The incidence, prevalence, severity, mechanism and body region of injury in elite junior Australian football players: A prospective cohort study over one season

Ankle sprain, concussion, and anterior cruciate ligament injuries are common and burdensome in sub-elite female Australian football players

OBJECTIVES

To describe the epidemiology of injuries in sub-elite female Australian Football (AF).

DESIGN

Prospective cohort.

METHODS

424 athletes were tracked across a 12-match season. Injury characteristics (location, severity, mechanism) were reported. Injury incidence (injuries per 1000 h) and injury burden (days absent per 1000 h) were calculated. Severity was considered as the number of days missed between injury onset and return to full training. Incidence was compared using incidence rate ratios, and severity using a Mann-Whitney U test.

RESULTS

Total injury incidence was 10.8 (95 % confidence interval [CI] = 9.0, 12.8) injuries per 1000 h. Match incidence was 34.6 (95 % CI = 28.0, 42.4) injuries per 1000 h. Ankle sprain injuries (2.2 per 1000 h, 95 % CI = 1.4, 3.1) and concussion (1.6 per 1000 h, 95 % CI = 1.0, 2.5) injuries were the most frequent, followed by anterior cruciate ligament (ACL) injuries (0.9 per 1000 h, 95 % CI = 0.4, 1.6). ACL (40.4 days per 1000 h, 95 % CI = 36.9, 44.1), ankle sprain injuries (31.4 per 1000 h, 95 % CI =28.4, 34.7), and concussion (19.9 per 1000 h, 95 % CI = 17.5, 22.5) injuries were also the most burdensome. There were 78 mild, 34 moderate, and 21 severe injuries. ACL injuries were the most severe injury (56.0 [77.0] in-season days missed).

CONCLUSIONS

This research describes the first large-scale injury profile of sub-elite female AF, reporting time-loss measures of incidence and burden for many injury types. Ankle sprain injuries, concussions, and ACL injuries are common and burdensome, and should be prioritised for prevention.

Pre-season body composition has minimal influence on in-season match availability, and match performance in female Australian Football League (AFLW) players

This study examined the relationship between pre-season body composition, in-season match performance, and match availability in female players competing in the Australian Football League Women's (AFLW) competition. With the outlawing of body composition assessments as part of pre-draft player evaluations in the AFLW, this study seeks to examine whether this is justified. Twenty-two (n = 22) players had body composition assessed with dual-energy x-ray absorptiometry at the beginning of the 2021 AFLW pre-season (whole-body and regional fat mass and lean soft-tissue mass [LSTM]). In-season match availability and match performance data (Coaches Score [CS], Champion Data Player Rank, average disposals, disposal and kicking efficiency) were collected throughout the 2021 competition. Pearson correlations were performed to assess if associations existed between body composition and in-season match performance and availability. A median split was performed to divide players into higher and lower performing groups for match performance variables. Two-sample independent t-tests were then used to assess differences between groups. No body composition characteristics could differentiate between in-season match availability groups (100% availability vs. <100% availability) or higher and lower performing groups for all match performance variables. Total leg LSTM asymmetry shared a moderate negative association with CS. Body composition may not be important for determining in-season match availability and performance in female AFLW players. Thus, the repercussions following the removal of pre-draft body composition assessments across the league may not be as significant as is currently perceived. Other physiological, biomechanical, or performance qualities are more variable and may mask the effect of body composition in these players. AFLW practitioners should prioritize the development of other important attributes, such as aerobic fitness, muscular strength and power, and technical skill.

Elite Junior Australian Football Players With Impaired Wellness Are at Increased Injury Risk at High Loads

BACKGROUND

Elite junior Australian football players experience high training loads across levels of competition and training. This, in conjunction with impaired wellness, can predispose athletes to injury.

HYPOTHESIS

Elite junior Australian football players exposed to high loads with poor wellness are more likely to be at risk of injury than those with improved wellness.

STUDY DESIGN

Longitudinal prospective cohort study.

LEVEL OF EVIDENCE

Level 3.

METHODS

Data were collected and analyzed from 280 players across the 2014 season. Internal load was measured via session rating of perceived exertion. Player wellness was reported according to ratings of sleep quality, fatigue, soreness, stress, and mood. Week- and month-based training load measures were calculated, representing a combination of absolute and relative load variables. Principal component analysis factor loadings, based on 17 load and wellness variables, were used to calculate summed variable covariates. Injury was defined as "any injury leading to a missed training session or competitive match." Associations between covariates and injury risk (yes/no) were determined via logistic generalized estimating equations.

RESULTS

A significant interaction term between load and wellness on injury was found [odds ratio (OR) 0.76; 95% CI 0.62-0.92; P < 0.01), indicating that wellness acts as a "dimmer switch" of load on injury. Further, there was evidence of moderated mediation (OR 0.71; 95% CI 0.57-0.87; P < 0.01). When wellness was low, injury risk started to increase substantially at a 1-week load of 3250 au.

CONCLUSIONS

Subjective measures of training load are associated with injury risk through a nonlinear relationship. This relationship is further influenced by player wellness, which can amplify the risk of injury. There is evidence that higher stress is linked with injury and that soreness and sleep mediate any stress-injury relationship.

CLINICAL RELEVANCE

Coaching efforts to manage training load and player adaptive responses, including wellness, may reduce the risk of injury, with stress, soreness, and sleep particularly relevant at this level.

Injury profiles of Australian football players across five, women's and girls' competition levels

OBJECTIVES

To describe injury profiles of Australian football players and explore trends across five, women's and girls' competition levels.

DESIGN

Prospective cohort study.

METHODS

Injuries were prospectively recorded by team personnel across one or two seasons of Australian football (2017-18 and/or 2018-19) including five, women's and girls' competition levels (elite senior, non-elite senior, high-level junior, non-elite junior (14-17 years), and non-elite junior (10-13 years)). Injury incidence rates were calculated per 1000 h and injury prevalence calculated for pre-season, early-season, mid-season, and late-season. Descriptive statistics present injury profiles according to activity, body region, pathology, mechanism, and severity.

RESULTS

From the 392 included players, 760 injuries were recorded. Overall injury incidence was 20.9 injuries per 1000 h. Injury prevalence was highest during pre-season (64.1%). Most injuries were to the lower extremity (n = 440; 58.0%). Ligament/joint sprain injuries were common (n = 147, 19.3%). Several injuries resulted from contact mechanisms (n = 314, 61.4%), with many due to contact with another player (n = 131, 52.8%). Injuries resulting in time lost from participation were common (n = 444, 58.9%). Competition level injury trends were observed, with elite senior (125.1 injuries per 1000 h) and high-level junior (116.9 injuries per 1000 h) players having greater match injury incidence compared to their non-elite counterparts (15.5-41.4 injuries per 1000 h).

CONCLUSIONS

This study provides preliminary insight into injury profiles of Australian football players in women's and girls' competitions. These findings can drive future injury risk reduction research specific to this population across the developmental pathway.

Gender differences in female and male Australian Football injuries - A prospective observational study of emergency department presentations

OBJECTIVES

To compare injury-profiles of females and males presenting to Emergency Departments (EDs) with an Australian Football injury.

DESIGN

Prospective observational study.

METHODS

All patients presenting to one of 10 EDs in Victoria, Australia, with an Australian Football injury were included in the study. Data were prospectively collected over a 10 month period, coinciding with a complete Australian Football season, including pre-season training and practice matches. Relevant information was extracted from patient medical records regarding injury-type, body part injured, investigations and treatments required. Female and male data were compared with chi-squared and Fisher's exact tests.

RESULTS

1635 patients were included, of whom 242 (14.8%) were female. Females had a higher proportion of hand/finger injuries (34.3% v 23.4%), neck injuries (6.6% v 2.5%) and patella dislocations (2.9% v 0.6%). Males had a higher proportion of shoulder injuries (11.5% v 5.8%), skin lacerations (8.0% v 1.7%), and thorax/abdominal/pelvic injuries (5.7% v 2.1%). Concussion rates were similar between the genders, occurring in 14.1% of all patients. Anterior cruciate ligament injuries were infrequent (1.0%) and not significantly different between genders. Females received more imaging investigations (83.1% v 74.7%) and analgesia (62.4% v 48.5%). A higher proportion of males required admission to hospital (5.0% v 2.1%), usually for surgery.

