ACL Prevention: Risk Factors and Evidence-Based Strategies to Reduce Injury

One of the most common questions Dr. Burnham hears in the clinic is, “How can I prevent an ACL tear?” It’s often asked by an athlete who’s just watched a teammate go down with a non-contact injury, or by a parent worried about their child’s risk going into the season. ACL tears are not inevitable. While injury cannot be completely eliminated, the evidence overwhelmingly shows that thoughtful, athlete-specific prevention programs significantly reduce injury rates.

Over his career at Ochsner-Andrews Sports Medicine Institute, Dr. Burnham has worked with athletes across every level, from high school to NFL. He’s seen firsthand how the right combination of screening, targeted strengthening, and movement retraining can transform an athlete’s durability. This article walks through the evidence-based risk factors that matter most, the prevention strategies that actually work, and how to implement them in training.

Who Is at Risk for ACL Tears?

Not all athletes face the same ACL injury risk. Contact sports (American football, rugby, ice hockey) see ACL injuries during tackles or collisions. In cutting and jumping sports (soccer, basketball, volleyball, skiing, tennis), the majority of ACL tears occur non-contact, during deceleration or change of direction.

Sex differences in ACL injury rates are striking. Female athletes tear their ACLs at rates 2 to 8 times higher than males in the same sports, depending on sport and competition level. In Dr. Burnham’s 2017 publication in Clinics in Sports Medicine, this disparity was examined. It’s not a single anatomic or hormonal factor, but rather a constellation of differences in neuromuscular control, movement patterns, ligament properties, and knee geometry that combine to increase female athlete risk.

Age matters too. Peak ACL injury rates in females occur between 16 and 25 years old; in males, the peak is slightly later (18 to 27). The transition from youth to competitive adult sport is a high-risk window for both sexes, when training volume and intensity ramp up faster than the body can adapt.

Sport-specific risk is also significant. Female soccer players face particularly high ACL injury rates, as do female basketball players and skiers. Multidirectional cutting, rapid deceleration, and midair transitions create an environment where biomechanical and neuromuscular deficiencies are exposed most acutely.

Biomechanical Risk Factors

When athletes are filmed and their movement is analyzed, certain patterns consistently precede non-contact ACL injuries. The most critical is knee valgus, or inward collapse of the knee during dynamic tasks like landing, cutting, or jumping. When the knee drifts inward (valgus) during a landing or deceleration, the ACL is placed under enormous tensile load, especially if the hip is internally rotated and weak.

Poor landing mechanics are foundational. An athlete who lands from a jump with a straight, stiff knee and minimal hip or ankle contribution is at higher risk than one who lands with hip and knee flexion and appropriate hip control. The “stiff knee” landing distributes forces through the ligaments rather than the muscles, placing the ACL in a vulnerable position.

Hip weakness cascades into problems throughout the chain. When the hip external rotators and abductors are weak, the femur cannot maintain neutral alignment during deceleration. The result is dynamic knee valgus, increased tibial internal rotation, and excessive ACL stress. This is why hip screening and strengthening are central to any prevention program.

Hamstring-to-quadriceps strength imbalance also contributes. The hamstrings unload the ACL by resisting tibial anterior translation. When quads are disproportionately strong relative to hamstrings (a common pattern in quad-dominant athletes), the mechanical advantage shifts toward ACL strain during high-velocity movements.

Neuromuscular Training Programs: What the Evidence Shows

The single strongest intervention to prevent ACL injury is a well-designed neuromuscular training program. Multiple large randomized controlled trials and meta-analyses have demonstrated that systematic training programs reduce ACL injury risk by 20% to 70%, depending on program design, athlete population, and compliance.

The FIFA 11+ program, developed by FIFA and validated in multiple sports, combines dynamic stretching, balance work, strength exercises, and plyometrics in a 20-minute warm-up. When performed consistently (2 to 3 times per week throughout the season), it reduces ACL injury rates in soccer by approximately 41% in a landmark study. The program emphasizes control of dynamic knee valgus during movements like lateral bounds and single-leg landings.

The PEP Program (Prevent Injury and Enhance Performance), developed at Santa Monica Sports Medicine, focuses on dynamic balance and proprioceptive training combined with strengthening and plyometrics. In female soccer players, the PEP program reduced ACL injuries by 74% in the first year and 88% in the second year compared to standard warm-up. The 15 to 20-minute program integrates easily into training.

