Figure 1-21
Latissimus and trapezius removed on the right to show rhomboids and serratus posterior inferior.

With the cadaver in the prone position, identify the true back muscles. To access the deeper muscles, the superficial muscles that work the upper extremities will have to be identified and reflected.

The latissimus dorsi, superficial to the back muscles, has been cut at its posterior attachment. Likewise, the trapezius and rhomboids have been cut from their posterior attachments to vertebral spinous processes and scapula. Put these muscles in their natural position so you can understand their relationship to the deeper back muscles. (Figure 1-21)