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Hamstring Injury Risk in AFL: The Biomechanics of Kicking Leg Strain
- Greg Dea
- 3 days ago
- 3 min read
Why Hamstring Injuries Happen on the Kicking Leg: The Overlooked Role of Quadriceps Tightness
Quadriceps Mobility and Hamstring Injury Risk: A Biomechanical Perspective
Hamstring injuries occurring on the same side as a player's preferred kicking leg may not be mere coincidence. One important, and often overlooked, factor is quadriceps mobility — specifically the flexibility of the rectus femoris, a muscle heavily involved in the kicking motion.
As this muscle becomes stronger or fatigued through repetitive use, it can lose mobility, altering biomechanics in ways that increase the load on the hamstrings. This connection is supported by research conducted by Belinda Gabbe, who found that limited quadriceps flexibility — measured via the modified Thomas test — significantly increased the risk of hamstring strains in Australian football players1.
During high-speed running, particularly in the swing phase, the anterior thigh functions like a coiled spring. A tight rectus femoris can add recoil and acceleration to the femur, which increases the velocity of the tibia. The hamstrings are then responsible for braking this rapidly swinging lower leg — under greater load and often at longer lengths, making them more susceptible to injury.
Furthermore, tightness in the opposite leg’s quadriceps (commonly the plant leg during kicking) can cause anterior pelvic tilt during late stance. This affects the hamstring origin on the opposite side by pre-tensioning it during a moment of maximal deceleration force, increasing injury risk on the kicking leg.
What We’re Seeing in the 2025 AFL Season
Geelong has already reported four hamstring injuries this season — and tellingly, three of those occurred on the same side as the player’s kicking leg:
Patrick Dangerfield: Right hamstring strain (same side as kicking leg)
Jack Henry: Right hamstring strain (same side as kicking leg)
Jack Bowes: Right hamstring strain (same side as kicking leg)
Rhys Stanley: Hamstring strain (side not publicly reported)
This trend strengthens the argument for a closer examination of quadriceps mobility and pelvic mechanics in elite footballers. If a pattern is emerging, particularly in the kicking leg, it warrants further clinical consideration — not just post-injury, but in pre-season screening and load management.
A Concerning Trend for Geelong?
Geelong has already recorded four hamstring injuries in the 2025 AFL season:
Dangerfield: 1–2 week expected absence
Bowes: 2–5 weeks
Henry: 3–4 weeks
Stanley: Undisclosed
Collectively, these injuries represent an estimated 7–13 missed games. Compared to the AFL average of 14.34 missed games per club per season due to hamstring injuries (2023 AFL Injury Report), Geelong is already approaching or potentially exceeding the league benchmark.
This trend highlights how easily a club’s injury burden can swell — and how a talented player carrying unaddressed risk factors might ultimately become a talented player injured on the bench.
Clinical Takeaways for AFL Hamstring Injury
Incorporate bilateral quadriceps flexibility tests (e.g. modified Thomas test) into regular assessments.
Monitor anterior pelvic tilt tendencies, particularly in athletes with prior hamstring or quadriceps issues.
Include kicking-specific mobility and deceleration control drills in injury prevention programs.
For a deeper dive into foundational hamstring injury mechanisms and risk profiling, see our earlier blog post:👉 Hamstring Injury Risk Factors