Runner’s Knee – Explained
Runner’s Knee is the common term for Ilio Tibial Band Friction Syndrome (ITBFS). Runner’s Knee is a painful overuse knee injury that affects the outer part of the knee. It is fairly common in runners and cyclists. It is reported to affect 2-10% of all runners, while around a quarter of all knee injuries in cyclists are diagnosed as Runner’s Knee.
To fully understand Runner’s Knee it is necessary to be familiar with the anatomy of the outer side of the thigh and knee. The Ilio Tibial Band (ITB) is a tough length of fascia that attaches to the outer side of the pelvis (which is known as the Ilium), goes down the outer side of the thigh and inserts into the outer side of the shin bone (Tibia). As such, the Ilio Tibial Band forms a length of taught fibrous tissue that connects the hip and knee.
The Lateral Epicondyle is a bony prominence that is the widest point of the thigh bone. When the knee is straight the ITB is in front of the Lateral Epicondyle of the thigh bone and when the knee is fully bent the ITB is behind the Lateral Epicondyle of the thigh bone. During movements of the knee, the ITB moves over the Lateral Epicondyle of the thigh, with maximum friction at 30 degrees of knee bend.
During activities such as running and cycling, where there is repeated bending and straightening of the knee joint, the ITB can ‘impinge’ upon the Lateral Epicondyle and the resultant friction can lead to inflammation of the tissues. If the ITB is tight, then the degree of friction is increased and a tight ITB can predispose people to Runner’s Knee.
Between the ITB and the thigh there is a sac of fluid, called a bursa, which is meant to prevent friction. However, where there are repeated knee bending movements with a tight ITB, the bursa can become impinged between the ITB and the Lateral Epicondyle of the thigh. The bursa itself, as well as the ITB, can become inflamed and painful.
Runner’s Knee Signs & Symptoms
Typically there is pain located on the outer side of the knee joint. This pain may radiate up the thigh or down the outer side of the shin and is exacerbated by running or cycling activities. Usually, the pain from Runner’s Knee is only present during activity and settles when the person rests. However, in some cases it can also be extremely uncomfortable going up or down stairs.
Often there is severe tenderness when the Lateral Epicondyle of the thigh bone is palpated. There is usually maximum friction at the area of the Lateral Epicondyle when the knee is bent to around 30 degrees.
An x-ray of the knee will not show Runner’s Knee. It can be picked up on an MRI scan, where there is inflammation and thickening of the tissue. An Ultrasound scan is usually the most effective way of confirming the diagnosis. If the bursa underlying the ITB is inflamed it can be seen quite easily on the Ultrasound scan, as can inflammation in the surrounding tissue.
Runner’s Knee Treatment
What you can do
- Consult a sports injury expert
- Apply ice packs / cold therapy
- Wear a knee strap to relieve symptoms
Virtually all cases of Runner’s Knee respond well to physiotherapy treatment. The aims of treatment are to resolve the localised inflammatory response and identify and address any underlying postural and body alignment issues that may be contributing to the problem. Leg length differences, a knock kneed posture or a foot position where the arch of the foot lowers during running can all contribute to Runner’s Knee. A physiotherapist will check for these things during the physical assessment and will give specific advice to correct these problems before the person returns to activity, in order to prevent a recurrence of Runner’s Knee.
Local treatment is concerned with reducing inflammation in the tissues. Rest and ice therapy are very important and Non Steroidal Anti Inflammatory Drugs (NSAIDs) can be very helpful where there is acute pain. A Knee Cryo/Cuff Ice Therapy Device can provide excellent pain relief. Stretching of the ITB and the muscles that attach to it (Gluteus Maximus and Tensor Fascia Latae) is undertaken to try and relieve tension in the ITB.
In cases where rest and ice fail to settle the symptoms fully, then a corticosteroid injection into the area of the bursa over the Lateral Epicondyle of the thigh is usually very effective. Most doctors advise a period of seven days’ rest following the injection and postural and alignment faults should be corrected before returning to sporting activities.
In mild cases of Runners Knee a Knee Strap can relieve symptoms very effectively during running. It provides compressive forces above and below the knee cap which reduce tension in the Ilio Tibial Band and the pain associated with Runners Knee.
Runner’s Knee Prevention
What you can do
Wear supportive insoles to control pronation
Anything that increases friction between the ITB and the Lateral Epicondyle of the thigh can increase the likelihood of developing Runner’s Knee. Because tightness in the ITB can increase friction it would seem logical to stretch the ITB and the muscles that attach to it – the Gluteus Maximus and Tensor Fascia Latae.
Discrepancies in leg length can lead to Runner’s Knee. This is because there is more tension on the outer side of the knee in the longer leg. This tightens the ITB and causes increased friction. Leg length differences over 1cm should be corrected with a ‘build up’ insole on the shorter leg in order to restore symmetry.
A ‘false’ leg length discrepancy can be created if someone runs on a road that has a camber. The leg that is on the side closest to the gutter may experience increased tension in the ITB, which could lead to Runner’s Knee. For this reason it is wise to run on a flat surface.
Weakness in the Gluteus Medius muscle has been linked with Runner’s Knee in distance runners. The Gluteus Medius muscle is located at the top of the buttocks and is responsible for both raising the leg out to the side and turning the hip inwards. During running, it prevents the thigh from ‘buckling’ and rotating inwards. If there is a weakness and the knee ‘buckles’ then the tension in the ITB is increased. A strengthening programme to target the Gluteus Medius muscle can be very helpful for ITBFS, by helping to prevent the thigh from ‘buckling in’ during running.
Similarly increased pronation of the foot (uncontrolled lowering of the arch) can lead to increased tension in the ITB when running. Motion controlling running shoes that prevent excessive pronation can be effective in reducing this cause of increased ITB tension. Alternatively an Insole that supports the arch of the foot can help to control excessive pronation.