MCL Injuries

The medial collateral ligament (MCL) of the knee is a thick ligament found along the inside of the knee. Connecting the femur and the tibia this ligament stabilizes and limits the sideways motion, or “opening” the inside, of the knee joint.  The MCL is one of the most common knee injuries in competitive and recreational sports and can occur from impact in contact sports or from non-contact circumstances. MCL injuries can occur alone or in combination with injury to other ligaments of the knee.

Mechanism of Injury:

  • Any Valgus stress to the knee (Force applied to the outside of the knee, or combination of outside force and outside rotation force to the knee, or falling to the side with the foot firmly fixed)
  • The knee is usually partially flexed


Signs and Symptoms: 

  • Feel a “pop” in the knee (could be torn ligament)
  • Feel the knee shift (could be significant torn ligament)


There are 3 degrees of sprains to the MCL:


1st Degree: few ligament fibers are injured

  • Local tenderness and pain to the medial aspect of the knee
  • None or minimal swelling
  • Negative joint laxity to valgus stress test at 30 degree knee flexion but pain is apparent

2nd Degree: damage to ligament fibers but ligament is not completely torn

  • Local tenderness and pain to the medial aspect of the knee
  • Some swelling
  • Positive joint laxity to valgus stress test at 30 degree knee flexion but there is still a visible end point to lateral joint movement indicating the ligament is still attached
  • Knee is stable when fully extended

3rd Degree: full tear to the ligament

  • Local tenderness to the medial aspect of the knee
  • Knee is unstable and will “open” medially when valgus stress test at 30 degrees is applied with no distinct end point
  • Knee has difficulty going into full extension
  • The lateral meniscus may also be injured along with the anterior cruciate ligament (ACL)
  • Swelling will occur


On-Site Management:


PROTECT the area from further injury by avoiding exercises that produce pain. A neoprene sleeve, brace or taping technique can be used to support the MCL and weight bearing should be avoided.

REST: cutting back on the amount of training can be difficult, but key to recovery. Gradually return to any running or agility exercises with guidance from a therapist.

Place ICE on the inside of your knee for 10-20 minutes every 1.5 to 2 hours for the first 2 to 3 days or until the pain goes away.

COMPRESS the area by using a knee wrap with a compression bandage. This helps decrease swelling and bleeding. A hinged knee brace can allow the patient joint support and compression during the initial rehabilitation period which is usually 4-6 weeks in duration.  The level of bracing needed should be recommended by the therapist as knee braces available range in levels of support.

ELEVATION is important to encourage blood flow to the heart for healing.


Medical Referral and Rehabilitation:

When any degree MCL sprain it is important that the athlete seeks medical attention. A doctor may prescribe anti-inflammatory medication to help with pain and swelling. The athlete should be a certified therapist who can provide rehabilitation treatment and monitor the athlete’s return to play.


Most treatment and rehabilitation plans include:

  • Increasing flexibility in both flexion and extension
  • Cryotherapy and electrotherapy to promote healing
  • Manual therapy to assist in healing and range of motion
  • Gait re-education and patient education
  • Monitored exercises to gain strength, proprioception through neuromuscular retraining, sport specific movements and flexibility
  • A knee brace to control your joint movement.
  • Strengthening the quadriceps, hamstrings, VMO, calf, abductors and adductors are all important to strengthen as they aid in the ligaments abilities to stabilize the knee joint
  • Walking will progress to jogging, biking or swimming before progressing to agility movements and sport specific movements such as cutting, hoping and changing direction


Specific protocol including rehabilitation treatment techniques and timelines will alter depending on the degree of injury.   Crutches and/or a brace may be recommended initially post-injury but as rehabilitation progresses they will no longer be needed.



Although MCL strains through a severe force to the later aspect of the knee may be inevitable there are precautions athletes can take to avoid sustaining an MCL injury.

  • Balancing Exercises. Your workout routine should include any activity that challenges your ability to balance and keep your balance this initiates the proprioceptive mechanisms surrounding the knee to activate muscles involved in stabilizing the knee to control joint movement and avoid injury
  •  Stretch and Strengthen. To prevent a MCL injury, it is important that your muscles around the knee are well conditioned for your sport. This includes working on the strength and flexibility of all your muscles that make up your leg.
  • Footwear. A good pair of training and competition shoes will help to keep your knees stable. They also provide the necessary cushioning and support that your knees and lower leg needs during running.
  • Strapping. For an added level of support and stability strapping and taping can help weak and injured knees feel more stable.  These support mechanisms should not be solely relied on.
  • Technique.  Ensuring that proper biomechanical techniques both in running and sport specific movements are taught and followed can help to prevent MCL injury



Contributions by Nicole Cook


Brukner, P. and Khan, K. Brukner and Khan's Clinical Sports Medicine Brukner, P. and Khan, K. (2007) Brukner and Khan's Clinical Sports Medicine. 4th ed. North Ryde: McGraw-Hill.


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