Chondromalacia patellae ("Runners Knee")

During running certain mechanical conditions may predispose an athlete to the kneecap mistracking. The patella needs to track in the groove between the condyles of the femur and, if it does not, then there will be excess friction and wear on the underside of the kneecap. This will result in chronic anterior knee pain (in particular when ascending or descending stairs). This is sometimes referred to as the 'Movie Sign'. When watching a movie a person will be sitting with the knee bent for a prolonged period and a sufferer of chondromalacia patella may experience pain on getting up that will gradually dissipate when they start moving around.

Whilst the pain is experienced in the anterior knee, the likely cause of 'Runners Knee' lies in the feet and the thighs where, for one reason or another, they are not doing their jobs properly. When the knee joint is working efficiently then the patella moves smoothly and comfortably in the groove between the condyles of the femur. However, when the kneecap moves out of alignment and rubs against its side then over time the cartilage becomes worn. The main culprits for the kneecap moving out of alignment are weak quadriceps muscles and a lack of support from the foot.

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One of the roles of the quadriceps is to hold the patella in place. Running tends to develop the back thigh muscles (hamstrings) more than those in the front (the quadriceps), and the imbalance is sometimes enough to allow the kneecap to pull and twist to the side. In particular there becomes an imbalance between the vastus lateralis and the vastus medialis (particularly the vastus medialis obliques - VMO) which results in lateral force on the patella. Another factor which can increase the risk of developing runner's knee is the 'Q' angle (Quadriceps).

The Q angle can be considered as of the angle at which the quadriceps averages its pull. It is measured by drawing a line from the Anterior Superior Iliac Spine to the centre of the kneecap and a second line from the centre of kneecap to the patellar tendon insertion. Normal is considered to be less 12 degrees, abnormal is greater than 15 degrees.

The athlete's foot may also not be giving the required stability and for many runners their feet are making an incorrect motion each time they hit the ground. Overpronating (rolling of the foot in) or supinating (turning it out too much) coupled with the high number of repetitions of a serious runner are a recipe for knee problems.

Testing for Chondromalacia
In order to test for chondromalacia, then your therapist may seat you on the edge of a massage table and place a moderate amount of compression on the patella. The therapist will continue to apply compression as you extend your knee. If pain is felt under the kneecap as you extend the knee, then it is possible that there is some degeneration and softening of the cartilage.

Treatment of Chondromalacia
Chondromalacia is commonly treated by a combination of modifications to activity, rest and rebalancing the relationship between the quadriceps and the hamstrings. At an early stage running should be cut back to reduced stress on the knee and allow the joint to begin healing. Downhill running should be avoided whereever possible as the stresses on the knee are significantly greater.

In order to strengthen the quadriceps (in particular the VMO), then straight leg raises are generally considered to be a good starting point as they strengthen the Vastus Medialis without significantly adding to stress on the underside of the patella. For example, they can be performed in sets of ten times for each leg. Begin with around five sets of ten and increase over time up to ten sets of ten. Just lie on a carpet or yoga mat on the floor and hold the exercising leg straight (and non-exercising leg bent to avoid undue stresses on the back).

Massage is appropriate for lengthening tight posterior leg muscles (ie calf and hamstring muscles) which may make the foot pronate during activity. If any pronation is accompanied by an internal rotation of the leg then this can effectively increase the Q angle. Also releasing tightness in the iliotibial band (ITB) is considered to be important for chondromalacia.

Appropriately fitted footwear and orthotics can be helpful in reducing the impact of patellofemoral dysfunction. Decreasing the rate of internal rotation of the tibia can reduce stresses applied to the underside of the kneecap and the need for the VMO to maintain proper tracking and positioning of the patella.

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