How to Unlock a Locked Knee

What is Locked Knee?

A locked knee is a knee that cannot be bent or straightened — i.e. it is completely stuck in position and cannot be moved whether due to pain or a mechanical block. It may temporary (i.e. may resolve spontaneously or with the maneuvering of the leg) or permanent. 

Understanding the anatomy of the knee may help you to better understand this article. See our related articles on knee joint function (physiology) and structure (anatomy).

What causes a knee to lock?

The most common causes of knee locking are as follows:

Knee Pain

You may perceive that your knee locks up because it becomes suddenly painful. In this situation, there is not a true mechanical block, per se, but your motion becomes limited secondary to severe pain i.e. your body doesn’t want to cause you more pain so it reflexively prevents motion. 

While this is most common in the setting of painful arthritis, there are many causes of knee pain. These include: 

  • Knee trauma – e.g. fracture, dislocation, infection (arthritis, tendonitis, bursitis), or tendon tear, sprain or strain
  • Knee arthritis – may cause swelling, pain
  • Plica syndrome – Plica is the tissue the lines the inside of the knee. It can sometimes become injured or inflamed, which results in pain. 

Loose Bodies 

Loose bodies (or joint mice) are small or large fragments of cartilage or bone within the knee joint that can move or float into a position within the knee that causes it to become locked in a certain position.

Loose bodies may be formed as the result of trauma. 

Torn Meniscus

A meniscus is a disc-shaped structure that acts as as a shock absorber in the knee joint. There are two in each knee joint, a medial (inner) and lateral (outer) meniscus. Menisci are susceptible to damage with certain sudden, twisting, falling, awkward landing movements.

Menisci KneeTears of the meniscus can also cause the knee to lock. When the meniscus is torn, the torn portion can flap into the joint and block motion similar to how a loose body may also block motion. 

What to do when your knee locks:

If your knee locks suddenly and will not unlock, get help and call your physician or go to your nearest emergency department. 

If it locks and your are able to get it to unlock, call your physician to discuss options for treatment or to schedule a visit.

The following information may additionally be helpful when thinking about treatment options for a locked knee.

The work-up of a locked knee

The work-up of a locked knee begins with your doctor asking you questions about any injury that may have started your symptoms and the quality of your symptoms themselves. Your doctor will perform an examination of your knee to give him/her clues regarding your injury.

Regular X-rays may be ordered to look at the bones of the knee to make sure there are no obvious loose bodies, fractures, and to assess the overall alignment of the knee. Depending on your symptoms, an MRI scan may be ordered to get a better look at the soft tissue structures (i.e. non-bony structures) of the knee. An MRI is very good at evaluating the soft tissue structures around the knee, including the menisci and ligaments.  

Your doctor will determine whether your locking is due to a true mechanical lock or pain related (i.e. pseudo-locking — pain prevents movement).

Non-Surgical Treatment of a Locked Knee

The first step in treating a locked knee is to determine the cause of the locking. If the locking is intermittent or due to pain, non-surgical treatments can oftentimes be tried first. 

If knee pain is the cause for a locked knee, the goal of treatment will be pain control and reducing inflammation. Rest, ice, compression, elevation (RICE) and anti-inflammatory medications are typically first-line therapies. 

Knee TreatmentIce can be applied in an on-off fashion for 20 minutes increments to help with pain control and to reduce swelling (if present).  If the knee is swollen, elevation can also help. Elevate the knee and leg on a pillow or cushion so that it rests above the level of the heart. 

Non-steroidal-anti-inflammatory drugs (NSAIDs) or other over-the-counter pain relievers such as Tylenol, Ibuprofen and Naproxen can also help to reduce both pain and inflammation. If these don’t work well for you, your doctor can also prescribe you stronger anti-inflammatory medications. 

Cortisone is an anti-inflammatory medication that can be injected into a painful or swollen joint. This may additionally be an option for you. 

In addition to the above, physical therapy may be beneficial. You will learn exercises, stretches and movements that will help to improve the function of your knee, which may help to minimize pain and inflammation in the knee. 

Surgical Treatment of a Locked Knee

If your knee is permanently locked due to a mechanical block, or you have continued intermittent locking of the knee even after a trial of non-surgical treatments, arthroscopic surgery may be the next step in your treatment.

