Upper Extremity Muscles

Trapezius

Actions of Trapezius

Scapular elevation, depression, retraction. If fixed, can cause head abduction and/or extension

Levator scapulae

Actions of Levator Scapulae

Scapular elevation, scapular downward rotation

Rhomboids

Actions of Rhomboids

Scapular retraction

Latissimus dorsi

Actions of Latissimus Dorsi

Hammer stroke, shoulder extension/hyperextension, shoulder adduction, scapular depression

Pectoralis Major

Actions of Pectoralis Major

Extends a flexed shoulder to anatomical position, flexes a hyperextended shoulder to anatomical position, shoulder adduction

Pectoralis Minor

Actions of Pectoralis Minor

Scapula fixed elevates rib cage, rib cage fixed protacts scapula, scapular depression

Serratus Anterior

Actions of Serratus Anterior

Scapular protraction, holds scapula against rib cage, provides stablization for shulder abduction and arm horizontal movements

Deltoid

Actions of the Deltoid

Shoulder flexion, shoulder extension + hyperextension, shoulder abduction

Actions of Subscapularis

Stablizies glenohumeral joint, shoulder medial reotation, shoulder adduction

Supraspinatus

Actions of Supraspinatus

Stabilizes glenohumeral joint, shoulder abduction, prevents downward shoulder dislocation

Infraspinatus

Actions of Infraspinatus

Stabilizes glenohumeral joint, lateral shoulder rotation

Teres Minor

Actions of Teres Minor

Stabilize glenohumeral joint, lateral shoulder rotation

Biceps brachii

Actions of Biceps brachii

Supination, elbow flexion when forearm is supinated

Brachialis

Actions of Brachialis

Elbow flexion

Brachioradialis

Actions of Brachioradialis

Elbow flexion when forearm halfway between pronation and supination, stabilizes elbow during rapid extensions or rapid flexions

Triceps brachii

Actions of Triceps brachii

elbow extension: medial head is always active and lateal head and long head active with elbow extension against resistance

Palmaris longus

Actions of Palmaris longus

Tenses skin and fascia of palm

Flexor carpi ulnaris

Actions of Flexor carpi ulnaris

Wrist flexion and adduction

Flexor carpi radialis

Actions of Flexor carpi radialis

Wrist flexion and abduction

Pronator teres

Actions of Pronator teres

Pronation and elbow flexion

Extensor carpi ulnaris

Actions of Extensor carpi ulnaris

Wrist extension and adduction

Extensor digitorum

Actions of Extensor digitorum

Extension of fingers 2-5

Extensor carpi radialis longus

Actions of Extensor carpi radialis longus

Wrist extension and abduction

Rectus abdominis

Actions of Rectus abdominis

Trunk flexion and protects and supports the viscera

External oblique

Actions of External oblique

Rotates trunk contralaterally (contraction of right rotates trunk left and vice versa), protect and support viscera, trunk flexion

Internal oblique

Actions of Internal oblique

Rotates trunk ipsilaterally (contraction of right rotates trunk right and vice versa), protects and supports viscera, trunk flexion

Transversus abdominis

Actions of Transversus abdominis

Protect and support the viscera,

Sternohyoid

Actions of Sternohyoid

Depresses hyoid bone (enables speech + end stage of swallowing) and larynx (prevents food from entering resp. tract)

Sternocleidomastoid

Actions of Sternocleidomastoid

Contralateral rotation and flexion (contraction of right rotates head to left and vice versa), contraction of both flexes neck