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Medial Collateral
Ligament (MCL)


   Hand Out
Fig 1: Knee diagram showing an intact MCL.

The medial collateral ligament (MCL) runs on the inside of the knee from the thigh bone (femur) to the shin bone (tibia) along the inside of the knee joint. The MCL prevents the knee from buckling inward.

Most MCL injuries occur during sports when the knee is forced inward.


Many times injuries can be prevented by maintaining proper strength, conditioning, and body mechanics. However injuries to the MCL are usually a result of medial or inward pressure as a result of contact in sport and can not be prevented.

With a MCL injury patients usually note pain and tenderness on the inside of the knee joint. Pain with full straightening of the knee may occur. Patients also may note feelings of instability and knee stiffness. The MCL runs on the outside of the knee joint so a large amount of swelling in the joint is not common.
MCL injury is classified with Grade I through Grade III injury. Grade I refers to a mild sprain, Grade II moderate sprain and Grade III severe sprain / tear of the MCL.

Non Surgical Treatment
After an acute episode, the patient will be initially treated with RICE (rest, ice, compression, and elevation). A hinged knee brace and crutches may be warranted based on severity of injury and/ or degree of instability. Ranges of motion exercises are important to restore flexibility, and strengthening the quadriceps stabilize the knee joint. Physical therapy can be very helpful.
MRI may be useful to evaluate for any other knee injuries.

Most patients with a MCL injury will do very well with rehabilitation and will not require surgery. Patients who may require surgery will continue with instability despite rehabilitation.

Surgical Treatment
If patients failure to improve after nonsurgical treatment, a surgical reconstruction of the MCL may be indicated. This surgery is done through a small open incision where a new ligament is fixed into place.


The vast majority of patient with injuries tot heir MCL will not require surgery and will be able to fully rehabilitate with nonsurgical treatment and rest.


Strengthening Exercises
All exercises should not cause increased pain or swelling. Work up to at least 3 sets of 20 repetitions, at least 4 days a week. See Fig 2-7.

mcl range of motion
Fig 2: Range of Motion. Advancing motion but straightening
and bending the knee joint.

Fig 3: Quadricepts Isometrics. Lie with leg straight, tighten
quad as you push the back of the knee flat on the ground.
Hold and repeat.

Fig 4: Short Arc Quadriceps. Place a roll or bolster under the knee,
and tighten the front of the thigh while lifting the heel off the floor.
Hold and repeat.

Fig 5: Isometric Quadriceps Strengthening. Sit with knee bent 75- 90 degrees.
Palpate the muscle just above the kneecap on the inside of the thigh (VMO).
Push foot into the floor, tightening the thigh, concentrate on the VMO.
Hold and repeat.

Fig 6: Standing Quarter Squats. Start standing with weight on both legs,
then progress to weight on the affected leg.
Do not bend more that 45 degrees.

Fig 7: Leg Press. These are best done with one leg at a time
always with a low weight and high repetitions.
Do not bend the knees further than 45 degrees.

Fig 8: Stationary Bike and Eliptical machine are lower impact
cardiovascular exercise that promotes strengthening.

Fig 9: Hip Abduction. Lie on the side with weak side on top.
With upper leg straight, lift up leading with the heel
Hold, lower and repeat.

Fig 10: Hip Extension. Lie on your back with knees bent. Raise hips/buttocks off the floor,
keeping the pelvis straight. Start with two feet on the floor progress to one on the floor.

Fig 11: Hamstring Curls. Lie on the stomach, bend knee to 90 degrees.
Hold, slowly return to start and repeat.