Scapulohumeral Muscles

Deltoid Purposeful Activity:

Yoga poses with arms overhead; reaching for (anterior) and putting on (posterior) a seatbelt

Deltoid Action : Anterior

: • Anterior: shoulder flexion, shoulder internal rotation

Deltoid Action: Middle

shoulder ABDuction

Deltoid Action: Posterior

shoulder extension, shoulder external rotation

Deltoid Origin : Anterior

(clavicular): clavicle

Deltoid Origin: Posterior

spine of scapula)

Deltoid Origin: middle

(acromial): acromion

Deltoid Insertion:

deltoid tuberosity of humerus

Deltoid Innervation

Axillary nerve (C5, C6)

Deltoid Blood Supply

Posterior humeral circumflex

Rotator Cuff SITS muscles

◦ Supraspinatus

◦ Infraspinatus

◦ Teres minor

◦ Subscapularis

Supraspinatus Purposeful Activity:

Painting overhead; washing your hair

Supraspinatus Action:

Shoulder abduction; Stabilization of the humeral head on the glenoid fossa

Supraspinatus Origin:

Supraspinous fossa of scapula

Supraspinatus Insertion:

Superior facet of greater tubercle of humerus

Supraspinatus Innervation:

Suprascapular nerve (C4, C5, C6)

Infraspinatus Purposeful Activity:

Playing racket sports or table tennis

Infraspinatus Action:

Shoulder external rotation; Stabilization of the humeral head on the glenoid fossa

Infraspinatus Origin:

Infraspinous fossa of scapula

Infraspinatus Insertion:

Middle facet of greater tubercle of humerus

Infraspinatus Innervation:

Suprascapular nerve (C5, C6)

Infraspinatus Blood Supply:

Suprascapular artery

Teres Minor Purposeful Activity:

Washing the back of the head and neck

Teres Minor Action:

Shoulder external rotation of shoulder joint;

Stabilization of the humeral head on the glenoid

fossa

Teres Minor Origin:

Middle part of lateral border of scapula

Teres Minor Insertion:

Inferior facet of greater tubercle of humerus

Teres Minor Innervation:

Axillary nerve (C5, C6)

Teres Minor Blood Supply:

Circumflex scapular artery, posterior circumflex

humeral artery

Subscapularis Purposeful Activity:

Toileting, donning bra, throwing a baseball

Subscapularis Action:

Internal rotation of shoulder joint, ADDuction of shoulder, Stabilize the humeral head on the glenoid fossa

Subscapularis Origin:

Subscapular fossa

Subscapularis Insertion:

Lesser tubercle of humerus

Subscapularis Innervation:

Upper and lower subscapular nerves (C5, C6,

C7)

Teres Major Purposeful Activity:

Toileting and perineal care

Teres Major Action:

Shoulder adduction; shoulder internal rotation; shoulder extension

Teres Major Origin:

Inferior part of lateral border of scapula and

posterior surface of inferior angle of scapula

Teres Major Insertion:

Medial lip of lesser tubercle of humerus

Teres Major Innervation:

Lower subscapular nerve (C5, C6)

Teres Major Blood Supply:

Circumflex scapular artery, subscapular artery