Predictability of sports injuries. What is the epidemiological evidence?

A study protocol for the development and internal validation of a multivariable prognostic model to determine lower extremity muscle injury risk in elite football (soccer) players, with further exploration of prognostic factors

BACKGROUND

Indirect muscle injuries (IMIs) are a considerable burden to elite football (soccer) teams, and prevention of these injuries offers many benefits. Preseason medical, musculoskeletal and performance screening (termed periodic health examination (PHE)) can be used to help determine players at risk of injuries such as IMIs, where identification of PHE-derived prognostic factors (PF) may inform IMI prevention strategies. Furthermore, using several PFs in combination within a multivariable prognostic model may allow individualised IMI risk estimation and specific targeting of prevention strategies, based upon an individual's PF profile. No such models have been developed in elite football and the current IMI prognostic factor evidence is limited. This study aims to (1) develop and internally validate a prognostic model for individualised IMI risk prediction within a season in elite footballers, using the extent of the prognostic evidence and clinical reasoning; and (2) explore potential PHE-derived PFs associated with IMI outcomes in elite footballers, using available PHE data from a professional team.

METHODS

This is a protocol for a retrospective cohort study. PHE and injury data were routinely collected over 5 seasons (1 July 2013 to 19 May 2018), from a population of elite male players aged 16-40 years old. Of 60 candidate PFs, 15 were excluded. Twelve variables (derived from 10 PFs) will be included in model development that were identified from a systematic review, missing data assessment, measurement reliability evaluation and clinical reasoning. A full multivariable logistic regression model will be fitted, to ensure adjustment before backward elimination. The performance and internal validation of the model will be assessed. The remaining 35 candidate PFs are eligible for further exploration, using univariable logistic regression to obtain unadjusted risk estimates. Exploratory PFs will also be incorporated into multivariable logistic regression models to determine risk estimates whilst adjusting for age, height and body weight.

DISCUSSION

This study will offer insights into clinical usefulness of a model to predict IMI risk in elite football and highlight the practicalities of model development in this setting. Further exploration may identify other relevant PFs for future confirmatory studies and model updating, or influence future injury prevention research.

Prognostic factors for specific lower extremity and spinal musculoskeletal injuries identified through medical screening and training load monitoring in professional football (soccer): a systematic review

Background

Medical screening and load monitoring procedures are commonly used in professional football to assess factors perceived to be associated with injury.

Objectives

To identify prognostic factors (PFs) and models for lower extremity and spinal musculoskeletal injuries in professional/elite football players from medical screening and training load monitoring processes.

Methods

The MEDLINE, AMED, EMBASE, CINAHL Plus, SPORTDiscus and PubMed electronic bibliographic databases were searched (from inception to January 2017). Prospective and retrospective cohort studies of lower extremity and spinal musculoskeletal injury incidence in professional/elite football players aged between 16 and 40 years were included. The Quality in Prognostic Studies appraisal tool and the modified Grading of Recommendations Assessment, Development and Evaluation synthesis approach was used to assess the quality of the evidence.

Results

Fourteen studies were included. 16 specific lower extremity injury outcomes were identified. No spinal injury outcomes were identified. Meta-analysis was not possible due to heterogeneity and study quality. All evidence related to PFs and specific lower extremity injury outcomes was of very low to low quality. On the few occasions where multiple studies could be used to compare PFs and outcomes, only two factors demonstrated consensus. A history of previous hamstring injuries (HSI) and increasing age may be prognostic for future HSI in male players.

Conclusions

The assumed ability of medical screening tests to predict specific musculoskeletal injuries is not supported by the current evidence. Screening procedures should currently be considered as benchmarks of function or performance only. The prognostic value of load monitoring modalities is unknown.

A systematic approach to the characterisation of human impact injury scenarios in sport

Background

In contact sports (eg, American football or rugby), injuries resulting from impacts are widespread. There have been several attempts to identify and collate, within a conceptual framework, factors influencing the likelihood of an injury. To effectively define an injury event it is necessary to systematically consider all potential causal factors but none of the previous approaches are complete in this respect.

