Shoulder region intrinsic Flashcards
Deltoid origin
- anterior head: lateral 1/3 of clavicle
- lateral/intermediate head: acromion
- posterior head: spine of the scapula
Deltoid insertion
All three heads insert into deltoid tuberosity of the humerus
deltoid innervation
axillary nerve C5-C6
Deltoid function
- anterior fibres: assist pec major, flexion and medial rotation;
- intermediate fibres: take over arm abduction after supraspinatus abducts first 15 degrees;
- posterior fibres: extension and lateral rotation
teres major origin
posterior surface of inferior angle of scapula
teres major insertion
Medial lip of intertubercular groove of humerus
teres major innervation
lower subscapular nerve C6, C7
teres major functions
- medial rotation,
- adduction
- stabilisation of shoulder joint
teres minor origin
upper 2/3rds of lateral border of scapula
teres minor insertion
greater tuberosity of humerus
teres minor innervation
axillary nerve c4,c5,c6
teres minor functions
laterally rotates arm
stabilises shoulder joint
subscapularis origin
subscapular fossa
subscapularis insertion
lesser tuberosity of humerus
subscapularis innervation
upper and lower subscapular nerves C5,6,7
subscapularis function
medially rotates arm, stabilises shoulder joint
supraspinatus origin
supraspinous fossa of scapula
supraspinatus insertion
greater tuberosity of humerus
supraspinatus innervation
suprascapular nerve c4,5,6
supraspinatus function
abducts arm, stabilises shoulder joint
infraspinatus origin
infraspinous fossa of scapula
infraspinatus insertion
greater tuberosity of humerus
infraspinatus innervation
suprascapular nerve c4,5,6
infraspinatus function
laterally rotates arm
- stabilises shoulder joint
