The structure indicated is the levator scapulae muscle.
The levator scapulae muscle is one of the superficial muscles of the back. There are three groups of back mucsles:
The superficial group of back muscles consists of 5 muscles:
- Latissimus dorsi
- Levator scapulae
- Rhomboid major
- Rhomboid minor
The name “levator scapulae”, is the Latin for “elevator of the scapula”, which describes the function of this muscle.
Origin: Transverse processes of cervical vertebrae CI to C4
Insertion: Upper aspect of medial border of scapula
Action: Elevates scapula
Innervation: Dorsal scapula nerve
Learn more about the anatomy of the back muscles in this tutorial.