Arm and Deep Back Muscles Flashcards
Deltoid
thick, powerful muscle that functions as a prime abductor of the arm and forms the rounded contour of the shoulder.
What are the origin points of the deltoid?
clavicle, acromion, and scapular spine
What are the insertion points of the deltoid?
deltoid tuberosity of humerus
What are the actions of the deltoid?
Flex & medially rotate; Abducts; extend and laterally rotate humerus
Supraspinatus
one of four rotator cuff muscles that attach the scapula to the humerus; best used when you start to execute the pitch. by fully abducting the arm
What are the origin points of the supraspinatus?
supraspinous fossa of scapula
What are the insertion points of the supraspinatus?
greater tubercle of the humerus
What are the actions of the supraspinatus?
abducts the humerus
Infraspinatus
one of four rotator cuff muscles; one of two that help slow down the pitching arm upon completion of the pitch. These two muscles adduct and laterally rotate the arm
What are the origin points of the infraspinatus?
infraspinous fossa
What are the insertion points of the infraspinatus?
greater tubercle of the humerus
What are the actions of the infraspinatus?
adducts and lateral rotation of the humerus
Teres minor
One of four rotator cuff muscles; works with the infraspinatus; help slow down the pitching arm upon completion of the pitch;
synergist to infraspinatus - adduct and laterally rotate the arm
What are the origin points of the teras minor?
lateral border of scapula
What are the insertion points of the teres minor?
greater tubercle of humerus
What are the actions of teres minor?
adducts and lateral rotation of the humerus
Subscapularis
one of four rotator cuff muscles; used when you wind up for a pitch
What are the origin points of the subscapularis?
subscapular fossa of scapula
What are the insertion points of subscapularis?
lesser tubercle of humerus
What are the actions of subscapularis?
medial rotation of humerus
Teres major
works synergistically with the latissimus dorsi
What are the origin points of teres major?
posterior surface of inferior angle of scapula?
What are the insertion points of teres major?
lesser tubercle of humerus
What are the actions of teres major?
extends, adducts, and medially rotates arm
Triceps brachii
a large, three headed muscle on the posterior surface of the arm
What are the origin points of the triceps brachii?
infraglenoid tubercle of scapula and posterior humerus
What are the insertion points of triceps brachii?
olecranon process of ulna
What are the actions of triceps brachii?
extends forearm, extends and adducts arm
Biceps brachii
large, two headed muscle on the anterior surface of the humerus
What are the origin points of the biceps brachii?
supraglenoid tubercle; coracoid process
What are the insertion points of biceps brachii?
radial tuberosity
What are the actions of biceps brachii?
flexes arma and flexes forearm
Brachialis
deep to the biceps brachii and lies on the anterior surface of the humerus; it is the most powerful flexor of the forearm at the elbow