Rhomboid minor muscle

In human anatomy, the rhomboid minor is a small skeletal muscle of the back that connects the scapula to the vertebrae of the spinal column.^[1] It arises from the nuchal ligament, the 7th cervical and 1st thoracic vertebrae and intervening supraspinous ligaments; it inserts onto the medial border of the scapula, and is innervated by the dorsal scapular nerve. It acts together with the rhomboid major to keep the scapula pressed against the thoracic wall.^[2]

Rhomboid minor
Muscles connecting the upper extremity to the vertebral column. (Rhomboid minor in red)
Details
Origin	Nuchal ligaments and spinous processes of C7-T1
Insertion	Medial border of scapula, superior to the insertion of rhomboid major muscle
Artery	Deep branch of transverse cervical artery
Nerve	Dorsal scapular nerve (C4–5)
Actions	Retracts and rotates scapula, fixes scapula to thoracic wall
Antagonist	Serratus anterior
Identifiers
Latin	musculus rhomboideus minor
TA98	A04.3.01.008
TA2	2233
FMA	13380
Anatomical terms of muscle [edit on Wikidata]

Anatomy

Origin

The rhomboid minor arises from the inferior border of the nuchal ligament, from the spinous processes of the vertebrae C7–T1, and from the intervening supraspinous ligaments.^[3]

Insertion

It inserts onto a small area of the medial border of the scapula at the level of the scapular spine.^[4]

Innervation

It is innervated by the dorsal scapular nerve (a branch of the brachial plexus), with most of its fibers derived from the C5 nerve root and only minor contribution from C4 or C6.^[5]

Blood supply

The rhomboid minor receives arterial blood supply from the dorsal scapular artery.^[6]

Relations

It is located inferior to levator scapulae, and superior to rhomboid major.^{[citation needed]}

It lies deep to trapezius, and superficial to the long spinal muscles.^[3]

Variation

It is usually separated from the rhomboid major by a slight interval, but the adjacent margins of the two muscles are occasionally united.^[7]

Actions/movements

Together with the rhomboid major, the rhomboid minor retracts the scapula when the trapezius is contracted. Acting as a synergist to the trapezius, the rhomboid major and minor elevate the medial border of the scapula medially and upward, working in tandem with the levator scapulae muscle to rotate the scapulae downward. While other shoulder muscles are active, the rhomboid major and minor stabilize the scapula.^[8]

Additional images

• 
  Position of rhomboid minor muscle (shown in red).
• 
  Left scapula. Dorsal surface.
• 
  The scapular and circumflex arteries.
• 
  Full back muscle flex.