Tuesday, May 09, 2006

Runners Knee

The symptoms of runners knee include pain near the knee cap usually at the medial (inner) portion and below it. Pain is usually also felt after sitting for a long period of time with the knees bent. Running downhill and sometimes even walking down stairs can be followed by pain. This has been called the "movie theatre sign".

Runners Knee is also called Patellofemoral pain syndrome. It is often caused by the kneecap not tracking smoothly in its femoral groove. The symptoms are aggravated when the knee is bent since (with increased vectors of force) increased pressure exists between the joint surface of the knee cap and the articular surface of the femur (thigh bone). This increase in force over-stresses the injured area and leads to pain.

Some of the mechanical conditions that may contribute to this include:

Wide Hips (female runners)
Knock Knees (Genu Valgum)
Subluxating Patella
Patella Alta (high patella)
Small medial pole of patella or corresponding portion of femur
Weak Vastus Medialis
Weak Quadriceps Muscles
Tight Hamstrings or calf muscles
Pronation of the feet

Treatment of Runners Knee

At an early stage running should be decreased to lessen stress to this area and allow healing to begin. It is important to avoid downhill running which stresses the patello-femoral complex.

Exercises performed with the knee bent should be avoided. When the knee is bent the forces under the knee cap are increased.

Vastus Medialis is the muscle that helps stabilize the knee cap medially and prevents it from shifting laterally and tracking improperly at the patello-femoral joint. The Vastus Medialis Oblique (VMO) and Vastus Medialis Longus (VML) have been shown to be considerably weaker than the Vastus Lateralis (VL) in patients with Patellofemoral Pain Syndrome compared to normals (Makhsous et. al. 2004).

Straight leg lifts strengthen the vastus medialis muscles and do not significantly stress the undersurface of the knee cap. They should be done in sets of 10 times on each side. Start with 5 sets of 10 and work your way up to 10 sets of 10. Straight leg lifts are best performed lying on a cushioned but firm surface, with the exercising leg held straight and the non-exercising leg somewhat bent to take pressure off of the back. Lying on a carpet or mat on the floor is a perfect place to perform this exercise.

Tight posterior muscles should be stretched. In many cases tight calf muscles or hamstrings lead to a "functional equinous" and make the foot pronate while running or walking. This pronation is accompanied by an internal rotation of the leg which increases the Q angle and contributes to the lateral subluxation of the knee cap. On occasion a tight iliotibial band may contribute to PFPS.

“...Straight leg lifts strengthen the vastus medialis and do not significantly stress the undersurface of the knee cap.”

If you over-pronate make sure you use shoes that offer more anti-pronation features. Move up a ranking in the amount of stability and pronation control that your shoes offer. If further control of pronation is needed orthotics should be considered. The late George Sheehan, M.D., sports medicine physician and philosopher, was the first to popularize the notion that it was important to look at the foot when runner's knee occurs. It is also important to rule out other knee problems when knee pain occurs in runners and not just lump every pain as "runner's knee".

Some authors have suggested that core muscle strength may play a role in this problem. Suggestions for improving core body strength including gluteal muscles have been made. There is nothing wrong with this suggestion and it may help. Be sure to perform the above exercises first, since they are more specific to the problem being addressed.

Treatment Summary:

Rest or Relative Rest: Run Less
Avoid exercises or activities that require your knees to be bent
Avoid running or walking downhill, downstairs or down inclines
Do posterior muscle stretches (hamstrings and calf muscles)
Do Straight Leg Lifts (Start with 3 sets of 10, work up to 10 sets of 10)
Check Your Feet and Shoes, overpronation often contributes to this problem
Consider More Stable Shoes (with better anti-pronation features)
Orthotics If Needed (OTC or Custom)

Source: http://www.drpribut.com/sports/spknees.html

KVSSNRAO, 10th May 2006

No comments: