Muscles Flashcards
Deltoid
Shoulder muscle
Origin:
-Lateral 1/3rd of clavicle
-Acromion and spine of the scapula
Insertion: Deltoid tuberosity in humerus
Action:
-Clavicle portion: flex arm at shoulder (sideways) And medially rotates arm
-Acromion part: ABduction of arm at shoulder beyond 15 degrees
Biceps brachii
Bicep
Origin:
long head: supraglenoid tubercle of the scapula
short head: coracoid process of scapula
Insertion: Radial tuberosity of radius
Action:
-Flex arm at shoulder
-flex arm at elbow
-supinates forearm at elbow
Triceps brachii
Triceps
Origin: Infraglenoid tubercle of the scapula
Insertion: Posterior olecranon process of ulna
Action: extends the forearm at elbow
Pectoralis major
Pecs
Origin: Medial half of Clavicle and Sternum with costal cartilages
Insertion:
-lateral lip of intertubercular groove of humerus
-crest of greater tubercle of humerus
Action:
Sternum portion: extend arm at shoulder
Clavicle portion: Flex arm at shoulder
Both: Medially rotates the arm and adducts arm at shoulder
Subscapularis
Front middle portion of scapula
Origin: Subscapular fossa of scapula
Insertion: Lesser tubercle of humerus
Action: Adducts the humerus? and internally rotates it
Supraspinatus
Top muscle on scapula
Origin: Supraspinous fossa of the scapula
Insertion: superior aspect of the greater tubercle of the humerus
Action: abduction of the arm at the shoulder
Infraspinatus
Back main portion of scapula
Origin: Infraspinous fossa of the scapula
Insertion: Middle part of the greater tubercle of the humerus
Action: Laterally rotates the arm
Teres major
On the bottom part of the scapula
Origin: Lower lateral border and inferior angle of scapula
Insertion: Medial lip of the intertubercular groove of anterior humerus
Action:
-adducts the arm at shoulder
-medially rotates arm at shoulder
-extends arm at shoulder
Teres minor
Back side of the scapula (more shown there) at the bottom
Origin: Middle part of lateral axillary of scapula
Insertion: Inferior aspect of greater tubercle of humerus
Action: Laterally rotates the arm at shoulder and weakly adducts the arm
Latissimus dorsi
Sides of lower back
Origin: Vertebrae, sacrum, scapula, lower 3 or 4 ribs
Insertion: Floor of intertubercular groove of humerus
Action:
-Adducts arm at shoulder
-Medially rotates arm
-Extends arm
Extensor carpi ulni
In arm
Origin: Lateral epicondyle of humerus
Insertion: Base of 5th metacarpal
Action:
-Extends hand at wrist
-Adducts hand at wrist
Brachioradialis
Whole radius side of arm
Origin: Lateral supracondylar ridge of humerus
Insertion: Styloid process of radius
Action: Flexes forearm at elbow
Pronator teres
Starts at ulna side but goes under brachioradialis
Origin:
-Humeral head: medial epicondyle of humerus & distal supracondylar ridge
-Ulnar head: medial side of coronoid process of ulna.
Insertion: Middle of lateral surface of radius
Action:
-Pronates the forearm (twist)
-flexes the forearm at elbow
Brachilais
In between bicep and tricep
Origin: Anterior distal half of humerus
Insertion: Coronoid process and tuberosity of ulna
Action: Flexes forearm at elbow
Supinator
no clue
Origin:
-Lateral epicondyle of humerus
-Supinator crest of ulna
Insertion: Lateral, posterior and anterior surfaces of proximal 1/3 of radius
Action: supinate forearm
