Medial Collateral Ligament (MCL) Injury

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Medial collateral ligament (MCL) injury facts

  • The medial collateral ligament is one of four ligaments that help stabilize the knee.
  • MCL injuries are also called sprains or tears.
  • The MCL may be damaged by a direct blow or may be noncontact because of cutting or sudden deceleration or stopping.
  • Sprains can be graded as follows:
    • Grade 1 (Fibers are stretched but not torn.)
    • Grade 2 (Ligament fibers are partially torn.)
    • Grade 3 (The ligament is completely torn.)
  • The medical meniscus and anterior and posterior cruciate ligaments are structures in the knee that are also commonly injured.
  • Diagnosis of medial collateral ligament injury is usually made by the history and physical examination. X-rays and MRI of the knee may be needed.
  • Treatment does not usually require surgery. Physical therapy is recommended to return range of motion of the knee joint and to increase the strength of the muscles that surround and protect the knee.

What is the medial collateral ligament (MCL)?

The knee joint allows the lower leg to flex (bend) or straighten (extend). To make certain that those are the only two motions that occur, there are four ligaments in the knee that help control and protect it.

  • The medial collateral ligament (MCL) is located on the medial aspect of the knee (medial = the closest to the center of the body).
  • The lateral collateral ligament (LCL) is located on the lateral aspect of the knee (lateral = away from the center of the body).
  • The anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) prevent anterior (frontward) and posterior (backward) movement of the knee joint.

Ligaments are tough bands of tissue that span a joint and attach to the bones on each side of it. The MCL is located on the inner side of the knee and is attached to the femur and tibia bones. It holds the knee stable against stress when a force is place on the outer part of the leg that could potentially buckle the knee toward the center of the body.

Picture of the ligaments in the knee joint
Picture of the ligaments in the knee joint

The muscles that surround the knee, especially the quadriceps muscles located in the front of the thigh, and the hamstrings located in the back of the thigh, are also important stabilizers of the knee joint.

Medically Reviewed by a Doctor on 11/4/2015

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Exercises for MCL Injuries

During physical therapy for rehabilitation of a knee injury, the patient will be given specific exercises by the physical therapist in order to strengthen and stabilize the knee joint. These exercises include strengthening the front of the thigh (quadriceps), back of the thigh (hamstrings), calf, and hip.

Some exercises that your physical therapist may recommend include the following:

  • Quad sets
  • Straight leg raises
    • Straight-leg raise to the front
    • Straight-leg raise to the back
  • Hamstring curls
  • Heel raises
  • Heel dig bridging
  • Shallow standing knee bends