EMET Education
3D Anatomy
Shoulder
Supraspinatus muscle

Anatomy · Shoulder · Rotator cuff

The Supraspinatus Muscle in 3D

Q: Where does the supraspinatus insert?

On the superior facet of the greater tuberosity and the upper half of the middle facet. Its tendinous anterior portion also reaches the superior lesser tuberosity in 21% of specimens. Its footprint averages 12.6 mm wide and 6.9 mm long (Mochizuki, 26 shoulders).

Q: What nerve innervates the supraspinatus?

The suprascapular nerve, from the C5 and C6 roots.

Q: How do you assess supraspinatus atrophy on MRI?

On the oblique sagittal Y view: fossa occupation ratio (mean 0.70 in controls per Thomazeau) and the tangent sign (Zanetti).

Q: What is the rotator cable?

A thick bundle bordering the thin distal part of the supraspinatus and infraspinatus, the crescent. On average 2.59 times thicker, it takes up the crescent's stress like a suspension bridge (Burkhart).

Q: Why does it have two bellies?

By fiber insertion, the muscle divides into an anterior and a posterior belly. The anterior one has a 2.45 times larger physiological cross-sectional area and pulls through a thinner tendon (Roh).

Q: Are the MRI images on this page real?

No: they are synthetic, computed from the 3D model. They show where the muscle lies on a slice; they do not replace an actual exam.

The supraspinatus in 3D, layer by layer, then on labeled MRI slices. With its measured footprint, what anatomic studies have found over thirty years, and the landmarks for reading its atrophy.

See the MRI slices Open the rotator cuff in 3D

Latin musculus supraspinatus · French supra-épineux, sus-épineux

The supraspinatus in 3D seen from above and behind: from the supraspinous fossa to the greater tuberosity, under the acromion; infraspinatus and teres minor faded. — Render of the EMET Education 3D model.

12.6 mmAnteroposterior width of the footprint on the greater tuberosity (26 shoulders)
2.45Physiological cross-sectional area of the anterior belly relative to the posterior one (25 shoulders)
0.70Share of the fossa filled by the muscle on the Y-view MRI, in controls
2.59Rotator cable thickness relative to the crescent it protects

At a glance

Origin, insertion, innervation

Sources: Gray's Anatomy; insertion: Minagawa, Mochizuki; relations: Clark and Harryman.
Origin	Medial two-thirds of the supraspinous fossa and supraspinous fascia.
Course	Beneath the coracoacromial arch (acromion, coracoacromial ligament), separated from it by the subacromial-subdeltoid bursa, above the glenohumeral joint.
Insertion	Superior facet of the greater tuberosity and upper half of the middle facet; inconsistently, the superior lesser tuberosity (21% of specimens).
Innervation	Suprascapular nerve (C5, C6).
Blood supply	Suprascapular artery.
Action	Arm abduction with the deltoid; compression of the humeral head into the glenoid.
Relations	Anteriorly, the rotator interval, long head of biceps, and subscapularis; posteriorly, the infraspinatus, whose tendon partly covers it; superiorly, the coracoacromial arch and bursa; deep, the capsule.

Layer by layer

From the trapezius to the tendon

The same view, from above and behind the shoulder, removing one layer per image.

Trapezius and deltoidThe supraspinatus is hidden: the trapezius covers the fossa, the deltoid the humeral head.
The bursaTrapezius and deltoid removed: the subacromial-subdeltoid bursa caps the tendon.
The cuffBursa removed: the supraspinatus in its fossa above the spine, the infraspinatus below.
The supraspinatusOther muscles faded: from the fossa to the greater tuberosity, under the acromion.

Imaging

The supraspinatus on MRI and CT

Synthetic images. These slices do not come from a patient: they are computed from the 3D model, by cutting each structure and giving it the signal it would have in the chosen sequence, on MRI or CT. They are for learning where the muscle lies on a slice; nothing is measured on them.

