Knee Injuries – Part 1

If you train in BJJ or submission grappling, you will most likely sustain a knee injury at some point in time. If you train in BJJ or submission grappling, you will most likely sustain a knee injury at some point in time. Since the very nature of BJJ and submission grappling is to place your opponent in joint locks, it’s not a matter of will you injure your knee, it’s a matter of when. The knee is very susceptible to sprains and damage to the cartilage. In Part 1, I’ll cover two of the most common knee injuries occurring in combat sports – the ACL sprain and MCL sprain.

The ligamentous injuries that occur during grappling and BJJ movements are usually the result overeager novices or simply mistakes during the heat of competition. Sprains are injuries to the ligaments, which are the connective tissues that attach bone to bone like the anterior cruciate ligament (ACL) and medial collateral ligament (MCL). Since ligaments have very poor elastic properties any damage will usually be partial tearing or complete rupture of the ligament. These types of injuries are usually accompanied by a popping sensation followed by immediate pain – you will know when you tear a ligament simply by the sound and subsequent pain.

The ACL is a ligament that prevents your leg from shifting forward on the thigh (it prevents hyperextension of the knee). The knee bar specifically puts strain on the ACL, and if a competitor does not tap out there is strong chance for damaging the ACL. Another common mechanism for ACL injury is getting you knee hyperextended from standing and pivoting while resisting a single leg shoot.

One of the first symptoms of an ACL rupture is a loud pop followed by pain and swelling in the knee joint. The knee will feel very unstable and you will have difficulty walking. A competent sports physician should be able to diagnose a complete ACL tear, but an MRI is necessary to determine whether it is a grade I, II, or III sprain. A grade I sprain involves pain with minimal damage to the ligament. Grade II sprains involve more ligament damage along with mild laxity (looseness) of the knee joint. A Grade III sprain involves complete tearing of the ligament with instability at the knee.

If you sustain a complete tear and your desire is to continue training and competition, you will eventually need to have an ACL repair performed. Since the ACL does not heal itself, the surgery involves reconstruction using tendons or ligaments from another part of your leg or a cadaver. The good news is that your knee will be just as good as new once you have the surgery performed, but it is necessary to do the appropriate physical therapy and rehab post-surgery.

The medial collateral ligament (MCL) is located on the inside of your knee and holds the thigh and leg together. This ligament is often injured by a hit to the outside of the knee accompanied by twisting motions. If you sprain or tear your MCL you will feel pain on the inside of the knee, there may be some swelling, and your knee may feel unstable. Fortunately, most complete MCL tears rarely need surgery and recover nicely after appropriate rest and rehab. Preventing ACL and MCL injuries from occurring is a difficult task to accomplish because these injuries simply just happen – they are accidents. If you have any previous knee injuries and your knee feels unstable or “loose”, wearing a brace may be beneficial. It’s also important to get in the gym to do strengthening exercises for the quads and hamstrings. If you’re lacking flexibility, then a good stretching program may help reduce the chances of injuring any ligaments in the knee. As a rule, you should be able to return to competition when you can drill without pain. If pain and swelling persists, your knee feels unstable and gives out regularly, or you can’t fully flex or extend the knee without pain, then it’s time to get it checked out. For more info on ACL or MCL injuries, you can log onto the forum at and ask Doc.

Contact info: Dr. John H. Park, D.C., C.S.C.S.Progressive Spinal & Sports Rehab10076 Darnestown Road Suite 200Rockville, MD 20850www.ProSpineRehab.comwww.yourMMAdoctor.comPhone: (301) 294-5101

Dr. Park is a chiropractor specializing in sports medicine and orthopedics. He is also a BJJ blue belt under Mike Moses/Lloyd Irvin ( and continues to train and compete in BJJ.

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Dr. John H. Park