ACL Injuries Across the Lifespan: Age and Gender Differences from a Physiotherapist’s Perspective by Bill Kelly APA Physiotherapist
Anterior Cruciate Ligament (ACL) injuries are among the most common and serious injuries in athletes and active individuals. As a physiotherapist, I frequently work with patients of all ages recovering from ACL tears, and one thing that stands out is how these injuries differ between age groups and genders. Understanding these differences can significantly influence prevention strategies, rehabilitation protocols, and return-to-sport timelines.
Age Differences in ACL Injuries
1. Children and Adolescents
ACL injuries in youth athletes are rising, particularly with early sport specialisation and year-round competition. Adolescent athletes often sustain non-contact injuries during pivoting or jumping activities in sports like soccer and basketball. Growth plate involvement is a major consideration in this age group, influencing surgical timing and rehab strategies. Rehab must balance recovery with the demands of growing bones and developing neuromuscular control.
“ACL injuries in children and adolescents have increased 2.3% annually over the past 20 years.”
— Beck et al., 2017
2. Adults (18–40 years)
This group experiences the highest rate of ACL injuries, especially among competitive and recreational athletes. The focus here is often on surgical reconstruction and an intensive, evidence-based rehab program aiming for return to high-level sport. Psychological readiness and prevention of re-injury are key themes in rehab for this age group.
3. Older Adults (40+ years)
While less common, ACL injuries in older adults often result from skiing, falls, or high-stress pivoting movements. Many in this group opt for conservative management over surgery, especially if daily function, rather than return to sport, is the primary goal. Degenerative knee changes, comorbidities, and slower tissue healing must be factored into physiotherapy plans.
Gender Differences in ACL Injuries
Numerous studies have shown that females are 2–8 times more likely than males to sustain an ACL injury, especially in sports like netball, basketball, and soccer.
Key Factors Contributing to Gender Disparity:
Anatomical Differences: Women typically have a wider pelvis and a greater Q-angle (the angle between the hip and knee), contributing to knee valgus stress.
Hormonal Influence: Fluctuations in oestrogen levels, especially during the menstrual cycle, may affect ligament laxity and neuromuscular control.
Neuromuscular Control: Females tend to demonstrate different landing mechanics, such as less knee flexion and greater valgus collapse during cutting or jumping.
“Female athletes demonstrate different biomechanical and neuromuscular patterns that increase their risk of ACL injury.”
— Hewett et al., 2006
This necessitates gender-specific injury prevention programs. Neuromuscular training and movement retraining have been shown to significantly reduce ACL injuries in female athletes.
Physiotherapy Considerations Across Groups
Physiotherapists must tailor ACL rehab to each individual’s age, goals, and physical status:
Adolescents: Emphasise motor control, growth considerations, and parent/school/sport collaboration.
Adults: Focus on sport-specific agility, strength, and psychological readiness for return to play.
Older Adults: Target function, balance, and pain management, with careful return to moderate activity.
Across all groups, emphasis on early rehab, knee extension restoration, quadriceps strengthening, and gradual functional progression is key.
Conclusion
ACL injuries are not one size fits all. Age and gender significantly influence injury mechanisms, rehab needs, and outcomes. A personalised approach that considers these differences allows us as physiotherapists to better support each patient’s journey—whether they're returning to elite sport or simply regaining daily function.
References
Beck, N. A., et al. (2017). "ACL Tears in School-Aged Children and Adolescents." Journal of Pediatric Orthopaedics, 37(4), e247-e252.
Hewett, T. E., et al. (2006). "Mechanisms, prediction, and prevention of ACL injuries in female athletes." Journal of Athletic Training, 41(3), 261–268.
Herzog, M. M., et al. (2017). "Sex differences in ACL injury, treatment, and outcomes: a narrative review." Sports Health, 9(1), 61-67.
Ardern, C. L., et al. (2014). "Return to sport following ACL reconstruction surgery: a systematic review and meta-analysis of the state of play." British Journal of Sports Medicine, 48(10), 873–879.
Vavken, P., & Murray, M. M. (2011). "Age and growth plate status affect the outcome of ACL reconstruction in skeletally immature patients." The American Journal of Sports Medicine, 39(7), 1406–1412.