Sportsmetrics, another evidence-based program, emphasizes proper landing technique, balance training, and plyometric progressions. Originally designed for female basketball players, it has been adapted across many sports and consistently shows injury reduction rates in the 30% to 50% range.

The common thread in all these programs is repetition and specificity. Prevention programs work best when they are integrated into regular training, progressed as athletes adapt, and sport-specific (cutting patterns that mirror game demands). A single ACL prevention workshop in the offseason is unlikely to produce lasting impact; ongoing integration into the training plan is essential.

Hip and Core Strengthening: The Game-Changer

In Dr. Burnham’s 2026 publication in the International Journal of Sports Physical Therapy, current evidence on hip and core assessment protocols to reduce ACL injury risk was evaluated. Research demonstrates that targeted hip and core strengthening programs produce some of the most measurable reductions in ACL injury rates. Neuromuscular programs emphasizing hip and core strength show injury rate reductions ranging from 20% to 60% depending on baseline deficits and program adherence.

Hip strength is critical because the hip external rotators (especially the gluteus maximus and deep hip rotators) are the primary stabilizers of the femur during dynamic deceleration. When these muscles are weak, the femur internally rotates and adducts, the knee collapses into valgus, and the ACL is placed under maximum load. A strong, controlled hip stabilizes the femur and allows the knee to track properly through deceleration.

Core strength matters equally. The core (rectus abdominis, obliques, transverse abdominis, erector spinae) provides the foundation for lower extremity control. Athletes with strong cores maintain upright posture and pelvic control during dynamic movements, allowing the hips and knees to move through proper alignment. A weak core leaves the athlete in a compromised position, forcing the knees to compensate.

Specific exercises with the highest evidence for ACL injury reduction include:

• Single-leg glute bridges and clamshells: Directly activate gluteus maximus and medius, improving hip extension and abduction strength
• Side-lying hip abduction and external rotation: Target hip external rotators and abductors in positions that mimic athletic demands
• Bulgarian split squats and reverse lunges: Improve hip stability and unilateral leg strength under load
• Pallof presses and rotational core work: Build antirotation strength and improve dissociation between upper and lower body
• Single-leg balance and perturbation training: Develop reactive hip and core strength to respond to unexpected perturbations

The key is progressive overload and specificity. Exercises should start with controlled, bilateral movements and progress toward dynamic, unilateral, sport-specific patterns. An athlete performing air squats on a stable surface will not develop the reactive stability needed for rapid deceleration in a game. The progression must challenge the neuromuscular system in increasingly sport-relevant ways.

Sport-Specific Prevention Strategies

Prevention programs are most effective when tailored to the specific biomechanical demands of the sport. A soccer player’s deceleration patterns, cutting angles, and opponent contact differ from a volleyball player’s landing mechanics or a skier’s edge control demands.

Soccer: Prevention work should emphasize lateral deceleration (cutting and rapid directional changes), single-leg balance and control in awkward positions, and landing mechanics after headers and aerial challenges. Sport-specific plyometrics (lateral bounds, 90-degree cuts, acceleration and deceleration sequences) are essential in training.

Basketball: Rapid multidirectional cutting, vertical jump landing, and defensive slide mechanics dominate the injury risk landscape. Programs should emphasize jump landing control (knee and hip flexion on landing, avoiding knee valgus), lateral agility, and balance during fatigue. The end-of-quarter and end-of-game fatigue window carries elevated risk, so conditioning to maintain control is critical.

Skiing and Snowboarding: ACL injuries in skiing often occur during rapid deceleration or directional change at speed, when one ski catches or during a fall with the ski binding failing to release. Prevention focuses on balance training, eccentric quadriceps and hamstring strength (to control rapid deceleration), and proper technique progression.

American Football: Contact and collision are common ACL injury mechanisms, but non-contact cuts and rapid deceleration also cause injury, especially in defensive positions. Prevention includes hip stability, lateral agility, rapid deceleration control, and collision-specific training (maintaining leg strength through contact).

Sport-specific plyometrics and agility, integrated into the prevention program rather than treated as separate warm-up-only activity, dramatically improves compliance and effectiveness.

