If you’re a runner, chances are you’ve had pain in your knee. For example, among runners training for Vancouver’s Sun Run 10K – one of the biggest races in the world, with over 59,000 entrants this year – a staggering 66 per cent suffered from some form of knee pain, according to a study by researchers at the University of British Columbia. And the most common form of knee pain in runners is “anterior” knee pain (in the front of knee) – often called “runner’s knee,” appropriately enough.
Since runner’s knee strikes at the joint between the kneecap (or patella) and the thigh bone (or femur), it’s sometimes referred to as patellofemoral pain syndrome, or chondromalacia patella. Researchers at the University of Calgary found that this type of pain accounts for 57 per cent of all knee problems in Canadian runners. The injury occurs when the patella doesn’t line up properly with the structures underneath and can rub or stress the cartilage that is found on the under-surface of the patella. The tissues surrounding the kneecap get irritated and inflamed in response, and in severe cases, this can lead to softening or breaking down of the cartilage.
Despite the name, runner’s knee can also affect cyclists, jumpers, skiers and soccer players – but runners are the most common victims. There are several factors that increase the risk that a runner will develop runner’s knee. The first is inflexibility of the quadriceps muscles, which run down the front of the thigh. If the quads are tight, they will compress the patella against the structures underneath. Weakness in the quads can also be a problem: if the vastus medialis obliquus (the quad muscle on the innermost part of the thigh) is weak, that will cause the patella to track improperly, leading to irritation and pain in the surrounding tissues. Other controllable factors include training surfaces (hard vs. softer terrain), training methods (too much too soon), and improper footwear (worn out shoes, wrong fit).
There are also factors that are out of your control that can lead to runner’s knee. These are biomechanical or anatomical aspects such as leg length inequality, over-pronation of the foot during running, pelvic muscle imbalance, or the alignment of your leg bones.
Runner’s knee has an insidious onset, meaning that it comes on slowly – sometimes over the course of months. It shows up as pain on the underside or around the kneecap. The classic indicator is what is known as the “moviegoer’s sign,” which is pain behind the kneecap after prolonged sitting. Another sign is pain going up or down hills. Some patients even experience a feeling of instability or “giving way” in the knee, although this symptom is more associated with ligament injury.
To tackle runner’s knee, you might need several different methods of attack. In the initial stages, RICE (rest, ice, compression and elevation) helps to control inflammation and promote healing. Other treatment options include patellar taping and bracing, orthotic prescription, quadriceps strengthening and stretching, Active Release Techniques, Graston Techniques or another soft tissue release, and acupuncture. The key is to attack not only the current symptoms, but to fix the dysfunction that caused the symptoms to appear in the first place.
Dr. Jenn Turner is a chiropractor who works with Cycling Canada, and recently travelled to the Pan Am Championships with the team. She is a director at the Moveo Sport and Rehabilitation Centre in North Vancouver (www.moveo.ca).
ACTIVE RELEASE OR GRASTON TECHNIQUES
ART and Graston are both soft tissue techniques that break down adhesions or scar tissue that forms in muscle tissues and prevents muscles from lengthening fully. As the quads become tight the kneecap is pulled out of its regular alignment. Both of these techniques help to release the tissues and allow the patella to sit normally.
Orthotics can be useful in patients with patellofemoral syndrome who overpronate at the foot when they run. This overpronation causes the lower leg to rotate abnormally, and can disrupt normal movement of the patella.
Medical acupuncture stimulates the release of endorphins and cortosol which are endogenous painkillers, meaning they are already within the body. Research has shown that patellofemoral patients have a significant improvement with pain and function after acupuncture sessions.
In the initial stages of the injury, or after aggravating activities, rest, ice elevation and compression (RICE) is ideal to reduce inflammation and allow healing to begin in the damaged tissues. Modified rest is necessary as running will continue to aggravate the joint, but cross training can help maintain cardiovascular fitness.
TAPING OR BRACING
Taping or bracing for runner’s knee involves having some minor pressure to the outside border of the kneecap to slightly press it inwards thus improving tracking. By using a dynamic patellar brace or knee strap, pain can be significantly reduced and activity can be maintained to a certain extent.
STRENGTHENING AND STRETCHING
There are various methods to strengthen the quadriceps with the most recent research examining eccentric exercise. Eccentric exercise involves training the muscle while it is lengthening, such as a negative squat.
Other treatment options for runner’s knee include chiropractic manipulation of the SI joints and patella, ultrasound or interferential current, and anti-inflammatory medications.