The region bounded by the upper border of the latissimus dorsi, the lateral border of the trapezius, and the medial border of the scapula is known as the triangle of auscultation. Lung sounds can be heard most clearly from this location because minimal tissue intervenes between the skin of the back and the lungs. The deltoid, levator scapulae, and trapezius do not form the borders of the "triangle of auscultation." The latissimus dorsi, external abdominal oblique, and iliac crest form the border of Pettit's inferior lumbar triangle. The quadratus lumborum, internal abdominal oblique, and inferior border of the twelfth rib form the border of the Grynfeltt's superior lumbar triangle. The rectus abdominis, inguinal ligament, and inferior epigastric vessels form the border of the Hesselbach triangle. Petit, Grynfeltt, and Hesselbach's triangles are common sites for hernias.