The iliotibial (IT) band is a strong, thick band of fibrous tissue that starts at the hip and runs along the outer thigh, attaching on the outside edge of the shin bone (tibia) just below the knee. The band works with the quadriceps (muscles at the front of your thigh) to provide stability to the outside of the knee joint during movement.
Injury to or irritation of the iliotibial band—called iliotibial band syndrome—may cause an aching or sharp pain often felt on the outside of the knee. Sometimes, the pain spreads to the thigh and/or hip area. These symptoms typically appear gradually, but if they persist longer than four weeks this condition can significantly limit and interfere with your training.
ITB Syndrome may be treated many ways, including:
Anti-inflammatory medications such as ibuprofen
R.I.C.E. (Rest, ice, compression, elevation)
Physical therapy, including deep tissue massage and stretching
Muscle tightness or a lack of flexibility in the gluteal (buttock) muscles, tensor fascia latae (a hip muscle), and quadriceps may also increase a person's risk of developing IT band syndrome so it is important to keep your glutes, hip flexors and quads loose and flexible especially after strenuous training sessions.