Knee Pain

• The three most common forms of knee pain arise from ACL tears, degradation of cartilage until the femur and tibia make contact, and inflammation of the patellar tendon. An anterior cruciate ligament (ACL) tear is a sudden, traumatic event resulting from excessive lateral force on the knee and often requiring surgery. Scraping away of cartilage down to bone-on-bone contact generally takes several decades of wear. Both are readily diagnosed and the course of action tends to be clear.
  
  The time for patellar pain to arise lies somewhere in between these two extremes and is less amendable to treatment. It can happen after a few workouts, or it can take a few months of damaging habits.
  
  

The Patella

• The patella is the kneecap bone. It is encased in the patellar tendon, which attaches the quadriceps to the tibia. The patellar tendon tracks in grooves in the femur and tibia. The proper tracking path of the patellar tendon as the quadriceps contract is such that the patella makes a slight arc, pulling inward (i.e. toward the opposite knee) midway into the contraction.
  
  

Tracking

• The patellar tendon can be thrown off proper tracking in several ways, some of them surprising because of their distance from the site of pain. A weak vastus medialis or tight vastus lateralis can pull the patella out. This is of particular interest--as opposed to the reverse muscles being weak and tight--because the vastus medialis is not used much in daily use without exercise, so it atrophies quickly. Plus, the vastus is needed to pull the patella inward in the middle of its arc.
  
  A peripheral source of mistracking is foot pronation, also called flat feet or fallen arches. The flattening of the foot as it takes on a load leads to a twisting of the tibia, which travels up to the patellar tendon. The solution is to wear prescription orthotic inserts, which support the collapsed arch. Other non-local causes of mistracking are tight or weak hamstrings and tight calves. Counter-intuitively, stretching the hamstrings can have far more benefit to front knee pain than stretching the muscles directly attached to the patella.
  
  

Cold

• Put your hand on your kneecap, then on your quads. Notice how much cooler your knee cap feels. There is very little blood flowing through the patellar tendon, which is detrimental in two ways. It is slow to warm up for exercise, and thus can still be brittle when the exercise session begins. Also, it is slow to recover from workouts and slow to grow.
  
  Therefore, warming up gently over an extended period is important. Also, knees should be covered in cold weather. There's a saying among some cyclists: below 70 degrees, cover your knees. Some cycling coaches don't let their cyclists wear shorts at all.
  
  That cold could be a cause of tendon damage is somewhat ironic, since icing is promoted by physical therapists to reduce the swelling of tendonitis. While icing reduces swelling, knees should be given time to warm up again before exertion. For example, icing after a workout should not be followed immediately by a long walk, unless the knees have been adequately warmed up again.
  
  

Range of Motion

• When the vastus medialis is reconditioned after a layoff to prevent patellar mistracking, care should be given to avoid the two points of greatest knee instability: full extension and a 90-degree angle. Exercising between these ranges is preferable. While full-range exercises develop muscle faster, for damaged knees the regrowth rate is the limiting factor. Gaining the strength for proper tracking and building tendon tissue should be a higher priority than gross strength gain in cases of knee pain.