Who is at Risk of an ACL Injury?

- By Chi Hai Nguyen 

Anterior cruciate ligament (ACL) injuries most commonly occur in sports/activities which involve rapid deceleration, changes in direction, jumping and landing, or direct contact. In terms of physical mechanism, the injury occurs when the knee is hyperextended and a pivot (twisting) movement occurs at the same time which will stress the ACL and can damage it. 

You don’t have to be an athlete to suffer an ACL tear, they can happen to anyone who experiences an awkward fall. About 150,000 ACL ruptures occur per year in the USA and are common in both professional and recreational sports.

Female athletes are at a higher risk of sustaining an ACL tear than their male counterpart. Some of the factors contributing to this include anatomical differences, muscular strength, neuromuscular control and hormone differences!

• Wider pelvis: To accommodate for birth which will result in an increased Q angle (more ‘knock knee’d) which results in a greater stretch on the ACL and thus stress. 
• Joint laxity: Females on average have greater joint laxity which increases the risk of injury to their ligaments. (Landing in a more hyperextended position)
• Monthly hormone related changes: Affects the stiffness of the ACL
• Proportionately smaller intercondylar notch: The space in your knee in which the ACL/PCL attaches itself onto. If this space is smaller, there is less room for the ACL/PCL and leads to an increased likelihood of getting pinched and damaged during movements. 

Usually when an individual suffers an ACL injury they will hear or feel a “pop” in their knee as they fall. Depending on the degree of the injury, some common symptoms include:

• Swelling and redness
• Unable to bear weight
• Pain and loss of range of motion in knee
• Instability or “knee buckling” when walking/running

If you suspect you have an ACL injury, seek medical attention. A team of medical professionals will use diagnostic imaging (X-rays, ultrasound, MRIs) to confirm the diagnosis and the severity of the injury and will help plan with you accordingly for next steps. 

Return to competitive sport is usually 9-12 months after surgery. I’ve detailed the surgical options and pros and cons of the different types of ACL repairs in my other blog (LINKED HERE). Regardless if you undergo surgery or go the conservative route, a rehabilitation program is important to getting you back to your daily activities. A rehab program will incorporate regaining range of motion to the joint and surrounding muscles and will progress to a strength based one to protect the joint as the graft heals. Towards the end of the rehab program, sport specific exercises and drills are crucial getting the athlete back into play! 

We’ll go into more detail about the components of an ACL rehab program and prevention in our next blog! Stay tuned!