Muscles of the shoulder girdle

Shoulder Girdle Muscles: Anatomy and FunctionAnatomy, function, blood supply and innervation of shoulder girdle muscles
~ 3 min

In this pdf-note, we’ll start with the borders of the upper limb:

The anterior border is the deltopectoral groove
The posterior border is the posterior deltoid groove

Within the upper limb, there is a large number of regions:

Deltoid region (regio deltoidea)
Axillary region (regio axillaris)
Anterior region of the arm (regio brachialis anterior)
Posterior region of the arm (regio brachialis posterior)
Anterior region of the elbow (regio cubitalis anterior)
Posterior region of the elbow (regio cubitalis posterior)
Anterior region of the forearm (regio anterobrachialis anterior)
Posterior region of the forearm (regio anterobrachialis posterior)
Anterior region of the wrist (regio carpalis anterior)
Posterior region of the wrist (regio carpalis posterior)
Palmar region of the hand (regio palmaris manus)
Dorsal region of the hand (regio dorsalis manus)

Within these areas, the muscles of the upper limb are located.

These include:

Pectoral girdle muscles
Muscles of the free part of the upper limb
The muscles of the pectoral girdle form two layers: superficial and deep.
The surface muscles include the deltoid muscle (m. deltoideus).
Deltoid muscle (m. deltoideus)
Deltoid muscle (m. deltoideus)
Deltoid muscle (m. deltoideus)

Deltoid muscle
(m. deltoideus)

Origin:

Clavicular part (pars clavicularis) arises from the lateral third of the clavicle

Acromial part (pars acromialis) arises from the acromion

Spinous part (pars spinalis) arises from the spine of the scapula

Insertion: deltoid tuberosity of the humerus

Function: arm abduction (up to the horizontal level), the anterior bundles also flex and pronate the arm, while the posterior ones extend and supinate it

Innervation: axillary nerve (C5-C6)

Blood supply: thoraco-acromial artery, posterior circumflex humeral artery

The deep muscles include:
Supraspinatus muscle (m. supraspinatus)
Supraspinatus muscle (m. supraspinatus)
Supraspinatus muscle (m. supraspinatus)

Supraspinatus muscle
(m. supraspinatus)

Origin: supraspinatus fossa of the scapula

Insertion: greater tubercle of the humerus, capsule of the shoulder joint

Function: arm abduction, as well as stretching of the capsule of the shoulder joint

Innervation: suprascapular nerve (C5-C6)

Blood supply: suprascapular artery, circumflex scapular artery
Infraspinatus muscle (m. infraspinatus)
Infraspinatus muscle (m. infraspinatus)
Infraspinatus muscle (m. infraspinatus)
Infraspinatus muscle (m. infraspinatus)

Infraspinatus muscle
(m. infraspinatus)

Origin: infraspinous fossa of the scapula

Insertion: greater tubercle of the humerus, capsule of the shoulder joint

Function: arm supination, as well as stretching of the capsule of the shoulder joint

Innervation: suprascapular nerve (C5-C6)

Blood supply: circumflex scapular artery, suprascapular artery
Teres major muscle (m. teres major)
Teres major muscle (m. teres major)
Teres major muscle (m. teres major)
Teres major muscle (m. teres major)

Teres major muscle
(m. teres major)

Origin: lateral border of the scapula, inferior angle of the scapula

Insertion: crest of the lesser tubercle of the humerus

Function: arm pronation, arm adduction, arm extension

Innervation: subscapular nerve (C5-C7)

Blood supply: subscapular artery
Teres minor muscle (m. teres minor)
Teres minor muscle (m. teres minor)
Teres minor muscle (m. teres minor)

Subscapularis muscle
(m. subscapularis)

Origin: subscapular fossa (costal surface of the scapula)

Insertion: lesser tubercle of the humerus, crest of the lesser tubercle of the humerus, capsule of the shoulder joint

Function: arm pronation, arm adduction

Innervation: subscapular nerve (C5-C7)

Blood supply: subscapular artery
Subscapularis muscle (m. subscapularis)