Fig. 2
From: Posterior intercostal flap: an anatomical study and best flap design
A photograph of 2 intermediate zone musculocutaneous perforators (Pi). They come of the 6th and 7th intercostal spaces at the lateral border of erector spinae muscles (Es), pass through the back muscles, supply latissimus dorsi (Ld), and terminate in the skin (a, b, c, d). Perforator (d) further divides into 3 smaller cutaneous branches (1, 2, and 3). Note that these perforators are perpendicular to the fibers of Ld