Rhomboideus

The rhomboideus refers to the rhomboid muscle group comprising the rhomboideus major and rhomboideus minor, muscles of the upper back that connect the scapula to the vertebral column. They lie deep to the trapezius and lie medially along the scapular border.

Rhomboideus minor originates from the nuchal ligament and the spinous processes of C7 and T1, and inserts on the medial border of the scapula at the level of the spine. Rhomboideus major originates from the spinous processes of T2 through T5 and adjacent supraspinous ligaments, and inserts along the medial border of the scapula from the spine to the inferior angle.

The muscles are innervated primarily by the dorsal scapular nerve (C4–C5). They receive blood supply from the dorsal scapular artery or from the deep branch of the transverse cervical artery, with possible contributions from nearby vessels.

Functionally, the rhomboidei retract (adduct) the scapula, elevate it, and rotate the scapula downward to depress the glenoid cavity. They work with the trapezius to stabilize the scapula during arm movements and maintain proper shoulder mechanics.

Clinically, injury or palsy of the dorsal scapular nerve can weaken the rhomboidei, leading to medial border prominence of the scapula (scapular winging) during pushing or pulling activities and impaired scapular stabilization.