Rhomboid minor muscle

Rhomboid minor
File:Rhomboideus minor.png Muscles connecting the upper extremity to the vertebral column. (Rhomboid minor in red)
Details
Latin	musculus rhomboideus minor
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 transverse cervical artery
Nerve	dorsal scapular nerve (C4–5)
Actions	Retracts and rotates scapula, fixes scapula to thoracic wall
Antagonist	serratus anterior
Identifiers
Dorlands /Elsevier	m_22/12550544
TA
TH	{{#property:P1694}}
TE	{{#property:P1693}}
FMA	{{#property:P1402}}
Anatomical terms of muscle [[[d:|edit on Wikidata]]]

In human anatomy, the rhomboid minor is a small skeletal muscle on the back that connects the scapula with the vertebrae of the spinal column.

Located inferior to levator scapulae and superior to rhomboid major, it acts together with the latter to keep the scapula pressed against the thoracic wall. It lies deep to trapezius but superficial to the long spinal muscles.

Origin and insertion

The rhomboid minor arises from the inferior border of the nuchal ligament, from the spinous processes of the seventh cervical and first thoracic vertebrae, and from the intervening supraspinous ligaments.

It is inserted into a small area of the medial border of the scapula at the level of the scapular spine.

Action

Together with the rhomboid major, the rhomboid minor retracts the scapula when trapezius is contracted. Acting as an antagonist 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.

Innervation and blood supply

The nerve supply comes from the dorsal scapular nerve, with most of its fibers derived from the C5 nerve root and only minor contribution from C4 or C6.

The rhomboid minor gets its arterial blood supply from the dorsal scapular artery.

Variation

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

Additional images

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

References

This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)

External links

• Anatomy photo:01:st-0211 at the SUNY Downstate Medical Center