Muscles of the Scapula Region Flashcards
What are the muscles of the scapula?
Supraspinatus
Infraspinatus
Teres minor
Teres major
Subscapularis
Origin of the supraspinatus
Supra-spinous fossa of the scapula
Insertion of the supraspinatus
Greater tubercle of the humerus
Nerve supply of the supraspinatus
Supra-scapular nerve [C5,C6]
Action of the supraspinatus
Initiation of abduction of arm (0-15°) at shoulder joint
Origin of the infraspinatus
Infraspinous fossa of the scapula
Insertion of infraspinatus
Greater tubercle of the humerus
Nerve supply of infraspinatus
Supra-scapular nerve [C5,C6]
Action of infraspinatus
Lateral rotation of arm at the shoulder joint
Origin of teres minor
Upper 2/3 of lateral border on the posterior surface of the scapula
Insertion of teres minor
Greater tubercle of the humerus
Nerve supply of teres minor
Axillary nerve C5,6
Action of teres minor
Lateral rotation of arm at the shoulder joint
Origin of teres major
The lower 1/3 of the lateral border of the posterior surface of the scapula
Insertion of teres major
Medial lip of the inter-tubercular groove
Nerve supply of teres major
Lower subscapular nerve
Action of teres major
Medial rotation, adduction and extension of the arm at the shoulder joint
Origin of subscapularis
Subscapular fossa
Insertion of subscapularis
Lesser tubercle of humerus
Nerve supply of subscapularis
Upper & lower subscapular nerve
Action of subscapularis
Medial rotation & adduction
Origin of the deltoid muscle
Inferior edge of the crest of the spine of the scapula
Lateral border of the acromion
Anterior border of lateral 1/3 of clavicle
Insertion of the deltoid muscle
Deltoid tuberosity of humerus
Nerve supply of deltoid muscle
Axillary nerve
Action of deltoid muscle
Anterior fibers: Flexes & medially rotates the arm.
Middle fibers: Abduct the arm from 15 to 90 degree.
Posterior fibers: Extends & laterally rotates the arm
What are the spaces of the scapular region?
Posterior quadrangle space
Upper triangular space
Low triangular interval
What forms the borders of the posterior quadrangle space?
Superiorly: teres minor
Inferiorly: teres major
Laterally: humerus.
Medially: long head of triceps brachii
What are the contents of the posterior quadrangle space?
Axillary nerve
Posterior circumflex humeral vessels
What forms the borders of the upper triangle space?
Superiorly: teres minor.
Inferiorly: teres major.
Laterally: long head of triceps brachii.
What are the contents of the upper triangular space?
Circumflex scapular vessels
What forms the borders of the lower triangular interval?
Medially: long head of triceps brachii.
Laterally: the shaft of the humerus.
Superiorly: teres major.
What are the contents of the lower triangular interval?
Radial nerve
Profunda brachii artery