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

What are the origin points of the brachialis?
distal anterior humerus

What are the insertion points of the brachialis?
coronoid process of ulna

What are the actions of the brachialis?
flexes forearm
Brachioradialis
prominent muscle on the lateral surface of the forearm; it is a synergist in forearm flexion, effective primarily when the agonists of forearm flexion have already partially flexed the elbow

What are the origin points of brachioradialis?
lateral supracondylar ridge of humerus

What are the insertion points of the brachioradalis?
styloid process of radius

What are the actions of brachioradalis?
flexes forearm
Extensor carpi radialis (longus and brevis)
longus is a long, tapered muscle that is medial to the brachioradialis
brevis works synergistically with the extensor radialis longus

What are the origin points of extensor carpi radialis?
supracondylar ridge and lateral epicondyle of humerus

What are the insertion points of extensor carpi radialis?
base of 2nd and 3rd metacarpal

Extensor digitorum
splits into four tendons that attach to the distal phalanges of fingers 2-5

What are the origin points of extensor digitorum?
lateral epicondyle of humerus

What are the insertion points of extensor digitorum?
distal and middle phalanges of digits 2-5

What are the actions of extensor digitorum?
extends digits 2-5 and wrist
Extensor digiti minimi
attaches to the distal phalanx of finger 5; works with the extensor digitoum to extend the little finger

What are the origin points of extensor digiti minimi?
lateral epicondyle
What are the insertion points of extensor digiti minimi
extensor expansion, immediately medial to extensor digitorum
What are the actions of extensor digiti minimi?
extends 5th digit and wrist
Extensor carpi ulnaris
on medial surface of the posterior forearml attaches to the fifth metacarpal bone

What are the origin points of extensor carpi ulnaris?
lateral epicondyle of humerus

What is the insertion point of extensor carpi ulnaris?
5th metacarpal

What are the actions of extensor carpi ulnaris?
extends and adducts wrist
Pronator teres
located in the anterior compartment of the forearm; as well as pronator quadratus

What are the origin points of pronator teres?
medial epicondyle of humerus and coronoid process of ulna

What is the insertion point of pronator teres?
lateral radius

What is the actions of pronator teres?
pronates forearm
Flexor carpi ulnaris
part of the superficial layer of anterior forearm; on the anteromedial side of the forearm

What are the origin points of the flexor carpi ulnaris?
medial epicondyle of the humerus

What is the insertion point of flexor carpi ulnaris?
pisiform and hamate and fifth carpal

What is the actions of flexor carpi ulnaris?
flexes wrist and adducts the hand
Flexor carpi radialis
one of the anterior compartment muscles of the forearm; extends diagonally across the anterior surface of the forearm

What are the origin points of flexor carpi radialis?
medial epicondyle of humerus

What are the insertion points of flexor carpi radialis?
Base of 2nd and 3rdmetacarpals-tendon easily seen to guide taking pulse of radial artery

What are the actions of flexor carpi radialis?
flexes wrist; abducts hand
Palmaris longus
part of the superficial layer of anterior forearm muscles; absent in 10% of all individuals - narrow, superficial muscle on the anterior surface of the forearm weakly assists in wrist flexion

What are the origin points of palmaris longus?
medial epicondyle of humerus

What are the insertion points of palmaris longus?
flexor retinaculum and palmar aponeurosis

What are the actions of palmaris longus?
weak flexor of the wrist
Abductor pollicis longus
part of deep later that attaches directly to the posterior forearm bones proximally and distally to the wrist or hand bones; attaches to the first metacarpal

What are the actions of abductor pollicis longus?
abducts thumb
Extensor pollicis brevis
lies immediately medial to the abductor policis longus and attaches to the proximal phalanx of the thumb

What are the actions of extensor pollicis brevis?
extends thumb
Extensor pollicis longus
part of the deep layer that attaches directly to the posterior forearm bones proximally and distally to the wrist or hand bones; extends the MP and IP joints of the thumb

What are the actions of extensor pollicis longus?
extends thumb
Rhomboid (major + minor)
located deep to the trapezius; parallel bands that run inferolaterally from the vertebrae to the scapula

What are the origin points of the rhomboid muscles?
spinous processes of C7-T5

What are the insertion points of the rhomboid muscles?
medial border of scapula

What are the actions of the rhomboid muscles?
elevates and retracts scapula; inferior rotation of scapula
Erector spinae
iliocostalis, longissimus, and spinalis muscles
a group of muscles and tendons which run more or less the length of the spine on the left and right from the sacrum and hips to the base of the skull

What are the actions of erector spinae?
prime mover of back extension; maintains posture