Rhomboid major muscle

The rhomboid major is a muscle on the back that connects the scapula with the vertebrae of the spinal column.

Structure
The rhomboid major arises from the spinous processes of the thoracic vertebrae T2 to T5 as well as the supraspinous ligament. It inserts on the medial border of the scapula, from about the level of the scapular spine to the scapula's inferior angle.

The rhomboid major is considered a superficial back muscle. It is deep to the trapezius, and is located directly inferior to the rhomboid minor. As the word rhomboid suggests, the rhomboid major is diamond-shaped. The major in its name indicates that it is the larger of the two rhomboids.

Innervation
The rhomboid major, like the rhomboid minor, is innervated by the dorsal scapular nerve (C5).

Actions
The rhomboid major helps to hold the scapula (and thus the upper limb) onto the ribcage. It also acts to retract the scapula, pulling it towards the vertebral column.