Aims

First, to develop a superior deterministic contextual sequential (DCS) model to promote a complete and logical description of interrelated injury event factors. Second, to demonstrate systematic use of the model to construct enhanced perspectives for impact-injury research.

Method

Previous models were examined and elements of best practice synthesised into a new DCS framework description categorising the types of causal factors influencing injury. The approach's internal robustness is demonstrated by consideration of its completeness, lack of redundancy and logical consistency.

Results

The model's external validity and worth are demonstrated through its use to generate superior descriptive injury models, experimental protocols and intervention opportunities. Comprehensive research perspectives have been developed using a common rugby impact-injury scenario as an example; this includes: a detailed description of the injury event, an experimental protocol for a human-on-surrogate reconstruction, and a series of practical interventions in the sport of rugby aimed at mitigating the risk of injury.

Conclusions

Our improved characterisation tool presents a structured approach to identify pertinent factors relating to an injury.

Sports injuries in children

Sports injuries in children affect both growing bone and soft tissues, and can result in damage of growth mechanisms with subsequent lifelong growth disturbance. During growth, there are significant changes in the biomechanical properties of bone. In young athletes, as bone stiffness increases and resistance to impact diminishes, sudden overload may cause bones to bow or buckle. Epiphyseal injuries are usually due to shearing and avulsion forces, although compression also plays a significant role. Given the remarkable healing potential of bone in childhood, fractures that initially united with some deformity can completely remodel, and the bone may appear totally normal in later life. Most injuries in children’s sports are minor and self-limiting, suggesting that children and youth sports are safe. However, as the risk of injuries sustained by young athletes can be significant, training programmes should take into account their physical and psychological immaturity, so that growing athletes can adjust to their own body’s changes.

Risk factors for groin/hip injuries in field-based sports: a systematic review

BACKGROUND

Groin/hip injuries are common in the athletic population, particularly in sports requiring kicking, twisting, turning and rapid acceleration and deceleration. Chronic hip, buttock and groin pain account for 10% of all attendances to sports medicine centres. Understanding risk factors for field-based sports (FBS) players is important in developing preventive measures for injury.

OBJECTIVE

This systematic review aims to identify and examine the evidence for groin/hip injury risk factors in FBS.

METHODS

14 electronic databases were searched using keywords. Studies were included if they met the inclusion criteria and investigated one or more risk factors with relation to the incidence of groin/hip injuries in FBS. Studies were accumulated and independently analysed by two reviewers under a 12-point quality assessment scale (modified CASP (for cohort study design) assessment scale). Owing to the heterogeneity of studies and measures used, a meta-analysis could not be conducted. As a result risk factors were pooled for analysis and discussion.

RESULTS

Of the 5842 potentially relevant studies, 7 high-quality studies were included in this review. Results demonstrated that previous groin/hip injury was the most prominent risk factor, identified across four studies (OR range from 2.6 (95% CI 1.1 to 6.11) to 7.3, (p=0.001)), followed by older age (OR 0.9, p=0.05) and weak adductor muscles (OR 4.28, 95% CI 1.31 to 14.0, p=0.02) each identified in two studies. Eight other significant risk factors were identified once across the included studies.

CONCLUSIONS

11 significant risk factors for groin/hip injury for FBS players were identified. The most prominent risk factor identified was previous groin/hip injury. Future research should include a prospective study of a group of FBS players to confirm a relationship between the risk factors identified and development of groin/hip injuries.

Ballet injuries: injury incidence and severity over 1 year

STUDY DESIGN

Prospective, descriptive single-cohort study.

OBJECTIVE

To assess the incidence and severity of injuries to a professional ballet company over 1 year.

METHODS

Data for an elite-level ballet company of 52 professional dancers were collected by an in-house medical team using a time-loss injury definition.

