Iliotibial Band Syndrome causes lateral (outer-side) knee pain , frequently related to intense activity causing chronic inflammation. Runners, cyclists, trades people, defense personnel, and gymnists are prone to this syndrome.
Some studies have found that iliotibial band syndrome accounts for 12% of runners’ injuries.
Many other conditions can be a cause of ITB syndrome, including malaligned foot and knee, foot pronation/ flat foot, leg length discrepancy, poor training technique, bad shoe wear, prominent outer epicondyle/ condyle, exostosis , tight ITB, and other causes.
It is caused by friction of structures during continuous flexion and extension of the knee. The snapping phenomenon, inflammation, oedema and other related conditions are diagnosed by ultrasound.
Your practitioner may refer you also following positive clinical tests.
Also, the same pathology can be found over the greater trochanter in the hip also.