Rhomboid Major
Shoulder & Scapula · Upper Limb
The rhomboid major is a flat, quadrilateral muscle of the upper back that lies deep to trapezius. It arises from the spinous processes of T2 to T5 and runs downward and laterally to the medial border of the scapula below the spine. When it contracts it retracts (adducts) the scapula toward the vertebral column, downwardly rotates the glenoid cavity, and helps elevate the scapula, together anchoring the shoulder blade to the trunk during pulling movements. It is supplied by the dorsal scapular nerve (C4, C5).
Origin, Insertion, Action & Nerve
Origin
Spinous processes of T2–T5
Insertion
Medial border of scapula, below the spine
Action
Retracts (adducts) the scapula, downwardly rotates the glenoid cavity, and elevates the scapula
Nerve
Dorsal scapular nerve (C4, C5)
Attachments explained
The Rhomboid Major is defined first by where it attaches. Its origin is the more fixed anchor, usually the proximal or more stable end that stays put during contraction, while its insertion is the more mobile point that is pulled toward the origin when the muscle shortens.
Origin
Spinous processes of T2–T5
Insertion
Medial border of scapula, below the spine
Action & function
When the Rhomboid Major contracts, it produces the following movement: Retracts (adducts) the scapula, downwardly rotates the glenoid cavity, and elevates the scapula.
As part of the Shoulder & Scapula group of the Upper Limb, it works alongside neighbouring muscles to generate smooth, coordinated movement and to stabilise the structures it acts on.
Nerve supply & clinical relevance
The Rhomboid Major receives its nerve supply from the Dorsal scapular nerve (C4, C5). This nerve carries fibres from spinal segment(s) C4, C5.
Because a muscle can only contract when its nerve is intact, injury to the Dorsal scapular nerve or to its spinal roots (C4, C5) can weaken or paralyse the Rhomboid Major, impairing the movements it normally produces (retracts (adducts) the scapula, downwardly rotates the glenoid cavity, and elevates the scapula). This is why knowing the innervation is central to localising nerve lesions in clinical practice.
How to study the Rhomboid Major (the OIANS method)
Picture the rhomboids as diagonal straps running from the spine down to the medial border of the scapula; that downward-and-outward line of pull is why they retract the scapula toward the backbone. Learning rhomboid major and minor together works well, since they differ mainly in size and vertebral level rather than function.
Remember the dorsal scapular nerve as the shared supply of both rhomboids, and note it is one of the muscles that fixes the scapula so other muscles can move the arm. Squeezing your shoulder blades together and feeling the pull between spine and scapula makes the retraction action stick.
Frequently asked questions
Where is the Rhomboid Major located?
The Rhomboid Major is a muscle of the Shoulder & Scapula group, located in the Upper Limb.
What is the origin of the Rhomboid Major?
Spinous processes of T2–T5
What is the insertion of the Rhomboid Major?
Medial border of scapula, below the spine
What movements does the Rhomboid Major produce?
Retracts (adducts) the scapula, downwardly rotates the glenoid cavity, and elevates the scapula
What nerve supplies the Rhomboid Major?
Dorsal scapular nerve (C4, C5)
Is the Rhomboid Major free to study in OIANS?
Yes. The Rhomboid Major is free in OIANS: its full origin, insertion, action and nerve details are open to everyone in the Muscle Directory, and because it belongs to the Upper Limb it is also covered by the free Quiz and Flashcard decks. The other regions, the "All Muscles" deck, and the Progress and Explore tools are unlocked with a one-time Lifetime purchase.
Related muscles
Study the Rhomboid Major
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