Shoulder Muscles Flashcards
Trapezius
Origin - Spinous processes of C1 - T12
Insertion - lateral 1/3 of clavicle, acromium and spine of the scapula
Innervation - Accessory Nerve
Action - shruggin of shoulders, rotates scapula during abduction of arm
Latimus Dorsi
Origin - Spinous processes of T7 - T12 and the posterior 1/3 of the iliac crest
Insertion - Intertubercular groove
Innervation - Thoracodorsal Nerve
Action - extension, adduction and internal rotation of arm
Rhomboid major and minor
Origin - C7 - T1, T2 - T5
Insertion - Medial margin of the scapula
Innervation - Dorsal Scapula nerve
Action - Retract and rotate scapula
Levator Scapulae
Origin - Transverse process of C1-C4
Insertion - medial border of the scapula
Innervation - Dorsal Scapular nerve
Action - elevation of the scapula
Deltoid
Origin - Acromiumn spine of scapula and lateral 1/3 of clavicle
Insertion -Deltoid tuberosity of humerus
Innervation - Axillary Nerve
Action - Abduction post 15 degrees
What are the 4 rotator cuff muscle
Supraspinatous, Infraspinatous, Subscapularis and Teres Minor
Supraspinatous
Origin - Medial side of the supraspinous fossa
Insertion - Greater tubercle of humerus
Innervation - Suprascapular nerve
Action - Abduction of the arm first 15 degrees
Infraspinatous
Origin - Medial side of the infraspinous fossa
Insertion - Greater tubercle of humerus
Innervation - suprascapular nerve
Action - external rotation
Subscapularis
Origin - Subscapular fossa
Insertion - lesser tubercle
Innervation - both subscapular nerves
Action - Internal rotation
Teres Minor
Origin - Upper 2/3 of lateral margin of scapula
Insertion - greater tubercle of humerus
Innervation - Axillary nerve
Action - external rotation
Teres Major
Origin - Inferior angle of the scapula
Insertion - Lesser tubercle of humerus
Innervation - Inferior subscapular nerve
Action - Internal rotation and adduction
