The financial and performance cost of injuries to teams in Australian professional soccer.

OBJECTIVES: To determine the relationship between injury incidence, player-salary cost and team performance in the professional Australian soccer league. DESIGN: Prospective observational cohort study. METHODS: Injury incidence, player-salary cost and team performance data were collected from the 10-club A-League competition (n=27 matches/season) over 6 seasons from 2012/13. Player-salary cost of injury was calculated from the salary cap, injury-induced missed matches and player exposure, and trends were reported from Poisson regressions. Team performance was determined from ranking, points, goals (scored, conceded and difference) and match outcome (win, loss or draw) per season and analysed via a mixed-effects Poisson models to estimate association with injury. RESULTS: Nine-hundred-and-sixteen injuries resulted in 3148 missed matches. Injury incidence remained stable apart from a decrease in 2015/16 (p=0.01). Missed matches were significantly higher in season 2013/14 (55.1 [50.7-59.9]; p<0.01) and 2014/15 (71.4 [66.4-76.8]; p<0.001) compared to 2012/13, without differences between other seasons. Player-salary cost ranged between AUD$187,990-AUD$332,680/team, peaking in 2014/15 (p<0.01). Multi-collinearity was detected for team performance variables except for matches lost. Teams who finished the season with greater positive goal differences were associated with 1% less injuries (p=0.003). Similarly, more missed matches were associated with 1% less league points and losses (p<0.001). CONCLUSIONS: Player-salary costs remained stable, concomitant with stable injury rates and missed matches. Despite injury being associated with goals difference, points and match losses; the magnitude of these relationships are small and team performance is more complex than injury occurrence alone. Injury prevention remains necessary for reducing injury-induced player-salary costs; however, additional services are required to improve team performance.

Injury epidemiology in Australian male professional soccer.

OBJECTIVES: To describe the injury epidemiology of the Australian male professional soccer league (A-League) over 6 consecutive seasons. DESIGN: Prospective observational cohort study. METHODS: Match-loss injury data was collected from each A-League club (n=10) for each competition match (n=27/season) over 6 seasons (2012/13-2017/18). Injuries were collected weekly through a standardised protocol and were classified by setting, mechanism, severity, the type and location on the body. Generalised Linear Models were used to estimate the injury incidences (injury/round/season), whilst rate ratios were reported for total injuries and within abovementioned injury classifications. RESULTS: Overall injury incidence was not significantly different ranging from 4.8 (95%CI:4.1-5.8) to 6.7 (95%CI:5.8-7.8) between seasons 2012/13 to 2017/18 (p>0.05). Match injuries remained stable whilst training injuries decreased across the 6 seasons (exp(ß) 0.59[95%CI:0.36-1.0]; p=0.04). Respectively, contact and non-contact injuries were not significantly different across the 6 seasons, although non-contact injuries were more common than contact injuries (p>0.05). Mild severity injuries decreased (exp(ß) 0.64 [95%CI:0.4-0.9];p=0.02), whilst moderate severity injuries increased (exp(ß) 1.7 [95%CI:1.0-2.8];p=0.04) in season 2017/18 compared to 2012/13. The most common injuries were at thigh (23-36%), of which the majority were hamstring injuries (54%-65%) of muscle/tendon type (50-60% of total injuries/season). Injuries remained stable across the seasons by type and location (p>0.05 and p>0.05, respectively). CONCLUSIONS: Injury rates, mechanisms, locations and types have remained relatively stable over recent seasons of the A-League. Current Australian professional soccer league medical practices may have contributed to the stability of injury rates.

Monitoring loads and non-contact injury during the transition from club to National team prior to an international football tournament: A case study of the 2014 FIFA World Cup and 2015 Asia Cup.

OBJECTIVES: Injured and non-injured national team footballers were compared for external and internal loads during transition from club to National team training camp. DESIGN: Prospective Case Study. METHODS: Load and injury data were collected from the same National team prior to and during training camps of 2 tournaments; World (n=17) and Asian Cups (n=16). External (number sessions) and internal (s-RPE) loads were collected 4-weeks prior to and during camps. The acute:chronic load ratio was calculated for the first week of camp based on the mean of previous 4-weeks. Respective loads and ratios were compared between injured and non-injured players for non-contact injuries occurring during camp. RESULTS: Seven non-contact injuries occurred during World Cup camp and 1 during Asian Cup (preventing statistical analyses). Small-to-moderate effect sizes were found for lower chronic internal loads (ES=0.57; 90% CI: 0.39-1.08) and higher acute:chronic ratio (ES=0.45; 90% CI: 0.31-0.87) for injured compared to non-injured players. Moderate-large effects (ES=0.83; 90% CI: 0.56-1.60) were evident for increased acute:chronic ratio for number of sessions in injured compared to non-injured players. However, small-moderate effect sizes were present for lower chronic training and match loads (ES=0.55; 90% CI: 0.38-1.06) in injured players prior to the World Cup camp, alongside an increased number of sessions in week 1 of camp (ES=0.47; 90% CI: 0.33-0.91). CONCLUSIONS: Players incurring non-contact injury during training camp prior to an international tournament performed less prior chronic external and internal load and a concomitant higher relative increase in camp, thus representing a practical marker to monitor in national teams.