ECSS Paris 2023: OP-MH36
INTRODUCTION: Lower-extremity muscle injuries contribute to nearly half of the overall injury burden in professional football, with incidence rates differing across major muscle groups for acute as well as overuse injuries. Importantly, lower-extremity muscle injuries are commonly associated with an increased susceptibility to subsequent injury especially in the weeks after return-to-play (RTP). However, the post-RTP risk trajectories following different lower-extremity muscle injuries remain insufficiently characterised. This descriptive study aimed to investigate the risk trajectories for non-contact subsequent injury after returning from major lower-extremity muscle injuries in professional football, differentiating acute from overuse index injuries. METHODS: Prospectively collected injury data from clubs in 1st and 2nd German Bundesliga over three seasons (2022/23 to 2024/25) were used for time-to-event analysis. Index injuries (i.e., injuries from which players returned to play) of interest included muscle injuries to hamstrings, quadriceps, adductors, and calf. Acute and overuse index muscle injuries were analysed separately across these locations. Non-contact time-loss subsequent injuries were considered as the event of interest. Built upon previously published methodology [1], the Kaplan-Meier survival function was used to estimate the cumulative hazard function, from which the continuous hazard function was derived. RESULTS: Over the three seasons, 374 acute and 304 overuse index injuries were identified at the four lower-extremity muscle groups. Observed subsequent-injury rates were hamstring 27.9%, quadriceps 26.2%, adductor 39.3%, and calf 21.2% for acute index injuries, and hamstring 28.1%, quadriceps 27.7%, adductor 27.2%, and calf 27.4% for overuse index injuries. While the time course of subsequent injury risk globally aligned with previous findings, differences between muscle groups were observed. Players returning from acute hamstring and adductor injuries showed elevated risk which diminished within approximately twelve and four weeks, respectively, and levelled off thereafter. By contrast, a delayed risk peak around three weeks after RTP was found for overuse calf index injuries. CONCLUSION: This descriptive study characterised the time-varying nature of subsequent injury risk for specific lower-extremity muscle injuries. The observed differences in risk trajectories across muscle groups highlighted the need for careful RTP decision-making based on each index injury. References 1. Zhang G, Brink M, Tröß T, et al. The time course of injury risk after return-to-play in professional football (soccer). Sports Medicine. 2024:1-9.
Read CV Guangze ZhangECSS Paris 2023: OP-MH36
INTRODUCTION: In professional football (soccer), the main purpose of the pre-season is to restore players’ strength and fitness following the off-season to ensure a successful transition into the in-season in terms of optimising performance and mitigating injury risk. However, the incidence of overuse injuries and re-injury in professional male footballers is in fact higher during pre-season than the in-season (Waldén et al., 2005), which suggests players are overloaded in pre-season. The extent to which injury patterns differ between pre- and in-season in professional female footballers, however, remains unknown, and such knowledge is vital for the design of effective injury prevention strategies. Thus, the objective of this study was to compare injury incidence rates (IIR), burden, and severity of different injury types/locations between pre- and in-season in professional female footballers. METHODS: Injury and exposure data were collected from 215 professional female footballers competing in England and Spain between 2015 and 2024. Muscle, ligament/tendon, bone, knee, ankle and thigh IIR and injury burden (days lost) were calculated per 1000 h match and training exposure during pre- and in-season. The proportion of injury severity classifications was also compared between pre- and in-season. RESULTS: In total, 390 injuries were recorded, with 78 (20.0%) occurring during pre-season and 312 (80.0%) during in-season. Muscle injury was the most prevalent injury type in both pre- (53.8%) and in-season (37.5%), with the quadriceps femoris muscle being the most common injury location during pre- (52.4%) and in-season (29.9%). Muscle IIR (2.96 [95% CI:2.12-4.12] vs. 1.81 [95% CI:1.44-2.26] injuries/1000h; p=0.016) and thigh IIR (2.15 [95% CI:1.43-3.22] vs. 0.98 [95% CI:0.71-1.33] injuries/1000h; p=0.003) were both higher during pre-season. Injury burden for both muscle (76 [95% CI:31-255] vs. 27 [95% CI:20-38] days/1000h; p=0.009) and thigh (69 [95% CI:25-244] vs. 16 [95% CI:10-26] days/1000h; p=0.001) was also higher during pre-season. There was a higher proportion of moderately severe (8-28 days lost) muscle injuries sustained in pre-season (71.4%) vs. in-season (45.3%) (χ²(1)=5.64, p=0.018). CONCLUSION: This is the first study to investigate differences in injury patterns between pre- and in-season in professional female footballers. Specifically, we show that muscle and thigh IIR and burden were higher during pre- than in-season, which appears to be driven primarily by a larger proportion of quadriceps femoris injuries occurring in pre-season. These results suggest that injury prevention strategies in professional female footballers should focus on muscle (particularly the thigh) during pre-season. References: Waldén M, Hägglund M, Ekstrand J. Injuries in Swedish elite football. Scand J Med Sci Sports. 2005;15:118–125.
