Skip to content
BodyworksPrime

Rhomboid Major Muscle Anatomy

Quick Overview View Flashcards
Origin
  • Spinous process of the T2 to T5 vertebrae
Insertion
  • Medial border of the scapula
Actions
  • Scapula retraction (adduction)
  • Scapula elevation
  • Scapula downward rotation
Innervation
  • Dorsal scapular nerve (C5)
Blood Supply
  • Dorsal scapular artery
Last updated: Estimated Reading Time: 8 min

Location & Overview

The rhomboid major is located in the upper back and plays a key role in connecting the vertebrae of the spine to the scapula (shoulder blade). The rhomboid major is one of the pair of muscles known as the rhomboids, which also include the rhomboid minor. The rhomboid major has an important role in maintaining the stability of the shoulder girdle and the scapula.[1,2]

The rhomboid major has a rhomboid shape, hence its name, and is larger and typically stronger than its minor counterpart. It is positioned inferior to the rhomboid minor and located deep to the broad and superficial trapezius muscle. As one of the deep back muscles, it lies against the thoracic vertebrae and the adjacent ribs. Lateral to the rhomboid major, you will find the serratus anterior, another muscle involved in scapular movement and stabilization. Anatomical variations of the rhomboid major and minor can occur, such as the fusion of the rhomboid major and minor into a single muscle.[1,2]

Given the significance of the rhomboid major in shoulder stability and scapular function, it is important to consider the potential problems that might arise from muscular weakness, functional abnormalities, or nerve issues. A noteworthy manifestation of such problems is scapular winging, a condition in which the scapula deviates away from the rib cage. This can occur when the rhomboids fail to exert their typical tension and control. Similarly, the inferior angle of the scapula may rotate as a result of rhomboid dysfunction, potentially leading to discomfort and a reduction in the range of shoulder movements.[3]

rhomboid major posterior view
Here we can see the rhomboid major from a posterior view.
rhomboid major posterolateral view
Here we can see the rhomboid major from a posterolateral view.
rhomboid major superior view
Here we can see the rhomboid major from a superior view.
rhomboid major and minor muscles together, posterior view
Here we can see the rhomboid major and minor together, seen from a posterior view.
rhomboid major highlighted in red among the other muscles of the body
Here we can see the rhomboid major highlighted in red among the other muscles of the body. Superficial muscles, such as the trapezius, have been removed to reveal the rhomboid major.

Origin & Insertion

The rhomboid major originates from the spinous processes of T2 through T5, which are located in the upper part of the thoracic spine. This region of the spine extends from the base of the neck down to the middle of the back. The second thoracic vertebra (T2) is found directly below the first thoracic vertebra (T1), and there are twelve thoracic vertebrae in total. The spinous processes of these vertebrae are projections from the posterior aspect of each vertebra. They are the pointed sections of bone that you can feel when you run your finger down the middle of your back.[3,4,1]

The rhomboid major inserts onto the medial border of the scapula, just below the insertion point of the rhomboid minor muscle. This location is the inner edge of the shoulder blade, closest to the vertebral column. Its insertion point is below the spine of the scapula. The spine of the scapula is a prominent bony ridge that runs horizontally across the posterior side of the scapula.[3,4,2]

origin of the rhomboid major muscle highlighted in red
Pictured here we can see the origin of the rhomboid major muscle. The spinous processes of the T2 to T5 vertebrae are highlighted in red.
insertion of the rhomboid major muscle highlighted in blue
Here we can see the insertion of the rhomboid major muscle highlighted in blue. It inserts on the medial border of the scapula.

