Definition: Pain and inflammation on the outside of the knee, where the iliotibial band (a muscle on the outside of the thigh) becomes tendinous, and results in a friction syndrome by rubbing against the femur (thigh bone) as it runs alongside the knee joint.
Initially, a dull ache 1-2 kilometres into a run, with pain remaining for the duration of the run. The pain disappears soon after stopping running, later, severe sharp pain which prevents running pain is worse on running downhills, or on cambered surfaces pain may be present when walking up or downstairs.
Local tenderness and inflammation
Anything that causes the leg to bend inwards, stretching the ITB against the femur overpronation (feet rotate too far inward on impact) tightness of the ITB muscle lack of stretching of the ITB incorrect or worn shoes excessive hill running (especially downhills) and running on cambered surfaces overtraining
For Treatment Methods go to http://www.time-to-run.com/injuries/thebig5/itb.htm