Why does the outside of my knee burn after 5 km?

Why it starts at the same point every run

The iliotibial band is a thick strip of tissue running down the outside of the thigh to just below the knee. As you run, the knee bends and straightens thousands of times, and the band compresses the sensitive fatty tissue over the bony bump on the outside of the knee, especially at around 20 to 30 degrees of bend.

Early in a run this is tolerated. Once enough repetitions build up, the area becomes irritated and pain switches on, often at a very consistent distance or time. Many runners say it feels like it is burning or stabbing, and that it forces them to stop or walk.

Common triggers

Look back at the weeks before it started:

• A sudden jump in weekly distance, often while training for a race
• More downhill running or stairs
• Always running the same direction on a track or a cambered road
• New shoes, or very worn ones
• A long ride on a bike set up too low
• Weak or tired hip muscles, so the knee drifts inwards

What to do now

Reduce running to a level that does not provoke the pain, rather than pushing through it. Short, flat runs on alternate days, or swapping to swimming or cycling for a week or two, often helps. Start hip and glute strengthening, and ice the outside of the knee after activity if it is sore. Check your shoes and route.

Running through the burn usually makes it last longer.

When to see a knee surgeon

Book an assessment if pain is present when walking or at rest, the knee swells, locks or gives way, the pain followed a twist rather than gradual build-up, or it has not improved after six to eight weeks of sensible changes. These features suggest something other than, or as well as, the IT band, such as a lateral meniscus tear.