College of Massage Therapists of British Columbia (CMTBC) Practice Exam

In which order are these structures arranged from most superficial to deepest?

1. longissimus, rhomboids, rotatores, trapezius, serratus posterior superior

2. trapezius, rhomboids, serratus posterior superior, longissimus, rotatores

3. trapezius, longissimus, rhomboids, serratus posterior superior, rotatores

4. serratus posterior superior, trapezius, rhomboids, longissimus, rotatores

The correct answer is: trapezius, rhomboids, serratus posterior superior, longissimus, rotatores

The arrangement from most superficial to deepest in the correct choice accurately reflects the anatomical relationships of the structures listed. Starting with the trapezius, this large muscle covers the upper back and neck, making it easily accessible and thus the most superficial structure. Following the trapezius, the next structure is the rhomboids, which lie beneath the trapezius but are still relatively superficial compared to deeper muscle layers. The serratus posterior superior, while involved in respiratory mechanics, is situated more posteriorly and deep to the trapezius, placing it beneath the rhomboids in terms of depth. The longissimus is part of the erector spinae muscle group, positioned deeper than the aforementioned muscles; it runs along the spine and contributes to maintaining posture and supporting the back. Lastly, the rotatores are the deepest of the listed structures. These are small muscles situated within the spinal column, primarily involved in the rotation and stabilization of the vertebral column. This order effectively demonstrates the hierarchy of superficial to deep muscle layers in the back, making it clear why the choice correctly emphasizes the anatomical positioning of these structures.