AP1U4 Lab: Muscles of the arm, wrist and hand
rotator cuff muscles
1. supraspinatus 2. infraspinatus 3. teres minor 4. subscapularis
extensor digitorum
Extends fingers and the wrist, flare (abduct) fingers
extensor carpi radialis brevis
Extends wrist and abducts hand
extensor carpi radialis longus
Extends wrist and abducts hand
latissimus dorsi
Extends, adducts, and medially rotates the arm; draws the shoulder downward and backward - prime mover of arm extension - bringing arm down in a power stroke such as with a hammer
Infraspinatus
Laterally rotates shoulder; stabilizes the head of the humerus in glenoid cavity; one of the "rotator cuff" muscles
Supraspinatus
abduction of arm stabilizes the shoulder joint
pronator teres
acts synergistically with pronator quadrates to pronate forearm -weak elbow flexor
supinator
acts with biceps brachia to supinate the forearm antagonist of pronator muscles
teres major
extends, adducts, and medially rotates arm synergist of latissimus dorsi
Coracobrachialis
flexes and adducts arm
palmaris longus
flexes wrist (weak) tenses skin and fascia of the palm
flexor carpi radialis
flexes wrist and abducts hand
brachialis
major forearm flexor
Subscapularis
medially rotates arm, stabilizes the shoulder joint
biceps brachii
powerful flexion at elbow, supination of forearm -turns the corkscrew and pulls the cork. -weak arm flexor
flexor carpi ulnaris
powerful flexor of wrist; adducts hand
triceps brachii
powerful forearm extensor; antagonist of biceps brachii and brachialis
Deltoid
prime mover of arm abduction can aid in flexion, extension and rotation of the humerus
pectoralis major
prime mover of arm flexion; adducts, medially rotates arm pulls chest up in forced respiration
teres minor
rotates arm laterally, similar to infraspinatus
bracioradialis
synergist in forearm flexion