Lateral (outer) knee pain
- Mr Damian McClelland, Trauma and Orthopaedic Consultant, and Clinical Director for Musculoskeletal Services at Bupa
- Rachael Mayfield-Blake, Freelance Health Editor
Outer knee pain (lateral knee pain) is pain on the outer side of your knee. That’s the right side of your right knee, or the left side of your left knee. It might just affect your knee or the pain may spread up your thigh.
Types of outer knee pain
There are several health conditions that may cause outer knee pain.
Iliotibial band syndrome can develop if a band of connective tissue rubs on the outside of your knee. The iliotibial band is a thick band of fibrous tissue that runs from your hip to below your knee on the outside of your leg. If you bend and straighten your leg a lot, it can cause this tissue to become sore and inflamed where it passes over the bottom of your thigh bone and meets your knee. This type of problem is common in runners and cyclists.
Lateral collateral ligament injury happens when the outside (lateral side) of your knee is stretched, which injures the ligament. This is caused by a blow to the inside of your knee. A ligament is a band of tissue that connects one bone to another. The lateral collateral ligament runs down the outer side of your knee.
Meniscal tear is damage to the meniscal cartilages inside your knee. These cartilages act like shock absorbers and may tear when you twist your knee with your foot still on the ground. This type of injury is common in sports where you have to change direction suddenly – for example, football and skiing. It can also happen in jobs that involve lifting and twisting, such as construction or manual labour. The meniscus can also tear without any particular injury as you get older because of wear and tear.
Anterior cruciate ligament injury is overstretching or tearing a ligament that runs across your knee from your thigh bone to your shin bone. A tear may be either complete or partial. The injury happens suddenly if you twist or rotate your knee. It can happen if you suddenly slow down, stop or change direction and is nearly always linked with sports.
Osteoarthritis of the knee is a common cause of knee pain. The smooth, shiny cartilage that covers the bones in your knee joint becomes worn and rough. This causes pain and damages your knee over time. It mostly affects people over 50. The older you are, the more likely you are to get it.
Causes of outer knee pain
Outer knee pain may be caused by a number of things. For example, you may have some damage inside your knee or swelling of a band of fibrous tissue that runs down from your hip to your knee. These things may happen because you:
- have a sports injury
- overused your knee during exercise
- are older
Outer knee pain is more common if you:
- are a distance runner or run a long distance each week
- are an inexperienced runner or suddenly increase the distance and frequency of your runs
- cycle
- have an injury that pushes your knee outwards (away from your other leg)
- do activities that involve twisting your knees or squatting
- are ‘knock-kneed’ or ‘bow-legged’, both of which place a strain on your outer knee
Symptoms of outer knee pain
The symptoms of outer knee pain will vary depending on the type of injury you have. Outer knee pain may feel dull and your knee may ache, or the pain can be sharp and limited to one area. You may have swelling from fluid that collects, or your knee may click or lock (get stuck in one position).
If you have iliotibial band syndrome, you may have pain all over the outside of your knee or the pain may be sharp and in one area. If your injury is mild, you might notice the pain come on after a certain time or distance when you’re running, for example. And it may get better when you stop. If your injury is more severe, it might be painful to walk or even sit with your knee bent.
If you have a lateral collateral ligament (LCL) injury, the outside of your knee will be painful. Your LCL helps to keep your knee stable, so you may feel as if your knee is going to give way. You may have swelling around your knee or have pins and needles in your foot. You might find the pain is worse when you walk or run on uneven ground.
Symptoms of a meniscus tear include pain and your knee may feel stiff, and lock or catch. There may be some swelling that may gradually get worse and you may find it difficult to fully straighten your leg.
Pain from an anterior cruciate ligament injury will be sudden and you may hear a pop. Your knee is likely to swell from internal bleeding and may feel as if it’s going to give way.
Osteoarthritis usually causes pain when you bear weight on it, and gets better when you rest. Your knee may be stiff and you might not be able to move it as well first thing in the morning (but for no longer than 30 minutes), or after you sit for a while. This usually eases once you start moving around. You may also have some swelling in your knee.
Diagnosis of outer knee pain
Your doctor will examine your knee and ask about your medical history and symptoms, including:
- the type of pain you have, when it started and if it comes and goes
- how active you are
- any activity, accident, or injury that could have caused it
They may suggest an X-ray or a magnetic resonance imaging (MRI) scan, but this isn’t always necessary. Your doctor may be able to diagnose the injury from examining you and asking about your symptoms.
If you have cartilage or ligament damage, your doctor may suggest a procedure to look inside your knee. This is called an arthroscopy (keyhole surgery). Your doctor will make a small cut in your knee and pass a thin tube with a camera on the end through the cut. As well as diagnosing the problem, your doctor can also repair or remove damaged tissue.
Self-help for outer knee pain
There’s a lot you can do to help yourself if you have an outer knee injury. It’s a good idea to follow the POLICE procedure.
Protect. Protect your injury from further damage. Rest immediately after the injury but not for long. Consider using some form of support or crutches.
Optimal Loading. Get active sooner rather than later. Start to put weight on your knee and build up your range of movement. Do this gradually – be guided by what feels right for you.
Ice. Place a cold compress such as a bag of ice or frozen peas wrapped in a towel onto your knee. Do this for around 20 minutes every couple of hours for the first two to three days.
Compression. Compress your knee using a bandage to help reduce swelling.
Elevation. Elevate your knee above the level of your heart to reduce swelling. Sit or lie on a chair and use a cushion to raise your leg.
Infographic: POLICE principles
Bupa's POLICE infographic (PDF, 0.5 MB), illustrates the ‘POLICE principles’ to reduce your pain and help you to recover. Click on the POLICE image below to download the PDF.