RESULTS

A total of 355 injuries were recorded, with an overall injury incidence of 4.4 injuries per 1000 hours (female, 4.1; male, 4.8; P>.05) and a mean of 6.8 injuries per dancer (female, 6.3; male, 7.3; P>.05). Mean injury severity was 7 days (female, 4; male, 9; P<.05). Most injuries were classified as overuse (64%; female, 68%; male, 60%; P>.05); mean severity of injury was 3 days for females and 9 days for males (P<.05). The percentage of traumatic injuries was 32% for females and 40% for males (P<.05); the corresponding severity was 6 and 10 days, respectively (P<.05).

CONCLUSION

The relatively high number of injuries reported and the resulting loss of dance time support the need to introduce interventions to reduce the risk of injury in professional dancers.J Orthop Sports Phys Ther 2012;42(9):781-790. Epub 19 July 2012. doi:10.2519/jospt.2012.3893.

Does a SLAP lesion affect shoulder muscle recruitment as measured by EMG activity during a rugby tackle?

BACKGROUND

The study objective was to assess the influence of a SLAP lesion on onset of EMG activity in shoulder muscles during a front on rugby football tackle within professional rugby players.

METHODS

Mixed cross-sectional study evaluating between and within group differences in EMG onset times. Testing was carried out within the physiotherapy department of a university sports medicine clinic. The test group consisted of 7 players with clinically diagnosed SLAP lesions, later verified on arthroscopy. The reference group consisted of 15 uninjured and full time professional rugby players from within the same playing squad. Controlled tackles were performed against a tackle dummy. Onset of EMG activity was assessed from surface EMG of Pectorialis Major, Biceps Brachii, Latissimus Dorsi, Serratus Anterior and Infraspinatus muscles relative to time of impact. Analysis of differences in activation timing between muscles and limbs (injured versus non-injured side and non injured side versus matched reference group).

RESULTS

Serratus Anterior was activated prior to all other muscles in all (P = 0.001-0.03) subjects. In the SLAP injured shoulder Biceps was activated later than in the non-injured side. Onset times of all muscles of the non-injured shoulder in the injured player were consistently earlier compared with the reference group. Whereas, within the injured shoulder, all muscle activation timings were later than in the reference group.

CONCLUSIONS

This study shows that in shoulders with a SLAP lesion there is a trend towards delay in activation time of Biceps and other muscles with the exception of an associated earlier onset of activation of Serratus anterior, possibly due to a coping strategy to protect glenohumeral stability and thoraco-scapular stability. This trend was not statistically significant in all cases.

Epidemiology of injury in child and adolescent sports: injury rates, risk factors, and prevention

The epidemiology of sports injuries in children and youth is an important area of research that has been largely overlooked in the medical and sport science literature. This article presents an overview of the analytic aspects of pediatric sports injury epidemiology, focusing on injury risk factors and preventive measures. The review indicates that few modifiable injury risk factors have been statistically evaluated, and not many studies have been designed to determine the effect of injury prevention measures in pediatric sports. However, initial results are promising. Specific directions for further analytic research are presented.

Injury incidence, mechanism and diagnosis in top-level teamgym: a prospective study conducted over one season

The aim of this study was to evaluate injury incidence, mechanism and diagnosis in Swedish teamgym. Sixteen male and 26 female gymnasts with international experience were prospectively followed during one season of training and competition. Injuries leading to a modified participation or total absence from gymnastics during 1 week or more were registered. Twenty-seven of the 42 gymnasts sustained 42 injuries. The injury incidence was 2.2/1000 gymnastics hours. No gender differences were found. Sixty-two percent of the injuries were located to the lower extremity, 28.5% to the back and 9.5% to the upper extremity. The most common injury was ankle sprain and the most frequent mechanisms were joint compression and joint rotation. The majority of the injuries occurred in the landing phase of the gymnastics skills and 50% of the injuries were reported at the end of the training session. Eighteen injuries occurred while the gymnasts were in a negative state of mood such as stressed or afraid. Injury prevention programs should be developed with respect to these findings. Special emphasis must be placed on the landing phase of the gymnastics skills as this phase seems to be critical.

What are the Risk Factors for Groin Strain Injury in Sport?

