Otherwise known as Iliotibial band syndrome or Friction syndrome, Runner’s knee is a common condition in distance runner.
The problem is a pain on the outside of the knee over the kneecap and to the side. It is often difficult for patients to be specific about where they feel it. It is an achy sort of pain that builds up when running – more often sore to start. It can ease up as you run only to be sore later after you have stopped, especially after sitting for a bit then trying to bend the knee.
There is sometimes a small bit of swelling but not a lot. The knee feels stable but can be sore to fully bend. The knee cap often feels tight and ‘odd’, as if it is not running freely.
Rest does not help in all but the most inflamed cases.
The outside of the thigh has a tight structure called the Ilio-tibial band (ITB) which stretches from the top of the hip to the top of the shin bone and to the outside of the kneecap. As it passes over the outside of the bottom end of the thigh bone it rubs against the ‘knuckle’.
The ITB is made of fibrous elastic tissue and its job in life is to act as an elastic band. When the leg goes behind you it tightens and as the foot leaves the floor the elasticity helps to swing the leg forwards. It adds to the efficiency of our walking/running. However, it can also cause problems, especially if it is allowed to get too tight. In the case of Runner’s knee, the tightness increases the rubbing effect on the outside of the femur and this leads to inflammation and pain. There is a bursa or a fluid filled sack between the ITB and the bone which is there to absorb the friction but it can only cope with so much. Each time we take a step the ITB passes over the bone as the knee bends through around 20 degrees. Roughly there are 2000 steps to a mile, so the friction soon adds up.
The ITB can become tight for a number of reasons. Sitting is a good way, cycling another. Prolonged periods with the hip flexed essentially. Other issues are problems around the pelvis with the Sacro-iliac joint, hip joint issues which affect the motion and direct trauma which makes the band less elastic. If you see a Physio all these things should be checked out.
This is something we see a lot of and find is poorly diagnosed and treated. There is a lot that can be done so get it seen!