Rhomboid major
Back
Deep muscle — it lies under other muscles. X-ray makes the muscles over it see-through.
- Origin
- Spinous processes of T2 to T5
- Insertion
- Medial border of the scapula, below the spine
- Action
- Retracts the scapula and rotates it downward
- Nerve supply
- Dorsal scapular nerve (C4–C5)
The larger, lower rhomboid. It sits under the trapezius and pulls the shoulder blade toward the spine in every rowing movement.