Week 12: Muscles of the Arm and Shoulder

name the three prime shoulder movers

the deltoid, pectoralis major, and latissimus dorsi

name the two major heads of the pectoralis major

clavicular head (upper chest), and sternocostal head (middle + lower chest)

action of the pectoralis major

clavicular head- humeral flexion

sternal head- adduction, medial rotation, shoulder girdle depression

origin of the pectoralis major

clavicular head- medial portion of clavicle

sternal head- sternum and costal cartilage of true ribs

insertion of pectoralis major

intertubercular groove of humerus

action of latissimus dorsi

• humeral extension, adduction, and internal rotation

• shoulder girdle depression and adduction (retraction)

origin of latissimus dorsi

spinous process of T7-T-12 and L1-L5, sacrum, iliac, ribs 9-12

insertion of latissimus dorsi

intertubercular groove of humerus

what are the three heads of the deltoid

anterior, medial, and posterior

action of the deltoid

• anterior- shoulder flexion, transverse adduction, internal rotation

• medial- shoulder abduction

• posterior- shoulder extension, transverse abduction, external rotation

origin of deltoid

lateral clavicle, acromion, spine of scapula

insertion of deltoid

deltoid tuberosity of humerus

name the five arm movement synergists/fixators

supraspinatus, infraspinatus, sucscapularis, and the teres minor, teres major

supraspinatus action, origin, and insertion

• action- shoulder abduction

• origin- supraspinatous

• insertion- greater tubercle
  

infraspinatous action, origin, and insertion

• action- shulder external rotation, transverse abduction

• origin- infraspinous fossa

• insertion- greater tubercle

subscapularis action, origin, and insertion

• action- shoulder internal rotation

• origin- subscapular fossa

• insertion- lesser tubercle

teres minor action, origin, and insertion

action- shoulder external rotation and transverse abduction

origin- lateral border of scapula

insertion- greater tubercle

teres major

action- shoulder extension, adduction, internal rotation, transverse abduction

origin- inferior angle of scapular

insertion- inter tubercular groove of humerus

what are the four arm movers and synergists

biceps brachii (two heads), brachialis, brachioradalis, and triceps brachii (three heads)

what are the two heads of the biceps brachii and what are their origins

• long head- supraglenoid tubercle

• short head- coracoid process

biceps brachii action and insertion

• action - elbow and shoulder flexion, supination

• insertion- radial tuberosity

brachial action, origin, and insertion

• action- elbow flexion

• origin- distal anterior portion of humerus

• insertion- anterior surface of the coronoid process

brachioradialis action, origin, and insertion

• action- elbow flexion

• origin- proximal to lateral epicondyle of humerus

• insertion- styloid process of radius

triceps brachii actions

• all heads- elbow extension

• long head- shoulder extension and adduction

origin of triceps brachii

• proximal posterior humerus

• infraglenoid tubercle (long head)

insertion of triceps brachii

olecranon process

wrist flexors and extensors of the forearm

flexor carpi radialis, palmaris longus, extensor carpi radialis, and extensor digitorum

flexor carpi radialis action, origin, and insertion

• action- wrist flexion and abduction, pronation

• origin- medial epicondyle of humerus

• insertion- based of metacarpal 2/3

palmaris longus action, origin, and insertion

• action- wrist flexion

• origin- medial epicondyle of humerus

• insertion- palmar aponeurosis

extensor carpi radialis action, origin, and insertion

• action- wrist extension and abduction

• origin- lateral supracondylar ridge (longus), lateral epicondyle of humerus (brevis)

• insertion- dorsal metacarpal 2 (longus) and 3 (brevis)

extensor digitorum action, origin, and insertion

• action- wrist extension; extension of phalanges 2-5

• origin- lateral epicondyle

• insertion- dorsal metacarpals 2-5

list the forearm pronators and supinators

pronator teres, pronator quadratus, supinator

pronator teres action, origin, and insertion

• action - forearm pronation and flexion

• origin- medial epicondyle of humerus, coronoid process of ulna

• insertion- lateral radius

pronator quadratus action, origin, and insertion

• action- forearm pronation

• origin- distal anterior ulna

• insertion- distal anterior radius

supinator action, origin, and insertion

• action- forearm supination

• origin- lateral epicondyle of humerus and lateral ulna

• insertion- lateral aspect of radius