Intrinsic muscles of the glenohumeral joint Flashcards
(24 cards)
Where does deltoid originate?
Anterior: upper surface of lateral 1/3 clavicle.
Lateral: acromion process
Posterior: posterior border of spine of scapula
Where does deltoid insert?
Deltoid tuberosity
What innervates deltoid?
Axillary Nerve (C5, C6)
What are the actions of deltoid?
Anterior: flexion
Posterior: retraction
All fibres: abduction
Where does supraspinatus originate?
Medial 2/3 of supraspinous fossa
Where does supraspinatus insert?
Most superior facet on the greater tubercule
What innervates supraspinatus?
Suprascapular Nerve C5, C6
What is the action of supraspinatus?
Abduction to 15 degrees
Where does infraspinatus originate?
Medial 2/3 of infraspinous fossa
Where does infraspinatus insert?
Middle facet on posterior surface of greater tubercule
What innervates infraspinatus?
Suprascapular Nerve C5, C6
What is the action of Infraspinatus
Lateral rotation
Where does teres minor originate?
Upper 2/3 of lateral border of the scapula
Where does teres minor insert?
Inferior facet of posterior surface of the greater tubercule
What innervates teres minor?
Axillary Nerve (C6, C6)
What is the action of teres minor?
Lateral Rotation
What is the origin of teres major?
Lower part of lateral border of and inferior angle of the scapular
Where does teres major insert?
Medial lip of the intertubercular groove
What is the innervation of teres major?
Lower subscapular nerve (C5, C6)
What is the action of teres major?
Medial rotation and extension, (but not hyper extension and adduction)
What is the origin of subscapularis?
Subscapular fossa
Where does subscapularis insert?
Lesser tubercle
What is the innervation of subscapularis?
Upper and Lower subscapular nerves (C5, C6)
What is the action of subscapularis?
Medial rotation