Supraspinatus outline

Synthetic MRI, oblique sagittal Y view: rounded supraspinatus in the supraspinous fossa. — **Oblique sagittal Y view**Through the medial border of the coracoid, where the spine, coracoid, and scapular body form a Y. The reference view for atrophy: the muscle fills 70% of the fossa in controls, 62% in degenerative cuffs without tear, 44% after operated tears (Thomazeau). A healthy muscle crosses the line joining the superior borders of the spine and coracoid: the tangent sign is negative (Zanetti).

Synthetic MRI, oblique coronal view: the supraspinatus from the fossa to the greater tuberosity, under the acromion. — **Oblique coronal view**Along the muscle, parallel to the scapular plane: the muscle in the fossa, the tendon under the acromion, the bursa above it, the insertion on the greater tuberosity.

Synthetic MRI, axial view above the humeral head: supraspinatus belly and tendon. — **Axial view**Above the humeral head: the muscle belly in the fossa, medially, and the tendon wrapping the head anteriorly.

3D shoulder model with the oblique sagittal Y-view plane.

Where the Y view cuts

The oblique sagittal plane (green) on the 3D model: parallel to the glenoid, it crosses the scapula where the spine still meets the body. Hover over a slice and click “Scroll” to page through it as on a workstation: the muscle tapers into tendon laterally.

In numbers

The footprint and the muscle, measured

Published mean values, with sample size and source under each figure.

Footprint anteroposterior width, in ascending order
Value	Reference	Year	Sample	Note
12.6 mm	Mochizuki	2008	26 shoulders	Mean maximum; triangular footprint, part of the surface being occupied by infraspinatus
23 mm	Curtis	2006	20 cadavers	Mean maximum length (23 × 16 mm); orientation to be confirmed in the full text to be confirmed
25 mm	Ruotolo	2004	17 specimens	Mean; 17 intact specimens kept out of 48, mean age 70 years

Footprint medial-to-lateral length, in ascending order
Value	Reference	Year	Sample	Note
6.9 mm	Mochizuki	2008	26 shoulders	Mean maximum
12.1 mm	Ruotolo	2004	17 specimens	Mean, at mid-tendon (11.6 at the rotator interval, 12 at the posterior edge)
14.7 mm	Dugas	2002	10 specimens	Minimum transverse dimension of the whole cuff insertion at mid supraspinatus (± 3.2); lower bound of the calculation
16 mm	Curtis	2006	20 cadavers	Mean maximum width (23 × 16 mm); orientation to be confirmed in the full text to be confirmed

Insertion area, in ascending order
Value	Reference	Year	Sample	Note
1.55 cm²	Dugas	2002	10 specimens	Mean (± 0.66; 0.68 to 2.64), 3D digitizer mapping

Distance from the articular cartilage to the insertion, in ascending order
Value	Reference	Year	Sample	Note
< 1 mm	Dugas	2002	–	Less than 1 mm along the anterior 2.1 cm of the cuff insertion
1.7 mm	Ruotolo	2004	17 specimens	Mean (1.5 to 1.9), from the cartilage margin to the bony tendon insertion

Published means, from smallest to largest. Sample size is as each study reports it (shoulders, cadavers or specimens); measurement protocols differ from one study to the next.

Maximum dimensions, to scale: a bounding box, not the shape of the footprint.

12.6 mmAnterior half of the superior cuff tendon, supraspinatus only (± 1.1)Mean, 10 shoulders · Minagawa 1998
140 mm²Anterior belly physiological cross-sectional area (± 43), 2.45 times the posteriorMean, 25 shoulders · Roh 2000
3.5 mmSuperior capsule, minimum attachment width on the greater tuberosityNimura 2012
2.59Cable thickness relative to crescent thicknessMean, 20 shoulders · Burkhart 1993
0.70Fossa occupation ratio on the Y view, controlsMean, 15 shoulders · Thomazeau 1996

Published insertion dimensions vary from study to study. Mochizuki found a smaller footprint than previously described, with the infraspinatus occupying part of the area; Nimura showed that the capsule also attaches to the greater tuberosity, and that studies not separating it overestimated the footprint.

