MCL Sprain.

An MCL sprain is one of the most common injuries to the knee. This post will teach you about how the MCL works, how to manage an injury as well as the outcomes to your injury.

Anatomy Of The MCL

The MCL is one of four primary ligaments that stabilize the knee. It resists valgus force at the knee. The MCL accounts for 40% of all knee sprains.

Valgus force to the knee causes an MCL sprain.

The MCL provides the most active stability between 25-30 degrees of knee flexion (source). This matters when it comes to the evaluation when doing a valgus stress test. If there is pain/laxity at full extension it is a joint capsule injury. If there is pain/laxity at slight knee flexion, it is an MCL injury.

What Causes An MCL Sprain

The MCL is injured in 2 ways:

  1. Non contact valgus collapse (knee buckles)
  2. Valgus force from the outside of the knee (interior offensive lineman falls onto a teammate’s knee)

When it comes to the MCL in isolation, contact injury is usually worse for an MCL sprain.

However, the MCL is usually not injured in isolation. Any type of sprain to the MCL increases the load on the ACL, leading to a higher risk of injury to the ACL. Read more about ACL sprains here.

The MCL also attaches to the medial meniscus. Learn how to assess a meniscus injury here.

Given the nature of the MCL, a meniscus and ACL injury need to be ruled out as an MCL sprain usually comes with additional trauma.

How To Prevent An MCL Sprain

For athletes, knee braces and taping can reduce the risk. See the video below for knee bracing

Tape job for an MCL sprain

Another prevention/management technique for an MCL sprain is to tape the MCL. This works similarly to a knee brace. This technique artificially shortens the MCL, taking stress off the ligament

Nothing can be fully prevented but risk can be reduced

MCL Healing Times

Recovery time. General guidelines, can vary person to person:

  1. Grade 1 – 3-10 days
  2. Grade 2 – 2-4 weeks
  3. Grade 3 – 4-8 weeks
Grades of an MCL sprain.

The MCL has extremely good blood flow As such, it heals quickly and reliably. For this reason, surgery is almost never needed (I personally have never had an athlete need surgery for an MCL)

MCL Sprain Treatment

The goal is to restore ROM as soon as possible

See the early knee ROM guide here

Once ROM is restored, strength is the goal

Any way you can load the knee, you will strengthen it

The VMO provides some dynamic stability to the MCL. While you cannot completely isolate it, you can bias it some

For some knee strengthening exercises, see the guide here.

See below for a full 6 week knee rehab program.

In summary, an isolated MCL injury will heal very reliably with conservative rehab

  • Restore ROM
  • Get strong
  • Add in plyometrics