Read CV Joonsung LeeECSS Paris 2023: OP-MH36
INTRODUCTION: Young competitive gymnasts are exposed to high training volumes and repetitive extreme movements from an early age, placing them at increased risk for musculoskeletal injuries, particularly in the lower extremities and spine. Identified intrinsic risk factors include reduced muscle strength, elevated BMI, delayed biological maturation, and absence of menarche. Most existing studies are retrospective and seldom differentiate between gymnastics disciplines. Purpose: to prospectively examine the prevalence of lower-extremity musculoskeletal injuries in young competitive gymnasts over 2 years, to compare injury incidence across 3 gymnastics disciplines, and to identify factors predictive of these injuries. METHODS: A total of 129 young competitive gymnasts (11.6 ± 1.8 years) from rhythmic (n = 69), acrobatic (n = 35), and artistic (n = 25) gymnastics were followed during two years. The following assessments were conducted at baseline, one year later (1st follow-up) and two years later (2nd follow-up): training volume, anthropometric characteristics, bone properties and muscle strength. Musculoskeletal injuries of the ankle, shin, knee, hip, and spine were clinically assessed by a physiotherapist at each evaluation session. Injuries were categorized into three groups: tendon, joint, and bone. RESULTS: In the overall sample, the prevalence of tendon and joint injuries increased from baseline (11.6%, 38.8% respectively) to the 1st follow-up (73.8%, 58% respectively), followed by a moderate decline at the 2nd follow-up (51.5%, 47.7% respectively) (p < 0.001 ; p = 0.0025). Bone injury prevalence demonstrated a gradual increase across time points, from baseline to the 1st and 2nd follow-ups (28.7%, 36.6%, 39.8% respectively), although this trend did not reach statistical significance (p = 0.054). Artistic gymnasts exhibited the highest injury prevalence across disciplines: bone injuries at baseline (48%), joint and tendon injuries at the 1st follow-up (61.1% ; 83.3%, respectively), despite no statistically significant differences between disciplines (p > 0.05). Generalized Estimating Equations (GEE) regression analyses indicated that higher BMI and greater muscle strength were associated with increased odds of tendon injuries (OR = 1.30 and 1.53 respectively; p = 0.042), while older age reduced the odds (OR = 0.51; p = 0.018). Higher training level predicted lower odds of joint injuries (OR = 0.75; p = 0.031). No significant predictors of bone injuries were identified. CONCLUSION: Musculoskeletal injuries are highly prevalent among young competitive gymnasts, with injury patterns varying across disciplines. Modifiable factors, including BMI, muscle strength, and training volume, are associated with injury risk. These findings highlight the need for discipline-specific monitoring and targeted prevention strategies to protect the musculoskeletal health of young gymnasts
Read CV Liav ElbazECSS Paris 2023: OP-MH36