CONCLUSION

Australian Football injury profiles differed between females and males. Gender-specific injury prevention and management programs would be indicated based on the study findings.

Soft-shell headgear, concussion and injury prevention in youth team collision sports: a systematic review

OBJECTIVES

To assess the association between soft-shell headgear (HG) use and sports-related concussion (SRC). Secondary objectives were to assess the association between HG and superficial head injury and investigate potential increase in injury risk among HG users.

DESIGN

A systematic search in Ovid MEDLINE, Cochrane Library, Scopus, PsycINFO and SPORTDiscus was conducted in April 2020. Inclusion criteria were youth <18, English language, in vivo studies published after 1980 that evaluated SRC and other injury incidence in HG users compared with non-users.

OUTCOME MEASURES

Incidence rates of SRC, superficial head injury or other injuries.

RESULTS

Eight studies were eligible. The majority (n=5) reported no difference in the rate of SRC among HG users versus non-users. One rugby study identified significantly lower risk of SRC for non-HG users (risk ratio (RR) 0.63; 95% CI 0.41 to 0.98) compared with HG users, whereas a cross-sectional survey of soccer players indicated higher risk of SRC for non-HG users (RR 2.65; 95% CI 1.23 to 3.12) compared with HG users. Three of the four studies investigating superficial head injury found no significant differences with HG use, though the soccer survey reported reduced risk among HG users (RR 1.86; 95% CI 0.09 to 0.11). Increased incidence of injuries to all body regions for rugby HG users was reported in two studies with adjusted RRs of 1.16 (95% CI 1.04 to 1.29) and 1.23 (95% CI 1.00 to 1.50).

CONCLUSIONS

HG use was not associated with reduced rates of SRC or superficial head injury in youth soccer and rugby. The possibility of increased injury risk to all body regions for rugby HG users was raised. The need for research specific to youth and female athletes was highlighted.

PROSPERO REGISTRATION NUMBER

CRD42018115310.

Recurrent and Subsequent Injuries in Professional and Elite Sport: a Systematic Review

BACKGROUND

Injury surveillance in professional sport categorises injuries as either "new" or "recurrent". In an attempt to make categorisation more specific, subsequent injury categorisation models have been developed, but it is not known how often these models are used. The aim was to assess how recurrent and subsequent injuries are reported within professional and elite sport.

METHODS

Online databases were searched using a search strategy. Studies needed to prospectively report injury rates within professional or elite sports that have published consensus statements for injury surveillance.

RESULTS

A total of 1322 titles and abstract were identified and screened. One hundred and ninety-nine studies were screened at full text resulting in 81 eligible studies. Thirty studies did not report recurrent injuries and were excluded from data extraction. Within the studies that reported recurrent injuries, 21 reported the number and percentage; 13 reported only the proportion within all injuries; three reported only the number; five reported the number, percentage and incidence; and two only reported the incidence. Seven studies used subsequent injury terminology, with three reporting subsequent injury following concussion, one using an amended subsequent injury model and three using specific subsequent injury categorisation models. The majority of subsequent injuries (ranging from 51 to 80%) were categorised as different and unrelated to the index injury. The proportion of recurrent injuries (exact same body area and nature related to index injury) ranged from 5 to 21%.

CONCLUSIONS

Reporting recurrent or subsequent injuries remains inconsistent, and few studies have utilised subsequent injury models. There is limited understanding of subsequent injury risk, which may affect the development of injury prevention strategies.

TRIAL REGISTRATION

CRD42019119264.

Lower limb MSK injuries among school-aged rugby and football players: a systematic review

Objective

The objective of this systematic review was to explore the incidence of lower limb musculoskeletal (MSK) injuries sustained by rugby union, rugby league, soccer, Australian Rules and Gaelic football players under 18 years. The review sought to identify the mechanisms and types of injury sustained and to compare between sports.

