The middle part of the upper line is the place where the blood vesel nerves in the superior gluteal come and the blood vesel nerves of the lower line of the lower hole of the piriformis.

• 上线中部是臀上血管神经入臀处，下线中、内部是梨状肌下孔穿行的血管神经；三线区为梨状肌的体表位置。