HEALTH What is runner’s knee?

PAINFUL?Many factors can contribute to developing patellofemoral pain, or ‘runner’s knee’.

Weak at the knees


Health
Andrew O'Brien

‘I can’t run, it kills my knees’. ‘I wouldn’t do a marathon, you’d end up with arthritis’.
How often have we heard these statements and just accepted that running is bad for the knees? And running on the road? Well, everyone knows someone whose uncle has a whole book full of reasons why you shouldn’t be doing that.
But what is runner’s knee? And is it really something that you will probably just get at some stage if you are a runner?
Runner’s knee
Runner’s knee is so-called because it is common amongst runners. The clinical name is quite self-explanatory as well. Patellofemoral pain syndrome refers to pain coming from the articulation between your patella (kneecap) and femur (thigh bone). There is a large knuckle at the bottom of your femur, with a groove in it. On the back of your kneecap is a slight ridge that should settle into that groove, keeping the kneecap in place and allowing it to run up and down.
If, for some reason, the kneecap doesn’t run smoothly within the groove, the back surface of it will get irritated and become painful. Initially, the pain might only present towards the end of a run. Over time though, it can become quite debilitating, causing pain when walking – especially on stairs, and sometimes even when sitting.
What makes the kneecap start to run off track in the first place? Many factors can contribute to developing patellofemoral pain, including genetic factors such as hip width and patella shape; muscle balance issues; and biomechanical factors – how your body interacts with the ground as you run.
Typically, people who develop patellofemoral pain show weakness and sluggish contractions at the medial quads (the inside of the thigh, just above the knee) and relative tightness at the lateral side, which is thought to allow the kneecap to track laterally. Often the glute muscles are weak, which causes the knee to buckle in slightly when running, changing the angle of the patellar groove.
It has been claimed in the past that overpronation, or excessive flattening of the feet, contributes to patellofemoral pain. However, this is open to debate. Given that there is no definitive definition of ‘excessive’ pronation, it is difficult to say that it contributes to anything. More important is where, and how, your foot strikes the ground.
Most runners these days over stride, landing on their heel out in front of the body, often with an almost straight knee. This creates a braking force that effectively slows forward progress, and a sharp spike in ground-reaction force, that sends a shockwave to the knee. Finally, because the foot is so far in front at contact, and creating a braking force that has to be overcome by the opposite leg on each stride, the runner is spending more time on the ground than is ideal, increasing the torque, or load, around the joint, and therefore the risk of injury.

What to do
What can a runner with knee pain do? First and foremost, back off the running for now. Continuing to run on an already irritated knee will only increase the symptoms. Secondly, make an appointment to see a chartered physiotherapist for an accurate diagnosis and treatment plan. Whilst you might find something that matches your symptoms on Dr Google, he’s generally not the best at assessing and treating you as a person!
In most cases, a period of rest, combined with a focused exercise programme, and a gradual return to training, is enough to do the trick. If you have a long-term problem or if you keep breaking down as you increase your training, it’s time to analyse how you run, and how your technique contributes to your injury, which is best done with video analysis.

A lifetime of pain?
Does runner’s knee lead to arthritis and a lifetime of pain? If you keep training through it, there is a possibility of degenerative problems developing.
If you settle the symptoms and address the causes, no, the risk of arthritis hasn’t been shown to be any higher in runners than non-runners. So, don’t listen to your cousin’s aunt, keep up the running, enter a marathon if you like – just don’t keep running on a sore knee!

Andrew O’Brien is a chartered physiotherapist and the owner of Wannarun Physiotherapy and Running Clinic at Westport Leisure Park. He can be contacted on 083 1593200 or at www.wannarun.ie.