Blog authors: Chelsea Oxendale, Matthew Green, Keith Stokes, Sean Cumming, Gemma Nicole Parry, Sean Williams
In this blog, we provide insights from our latest article published in the British Journal of Sports Medicine (available here), where we examined over 16,000 player-seasons from Premier League and Category One Academies to understand how apophyseal (growth-related) injuries vary by age and body location.
Why is this study important?
During adolescence, boys typically experience a growth spurt in their early teenage years. During this time, parts of the bone known as the apophyses are still developing and less able to tolerate repetitive loading. Football specific movements such as jumping, sprinting and changing direction places considerable strain on these sites, making them more susceptible to injury.
Current evidence highlights apophyseal injuries are common in academy players and can lead to prolonged periods of recovery which disrupt training and long-term player development. We also know that injury location follows patterns of human growth, progressing from the foot and ankle (i.e., distal sites) in younger players to the hip (i.e., proximal sites) as the player ages. However, what is currently missing is a detailed understanding of when, where, and how impactful apophyseal injuries are across different player phases in academy football. Addressing this gap was the primary aim of our study.
How did the study go about this?
This prospective cohort study tracked 16,024 player-seasons from male youth academy footballers ranging from U9s to U21s over two seasons. Injuries were recorded through standardised injury surveillance systems, allowing for the analysis of incidence (how often injuries occurred), severity (the typical recovery time) and burden (overall impact and days lost) across player age and body location.
What did the study find?
First, we confirmed apophyseal injuries shift from the ankle and foot towards the hip with increasing age. In younger players (U9 to U11), most apophyseal injuries occurred in the ankle and foot. The knee was the predominant injury site in U12 players and in older adolescents (U15 to U18), hip and groin apophyseal injuries were most frequent.
Second, we found the severity of apophyseal injuries increased with age. Median time loss increased from 20 days in U9 to U11 players to 38 days in U15 to U16 players. Interestingly, injury burden was similar in the U9 to U11 and U18 to U21 groups. This suggests that apophyseal injuries warrant attention across all player phases in academy players.
The most novel finding was the hip/groin and knee regions carried the highest burden across all ages, resulting in twice the number of days lost compared with ankle and foot apophyseal injuries. This demonstrates that while young players often sustain apophyseal injuries, the impact in terms of time loss peaks during mid-adolescence in U12 to U16 players.
What are the key take-home points?
- Apophyseal injuries follow predictable, age-related patterns. Younger players are more likely to sustain injuries in the ankle and foot, while hip and groin injuries predominate in older adolescents.
- The U12 to U16 age group carries the highest injury burden, suggesting this period should be a priority for targeted monitoring and load management strategies.
In summary, our BJSM study quantifies apophyseal injuries in one of the largest youth football cohorts to date. These findings can help inform age- and site-specific approaches to monitoring and injury prevention. Ultimately, tailoring strategies to the developmental stage of the player may better support long-term athlete health and performance.
