Patellofemeral knee pain and running
How to treat anterior knee injuries
Patellofemeral knee pain related to the patellofemoral joint which is found just under the surface of the patella (knee cap) and the lower end of the femur (your thigh bone). It is the most common symptom which runners present to specialists and it is the most common overuse injury in sports people generally.
So what is patellofemeral pain syndrome and how is it caused?
The patella (knee cap), is a piece of free-floating bone situated within the body of the quadriceps tendon. It acts as a pulley to allow the quads tendon to run smoothly and efficiently over the front of the thigh, to move and control movement of your tibia (shin bone).
As the knee bends and straightens the patella tracks up and down the groove on the front of the lower end of the femur (thigh bone). It is guided and held in place by a number of structures including contractile (muscle) and non-contractile structures, such as the ligaments at the front of the knee (retinaculum) and the patella tendon. Other factors also figure in the equation such as the shape of the runner's patella itself.
Problems arise, when these structures fail in their function or alter how the patella moves. Contributory factors which affect the mechanics of the how the patella moves include alignment of the running leg and thus how forces, when you run, are transmitted from the foot.
Some of following all have an impact on the the mechanics of the patellofemeral joint and how the patella is loaded during running:
- Stiff hip joints.
- Tight hamstrings, calf and quadricep muscles.
- Poor quads function and strength, particularly the portion of the quads known as VMO (Vastus Medialis Oblique).
Poor tracking of the patella can be compared to poor tracking on a front tire of your car which leads to uneven wear of the tire. When load is distributed inadequately across the patella under surface, the patella cartilage can get damaged.
Pain may also arise from soft tissue structures around the knee, such as the fat pad which lies just under the patella (and gives rise to a 'puffy' knee) and irritation to the nerves supplying the knee joint.
Symptoms of patellofemeral knee pain in runners
Pain is typically felt over the front of the knee without being able to pinpoint the actual source. Usually pain is felt during and after running. In some instances, the pain may be severe enough to limit running or not allow any running at all.
Typical symptoms include:
- Pain when going up or down stairs or squatting.
- A 'creaking' under the patella when running.
- Stiffness and swelling around the patella.
- Possible loss of muscle bulk in the quads.
- 'Puffy' knees when running.
Treatment of patellofemeral pain
Initial treatment will usually be aimed at reducing any inflammation. One popular method of doing this is to employ TENS, which is a a method of treating chronic pain by applying electrodes to the skin and passing small electric currents through sensory nerves and the spinal cord, thus suppressing the signal of pain signals. Other option for treatment include interferential techniques and acupuncture. Any running activity that aggravates the problem must be ceased.
Further treatment once any inflammation has passed will be directed towards improving the mechanics of the lower limb. This could involve a program of stretching for muscles, along with orthotics if required. Strengthening of the quadricep muscles, often the VMO, is also an important part of the rehabilitation process.
The thing to remember here is that it is vitally important to seek advice at the first signs of any knee pain, rather than ignoring it. Professional advice should be sought sooner rather than later to prevent a longer than would have been required lay-off.