ACL health and movement loading: why pre-puberty and puberty may be the window that matters most
ACL injury prevention is often discussed as a technique problem. Teach better landing. Improve knee alignment. Strengthen the hips. Those things matter, but they are only part of the picture. A more useful question is whether childhood and adolescence are periods in which we can build a more resilient system: stronger muscles, better movement solutions, and possibly healthier ligament adaptation under well-designed load. The current evidence strongly supports the first two and increasingly points toward the third, although direct long-term proof for ACL tissue adaptation in youth is still emerging.
Growth and maturation change the injury landscape. Across adolescence, especially in girls, lower-limb biomechanics often shift in ways associated with greater ACL risk: less knee flexion, greater knee valgus-related patterns, and reduced control during landing and cutting. A 2024 systematic review reported that late- and post-pubertal females more often display biomechanics linked to elevated ACL injury risk, while a 2025 review on biological maturity similarly highlighted reduced knee neuromuscular control during maturation as one of the clearest maturity-related findings.
That matters because puberty is not just a time of rapid growth; it is also a time of temporary mismatch. Body mass increases, segment lengths change, movement demands rise, sport becomes faster, but neuromuscular control does not always keep pace. Broader youth athlete evidence shows that growth and maturation are meaningfully associated with injury burden, which supports a developmental rather than purely reactive approach to prevention.
This is where targeted loading becomes important. The phrase should not mean simply “more training.” It means the right loading, at the right time, with the right progression. In practice, that includes progressive strength training, plyometrics, balance and deceleration work, change-of-direction mechanics, trunk control, and regular exposure to well-coached landing and cutting tasks. Exercise-based injury prevention programmes and neuromuscular training programmes consistently reduce knee and ACL injury risk, and recent evidence suggests the best effects come from regular, sustained implementation rather than occasional add-ons.
There is also good evidence that resistance training in children and adolescents is safe and beneficial when supervised appropriately. Consensus and review papers describe youth resistance training as an effective means of improving strength, power, movement skill, and general injury resistance. That matters for ACL prevention because stronger, more competent young athletes are generally better able to tolerate and control the forces that occur in sport.
The more interesting and forward-looking idea is that targeted loading may influence ligament health itself, not just the muscular system around it. A 2025 review on ligament adaptation concluded that mechanical loading is central to ligament biology but also emphasised that major knowledge gaps remain, particularly around how dose, timing, maturation, and recovery interact. Related work in ACL imaging and graft research shows that quantitative MRI markers can reflect meaningful changes in ligament structure and mechanical properties, which strengthens the case that tissue quality is measurable and responsive to loading history. What we cannot yet say with confidence is that a specific childhood or pubertal loading programme has been proven to enhance native ACL tissue resilience over the long term in humans. That is the hypothesis, and it is a plausible one, but it is not yet settled science.
So the most defensible message is this: pre-puberty and puberty may be the key developmental window for reducing later ACL injury risk because these years are highly trainable, biomechanically sensitive, and responsive to neuromuscular and strength-based intervention. Whether that benefit is driven mainly by improved coordination and force control, or also by direct ligament adaptation, is still being worked out.
For coaches, parents, and clinicians, the practical implication is not early specialisation or aggressive loading. In fact, broader youth sport literature warns against poorly regulated load, fatigue, and narrow repetitive exposure. The implication is to build robust movement foundations early: competent squatting, hinging, landing, hopping, cutting, sprint mechanics, and progressive strength training delivered with technical feedback and adequate recovery. Puberty should be treated as a time to intensify support, not merely intensify sport.
In girls especially, this may be crucial. Female athletes experience a marked rise in ACL injury risk after puberty, and current consensus work in female athlete injury prevention has reinforced the need for context-specific, developmentally informed strategies rather than one-size-fits-all programmes. That does not mean girls are fragile. It means the system around them must be smarter about timing, dosage, progression, and coaching quality.
The real opportunity, then, is to shift the conversation from prevention-as-warm-up to prevention-as-development. If we wait until late adolescence to address landing quality, force absorption, and lower-limb strength, we may be intervening after risk patterns are already established. But if we use pre-puberty and puberty to build movement competence and progressively expose young athletes to well-designed loading, we may do more than reduce immediate injury risk. We may help build a healthier, more resilient knee for the years that follow. That is not yet a completed evidence story, but it is one of the most important directions in ACL prevention science.
References
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Ramachandran, A. K., Pedley, J. S., Moeskops, S., Oliver, J. L., Myer, G. D., & Lloyd, R. S. (2024). Changes in lower limb biomechanics across various stages of maturation and implications for ACL injury risk in female athletes: A systematic review. Sports Medicine, 54(7), 1851-1876. https://doi.org/10.1007/s40279-024-02022-3
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