Shoulder Muscles Flashcards
What are the 9 muscles of the shoulder joint?
Pectoralis Major
Latissimus Dorsi
Deltoid
Coracobrachialis
Teres Minor Infraspinatus Teres Major Supraspinatus Subscapularis
Pectoralis Major - Origin - two heads
Clavicular Head
O= Medial half of clavicle
Sternal Head
O= Sternum and costal cartilidge (1-6)
Pectoralis Major - Insertsion
I= Greater tubercle crest of Humerus
Pectoralis Major - Actions - Clavicular head
Shoulder Horizontal adduction
Medial rotation of the shoulder
Assists with shoulder flexion
Pectoralis Major - Actions - Sternal head
Shoulder Horizontal adduction
Shoulder adduction
Medial rotation of the shoulder
Assists with Shoulder extension
Latissimus Dorsi - Origin (5 - R Sits)
R - Ribs - Lower 3 or 4
S - Sacrum
I - Iliac Crest
T - Thoracolumbar Fascia
S - Spine - Thoracic 7-12 & Lumbar 1-5
Latissimus Dorsi - Insertion
I= Humerus - Floor of intertubercular groove
Latissimus Dorsi - Actions
Shoulder Extension
Shoulder Adduction
Shoulder Internal (Medial) rotation
Deltoid - Anterior - Origin
O= Lateral 1/3 of clavicle
Deltoid - Anterior - Insertion
I= Deltoid tuberosity of Humerus
Deltoid - Anterior - Actions 4
Shoulder Flexion
Assists with:
Horizontal Shoulder Adduction
Shoulder Abduction
Shoulder internal (medial) rotation
Deltoid - Middle - Origin
O= Scapula - Acromion - lateral margin, superior surface
Deltoid - Middle - Insertion
I= Deltoid Tuberosity of Humerus
Deltoid - Middle - Actions 2
Shoulder Abduction
Assists with shoulder flexion
Deltoid - Posterior - Origin
O= Spine of the scapula - Inferior lip of posterior border