Knee arthroscopy is a minimally invasive procedure that is performed by inserting a camera and specialized tools into the knee. It allows your orthopedic surgeon to directly see within your knee joint.  Ultimately, it can be used to address multiple issues within the knee. 

How to help someone who’s knee has locked:

If someone you are with has a locked knee, help them to sit or lay down. If they are experiencing pain, consider providing them with an ice pack and something to elevate their leg on (if it is possible to elevate the locked knee). Consider getting them a pain medication (such as Tylenol, Aspirin, Ibuprofen or Naproxen) to take. 

Then assist them to find medical help. Call their physician or consider driving them to the doctor’s office, urgent care, or emergency department. 

Note that the information in this article is purely informative and should never be used in place of the advice of your treating physicians.

Dr. Andrew Chung is a Spine Surgeon at Sonoran Spine in Tempe, Arizona. He is a graduate of the Philadelphia College of Osteopathic Medicine and was formerly Spine Surgeon Clinical Fellow at Cedars-Sinai, Spine Surgery Fellow at Keck Hospital, University of Southern California and Chief Resident and an Instructor of Orthopedic Surgery in the Department of Orthopedic Surgery at the Mayo Clinic in Arizona. Dr. Chung's research.


  1. Hello sir.
    I had meet with an accident in the year 2010. Whrn i consulted the doctor after doing mri scan for left knee the doctor said should undergo the surgery the doctor informed that its a lingament tear in the left side of the knee but its not an emergency later the pain got reduced and was normal.. Accidentally i slipped while climbing the stairs recently. For couple of days there was a pain in the left knee later the pain got reduced but now there is a knee lock in the right side of the left knee while walking.

  2. Zehuman Chazierman says

    When my knee locks up I use the “mulligan techniques” so far it has worked every time my knee locks up.,

  3. Neil McGarva says

    I have a history of damage (ligiament and meniscus) to my knee. it is only occasionally painful when exercising (walking). I am told there is no or very little meniscus left. Ocasionally, i am woken up at night because my body wants to change position but doing so is extremely painful because I have been sleeping in my back with a straight leg and my knee has pseudo locked. Is there anything I can do to stop my knee from pseudo locking if I sleep on my back? Or anything I can do to stop leeping on my back?

  4. Kenny mahungele says

    What is the best medicine that can enable yo loosen locked knees

  5. Hello I have a question I had surgery on my legiment in summer of 2019 and I didn’t show up to my doctor for a follow up 35 days later than furned in months. I still haven’t went in but anyway I rarely did my stretches on straighting my knee would that mean it might be permanently stuck bent now ?. If it is there any way I can get it surgery done on it somehow?. And how much does knee surgerys cost?.

  6. Gary Mccartney says

    Had both knees replaced year and a half apart.
    L knee , no problem. R knee , 12 weeks pt, knee has not straightened. Can’t mri because of the metal. X ray looks fine, what now…?

  7. I’ve had consistent locked knee for a week since I woke up one morning with a stiff knee. When I went to the doctors several months ago for similar issue, they said”Carpenter’s knee”. But since I’m one to refuses to get on knees outside of bed, I disagree, especially since I have a history with other arthritis symptoms.
    But since this Corona virus is an issue, I don’t look forward to going to hospital. Otherwise I prob would have been there days ago. I have been performing RICE treatment for prob over 20hrs a day since day 1. I have used less ibuprofen than normal (mostly at times when my knee got really swollen and hot). Most of the time it was so hot and swollen, that I could leave a large ice pack on till it became warm- normally it’s too cold for me to leave on directly, for more than a couple minutes before pain from cold kicked in. But quite often I would forget it was on, due to discomfort at all.
    It’s still swollen, a lil less so I think. But still can’t bend, still feels like the stretchable part isn’t stretchable any more. There’s not much pain to the touch, only sharp pain is off I don’t support it, causing it to bend.

  8. I hyperextended my knee over 4 years ago. 2 years ago I went to a specialist, told him I could not straighten my knee, not bend it without pain. Never told me I had a lock or a bakers cyst. Gave me a brace that still allowed me to straighten it( ouch!!!). Fast forward 2 years later. One day I had a BIGGER lock, same knee. 9 days later, BOTH came out! Stuck with knee 1 inch from straight, 1 inch away from bent. Forever. Now other knee cartilage is totally gone. Bakers cyst there now too😑I have no choice but to go back to same ” specialist”.

