Triangle of auscultation

The triangle of auscultation of the lungs is a relative thinning of the musculature of the back, situated along the medial border of the scapula.

To better expose the triangle and listen to respiratory sounds with a stethoscope, patients are asked to fold their arms across their chest, medially rotating the scapulae, while bending forward at the trunk, somewhat resembling a fetal position.

Due to the relative thinning of the musculature of the back in the triangle, the posterior thoracic wall is closer to the skin surface, making respiratory sounds able to be heard more clearly with a stethoscope.