Action & Function

The rhomboid major, like its minor counterpart, plays an important role in scapular movement. One of its main functions is to retract the scapula, drawing it inward toward the spinal column. This is the action of bringing the shoulder blades together, toward the midline of the body.[1,5,6]

Additionally, the rhomboid major assists in elevating the scapula, the equivalent to lifting the shoulders in a shrug.[1,5,6]

Finally, the muscle plays a role in the medial (downward) rotation of the scapula. This function positions the glenoid cavity, the cup-shaped socket in the shoulder joint, downward. The depression of the glenoid cavity through this rotation is essential for enabling a variety of arm movements and maintaining stability in the shoulder joint.[1,5,6]

Image of a person demonstrating the movement of scapula retraction.
This image shows scapula retraction, also known as scapula adduction, where the shoulder blades move toward the spine, as in the action of pinching the shoulder blades together. The opposite of scapula retraction is scapula protraction, also known as scapula abduction, where the shoulder blades move away from the spine, as in the action of reaching forward. Both the rhomboid major and minor retract the scapula.
Image of a person demonstrating the movement of scapula elevation.
This image shows scapula elevation, where the shoulder blade moves upward, drawing the shoulder joint superiorly. This movement happens when shrugging the shoulders or lifting a weight overhead. The opposite of scapula elevation is scapula depression. Both the rhomboid major and minor contribute to the elevation of the scapula.
Image of a person demonstrating the movement of scapula downward rotation.
This image shows scapula downward rotation, where the shoulder blade moves medially and inferiorly, tilting the glenoid cavity downward. This movement is typical when lowering the arm from an overhead position, bringing it back to the side. The opposite of scapula downward rotation is scapula upward rotation. Both the rhomboid major and minor assist with downward rotation of the scapula.

Innervation

The rhomboid major muscle receives its primary neural supply from the dorsal scapular nerve, a branch of the brachial plexus that originates from the spinal nerve root of C5. Located in the neck region, the brachial plexus is a complex arrangement of intersecting nerves. It has the important task of facilitating the transmission of neural signals between the spinal cord and the upper extremities, including the rhomboids.[1,2]

dorsal scapular nerve
Pictured here we can see the dorsal scapular nerve, which innervates the rhomboid major. This nerve generally originates from C5.

Blood Supply

The blood supply of the rhomboid major muscle is provided predominantly by the dorsal scapular artery. This artery usually originates from the second or third segment of the subclavian artery, a primary artery involved in delivering blood to the upper part of the body. However, in some individuals, there is a variation in which the dorsal scapular artery arises from the thyrocervical trunk instead. The thyrocervical trunk is another important artery located in the neck region.[1,7]

The dorsal scapular artery passes through the brachial plexus. The brachial plexus is a complex set of nerves found in the neck. The dorsal scapular artery and dorsal scapular nerve run inferiorly together; the nerve innervates the rhomboid muscles, while the artery supplies them with blood.[1,7]

Furthermore, an anatomical variation can occur in some individuals, in which the rhomboid major muscle is supplied by a deep branch of the transverse cervical artery. This is another artery located in the neck and shoulder area.[7,4]

References

  1. [1] Standring S. (2015). Gray’s Anatomy: The Anatomical Basis of Clinical Practice, 41st Edn. Amsterdam: Elsevier.
  2. [2] Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincott Williams & Wilkins; 2017.
  3. [3] Farrell C, Kiel J. Anatomy, Back, Rhomboid Muscles. (Updated 2022 May 20). In: StatPearls (Internet). Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK534856/
  4. [4] Mitchell B, Imonugo O, Tripp JE. Anatomy, Back, Extrinsic Muscles. (Updated 2022 Aug 25). In: StatPearls (Internet). Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK537216/
  5. [5] Martin RM, Fish DE. Scapular winging: anatomical review, diagnosis, and treatments. Curr Rev Musculoskelet Med. 2008 Mar;1(1):1-11. doi: 10.1007/s12178-007-9000-5. PMID: 19468892; PMCID: PMC2684151.
  6. [6] Paine R, Voight ML. The role of the scapula. Int J Sports Phys Ther. 2013 Oct;8(5):617-29. PMID: 24175141; PMCID: PMC3811730.
  7. [7] Ikka L, Mihalea C, Achour NB, Khalek HA, Vacher C. The origin of the dorsal scapular artery: anatomic variations and surgical applications. Surg Radiol Anat. 2016 Nov;38(9):1021-1027. doi: 10.1007/s00276-016-1656-3. Epub 2016 Feb 26. PMID: 26920558.

New Content

View the Latest Posts

View all posts