  9. Monica Lonigan says

    I vegan having PT on my left due to it locking up. I was able to walk and move around after my third session with PT – I was sitting with my husband at his doctors office an my knee locked up. Making unbearable to stand, pivot, or walk.
    Using the bathroom is a struggle since I can’t walk
    The pain is so ugly that I can’t hello but break down an cry.
    How long will a knee stay locked?

  10. Bo Whiteford says

    Dear sir, I am a 17 year old boy and over the last two years my knee locks about once every two months. But it only locks when I am sitting in a chair. This comes with extreme pain and I need somebody to assist me to un-lock it. After it is unlocked it is only sore for a couple of days than it is fine. I have gotten both an mri and an X-ray and both have come out perfect. What do you think it is?

  11. I have had locked knees on LT & RT knees on and off since few months ago. However, my left knee is locked since last week. X ray is done and awaiting for MRI. Emotionally I’m not doing well also, because unable to be active like before 😌, any advice?

  12. My right knee started locking about a year ago and has got worse since. Seems to be mostly when sitting in a hard chair. As soon as I get up, my knee won’t straighten out for a min to several min and there is some pain associated with it. Sometimes kneeling down on that knee, (not thinking), I either need something to pull myself up or sometimes even need to roll on the ground to straighten it out before getting up. As soon as it straightens out, I can walk on it and the pain goes away. Long hikes, (6-10 miles), or steep hill climbing tend to make it burn while my left knee doesn’t like the downhill, causing a burning pain after a short steep downhill. I did a lot of foolish things growing up, (jumping off high things), and maybe this is payback. I am late 50’s now but still weigh around 160

  13. I have a lock knee 12 yrs ago already due to surgery.I was diagnosed of chronic inflammation. After 5mons of rest we tried to undergo physical therapy in 3months but since no improvement,till now I’m suffering for movement difficulties.sometimes this already permanent,is this still have a remedy to bent.. 🙁please give me some advice..and thank you in advance☺️

  14. Annette Williams says

    My knee locked for 5th time in 3 weeks …staying locked for longer and in nasty pain. This time from 11 pm last night and is still locked. Going to A & E tomorrow as can’t literally stand any more.

  15. Dear Sir, I keep having locking of the knee, 6 times in the last 6 months, The pain is intense, it last for 10 hours or more. I have been to an orthopedic surgeon who has sent me for physio, also had acupuncture, but I am still having the problem. I exercise every day. I have a tear to the meniscus. I wonder what you recommend to do.

  16. Maria Faulkner says

    IHave Knee Injections,P Therapy, And Aqua Therapy,Pain Medication’s Of All Kinds My Left Kee Is Looked As Of 3/11 To This Present Day..I Want Out Of This Power Chair. And To Walk Again. I Live In Chicago IIinois What Do I Do To Get Back To Walking? Ortho Scopic Done On Right Knee Over 20+ Year’s Ago Arthritis But Can Stand And It’s Not Locked. Please Help Me With Some Advice.Thank You.

  17. Tania Cannavo says

    my son (who is 14yrs old) has a knee that locks it is accompanied by alot of painbut no swelling. He has had this problem since he was about 6yrs old, initially it used to stay locked for 10 minutes or so but recently the locking time has increased to between 45minutes and in one case over an hour at school where they had to call the ambulance who gave him gas and it eventually unlocked. The doctors have sent him for physiotherapy and then a foot doctor, but they have never x rayed or scanned his knee. It’s reached the point where he doesn’t like physical activity and is very fearful that it will happen in public( so doesnt like to go on school trips etc just in case) as the pain is so bad that he actually cries. what can we do to help him?

  18. Jorge Thomas says

    Dear Sir, I have been in a accident a year ago. Broke my leg just under the knee and have had operation and some screws. The doctor told me that they have removed some bones fragments , and since I can’t bend my knee or stretch 100% . They recommend knee prosthesis but I am to young for prosthesis. I am worried about since I can’t go back to my training and other activities I am limited to do. Just wondering if there is any other treatment available so I don’t need prosthesis. Kind regards Jorge

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