History

How its description has changed since 1992

Classic anatomy describes an insertion on the superior facet of the greater tuberosity. Anatomic studies published since have refined it, step by step.

1992
A common insertion
The cuff tendons do not insert separately: they interdigitate into a continuous, five-layered insertion. Clark and Harryman
1993
The suspension bridge
A thick cable borders the crescent, the thin distal part of the supraspinatus and infraspinatus, and shields it from stress. Burkhart
2000
Two bellies
The anterior belly, with the larger physiological cross-sectional area, pulls through a thinner tendon: stress is higher in the anterior tendon, which should be included in any repair. Roh
2002
Right at the cartilage
Along its first 2 cm, the cuff insertion lies within 1 mm of the articular margin. Dugas
2008
A small triangle
The supraspinatus footprint is a triangle at the front of the greater tuberosity, smaller than described; the infraspinatus occupies much of the area once attributed to it. Mochizuki
2012
The capsule too
The capsule also attaches to the greater tuberosity: by not separating it, earlier studies overestimated the footprint. Its thinnest point lies at the posterior edge of the supraspinatus insertion. Nimura

In practice

What anatomy changes in practice

Reading atrophy. On the Y view: fossa occupation ratio (Thomazeau) and the tangent sign, positive in 9 of 10 patients with large tears and in none of 70 asymptomatic subjects (Zanetti).
Grading fatty infiltration. On CT (Goutallier) and on MRI, each method is reproducible between observers, but agreement between them is only fair to moderate: the two gradings are not interchangeable (Fuchs).
After repair. Moderate supraspinatus fatty infiltration regressed in 6 of 14 patients; infraspinatus infiltration weighed heavily on the outcome (Goutallier).
Repairing the right tendon. The anterior tendon is the muscle's primary contractile unit (Roh).

Your turn

Where is the supraspinatus?

Six unlabeled synthetic slices, in random order: click the supraspinatus. The answer shows its outline.

Unlabeled synthetic MRI slice of the shoulder.

Click the supraspinatus.

Conditions

Related conditions

Rotator cuff tear3D model: full-thickness or partial tear, calcification, repair

Classifications

Related classifications

HamadaMassive rotator cuff tears: grades 1 to 5, in 3D
PatteSupraspinatus tendon retraction: stages 1 to 3, in 3D and in section
SoonGoutallierFatty infiltration of the cuff muscles, on CT (1994)
SoonThomazeauSupraspinatus atrophy on the Y-view MRI (1996)

Neighbors

Its neighbors

InfraspinatusPosterior
SubscapularisAnterior
SoonLong head of bicepsAnterior
SoonCoracoacromial ligamentSuperior
SoonSubacromial bursaSuperficial
SoonDeltoidSuperficial
SoonTrapeziusSuperficial
SoonJoint capsuleDeep

Questions

Frequently asked questions

Where does the supraspinatus insert?

On the superior facet of the greater tuberosity and the upper half of the middle facet. Its tendinous anterior portion also reaches the superior lesser tuberosity in 21% of specimens. Its footprint averages 12.6 mm wide and 6.9 mm long (Mochizuki, 26 shoulders).

What nerve innervates the supraspinatus?

The suprascapular nerve, from the C5 and C6 roots.

How do you assess supraspinatus atrophy on MRI?

On the oblique sagittal Y view: fossa occupation ratio (mean 0.70 in controls per Thomazeau) and the tangent sign (Zanetti).

What is the rotator cable?

A thick bundle bordering the thin distal part of the supraspinatus and infraspinatus, the crescent. On average 2.59 times thicker, it takes up the crescent's stress like a suspension bridge (Burkhart).

Why does it have two bellies?

By fiber insertion, the muscle divides into an anterior and a posterior belly. The anterior one has a 2.45 times larger physiological cross-sectional area and pulls through a thinner tendon (Roh).

Are the MRI images on this page real?

No: they are synthetic, computed from the 3D model. They show where the muscle lies on a slice; they do not replace an actual exam.