Groin injury is among the most common cited injuries in the sports of ice hockey, soccer, Australian Rules football, calisthenics and cricket. There are very few prospective studies examining risk factors for groin strain injury in sport. There is support for an association of previous injury and greater abductor to adductor strength ratios as well as sport specificity of training and pre-season sport-specific training, as individual risk factors in groin strain injury in athletes. Core muscle weakness or delayed onset of transversus abdominal muscle recruitment may increase the risk of groin strain injury. Debate exists in the literature regarding the role of adductor strength and length as well as age and/or sport experience as risk factors for groin injury. There is no strong evidence to support a causal association for any of these risk factors and groin injury.

A prospective study of injuries and training amongst the England 2003 Rugby World Cup squad

OBJECTIVES

To assess the aetiology, incidence, severity, and causes of injuries to England rugby union players during preparation for and participation in the 2003 Rugby World Cup.

METHOD

A 63 week prospective design was employed to study the training practices and injuries of England rugby players. The team physician reported all training and match injuries and provided details of the location, diagnosis, severity, and mechanism of each injury. The team fitness coach reported details of the number and duration of training sessions and the time dedicated to rugby and conditioning training. Players' stature, body mass, and skinfolds were measured at the beginning and end of the study period.

RESULTS

The overall incidence of injury was 17 injuries/1000 h of exposure (match: 218 injuries/1000 h; training: 6.1 injuries/1000 h). The major locations of injuries were the lower (60%) and upper (17%) limbs and the most common diagnoses were muscle and tendon (50%) and joint (non-bone) and ligament (41%) injuries. The highest incidences of match injuries occurred whilst being tackled (50 injuries/1000 h) and in a ruck or maul (35 injuries/1000 h), whilst the greatest incidences of training injuries occurred during endurance running (24 injuries/1000 h) and contact activities (20 injuries/1000 h). Players' average body mass increased and skinfold measurement decreased significantly over the study period.

CONCLUSIONS

The incidence of match injuries at international level was found to be higher than previously reported. The tackle, ruck, and maul elements of match play and the endurance running and contact elements of training presented the highest risk of injury for all players.

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.

The application of risk management in sport

The process of risk management can be implemented as part of a best practice management system within the sport and leisure sector. The process enables risk factors that might lead to injuries to be identified and the levels of risk associated with activities to be estimated and evaluated. This information can be utilised proactively by sports governing bodies and participants to identify preventive and therapeutic interventions in order to reduce the frequency of occurrence and/or severity of injuries within their sports. The acceptability of risk within specific sports, however, is dependent on the perceptions of the participants involved.

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.

The influence of tackle parameters on the propensity for injury in international football

PURPOSE

To understand how tackling leads to injury in football, to develop a framework for classifying tackles, and to identify tackles with the greatest propensity to cause injury.

METHOD

Video recordings of 123 matches in three FIFA tournaments were used to identify tackling parameters. Team physicians prepared reports of postmatch medical attention to players.

RESULTS

Tackles from the side were twice as likely to require postmatch medical attention as tackles from behind. Injuries to the head/neck of tackled and tackling players and the torso of tackling players were more likely to receive on-pitch medical attention than other injuries. Injuries to the foot for tackled and tackling players and the lower leg and thigh for tackling players were less likely to receive on-pitch medical attention than other injuries. Tackles with the greatest propensity for causing injury involved clash of heads and two-footed tackles for tackled players and clash of heads, two-footed tackles, jumping vertically, and tackles from the side for tackling players.

CONCLUSION

The laws of football relating to tackling should be reviewed to provide greater protection from injury by reducing the overall level of risk and, in particular, by protecting players from tackles with the highest propensity for causing injury.

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.

Risk factors for injury in child and adolescent sport: a systematic review of the literature

OBJECTIVE

The objective of this systematic review of the literature is to identify risk factors and potential prevention strategies that may modify risk factors for injury in child and adolescent sport.

