identify the risk factors and variables associated with higher incidences of injuries to Asian football players.

Risk factors for sports injuries--a methodological approach

The methodology for studies designed to investigate potential risk factors for sports injury is reviewed, using the case of hamstring strains as an example. Injuries result from a complex interaction of multiple risk factors and events. Therefore, a multivariate statistical approach should be used. In addition, the sample size of the study needs to be considered carefully. Sample size mainly depends on the expected effect of the risk factor on injury risk, and to detect moderate to strong associations 20-50 injury cases are needed, whereas small to moderate associations would need about 200 injured subjects. Studies published to date on the risk factors for hamstring strains have methodological limitations, and are too small to detect small to moderate associations.

Types and epidemiology of tendinopathy

During the last few decades, the role of sports and physical activity has become more and more important in all modern communities. The risk of tendon injury has thus increased, and prevention has become important. Epidemiologic studies are important when planning prevention programs for tendon injuries. Because of individual sport cultures and different sport habits in different countries, national epidemiologic studies are of importance in each individual country.

The efficacy of stretching for prevention of exercise-related injury: a systematic review of the literature

The objective of this study was to conduct a systematic analysis of the literature to assess the efficacy of stretching for prevention of exercise-related injury. Randomized clinical trials (RCTs) and controlled clinical trials (CCTs) investigating stretching as an injury prevention measure were selected. A computer-aided search of the literature was conducted for relevant articles, followed by assessment of the methods of the studies. The main outcome measures were scores for methodological quality based on four main categories (study population, interventions, measurement of effect, and data presentation and analysis) and main conclusions of authors with regard to stretching. One RCT (25%) and three CCTs (100%) concluded that stretching reduced the incidence of exercise-related injury. Three RCTs (75%) concluded that stretching did not reduce the incidence of exercise-related injury. Only two studies scored more than 50 points (maximum score=100 points) indicating that most of the studies selected were of poor quality. Neither of the two highest scoring RCTs showed positive effects for stretching. Due to the paucity, heterogeneity and poor quality of the available studies no definitive conclusions can be drawn as to the value of stretching for reducing the risk of exercise-related injury.

Long-term outcome of sports injuries: results after inpatient treatment

OBJECTIVE

To investigate whether sports injuries result in long-term disabilities and handicaps and to establish variables with a prognostic value for the occurrence of these long-term consequences.

MATERIALS AND METHODS

All patients older than 17 years of age and admitted to the University Hospital Groningen because of a sports injury were entered in the study. By filling in a questionnaire 1-4 years after the injury an inventory was made of the long-term consequences.

MAIN OUTCOME MEASURES

Absenteeism from work and sports, experienced disabilities or handicaps and the Sickness Impact Profile 68 (SIP68).

RESULTS

Out of 306 patients 229 (75%) returned a completed questionnaire. Sixty-seven per cent of the working population had been unfit for work up to one year, whereas 4% still had not resumed work. Absenteeism from sports was also considerable; nearly half of the population did not participate in sports for more than a year. Furthermore, 32% of the patients still experienced disability or handicap following the injury. This finding is in agreement with the results of the SIP68 (odds ratio 6.8; confidence interval (95% CI): 3.51-13.08). Two prognostic variables could be distinguished: 'gender' and 'type of sport'. Long-term consequences occur more often in women (p < 0.03) and with playing outdoor soccer, horse riding or skiing (p < 0.01).

CONCLUSIONS

Sports injuries can lead to long-term disabilities and handicaps. The variables 'gender' and 'type of sport' were of prognostic significance.

