You may suffering from iliotibial band syndrome. Iliotibial Band Syndrome (ITBS) is one of the most common overuse injuries among runners. It occurs when the iliotibial band, the ligament that runs down the outside of the thigh from the hip to the shin, is tight or inflamed. The IT band attaches to the knee and helps stabilize and move the joint.
To focus on a specific area of the IT band, locate the most tender area with the foam roller and stop. Bend your knee at a 90-degree angle, and then straighten. Repeat motion of bending and straightening the knee for 10 to 15 seconds. Switch sides.