Design

This systematic review focused on the incidence of lower limb injury in adolescent team sports that involved running and kicking a ball. A literature search of studies published prior to January 2020 was conducted using SportDiscus, Medline and PubMed databases. The Standard Quality Assessment Criteria appraisal tool was used to assess the quality of each article included in the review. Two or more authors independently reviewed all papers.

Results

Sixteen papers met the inclusion criteria; prospective cohort (N=14), retrospective (n=1) and longitudinal (n=1). These studies investigated injuries in rugby union and rugby league (n=10), football (soccer) (n=3), Australian Rules (n=2) and Gaelic football (n=1). There were a total of 55 882 participants, aged 7–19 years old, who reported 6525 injuries. The type, site and mechanisms of injury differed across sports.

Summary

Lower limb injuries were common in adolescent rugby, soccer, Gaelic football and Australian Rules football players, however these studies may not fully reflect the true injury burden where recurrent and overuse injuries have not been considered. There were differences between sports in the mechanisms, types and severity of injury.

Player Wellness (Soreness and Stress) and Injury in Elite Junior Australian Football Players Over 1 Season

Purpose: To investigate the association between player wellness and injury in elite junior Australian football players over 1 competitive season. Methods: Prospective cohort study. Elite junior Australian football players (N = 196, average age = 17.7 y, range = 16–18 y) were recruited in the under-18 state league competition in Victoria, Australia. They recorded their wellness (sleep, fatigue, soreness, stress, and mood) according to a 5-point Likert scale 3 times weekly, with injuries (missed match/training session) entered into an online sport-injury surveillance system. A logistic generalized estimating equation was used to examine the association (expressed as odds ratio [OR]) between wellness and injury (yes/no). Results: Soreness was associated with injury at each time point across the week, with the strongest association evident for soreness reported 6 d postmatch (OR = 1.30; 95% confidence interval [CI], 1.17–1.44; P < .001). Stress and injury were associated with injury for average stress values across the week, as well as specifically on day 1 postmatch (OR = 1.10; 95% CI, 1.01–1.21; P = .038). Mood reported in the middle of the week (3 d postmatch) was associated with injury (OR = 0.87; 95% CI, 0.78–0.97; P = .014), as was fatigue (OR = 1.10; 95% CI, 1.00–1.22; P = .044). Conclusions: This study demonstrates key associations between wellness and injury in elite junior Australian football, specifically soreness, stress, fatigue, and mood. Monitoring strategies help identify injury-risk profiles, which can help decision makers (coaches or medical staff) intervene when relevant to reduce injury risk.

Epidemiology of injuries in Australian junior rugby league players

OBJECTIVES

Conduct a large-scale epidemiological study of injury characteristics (location, type, mechanism, severity, burden) and incidence in community junior rugby league.

DESIGN

Prospective cohort epidemiology study.

METHODS

Injury surveillance was conducted in three district leagues (Penrith, Canberra, Melbourne) in under 6 (U6) to under 18 years (U18) age groups across the 2016 season. Club sports trainers recorded all match/training medical-attention injuries using a commercial electronic application which recorded injury circumstances and characteristics.

RESULTS

A total of 13,169 players from 897 teams participated and 408 (89% male) players sustained 485 injuries, 94% of which were match related. The overall injury incidence was 5.9 injuries/1000 player hours and highest in U13-U18 female players (22.2 injuries/1000 player hours). The mean injury severity of 16±31 days missed training/match-play caused an overall injury burden of 94.2 days missed/1000 player hours). Tackles accounted for 84% of injuries. Joint and contusion injuries were the most prevalent injury type and the head (35% total injuries, primarily bruising and bleeding) was the most injured body site.

CONCLUSIONS

This is the first study to report injuries across a large cohort of all-age Australian community junior rugby league players over one season. Injury prevalence was lower than previously reported in junior rugby league suggesting the sport has not become more dangerous for junior players. These findings provide an evidence-base to inform or revise policy, training and injury prevention programs and athlete development pathways in relation to game-wide safety and develop best-practice protocols in injury management for rugby league athlete support personnel.