DATA SOURCES

Seven electronic databases were searched to identify potentially relevant articles. A combination of Medical Subject Headings and text words were used (athletic injuries, sports injury, risk factors, adolescent, and child).

STUDY SELECTION

This review is based on epidemiological evidence in which the data are original, an exposure and outcome are objectively measured, and an attempt is made to create a comparison group. Forty-five studies were selected for this review.

DATA EXTRACTION

The data summarized include study design, study population, exposures, outcomes, and results. Estimates of odds ratios or relative risks were calculated where study data were adequate to do so. The quality of evidence is based on internal validity, external validity, and causal association.

DATA SYNTHESIS

There is some evidence that potentially modifiable risk factors including poor endurance, lack of preseason training, and some psychosocial factors are important risk factors for injury in child and adolescent sport. Concerns with study design, internal validity, and generalizability persist. The evidence is consistent, however, with more convincing evidence from adult population studies. The evidence for nonmodifiable risk factors for injury in adolescent sport (ie, age, sex, previous injury) is consistent among studies.

CONCLUSIONS

Sport participation and injury rates in child and adolescent sport are high. This review will assist in targeting the relevant groups and designing future research examining risk factors and prevention strategies in child and adolescent sport. Future clinical trials addressing modifiable risk factors to reduce the incidence of sports injury in this population are necessary.

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.

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

OBJECTIVES

Although the nature of rugby injury has been well documented, little is known about key risk factors. A prospective cohort study was undertaken to examine the association between potential risk factors and injury risk, measured both as an injury incidence rate and as a proportion of the playing season missed. The latter measure incorporates a measure of injury severity.

METHODS

A cohort of 258 male players (mean (SD) age 20.6 (3.7) years) were followed through a full competitive season. At a preseason assessment, basic characteristics, health and lifestyle patterns, playing experience, injury experience, training patterns, and anthropometric characteristics were recorded, and then a battery of fitness tests were carried out.

RESULTS

A multiple regression model identified grade and previous injury experience as risk factors for in season injury, measured as an injury incidence rate. A second model identified previous injury experience, hours of strenuous physical activity a week, playing position, cigarette smoking status, body mass index, years of rugby participation, stress, aerobic and anaerobic performance, and number of push ups as risk factors for in season injury, measured as proportion of season missed.

CONCLUSIONS

The findings emphasise the importance of previous injury as a predictor of injury incidence and of missing play. They also show the importance of considering both the incidence rate and severity of injury when identifying risk factors for injury in sport.

Subtalar subluxation in ballet dancers

Ankle injuries frequently occur in dancers. Among these injuries, only a few cases of talar subluxation have been reported in the literature. In our series, we diagnosed and treated 25 subtalar subluxations over a 1-year period in the Ballet Béjart Lausanne company. The subluxations occurred after a grand plie on pointes or at the landing of a jump on demi-pointes, without any mechanism of ankle sprain. The dancer usually noted a sudden and sharp pain in the talonavicular joint and hindfoot with a feeling of "forward displacement" of the foot. At palpation, the talonavicular ligament, the anterior talofibular ligament, and the posteromedial part of the subtalar joint were painful. A limitation of the ankle extension and a clear hypomobility of the subtalar joint were noted. Under the effect of shearing forces on the midtarsal joint, a posteromedial subtalar subluxation occurred. Treatment consisted of a manipulation that reduced the subluxation. Continuous taping, which locks the talonavicular joint in the anterior direction, was recommended for 6 weeks. Dancing could be resumed in a swimming pool after 2 weeks, and on the ground after 3 to 4 weeks. We found that subluxation could recur, and that it could eventually become chronic.

Assessment of the flexibility of elite athletes using the modified Thomas test

AIM

To analyse the modified Thomas test and obtain measures of flexibility for the iliopsoas, quadriceps and tensor fascia lata/iliotibial band.

METHOD

The modified Thomas test was used to determine the range of flexibility of 117 elite athletes in tennis, basketball, rowing, and running.

