Summer may be the season for rest and relaxation, but it’s also the perfect time for athletes to get their bodies in shape for the fall. One area that is often overlooked is the knee, which is prone to injury in most sports. The Anterior Cruciate Ligament, or ACL for short, is of particular concern as its rupture requires surgery to repair and a lengthy recovery process. Here, NEBH Athletic Trainers explain ACL injuries and an exercise you can do to help prevent them.
What is the Anterior Cruciate Ligament (ACL)?
The ACL is one of the four major ligaments of the knee, working alongside the PCL (Posterior Cruciate Ligament), the Medial Collateral, and Lateral Collateral Ligaments (on either side) to stabilize the joint. Specifically, the ACL limits rotational movement of the knee and primarily prevents the Tibia (shin bone) from moving too far forward on the Femur (thigh bone).
Injuries and Common Causes
An ACL injury can range from a sprain (overstretched) to a full length tear, usually as a result of hyperextension (the knee extends beyond its normal fully straightened position) or pivoting (excessive inward turning of the femur with a planted foot). Movements that often result in a tear are changing direction quickly, landing incorrectly from a jump, direct contact from a collision, or stopping suddenly.
While ACL injuries can be difficult to prevent altogether, research has allowed clinicians to improve strength in weak muscle areas, which are strong predictors for injury. Targeted training in proper jumping and landing mechanics has also been shown to significantly reduce the risk for injury. Alongside that, knee control and glute strength are key factors in preventing knee injuries. A good exercise to work these areas is eccentric squats. To do these:
Make sure your knees don’t come inwards or towards each other, and that your heels are in contact with the ground at all times. As they become easier, try and add a light jump on the way up to work on landing correctly as well. Jumping and landing should look exactly like doing the squat above, keeping your knees apart.
If you have any health concerns, always check with your doctor before beginning a new exercise routine. Learn more about ACL injury prevention.