Pre-season screening of the upper body and trunk in Australian football players: A prospective study

OBJECTIVE

To determine whether screening tests of upper body, trunk region, and of whole-body function could prospectively identify community AFL players who sustain in-season shoulder/head/neck injuries. Additionally, to present screening test reference values.

DESIGN

Prospective cohort; SETTING: Community sport; PARTICIPANTS: 142 male community AFL players (range 15-37 years).

MAIN OUTCOME MEASURES

(i) isometric shoulder external and internal rotation (ER/IR) strength; (ii) upper body combined elevation functional ROM; (iii/iv) whole-body functional jump ROM; (v) static thoracic spine angle; (vi) cervical joint proprioception, and (vii) trunk muscle size and function. Results were compared among players with (n = 21) and without (n = 121) an in-season shoulder, head, or neck injury. ROC analysis and odds ratios were used to determine the predictive values.

RESULTS

Two screening tests predicted an in-season shoulder, head, or neck injury; dominant and non-dominant isometric ER strength (AUC 0.629, 95%CI 0.51-0.74; optimal cut point 182 N and AUC 0.619, 95%CI 0.50-0.74; optimal cut point 184 N, respectively). The adjusted odds ratio for the strongest predictor: dominant ER muscle strength was 6.02 (95%CI 1.8-19.9).

CONCLUSION

Greater ER strength was associated with in-season shoulder/head/neck injuries in community AFL players; however, further research is required to determine the clinical significance of this finding.

Absolute and Relative Load and Injury in Elite Junior Australian Football Players Over 1 Season

PURPOSE

To investigate the association between training and match loads and injury in elite junior Australian football players over 1 competitive season.

METHODS

Elite junior Australian football players (n = 290, age 17.7 [0.3] y, range 16-18 y) were recruited from the under-18 state league competition in Victoria to report load and injury information. One-week load (session rating of perceived exertion multiplied by duration) and all time-loss injuries were reported using an online sport-injury surveillance system. Absolute load measures (weekly sums) enabled the calculation of relative measures such as the acute:chronic workload ratio. Load measures were modeled against injury outcome (yes/no) using a generalized estimating equation approach, with a 1-wk lag for injury.

RESULTS

Low (<300 arbitrary units [au]) and high (>4650 au) 1-wk loads were associated with significantly higher risk of injury. Furthermore, low (<100 au) and high (>850 au) session loads were associated with a higher risk of injury. High strain values (>13,000) were associated with up to a 5-fold increase in the odds of injury. There was a relatively flat-line association between the acute:chronic workload ratio and injury.

CONCLUSIONS

This study is the first investigation of elite junior athletes demonstrating linear and nonlinear relationships between absolute and relative load measures and injury. Coaches should focus player loads on, or at least close to, the point at which injury risk starts to increase again (2214 au for 1-wk load and 458 au for session load) and use evidence-based strategies across the week and month to help reduce the risk of injury.

Functional Movement Screen Pain Location and Impact on Scoring Have Limited Value for Injury Risk Estimation in Junior Australian Football Players

OBJECTIVE

To describe the location and severity of pain during Functional Movement Screen (FMS) testing in junior Australian football players and to investigate its effect on FMS composite score and injury risk.

DESIGN

Prospective cohort study.

METHODS

Junior male Australian football players (n = 439) completed preseason FMS testing. Pain location and severity (on a 0-to-10 numeric pain-rating scale [NPRS]) were assessed for painful subtests. The FMS composite score was calculated using 3 scoring approaches: "traditional," a score of zero on painful subtests; "moderate," a score of zero on painful subtests if an NPRS pain severity was greater than 4; and "raw," did not adjust painful FMS subtest scores. Players were monitored throughout the competitive season and considered injured when 1 or more matches were missed due to injury.

RESULTS

One hundred seventy players reported pain during FMS testing. The pain-scoring approach affected mean composite score values (raw, 14.9; moderate, 14.5; traditional, 13.6; P<.001). Sixty-eight percent of pain was mildly severe (NPRS of 4 or less). Back pain (50%) was more common than upper-limb (24%) or lower-limb (26%) pain (P<.001). Upper-limb pain was associated with a small increase in injury risk (hazard ratio = 1.59, P = .023). No other FMS pain location influenced injury risk, nor did pain severity (P>.280). The FMS composite score was not associated with injury risk, regardless of pain-scoring approach (P≥.500).

