Injury Without Contact: ACL injuries and what you can do to prevent them

This Fall there have been a rash of season ending ACL injuries in the NFL.  45 injuries in 8 weeks to be exact, and the majority have been non-contact.  In my opinion, injuries of this nature should not occur at the rate they do.  They aren’t always preventable, but you can significantly reduce your chances of an ACL injury with proper off-season and in-season strength-training protocols.

Below are 3 things that will significantly reduce your risk of an ACL injury.

  1. Strengthen the VMO
    The Vastus Medialis Oblique or VMO is the inner, teardrop shaped Quadriceps muscle that crosses the knee and is essential for stability of the joint.  If VMO strength is in balance with the rest of the quadriceps, the kneecap will be able to track properly.  Furthermore, by strengthening the VMO you can expect an increase in sprinting and jumping ability.  You can strengthen your VMO by performing: Poliquin step-ups, Petersen step-ups, VMO sled drags, Split Squats, and Full Squats.
  2. Improve ham to quad strength ratio
    Hamstrings act as dynamic stabilizers of the knee.  If the hamstrings aren’t strong enough the knee joint can experience significant shearing forces, such as when the lower portion of the leg is fixated into the ground and the upper portion of the leg is forced forward.  You see this occur during non-contact ruptures in sports when a player suddenly falls to the ground after making a cut or jump.  Most physical therapists recommend a hamstring-to-quadriceps ratio of 66 percent, meaning that your hamstrings should be able to produce 66 percent of the force of the quadriceps.  If the quads are overdeveloped compared to the hamstrings, shearing forces will occur and a great deal of stress will be placed on the ACL leading to a partial or complete tear.  To achieve structural balance and protect your knee joint, it is important to train both functions of the hamstrings – knee flexion and hip extension – and use proper loading parameters.  As knee flexors, the hamstrings are predominantly fast twitch muscle fibers so using a protocol with a lower rep range (4-6 reps) would be appropriate to create a sufficient overload.  Slightly higher rep ranges should be used with hip extension movements.  Hamstrings work includes Leg Curl variations, RDL’s, Good Mornings, Back Extensions and Glute Ham Raises.
  3. Improve ankle mobility
    Lack of ankle mobility, specifically dorsi flexion, is often overlooked as a culprit to many knee injuries.  Take Derrick Rose of the Bulls for example.  Rose suffered a myriad of injuries toward the end of the ’11-’12 season including a significant ankle sprain before suffering a season ending ACL tear.  After an injury to any joint, such as an ankle sprain, it is common for that joint to lose normal range of motion.  Then slap a brace or ankle tape on and the joint is completely locked up, inhibiting movement.  When there is limited mobility in the ankle, whether it’s from tape, a brace, high top Nike’s or just natural tightness, the body will look elsewhere to create the range of motion needed to complete a movement.  In many cases that happens to be the knee joint which is intended to be a stable joint.  If the aforementioned VMO and Hamstrings strength are not up to par then something will need to give and often it is the ACL.  To ensure optimal ankle mobility especially after an ankle sprain, visit an Active Release Technique (ART) specialist or a Fascial Stretch Therapist in your area.

In-Season training is equally as important as following a properly designed off-season strength program to reduce injury risk.  Training during the season will allow you to maintain your strength levels and address tissue quality for greater mobility.

 An ACL injury can be a major setback to an athlete’s career.  It can even mean an early end your playing days.  Take action now and stay on the field.