Sechenov School
Home › Human Anatomy › Teres Minor and Major Muscles: Anatomy and Innervation

Shoulder Girdle Muscles: Teres Minor and Teres Major

Musculus teres minor

For medical students2 min readUpdated 2026-10-10

The teres minor muscle is an essential component of the shoulder girdle, responsible for lateral rotation of the arm. While this overview covers both the teres major and teres minor muscles, we will focus in detail on the topography, innervation, and function of the teres minor, as well as briefly examine the flexor carpi ulnaris.

ActionLaterally rotates the arm and retracts the articular capsule
InsertionInferior facet of the greater tubercle of the humerus
Blood supplyCircumflex scapular artery (a. circumflexa scapulae)
BursaSubtendinous bursa of teres minor muscle (bursa subtendinea m. teretis minoris)

Attachment Sites of the Teres Minor Muscle

The teres minor muscle (m. teres minor) has well-defined points of origin and insertion that determine its biomechanical role in the glenohumeral joint:

Function, Innervation, and Blood Supply

Understanding muscle function requires knowledge of its neurovascular supply.

Function (Actio): Its primary role is lateral rotation (supination) of the arm. Additionally, during joint movement, it retracts the capsule of the shoulder joint, preventing it from becoming impinged between the articular surfaces.

Innervation (Nervus): Motor impulses are supplied by the axillary nerve (n. axillaris). This nerve arises from the C₅–C₆ spinal nerve roots.

Blood Supply (Vasa): Tissue perfusion is provided by the circumflex scapular artery (a. circumflexa scapulae).

Notably, a key topographical feature is the presence of the subtendinous bursa of the teres minor (bursa subtendinea m. teretis minoris) located between the muscle and the shoulder joint capsule, which reduces friction during contraction.

Flexor Carpi Ulnaris (Additional)

As part of studying the upper limb musculature, the flexor carpi ulnaris (m. flexor carpi ulnaris) is also notable.

Attachment Sites:

Biomechanics and Blood Supply: This muscle flexes and adducts the wrist (ulnar deviation). Blood supply is provided by the ulnar artery (a. ulnaris) along with the superior and inferior ulnar collateral arteries (a. collateralis ulnaris superior et inferior). Innervation is supplied by the ulnar nerve (n. ulnaris, C₇–C₈).

Frequently asked questions

Where does the teres major muscle originate?

The teres major muscle (m. teres major) originates from several structures on the scapula:

  • Inferior angle of the scapula (angulus inferior scapulae).
  • Lateral border of the scapula (margo lateralis) — from the lower half of this border.
  • Infraspinatous fascia (fascia infraspinata) — from the outer surface of this fascia.
Where does the teres major muscle insert?

The teres major muscle (m. teres major) inserts into the proximal humerus:

  • Crest of the lesser tubercle (crista tuberculi minoris humeri) — the ridge extending distally from the lesser tubercle of the humerus.

Near its insertion, a bursa (bursa subtendinea m. teretis majoris) lies between its tendon and the tendon of the latissimus dorsi.

What are the functions of the teres major muscle?

The teres major performs several actions on the arm:

  • Adduction — pulls the upper limb toward the trunk.
  • Extension — brings the arm from a flexed position posteriorly.
  • Medial rotation — turns the humerus medially.
  • Lowering an elevated arm — returns the limb to the anatomical position.
What is the innervation of the teres major muscle?

The teres major muscle (m. teres major) is innervated by:

  • Lower subscapular nerve (n. subscapularis) — C₆–C₇.

Additionally, sources classify the teres major as being closely related to muscles innervated by the thoracodorsal nerve (C₅–C₈, from the posterior cord of the brachial plexus).

Which shoulder girdle muscles laterally rotate the arm?

Lateral rotation of the arm is performed by several shoulder girdle muscles:

  • Teres minor muscle (m. teres minor) — additionally retracts the joint capsule.
  • Infraspinatus muscle (m. infraspinatus) — also pulls on the joint capsule to prevent impingement.
  • Supraspinatus muscle (m. supraspinatus) — assists with lateral rotation and arm abduction.
Where does the teres minor muscle originate?

The muscle originates from the lateral border of the scapula.

Which artery supplies the teres minor muscle?

Blood supply is provided by the circumflex scapular artery (a. circumflexa scapulae).

What is the function of the flexor carpi ulnaris?

It flexes the wrist and adducts the hand toward the ulnar side.

Go deeper

More topics in Human Anatomy

Subclavian VeinThoracic NervesFacial Muscles of the MouthCerebral Cortex: Anatomy, Layers and TypesLumbar, Sacral and Coccygeal NervesMeninges: Anatomy, Layers, and SpacesLumbar PlexusSuperior Mesenteric ArteryExtensor Indicis Muscle: Anatomy, Origin, and FunctionNeural Pathways of the Nervous SystemSciatic NerveCommon and External Iliac ArteriesHuman Anatomy →