RESULTS AND CONCLUSION

The study has provided objective data for a clinical test measuring flexibility of the iliopsoas, quadriceps, and tensor fascia lata/iliotibial band. It is recommended that sufficient flexibility is obtained to perform a specific sport and that asymmetries between limbs are addressed.

Predictors of injury in ice hockey players. A multivariate, multidisciplinary approach

Eighty-six male high school ice hockey players participated in this prospective study to determine both the incidence of injury in high school ice hockey and the influence of physical, situational, and psychosocial factors. Physical factors included height, weight, vision, previous injuries, musculoskeletal abnormalities, and injuries present at the time of screening evaluations. Situational factors examined were level of participation, playing time, player position, and games versus practices. Psychosocial factors such as confidence, stress, social support, positive states of mind, and mood states were also examined to determine their influences on injury. Twenty-seven injuries occurred during the 1994 to 1995 season. As hypothesized, the overall incidence of injury in high school hockey games (34.4 per 1000 player-game hours) was less than the incidence of injury in Junior A hockey (96.1 per 1000 player-game hours) and was more than previously reported for Bantam youth hockey (10.9 per 1000 player-game hours). Injuries occurred more often in games than in practices, usually as a result of collisions. Physical factors such as player position and previous injuries did not significantly predict injuries, but players in the high playing time group were more likely to be injured. Psychosocial factors of low vigor and high fatigue as measured by the Incredibly Short Profile of Mood States (ISPOMS) significantly predicted high school ice hockey injuries.

Do selected kinanthropometric and performance variables predict injuries in female netball players?

The aim of this study was to determine which kinanthropometric and performance variables predict injuries in female netball players. In a prospective study, 72 volunteer grade A netball players (mean age 20.6 +/- 3.6 years, range 15-36 years) were measured for hypermobility, somatotype, static balance, jumping abilities and anaerobic fitness at the University of Western Australia Human Movement Performance Laboratory prior to the start of their 14-week season. Injuries were classified by site, diagnosis and severity, and were monitored throughout the entire season by the same physiotherapist at the Western Australia (WA) Matthews Netball Centre, Perth, Australia. A total of 22 injuries in 22 players were recorded, affecting the ankle joint lateral ligament complex (59%), knee ligaments (18%), back (18%) and Achilles tendon (5%). Injuries were more common among grade A1 players than other grades (54 vs 19%, P < 0.001). Within grade A1 players, the proportion of injuries decreased with age (P < 0.05). Players were more likely to have had an injury if they had better jumping ability, better anaerobic fitness and if they were low on the endomorphy somatotype scale (P < 0.05). After allowing for both jumping ability and endomorphy, there was no longer a significant difference between A1 and non-A1 players in their risk for injury. Young elite players are at a substantially increased risk of injury. This higher risk appears to be associated with--if not a direct consequence of--their being thinner, fitter and having more powerful jumping capabilities. This suggests that injury-prevention programmes should be targeted at elite players, especially the younger ones.

The New Zealand Rugby Injury and Performance Project: I. Design and methodology of a prospective follow-up study

Injury resulting from participation in sporting and physical recreational activities is a major contributor to the overall incidence of injury in the developed world. If sports injuries are to be reduced, a comprehensive approach must be taken to define the nature and magnitude of the problem, to establish models of relationships between risk factors, protective factors and injury experience, and to address injury through well designed intervention and evaluation programmes. The Rugby Injury and Performance Project (RIPP) is a prospective cohort study designed to examine the risk and protective factors for rugby injury. Data were collected on potential risk and protective factors from the RIPP cohort pre-season. Data on exposure to rugby, injury events and medical treatments were collected from the players each week during the season through telephone interviews. Pre-season measures were repeated post-season. A key feature of the design was that data were collected on both injured and non-injured players, allowing a longitudinal comparison of the injury experience of players with and without the factors of interest. A wealth of information was collected on each cohort member during the pre-season interview. A contact rate of 90% was achieved during the weekly follow-up phase. Post-season questionnaires were completed by 76% of the players and 88% of the coaches. Recommendations are made for the use of this methodology by other researchers and future directions for RIPP are described.