The Female Athlete’s ACL: Understanding the Disparity

The higher ACL injury rate in female athletes is one of the most consistent findings in sports medicine. In Dr. Burnham’s 2017 publication in Clinics in Sports Medicine titled “Update on Anterior Cruciate Ligament Rupture and Care in the Female Athlete,” the multifactorial nature of this disparity and the evidence-based prevention strategies most relevant to female athletes were outlined.

Anatomic differences contribute to, but do not fully explain, the disparity. Female athletes, on average, have wider pelvic geometry, different femoral anteversion angles, and smaller intercondylar notches than males. These anatomic differences may contribute to knee valgus positioning and potentially higher ligament stress. However, anatomic differences alone cannot explain a 2 to 8-fold difference in injury rates—many female athletes with these anatomic variations never tear their ACLs.

Neuromuscular and biomechanical differences are more substantial. Female athletes, on average, demonstrate greater knee valgus during landing, less hip abduction and external rotation strength, and different hamstring-to-quadriceps recruitment patterns compared to males. These are trainable deficits, and when targeted in a prevention program, they can be corrected.

Hormonal factors may play a role, though the evidence is complex and inconclusive. Some studies suggest that ACL injury rates vary with menstrual cycle phase, potentially due to estrogen effects on ligament laxity and neuromuscular control. However, this effect is modest compared to the impact of neuromuscular deficits, and hormonal factors alone do not account for the disparity.

Clinically, female athletes benefit from prevention programs that are at least as rigorous as male athletes’, and ideally more so, to correct the baseline neuromuscular and biomechanical differences that increase their risk. The same neuromuscular training programs (FIFA 11+, PEP, Sportsmetrics) that work for all athletes are effective for female athletes, but compliance and progressive challenge are essential.

Screening and Functional Testing: Identifying At-Risk Athletes

Not all athletes carry the same risk. Some have clear biomechanical or strength deficits that predispose them to injury. Screening helps identify these individuals and target prevention efforts.

Dynamic Knee Valgus Assessment: A simple single-leg squat or single-leg landing task, observed from the front, reveals knee valgus during deceleration. Athletes showing marked inward knee drift during these movements are at higher risk and should receive targeted hip strengthening.

Timed Single-Leg Step-Down Test: The athlete stands on one leg on a box and performs as many controlled step-downs as possible in 60 seconds. Poor control, with the pelvis dropping or the stance knee collapsing into valgus, indicates hip weakness or core dysfunction. Dr. Burnham’s research team recently presented data showing that performance on the timed single-leg step-down test is significantly correlated with hip and knee biomechanics as measured by 3D markerless motion capture. Athletes who completed more repetitions demonstrated better control of knee abduction and hip internal rotation, two movement patterns directly linked to ACL injury risk. This test is now used as a practical, clinic-friendly screening tool to identify athletes with higher-risk movement patterns before injury occurs.

Y-Balance Test: This assessment evaluates dynamic balance and lower extremity strength. Athletes reaching shorter distances, or showing asymmetry between legs (>4cm difference), have reduced neuromuscular control and benefit from balance and strengthening work.

Hip External Rotation Strength and Range of Motion: In research with the hip external rotation strength assessment (Kline et al., 2017), it was demonstrated that hip external rotation strength and mobility are critical components of ACL injury prevention. Athletes with limited hip external rotation or asymmetric strength benefit from targeted mobility and strength work.

Single-Leg Hop Tests: Single-leg hop distance, single-leg hop for distance symmetry, and hop test landing mechanics all provide information about lower extremity power and control. Athletes with significant asymmetries (>90% limb symmetry index) or poor landing mechanics during hops require additional intervention.

Screening should be repeated regularly (preseason, midseason, offseason) to track changes and adjust prevention programs. Athletes who show improvement in screening measures often demonstrate improved confidence and reduced perceived re-injury risk.

The Bottom Line

ACL tears are not inevitable. The evidence unequivocally shows that systematic, progressive neuromuscular training programs reduce ACL injury risk by 20% to 60%, depending on program design and compliance. Prevention is most effective when it combines hip and core strengthening, improved landing mechanics, sport-specific plyometrics, and balance training integrated into regular training, not relegated to a separate warm-up.

For female athletes, baseline risk is higher, but so is the potential benefit of targeted prevention. A female athlete completing a rigorous, consistent prevention program significantly improves her odds of staying healthy and competing at her best.

