What is runner’s knee?

Runner’s knee is an umbrella term for repetitive stress injuries that commonly occur at the knee. Here physiotherapist James Bainbridge explains those injuries and details their causes and prevention

Man running with bad knees

Runner’s knee is not a singular condition, but rather an umbrella term for repetitive stress injuries that commonly occur at the knee as a result of running. The two most common types of runner’s knee are iliotibial band syndrome (ITBS) and patellofemoral pain (PFP).


What are the causes of runner’s knee?

The causes of runner’s knee, with either condition, are very similar. The most common cause of runner’s knee, along with any running injury, is training error. Training error accounts for up to 60-80% of all running injuries. This can be an error in your training frequency, intensity, variability of training, adequate rest or cross training.

Other than training error, causes for runner’s knee include muscular weakness, muscular tightness, your natural biomechanics, your running gait and footwear.

What are the symptoms of runner’s knee? And how does ITBS differ to PFP?

The leading symptom that people with runner’s knee present with is pain, however a key difference between ITBS and PFP is the location of this pain. The iliotibial band (a thick strip of fibrous tissue) runs down the outside of the leg from the hips top the knee. In ITBS, the pain is typically on the outer aspect of the knee or outer thigh, whereas in PFP the pain will be more central.

Pain in runner’s knee is usually described as dull and achy at rest, but much sharper and intense on activity. The common activities that trigger runner’s knee pain are running, stairs (with down typically worse than up), squatting, sitting with legs crossed, and jumping. In runner’s knee, the pain is often quite specific to a location at the knee and can be easily pointed to.

Less common symptoms in runner’s knee include swelling, bruising, heat and feelings of weakness/giving way in the knee.

What is the treatment for runner’s knee?

Prior to treatment, diagnosis of the cause of your runner’s knee is important. Although similar in symptoms and causes, your treatment will differ depending on whether you have an ITBS runner’s knee or a PFP runner’s knee. Diagnosis is best determined by a physiotherapist, who will initially take a detailed history of your symptoms and goals, followed by a physical exam of your knee among other structures.

Once your runner’s knee has been identified, treatment will typically consist of a tailored exercise programme targeting the strengthening of weak muscles and the lengthening of tight muscles. Alongside your exercises, manual therapy such as massage and acupuncture may be beneficial for reducing pain and facilitating a return to activity.

When discussing the history of your symptoms and your current physical activity schedule, you may also be encouraged to adapt your training mileage, intensity or type of training while you recover from your injury. Your physiotherapist should be on hand to help you build your running back up while simultaneously improving your symptoms and relieving pain.

Going through a detailed gait analysis can also be helpful, not only to the diagnosis but also the treatment of your injury. By seeing how you run, your physiotherapist can identify any issues with your running gait, not just at the knee but also at the hip and ankle, which can be a factor in your injury. Your running gait will help tailor your exercises to you, and you may also discuss visual or verbal cues to help you consciously improve your running style and performance.

What’s the prognosis and likelihood recovery from runner’s knee?

With runner’s knee, prognosis is very variable. With most repetitive strain injuries, the longer you wait to do something about it, the longer it typically takes to improve. The pain of a runner’s knee can ease up quite quickly, especially if a recent injury; however, in more persistent cases of runner’s knee the pain can take longer.

Pain relief from massage or acupuncture can be quite fast in some people, however to treat the primary issue usually will need muscular strengthening to occur. For tissue adaptation to occur, that is for the muscles to respond and change as a result of your exercises, it can take between 6-8 weeks. This will depend on a variety of factors, such as the duration of your pain, how often you do the exercises and your starting muscle strength.

How can you prevent runner’s knee?

Prevention of runner’s knee is all down to your training and the way in which you condition yourself for running. My top tips for preventing runner’s knee are:

1. Track and monitor your runs. When progressing mileage, you shouldn’t look to progress by more than 10% of your total weekly mileage each week. For example, if you’re running three times a week for a total of 12 miles, your 3 runs over the next week should not exceed 13.2 miles. With technology and GPS software, it’s never been easier to break down and track your running distances to ensure you gradually build up your running in a way in which your body can keep up.

2. Diversify your training. While running is a great activity for your cardiovascular system, running alone doesn’t do wonders for increasing your global muscular strength. By adding strength and conditioning such as squats and deadlifts into your programme, you can ensure that the muscles and other structures associated with runner’s knee are strong enough to keep up with your running. In addition, there’s good evidence to suggest that adding other cardio once a week, such as swimming or cycling, into your training can diversify the load placed on your muscles and therefore reduce the likelihood of a repetitive strain injury such as runner’s knee.

3. Rest up! In today’s world, less and less importance is placed on getting a good night’s sleep, but the benefits of getting adequate rest are hugely important in injury prevention. Research shows that sleep is important for bone strength, maximum muscle contraction, concentration, mood, general health and muscle energy storage. Typically, we perform best on 7-9hrs a night, however in the athletic population there are recognised benefits of sleeping 8-10hrs per night.

How to prevent runner’s knee, and four exercises to treat it

If you have any concerns at all, like with any health issue, seek medical advice from a qualified medical practitioner, whether that’s a doctor or physiotherapist.   

James Bainbridge is a senior physiotherapist with Capital Physio

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Image credit: Getty Images/Mikhail Druzhinin /EyeEm