Runners Knee is one of the most common causes of front knee pain and accounts for approximately 25% of all knee injuries seen in sports injury clinics.
Runners Knee is also known as "Patellofemoral Syndrome" or "Anterior Knee Pain" and refers to pain under and around the kneecap. It is caused by a problem with the way the knee cap moves resulting in friction on the back of the knee.
Symptoms tend to come on gradually and come and go depending on your activities. Runners Knee is not the only cause of knee pain from running and despite the name, it affects both active and
sedentary people e.g. office workers.
Here we will look at the causes, symptoms, treatment options and recovery process from Runners Knee, frequently asked questions such as can I run on runners knee, as well as other knee conditions commonly misdiagnosed as Patellofemoral Syndrome.
Runners Knee is thought to be caused by a problem in the way the patella (kneecap) moves which places extra stress on the cartilage.
The kneecap sits in a groove (patella/trochlear groove) at the front of the knee on the femur (thigh bone) and is lined with very thick cartilage. It can glide, tilt and rotate upwards, downwards and sideways in this groove.
There are a number of things that stop the
patella from moving properly, all of which increase the
forces and friction going through the kneecap, causing patella femoral syndrome. These include:
1) Muscle weakness: Weakness in the muscles reduces the support around the knee causing more weight to go through the kneecap. Also, if the muscles on one side of the knee are weak while the muscles on the other side are too strong, the kneecap will shift slightly to one side in the groove, resulting in friction
2) Muscle Tightness: If the muscles around the kneecap are tight, they will pull it up slightly and possibly slightly to the side, increasing knee cap pain and friction
3) Foot Position: An abnormal foot
position, such as flat feet, causes the foot to roll inwards which
alters the way the forces go through the knee, increasing pressure on the kneecap
4) Q Angle: This refers to the angle of the thigh bone. An increase in the Q angle puts more strain on the kneecap
5) Anatomy: there
can be a problem with the shape of the groove and/or kneecap which
result in the two not lining up properly which can restrict the movement
and cause friction, predisposing you to patellofemoral syndrome
Runners Knee usually comes on gradually – it is not triggered by a specific incident. People describe it as an ill-defined ache around the kneecap, particularly underneath and at the sides of the patella. This short video from ClearDoc explains what is going on with the patella in patellofemoral syndrome.
There may also be grinding/grating sounds associated with
leg movement in patellofemoral syndrome – this is known as crepitus and
is caused by friction on the kneecap. Sometimes, there can also be some
mild knee swelling.
The pain tends to come and go rather than being constant but is usually worse with:
1) Prolonged Activity: e.g. running long distances, sports, skiing especially when going downhill
2) Stairs: especially coming downstairs
3) After sitting for Long Periods: e.g. at the cinema, office workers, driving long distance. The knee tends to be sore when you first get up and then eases with movement
Treatment for Runners Knee aims to reduce the kneecap pain and swelling, and address any muscle imbalance in the leg. The most common treatments for patellofemoral syndrome are:
People with Runners Knee often have weak Glutes (buttocks) and Quads muscles. Strengthening these muscles will reduce the weight going through the knee. Visit the knee strengthening section for exercises that can help.
Also, exercises that specifically target the muscles that control the kneecap make a big difference, improving the way the kneecap glides in the patellar groove- see the kneecap exercises section for more information.
Reducing any muscle tightness will also improve how the knee cap
glides in the patellar groove reducing the friction on the kneecap.
Visit the knee stretches section for simple tests to see if muscle tightness is causing your patellofemoral syndrome pain and exercises that can help.
Braces can help to improve the support around the knee and the position of the patella reducing the pain associated with patellofemoral syndrome. There are a whole range of styles, but generally the best ones for Runners Knee have a hole at the front to prevent any extra pressure on the kneecap. Visit the Knee Brace Guide for help finding the right brace for you.
There are special insoles that can be worn on your shoes to correct your foot position and Q angle and therefore reduce the forces going through the kneecap. Your doctor can refer you to an orthotist to get your feet assessed and provide appropriate insoles.
Runners Knee often develops after an increase in activity levels. It may be advisable to rest for a few days to let your knee pain settle down, and then gradually build up the amount of exercise you do, or switch to non-impact exercise such as swimming. Remember, pain doesn’t always come on during an activity, it often develops later that day or overnight, so start slowly and gradually increase.
Using ice for ten minutes after activity can help to reduce patellofemoral syndrome pain and swelling. Visit the Ice section for advice on how to safely and effectively use Ice therapy and the ice wrap section for the best ways to apply ice.
If your pain comes on after sitting for long periods, try to avoid keeping your leg still. At work, get up and have a little walk around every thirty minutes or so or if that’s not possible, gently move your leg backwards and forwards a few times. This keeps the joint loose and lubricated which can help reduce patellofemoral syndrome pain.
Over the counter painkillers and non-steroidal anti-inflammatories e.g.
Advil/Ibuprofen can be useful to reduce the pain associated with Runners
Knee. Always consult your doctor before taking medication.
It is very rare that patellofemoral syndrome requires surgery. However, if the above treatments do not work surgery may be indicated to release tight structures around the knee or to remove bits of bone that are irritating the knee cap.
The correct treatment will depend on the cause of your patellofemoral syndrome, so it is always advisable to see your Health Professional who can accurately assess what is causing your problem.
It can take anywhere from six weeks to six months to recover from Runners Knee. It usually takes a few weeks of doing strengthening and stretching exercises for muscle strength and length to improve, so don’t give up. Also, don’t be tempted to increase your activity levels too quickly. Pace yourself so as not to aggravate your knee.
If you want to keep exercising, try lower impact work such as swimming and cycling. If you do want to run, make sure you have good running shoes and try to avoid running on concrete as the hard surface puts more strain through the knee.
There are a number of other conditions that cause front knee pain and Runners Knee is often incorrectly diagnosed as:
1) Chondromalacia Patella: where there are actually changes in the cartilage lining the kneecap
2) Jumpers Knee: irritation of the patellar tendon just below the knee
3) Iliotibial Band Syndrome: irritation of the ITB on the outer side of the leg
Whilst these conditions may have similar presentations, there are important subtle differences to patellofemoral syndrome so do check out these other sections.
People often have a lot of questions about Runner's Knee. In the Patellofemoral Syndrome FAQ's section, you will find answers to the most commonly asked questions such as, How do I know if I've got it? Do braces really help? And Can I run on runner's knee?
If Runners Knee isn't sounding quite like your problem and you want help working out what is wrong with your knee and why you have pain, visit the knee pain diagnosis section