When an athlete shows signs of biomechanical deficiency during screening (knee valgus, single-leg control issues, strength asymmetries), investing in targeted prevention now is critical. Prevention is far simpler than recovery from an ACL injury. At Ochsner-Andrews Sports Medicine Institute, individualized prevention programs are designed based on each athlete’s specific risk profile and goals. To discuss an athlete’s ACL injury risk and prevention strategy, contact the clinic.

Related reading:

• ACL Reconstruction and ACL Surgery – Surgical management when an ACL tear occurs.
• ACL Repair with BEAR Implant – A newer approach to ACL treatment for select patients.
• Quadriceps Tendon: The Graft of the Future – Emerging graft options for ACL reconstruction.
• Knee Injuries and Treatments – Comprehensive guide to common knee conditions.

About Dr. Jeremy Burnham: Dr. Burnham is a board-certified orthopedic surgeon and sports medicine specialist at Ochsner-Andrews Sports Medicine Institute in Baton Rouge, Louisiana. He has published over 50 peer-reviewed articles on ACL biomechanics, prevention, and surgical reconstruction, including research on hip and core assessment for ACL injury prevention (International Journal of Sports Physical Therapy, 2026). His clinical focus is on anterior cruciate ligament injuries in athletes across all levels, from high school to professional. Dr. Burnham earned his medical degree from Louisiana State University Health Sciences Center in Shreveport, completed his orthopaedic surgery residency at the University of Kentucky, and his sports medicine fellowship at the University of Pittsburgh Medical Center. He was a varsity football letterman at LSU and brings both clinical expertise and an athlete’s perspective to his patient care.

References

1. Burnham JM, Drazick AT, Aminake G, et al. Current concepts in hip and core assessment to reduce the risk of ACL injury. International Journal of Sports Physical Therapy. 2026;21(2):210-222. https://doi.org/10.26603/001c.155471
2. Burnham JM, Wright V. Update on anterior cruciate ligament rupture and care in the female athlete. Clinics in Sports Medicine. 2017;36(4):703-715. https://doi.org/10.1016/j.csm.2017.05.004
3. Kline PW, Burnham JM, Yonz M, et al. Hip external rotation strength predicts hop performance after anterior cruciate ligament reconstruction. Knee Surgery, Sports Traumatology, Arthroscopy. 2017;26(4):1137-1144. https://doi.org/10.1007/s00167-017-4534-6
4. Hewett TE, Myer GD, Ford KR, et al. Biomechanical measures of neuromuscular control and valgus loading of the knee predict anterior cruciate ligament injury risk in female athletes: a prospective study. The American Journal of Sports Medicine. 2005;33(4):492-501. https://doi.org/10.1177/0363546504269591
5. Mandelbaum BR, Silvers HJ, Watanabe DS, et al. Effectiveness of a neuromuscular and proprioceptive training program in preventing anterior cruciate ligament injuries in female athletes: 2-year follow-up. The American Journal of Sports Medicine. 2005;33(7):1003-1010. https://doi.org/10.1177/0363546504272261
6. Soligard T, Nilstad A, Steffen K, et al. Compliance with a comprehensive warm-up programme to prevent injuries in youth football. British Journal of Sports Medicine. 2010;44(11):787-793. https://doi.org/10.1136/bjsm.2009.070672
7. Gilchrist J, Mandelbaum BR, Melancon H, et al. A randomized controlled trial to prevent noncontact anterior cruciate ligament injury in female collegiate soccer players. The American Journal of Sports Medicine. 2008;36(8):1476-1483. https://doi.org/10.1177/0363546508318188
8. Kowalczuk M, Herbst E, Burnham JM, et al. A layered anatomic description of the anterolateral complex of the knee. Clinics in Sports Medicine. 2017;37(1):1-8. https://doi.org/10.1016/j.csm.2017.07.001
9. Pfeiffer TR, Kanakamedala AC, Herbst E, et al. Female sex is associated with greater rotatory knee laxity in collegiate athletes. Knee Surgery, Sports Traumatology, Arthroscopy. 2017;26(5):1319-1325. https://doi.org/10.1007/s00167-017-4684-6
10. Roy C, Aminake G, Burnham JM. Performance on the timed single-leg step-down test correlates with hip and knee biomechanics measured by 3D markerless motion capture. Clinical Practice in Athletic Training. 2026;8(3). Presented at ATPPS Annual Conference, March 2026.

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