Sources

Author and references

Designed by Mikaël Chelli, MD, orthopedic surgeon, from Gray's Anatomy and articles whose abstracts were checked on PubMed. Last reviewed October 7, 2026.

Standring S, ed. Gray's Anatomy: The Anatomical Basis of Clinical Practice. 42nd ed. Elsevier; 2020.
Clark JM, Harryman DT 2nd. Tendons, ligaments, and capsule of the rotator cuff. Gross and microscopic anatomy. J Bone Joint Surg Am. 1992;74(5):713–725. PMID 1624486
Burkhart SS, Esch JC, Jolson RS. The rotator crescent and rotator cable: an anatomic description of the shoulder's "suspension bridge". Arthroscopy. 1993;9(6):611–616. doi:10.1016/s0749-8063(05)80496-7
Goutallier D, Postel JM, Bernageau J, Lavau L, Voisin MC. Fatty muscle degeneration in cuff ruptures. Pre- and postoperative evaluation by CT scan. Clin Orthop Relat Res. 1994;(304):78–83. PMID 8020238
Thomazeau H, Rolland Y, Lucas C, Duval JM, Langlais F. Atrophy of the supraspinatus belly. Assessment by MRI in 55 patients with rotator cuff pathology. Acta Orthop Scand. 1996;67(3):264–268. doi:10.3109/17453679608994685
Minagawa H, Itoi E, Konno N, et al. Humeral attachment of the supraspinatus and infraspinatus tendons: an anatomic study. Arthroscopy. 1998;14(3):302–306. doi:10.1016/s0749-8063(98)70147-1
Zanetti M, Gerber C, Hodler J. Quantitative assessment of the muscles of the rotator cuff with magnetic resonance imaging. Invest Radiol. 1998;33(3):163–170. doi:10.1097/00004424-199803000-00006
Fuchs B, Weishaupt D, Zanetti M, Hodler J, Gerber C. Fatty degeneration of the muscles of the rotator cuff: assessment by computed tomography versus magnetic resonance imaging. J Shoulder Elbow Surg. 1999;8(6):599–605. doi:10.1016/s1058-2746(99)90097-6
Roh MS, Wang VM, April EW, Pollock RG, Bigliani LU, Flatow EL. Anterior and posterior musculotendinous anatomy of the supraspinatus. J Shoulder Elbow Surg. 2000;9(5):436–440. doi:10.1067/mse.2000.108387
Dugas JR, Campbell DA, Warren RF, Robie BH, Millett PJ. Anatomy and dimensions of rotator cuff insertions. J Shoulder Elbow Surg. 2002;11(5):498–503. doi:10.1067/mse.2002.126208
Curtis AS, Burbank KM, Tierney JJ, Scheller AD, Curran AR. The insertional footprint of the rotator cuff: an anatomic study. Arthroscopy. 2006;22(6):609.e1. doi:10.1016/j.arthro.2006.04.001
Ward SR, Hentzen ER, Smallwood LH, et al. Rotator cuff muscle architecture: implications for glenohumeral stability. Clin Orthop Relat Res. 2006;448:157–163. doi:10.1097/01.blo.0000194680.94882.d3
Mochizuki T, Sugaya H, Uomizu M, et al. Humeral insertion of the supraspinatus and infraspinatus. New anatomical findings regarding the footprint of the rotator cuff. J Bone Joint Surg Am. 2008;90(5):962–969. doi:10.2106/JBJS.G.00427
Nimura A, Kato A, Yamaguchi K, et al. The superior capsule of the shoulder joint complements the insertion of the rotator cuff. J Shoulder Elbow Surg. 2012;21(7):867–872. doi:10.1016/j.jse.2011.04.034
Patte D. Classification of rotator cuff lesions. Clin Orthop Relat Res. 1990;(254):81–86. PMID 2323151
Ruotolo C, Fow JE, Nottage WM. The supraspinatus footprint: an anatomic study of the supraspinatus insertion. Arthroscopy. 2004;20(3):246–249. doi:10.1016/j.arthro.2004.01.002