The rhomboid lies beneath the middle of the trapezius. It has 2 sections, the rhomboid major (lower) and the rhomboid minor (upper). It has two major actions: scapula adduction and downward rotation. The direction that the fibers run in the rhomboid makes the muscle ideally suited for downward rotation.
The rhomboid originates on the spinous processes of the upper thoracic vertebrae.
It inserts on the medial border of the scapula.
Scapula adduction and downward rotation.