Runner’s knee is a commonly used term to describe pain in the area of the kneecap. It’s common amongst runners, particularly if you’re relatively new to running, but it’s also common in skiers, cyclists and football players. It’s more common in women than men (and we’ll be discussing why when we talk about biomechanics), and it’s more likely to happen in middle age and if we’re a little overweight.
Runner’s knee encompasses several clinical scenarios, with ‘patellofemoral pain syndrome’ being the most common.
What Causes Runner’s Knee?
It’s first helpful to understand a bit about the anatomy of the knee.
The kneecap (aka patella) is actually a bone that sits within a tendon. The tendon connects the quadriceps (aka quads) muscle above to the tibia (shin) bone below. When we bend and straighten our knee, the kneecap slides up and down within a valley shape on the front of the femur (thigh bone) and the back of the kneecap is shaped like a widow’s peak.
It’s these complementary shapes that help to keep the kneecap in place during flexion and extension of the knee, and the surfaces of this joint (the patellofemoral joint) are coated with hard, shiny, articular cartilage. When have runner’s knee, we’re experiencing pain that’s sensed in this front area of the knee.
Why does my knee hurt when I run?
There are several factors that can contribute to runner’s knee, including:
When we’re just starting out as runners, it can take a little while for the knees to acclimatise to the impact of running. If we ramp up our training too quickly, increase our weekly mileage by more than 10% per week, or if we increase our mileage at the same time as increasing pace and hill work, we can make our knees sore. Not having sufficient recovery between runs can also bring on pain.
Previous injury to the knee
If you’ve previously had trauma to the knee, and have sustained cartilage damage to the joint surface, and or you’ve not gone through rehabilitation to your knee, you’re more at risk of getting kneecap pain.
Biomechanical problems and muscle weakness
Much of the runner’s knee pain we see in clinic is brought on by poor biomechanics and muscle weakness. For example, if you’re weak in your glutes (especially the gluteus medius muscles), you may drop your knees inwards when you’re running, instead of the knee moving forward over the toes. This tends to cause the kneecap to glide in a sub-optimal fashion, and create too much loading on one side of the kneecap (typically the lateral side).
Many patients are told that they have a tight IT Band (iliotibial band) which is ‘pulling’ on the kneecap. Whilst this may be true, the IT Band tends to tighten up as a result of the muscle imbalance between the (weak) gluteus medius muscle, and an overactive tensor fascia lata muscle, both of which connect into the IT Band. In other words, it’s usually weak glutes that are the cause.
Tightness in the quads and calf muscles can also contribute to excessive loading through the front of the knee.
Some runners tend to over-stride when they are running, which can happen if they have poor hip extension, and this can put more load through the front of the knee.
Some runners over-pronate (which is excessive inward rolling of the foot when it’s in contact with the ground), and this can cause the leg to rotate inwards, affecting the loading through the knee.
Some people were born with a kneecap that is abnormally shaped (aka dysplasia) or a have a very shallow groove on the front of the thigh bone, and others may have a kneecap which is naturally positioned high on the front of the knee (aka patella alta). This causes poor loading through the kneecap joint and in some instances may lead damage in the patellofemoral joint.
Women tend to have to wider hips than men, and this means that in women the vertical thigh alignment relative to the shin (known as the ‘Q’ angle) is larger, and this may contribute slightly to the lateral loading of the kneecap. This may be why runner’s knee is more common in women.
Being overweight means more load through the kneecap, but thankfully running generally helps us to maintain a healthy weight.
What are the symptoms of runner’s knee?
Most people describe having a pain in the front of the knee, either around or underneath the kneecap (patella).
It might be a pain you experience when bending and straightening your knee, when climbing stairs or walking down hill, or it might be a dull ache after or during exercise.
You might find you dislike kneeling on your knee or being sat for too long with your knee bent.
Some people experience grinding or clicking of the knee, and occasionally the knee may even swell a little.
How is Runner’s Knee Diagnosed?
When you come to clinic, we’ll ask about your symptoms, how the come on, when the pain started, what does it feel like, and we’ll ask about your running and other physical activity.
We’ll then carefully examine your knee for swelling, range of movement, how the kneecap tracks, and very importantly, how you move globally. Are you weak in your glutes, or have poor control through your ankle?
Do I Need an MRI Scan or an X-ray?
In most cases, an MRI or X-ray is not necessary to diagnose runner’s knee. These tests are typically only ordered if we suspect you may have a more serious knee injury or condition.
How is Runner’s Knee Treated?
When we’re treating your knee pain, we look at all the factors that led to the problem starting. We may carry out some soft tissue treatments to reduce pain and swelling, and then we’ll look to correct any biomechanical faults.
This may mean homework for you in terms of stretches for your quads and calf muscles, as well as strengthening exercises for your glutes. Sometimes we’ll use taping to guide the kneecap whilst you’re carrying out the exercises, and very occasionally we may recommend a support for your foot (aka an orthotic) to correct excessive pronation.
Very importantly, we’ll look at your training, closely. We’ll check and correct your running style and ensure you’re warming up sufficiently, not increasing your mileage too quickly, and ensuring you have an enough strength work in your regime. We may also make recommendations about your footwear.
Does Running Damage Knees?
Contrary to popular belief, running does not cause knee damage in healthy knees. In fact, running can strengthens the muscles and has benefits for the cartilage surfaces, plus it helps to keep weight off. Overall, runners have less knee arthritis than non-runners.
How Can I Prevent Runner’s Knee?
To prevent runner’s knee, it’s important to maintain a healthy weight, wear proper shoes, warm up before running, and gradually increase the intensity and duration of your runs. Strengthening exercises and stretching should be an integral part of your running regime.
If you’re experiencing runner’s knee, or if you have pain whilst training for a marathon, come and see us.