Soccer injuries in childhood

A prospective study of soccer injuries, involving 287 male youth players, from the ages of 12-15 was conducted in 24 Greek soccer clubs, during the course of one year. A total of 193 players sustained 209 injuries. The incidence of injuries was 4.0 injuries per 1000 h of soccer time per player, and the most common types of injuries were sprains and strains. Surprisingly, it was found that an increase of injury incidences occurred during practice. Fifty-eight injuries required medical assistance. The majority of injuries (80%) were located in the lower extremities. Collision with other players was the most common activity at the time of injury, accounting for 40% of all injuries. The conclusion of this study and the evidence from other studies suggests that youth soccer is a relatively low risk sport. However, a substantial amount of injuries could be prevented. It is necessary to identify the risk factors, which are associated with these types of injuries.

Feasibility of power-type strength training for middle aged men and women: self perception, musculoskeletal symptoms, and injury rates

OBJECTIVES

To examine the feasibility of a power-type strength training programme for middle aged men and women, the impact of the training programme on perceived health and fitness and on knee and low back symptoms, and the rate of exercise induced injuries.

METHODS

A total of 154 voluntary, healthy, sedentary men and women participated in a training programme lasting about four months. The explosive force of leg extensor muscles was measured by means of standing long jumps and vertical squat jumps. Perceived health, perceived fitness, and low back and knee symptoms were assessed before and after the intervention by using a questionnaire. Musculoskeletal disorders and exercise induced injuries were reported during the training programme.

RESULTS

Perceived fitness improved in both men (p<0.01) and women (p<0.0001), but perceived health only in women (p<0.01). Men with increased explosive force in squat jumping also showed better perceived health (p<0.05), and women with increased explosive force in standing long jump showed better perceived fitness (p<0.05). Exercising men who had increased knee symptoms had significantly higher body mass index than the other exercising men (p<0.05). The exercise induced injury rate was 19% in men and 6% in women.

CONCLUSIONS

Successful completion of the exercise programme, together with the increased physical activity and relatively low injury rate, may have contributed to the participants finding the exercise programme positive and stimulating and believing that their health and fitness had improved. The low rate of musculoskeletal injury suggests that this type of supervised exercise programme is feasible for untrained middle aged people.

Muscle flexibility as a risk factor for developing muscle injuries in male professional soccer players. A prospective study

BACKGROUND

Muscular tightness is frequently postulated as an intrinsic risk factor for the development of a muscle injury. However, very little prospective data exist to prove this.

HYPOTHESIS

Increased muscle tightness identifies a soccer player at risk for a subsequent musculoskeletal lesion.

STUDY DESIGN

Prospective cohort study.

METHODS

We examined 146 male professional soccer players before the 1999-2000 Belgian soccer competition. None of the players had a history of muscle injury in the lower extremities in the previous 2 years. The flexibility of the hamstring, quadriceps, adductor, and calf muscles of these players was measured goniometrically before the start of the season. All of the examined players were monitored throughout the season to register subsequent injuries.

RESULTS

Players with a hamstring (N = 31) or quadriceps (N = 13) muscle injury were found to have significantly lower flexibility in these muscles before their injury compared with the uninjured group. No significant differences in muscle flexibility were found between players who sustained an adductor muscle injury (N = 13) or a calf muscle injury (N = 10) and the uninjured group.

CONCLUSIONS

These results indicate that soccer players with an increased tightness of the hamstring or quadriceps muscles have a statistically higher risk for a subsequent musculoskeletal lesion.

CLINICAL SIGNIFICANCE

Preseason hamstring and quadriceps muscle flexibility testing can identify male soccer players at risk of developing hamstring and quadriceps muscle injuries.