And there are certain things you should avoid in the first three days after your injury so you don’t damage your knee further. These can be remembered as HARM, which stands for the following.
H – Heat. Don’t have hot baths, showers or saunas, and avoid heat packs and rubs.
A – Alcohol. Drinking alcohol can slow down your recovery and mask your symptoms – increasing the risk that you’ll injure yourself again.
R – Running. Don’t run or do any other form of moderate exercise.
M – Massage. Massaging the affected areas can cause more swelling and damage, so avoid this for the first day or two.
Infographic: HARM principle
Bupa's HARM infographic (PDF, 0.6 MB), illustrates the ‘HARM principle' of things you should avoid doing in the first three days after your injury. Click on the HARM image below to download the PDF.
Both of these are measures you can take to treat any type of soft tissue injury to your knee.
Try to keep your joints moving unless it is painful to do so.
If your injury is mild, you may not need to see a doctor or physiotherapist. But do go and see a doctor or physio if:
- you can’t put weight on your affected leg
- you have severe pain even when you don’t put any weight on it
- your knee buckles or painfully clicks or locks
- your knee is hot, red, very swollen or you have a fever
Treatment of outer knee pain
Treatment for outer knee pain will depend on what condition is causing the pain.
For information on how to treat outer knee pain, please see the relevant page for each type of knee condition. For example, treatments for:
Looking for physiotherapy?
You can access a range of treatments on a pay as you go basis, including physiotherapy.
To book or to make an enquiry, call us on 0370 218 6528∧
Your knee may hurt if you have damage inside your knee or because of swelling of tissue that runs from your hip to your knee. It usually happens as a result of a sports injury or overusing your knee during exercise, or just as part of getting older.
See our causes of outer knee pain section for more information.
The way you treat outer knee pain depends on what’s causing the pain. You may need some physiotherapy, for example, to help strengthen your knee and leg muscles. Or you may need surgery or just medicines to help with the pain.
See our treatment of outer knee pain section for more information.
If you have lateral collateral ligament (LCL) pain, the outside of your knee will be painful. It might feel like it’s going to give way too. Your knee may be swollen, and you may have pins and needles in your foot. The pain may be worse when you walk or run on uneven ground.
See our symptoms of outer knee pain section for more information.
With the right treatment for an iliotibial band (ITB) injury, most people recover and can go back to sports or running within six to eight weeks.
See our self-help for outer knee pain and treatment for outer knee pain sections for more information.
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This information was published by Bupa's Health Content Team and is based on reputable sources of medical evidence. It has been reviewed by appropriate medical or clinical professionals and deemed accurate on the date of review. Photos are only for illustrative purposes and do not reflect every presentation of a condition.
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- Soft tissue knee injury. Medscape. emedicine.medscape.com, updated 18 August 2021
- Iliotibial band syndrome. BMJ Best Practice. bestpractice.bmj.com, last reviewed 2 October 2023
- Knee pain. Patient. patient.info, last edited 16 February 2022
- Knee ligament injuries. Patient. patient.info, last edited 16 August 2022
- Ligament. Encyclopaedia Britannica. www.britannica.com, accessed 31 October 2023
- Knee joint anatomy. Medscape. emedicine.medscape.com, updated 30 November 2017
- Assessment of knee injury. BMJ Best Practice. bestpractice.bmj.com, last reviewed 2 October 2023
- Knee sprains and meniscal injuries. MSD Manuals. msdmanuals.com, reviewed/revised July 2023
- Meniscal tear. BMJ Best Practice. bestpractice.bmj.com, last reviewed 2 October 2023
- Anterior cruciate ligament injury. BMJ Best Practice. bestpractice.bmj.com, last reviewed 2 October 2023
- Knee pain. Versus Arthritis. www.versusarthritis.org, accessed 27 October 2023
- Osteoarthritis. BMJ Best Practice. bestpractice.bmj.com, last reviewed 2 October 2023
- Osteoarthritis. NICE Clinical Knowledge Summaries. cks.nice.org.uk, last revised October 2022
- Hadeed A, Tapscott DC. Iliotibial band friction syndrome. StatPearls Publishing. www.ncbi.nlm.nih.gov, last updated 23 May 2023
- Raj MA, Bubnis MA. Knee meniscal tears. StatPearls Publishing. www.ncbi.nlm.nih.gov, last updated 17 July 2023
- Overview of sprains and other soft-tissue injuries. MSD Manuals. msdmanuals.com, reviewed/revised July 2023
- Knee soft tissue injury (ACL, LCL, MCL, PCL) management in the ED. Medscape. emedicine.medscape.com, updated 18 August 2021
- Yaras RJ, O'Neill N, Yaish AM. Lateral collateral ligament knee injury. StatPearls Publishing. www.ncbi.nlm.nih.gov, last updated 20 May 2022
- Lateral collateral knee ligament injury. Medscape. emedicine.medscape.com, updated 30 November 2020
- Knee pain – assessment. NICE Clinical Knowledge Summaries. cks.nice.org.uk, last revised August 2022
- Orthopaedics. Oxford handbook of operative surgery. Oxford Academic. academic.oup.com, published May 2017
- Bezuglov E, Khaitin V, Shoshorina M, et al. Sport-specific rehabilitation, but not PRP injections, might reduce the re-injury rate of muscle injuries in professional soccer players: A retrospective cohort study. J Funct Morphol Kinesiol 2022; 7(4):72. doi: 10.3390/jfmk7040072
- Knee ligament injuries. Patient. patient.info, last edited 10 February 2023
