The knees function as hinges, allowing your legs to swing forwards and backwards smoothly as you walk, kick and run. The knee cap (the patella) sits at the front of the knee and has a variety of functions, including guiding the muscles that straighten the knee, protecting the knee joint and absorbing forces when the knee is bent. When something goes wrong and the patella doesn’t glide up and down smoothly, the soft tissue between the kneecap and the knee can become irritated, causing pain. This is called patellofemoral pain syndrome (PFPS), sometimes also referred to as PFJ syndrome, patella maltracking or runner's knee.
Pain is usually felt on the inside of the kneecap when running, squatting, jumping, bending, using stairs or hopping. Sitting for long periods of time or keeping your knees bent can also result in pain.
What Causes It?
The patella sits in a shallow groove at the front of the knee and usually moves up and down as the knee bends and straightens without too much trouble. The quadriceps muscles located at the front of the thigh contract and pull on the kneecap, which then attaches to the shin bone and acts to straighten the knee. If one side of the quadriceps is stronger or tighter than the other, it can cause the kneecap to pull more to one side and over time become irritated.
The cause of muscle imbalance or weakness can be varied. In general, the outer muscles of the thigh tend to be stronger and tighter than the inner muscles. If you have poor posture and hip position, this can cause the outer muscles to work harder and the inside muscles to become weaker. Lack of arch support in your feet or a physical anomaly of the knees can also contribute to this condition.
How Can Physiotherapy Help?
Diagnosing patellofemoral pain syndrome correctly is important because pain on the inside of the knee can also be caused by other injuries, dislocations, inflammation, arthritis and a variety of other less common conditions. With that in mind, it is helpful to know that your physiotherapist can diagnosis PFPS accurately and identify its likely causes.
Whether it is due to poor posture, a lack of arch support in your feet, or poor running technique, your physiotherapist will assess the problem and provide a specific treatment program to best approach your condition. PFPS usually responds well to biomechanical analysis and correction of any muscular weakness and imbalance. Having the correct shoes and orthotics can also make a huge difference. There are some short-term treatments, such as patella taping, dry needling, massage, trigger point therapy and ultrasound, which may help alleviate symptoms quickly and keep you active while you address the other factors contributing to your pain.
In the rare case that your condition is not helped by physiotherapy, surgery may be considered as a last resort. For more information, please ask your physiotherapist.