A comparison of two injury surveillance systems within sports medicine clinics

This study compares a comprehensive method of collecting injury data from sports medicine clinics, with a more simplified method of injury surveillance. The sports medicine injury surveillance (SMIS) project was implemented in a group of five allied sports medicine clinics in Melbourne. over two consecutive years. The injury surveillance method used in the second year (SMIS2) was a simplified version of that used in the first year (SMIS1). Methodological differences in the injury surveillance systems included form design, staff commitment and training, auditing process, financial incentives offered and employment of a project officer. Data were collected on 6479 new sports injury patients during SMIS1 and on 1682 patients during SMIS2. Comparative data from the two years of injury surveillance included patient profile (gender. age. days from injury to treatment, sport and context of injury) and injury information (site, cause and nature of injury). The SMIS2 methodology was associated with a lower sensitivity (p < 0.001) and a higher proportion of missing information (p < 0.001) than the SMIS1 methodology. There was also a significant difference in the nature and cause of injury variables (p < 0.001) between SMIS1 and SMIS2 and this was associated with coding changes. This study shows that the method of data collection influences both the proportion of missing information and the sensitivity of the system. A comprehensive method of injury surveillance will lead to a more complete data collection process. Methodological differences, however, do not appear to substantially alter conclusions about general patient characteristics, but do have some influence on the accuracy with which broad injury data are identified. Notwithstanding these comments, this study shows that injury surveillance activities can be successfully implemented in sports medicine clinics.

Rugby union injuries to the cervical spine and spinal cord

Injuries to the cervical spine are among the most serious injuries occurring as a result of participation in rugby. Outcomes of such injuries range from complete recovery to death, depending on the degree of spinal cord damage sustained. Much information has been gained regarding the mechanisms and frequency of such injuries, from case reports and case series studies. The most commonly reported mechanism of injury has been hyperflexion of the cervical spine, resulting in fracture dislocation of C4-C5 or C5-C6. Tracking both the trends of incidence of spinal injuries, and the effectiveness of injury prevention initiatives has proved difficult because of a lack of properly conducted epidemiological studies. Within the constraints of the research published to date, it appears that hookers and props have been at disproportionate risk of cervical spine injury, predominantly because of injuries sustained during scrummaging. While the scrum was the phase of play most commonly associated with spinal injuries throughout the 1980s in most rugby playing countries, there has been a trend through the 1990s of an increasing proportion of spinal injuries occurring in the tackle situation. The majority of injuries have occurred early in the season, when grounds tend to be harder, and players are lacking both practice and physical conditioning for the physical contact phases of the sport. A number of injury prevention measures have been launched, including changes to the laws of the game regarding scrummaging, and education programmes aimed at enforcing safe techniques and eliminating illegal play. Calls for case-registers and effective epidemiological studies have been made by researchers and physicians in most countries where rugby is widespread, but it appears to be only recently that definite steps have been made towards this goal. Well-designed epidemiological studies will be able to provide more accurate information about potential risk factors for injury such as age, grade, position, gender and ethnicity. Research into the long-term effects of participation in rugby on the integrity of the spinal column is warranted.

Sports injury experiences from the Western Australian Sports Injury Cohort Study

OBJECTIVE

The Western Australian Sports Injury Study is the first prospective cohort study of sports injuries sustained during community-level sports participation in Australia.

METHODS

The players were nonprofessional/non-elite participants of hockey, Australian football, basketball and netball from metropolitan Perth. Players completed a baseline questionnaire relating to their sports injury history, training practices, protective equipment use, demographic profile, general health and lifestyle factors. Sports participation and injury experiences were monitored by monthly telephone surveys over two consecutive five-month winter sporting seasons during 1997 and 1998.

RESULTS

Of the 1,512 players recruited into the initial cohort, 966 (i.e. 64%) responded to at least 700% of the callback surveys over the two-year follow-up. Across all sports, the injury incidence rate was 16.1 injuries/ 1,000 exposure hours (both games and training). Injury rates were highest in Australian football and lowest in netball. Lower limb injuries were twice as common as those to the upper limb (67% vs. 31%). Three-quarters of injured players sought treatment from a health care practitioner.

CONCLUSIONS AND IMPLICATIONS

This is the first longitudinal study of injuries to community-based sports participants in Australia. Compared with elite sports participants, the risk of injury is relatively low. The results provide valuable direction for the design and conduct of further aetiological studies.