Chondromalacia Patella
Also known as Patellofemoral Syndrome:  The knee is a complex joint. It includes the articulation between the tibia and femur (leg and thigh) and the patella (knee cap). The most common knee problems in running relate to what is called the "patello-femoral complex". This is the quadriceps, knee cap and patellar tendon. What is called runner's knee is a condition known to the medical community as Chondromalacia of the patella. This essentially means softening of the cartilage of the knee cap. Cartilage does not have the same blood supply that bone does. It relies on intermittent compression (succussive action) to squeeze out waste products and then allow nutrients to enter the cartilage from the synovial fluid of the joint. During running certain mechanical conditions may predispose you to a mistracking knee cap. Portions of the cartilage may then be under either too much or too little pressure and the appropriate intermittent compression that is needed for waste removal and nutrition supply may not be present. This may result in cartilage deterioration, which at the knee usually occurs on the medial aspect or
inner part of the knee cap. Symptoms Custom orthotics will prevent excessive pronation and reestablish proper weight distribution and biomechanics.  By maintaining neutral position of the subtalar joint during gait, it will keep the patella aligned in its groove on the femur.  This will prevent excessive erosion on the lateral side of the patella while providing succussive action of the medial aspect of the patella.  By restoring succussive action to the underside of the patella, you can expect some regeneration to the cartilage and a reduction of pain.