CONCLUSION

Pain was common during FMS testing in junior Australian football players and had a notable effect on the FMS composite score, but minimal effect on subsequent injury risk. J Orthop Sports Phys Ther 2020;50(2):75-82. Epub 17 Sep 2019. doi:10.2519/jospt.2020.9168.

Concussion incidence and time-loss in Australian football: A systematic review

OBJECTIVES

Australian football is associated with a risk of concussion. However, despite the extensive and varied nature of literature devoted to this issue, concussion incidence has not been systematically evaluated. To address this, we aimed to conduct a meta-analysis of concussion incidence in Australian football.

DESIGN

Systematic review. Prospero registration number: CRD42017064290.

METHODS

A systematic search of 14 databases using the terms 'concussion', and 'Australian football' (and variations) was used to obtain records that reported concussion incidence per 1000 players hours across age, sex, and level-of-play. Data were grouped based on how time-loss was applied to the concussion definition.

RESULTS

Forty-two studies met inclusion criteria. Incidence rates based on a possible time-loss definition per 1000 player hours, ranged from 2.24 to 17.63 at the elite level, and 0.35 to 14.77 at the community/amateur level. Return-to-play details were reported by six studies and only two studies measured head-impacts in real-time. Several limitations were identified with this literature. First, insufficient return-to-play details precluded a meta-analysis of incidence rates. Second, no longitudinal studies across levels-of-play were found. Third, concussion incidence data for junior and female players were notably scarce.

CONCLUSIONS

There was limited scope to determine concussion burden (i.e., incidence and severity) and only preliminary data for player exposure to head-impacts. To address these limitations, injury surveillance should capture sufficient information to permit comparisons within and across levels-of-play. This will also help determine the influence of interventions aimed at reducing the frequency and severity of concussive-injuries.

Australian Football League Injury Characteristics Differ Between Matches and Training: A Longitudinal Analysis of Changes in the Setting, Site, and Time Span From 1997 to 2016

Background:

Injury surveillance has been used to quantify the scope of the injury burden in Australian football. However, deeper statistical analyses are required to identify major factors that contribute to the injury risk and to understand how these injury patterns change over time.

Purpose:

To compare Australian Football League (AFL) injury incidence, severity, prevalence, and recurrence by setting, site, and time span from 1997 to 2016.

Study Design:

Descriptive epidemiology study.

Methods:

A total of 15,911 injuries and medical illnesses recorded by team medical staff at each club were obtained from the AFL’s injury surveillance system and analyzed using linear mixed models with 3 fixed effects (setting, time span, site) and 1 random effect (club). All types of injuries and medical illnesses were included for analysis, provided that they caused the player to miss at least 1 match during the regular season or finals. Five-season time spans (1997-2001, 2002-2006, 2007-2011, and 2012-2016) were used for comparisons. Incidence rates were expressed at the player level. Recurrences were recoded to quantify recurrent injuries across multiple seasons.

Results:

Compared with training injuries, match injuries had a 2.8 times higher incidence per season per club per player (matches: 0.070 ± 0.093; training: 0.025 ± 0.043; P < .001). Match injuries resulted in 1.9 times more missed matches per club per season (matches: 17.2 ± 17.0; training: 9.1 ± 10.5; P < .001). and were more likely to be recurrences (matches: 11.6% ± 20.0%; training: 8.6% ± 21.8%; P < .001). From the 1997-2001 to 2007-2011 time spans, overall injury severity increased from a mean of 3.2 to 3.7 missed matches (P ≤ .01). For the most recent 2012-2016 time span, injuries resulted in 3.6 missed matches, on average. Hip/groin/thigh injuries had the highest incidence (0.125 ± 0.120) and prevalence (19.2 ± 16.4) rates, and recurrences (29.3% ± 27.9%) were 15% more likely at this site than any other injury site.

Conclusion:

The risks of match injuries are significantly higher than those of training injuries in the AFL. Compared with the 1997-2001 time span, injuries became more severe during the 2007-2011 time span.