Were You Born with a Higher Risk of ACL Injury? – 3 Anatomical Traits That May Put Your Knee in Jeopardy
As Dr. William Sterett, a board-certified orthopedic surgeon and sports medicine specialist at Vail-Summit Orthopaedics & Neurosurgery in the active mountain town of Vail, and Frisco, Colorado, I’ve seen thousands of ACL injuries throughout my career. While many assume these injuries are purely a result of bad luck or poor technique, the truth is—some people are simply born with anatomical features that make ACL tears more likely.
In this overview, I’ll walk through three structural traits you may have inherited that increase your risk of ACL injury, explain how they influence biomechanics, and offer tips on how to work with—not against—your natural anatomy.
1. A Narrow Intercondylar Notch
The intercondylar notch is a groove at the end of your femur (thighbone) where the ACL sits. Some individuals are born with a narrower notch, which gives the ACL less space to move freely.
This tight space can cause increased friction on the ligament during physical activity—particularly in sports that involve cutting, pivoting, or jumping. Over time, or with one bad move, this added stress can lead to a tear.
How to protect your knees:
If you’ve had an MRI or X-ray that shows a narrow notch—or if you’ve already torn your ACL once—it’s wise to prioritize neuromuscular training and focus on joint-stabilizing exercises. Awareness is key, especially in high-risk sports.
2. Increased Q-Angle (Quadriceps Angle)
The Q-angle measures the angle between your hip and knee. A larger Q-angle means your knee is more angled inward, which is commonly seen in people with wider hips—often females. This inward angulation can create greater strain on the ACL, especially during landing or cutting movements.
This is one of the anatomical factors that contributes to higher ACL injury rates in female athletes.
How to protect your knees:
Training programs that target hip and core strength can help correct faulty movement patterns that arise from a larger Q-angle. Learning proper jumping and landing mechanics is especially important.
3. Generalized Ligamentous Laxity (a.k.a. Loose Joints)
Some people are naturally more flexible due to increased ligament laxity—what some might call being "double-jointed." While flexibility is often viewed as a good thing, overly loose ligaments can mean less stability in the knee, leaving the ACL more vulnerable to injury.
This trait is typically genetic and often observed in younger athletes or dancers.
How to protect your knees:
Strength is your best friend. Building up the muscles around the knee—especially the hamstrings and glutes—can provide the support your ACL needs. Balance and proprioception work can also help you better control joint motion during fast or awkward movements.
You Can’t Change Your Anatomy—But You Can Outsmart It
If you have one or more of these anatomical risk factors, it doesn’t mean you’re destined for an ACL injury. It just means you need to train smarter, focus on prevention, and—when in doubt—get evaluated by a specialist.
If you have questions about ACL injury prevention or want to assess your personal risk, schedule a consultation today with Dr. Sterett. Together, we can create a plan to keep you active and injury-free.
