This syndrome was first described by Youngman in 1928. It consists in the progressive pressure of the sciatic nerve by the apioid muscle. The pressure is exerted on the nerve outlet by the submandibular foramen and is usually associated with an acute buttock injury. The pain follows the path of the sciatic nerve. Sitting can be painful, and...

This is caused by various extraarticular or intra-articular causes.

The lagonopsis is the most powerful flexor of the hip and consists of the pelvis and the scapula, which attach to the minor trochanter with a common pulmonary tendon. The most common sites of sensation of noise and friction of the lagoon are in the iliac crest and in the minor trochanter.