week 12

muscles of the arm and shoulder

scapula review (anterior)

acromion, suprascapular notch, superior border, superior angle, medial border, inferior angle, lateral border, subscapular fossa, neck

scapula review (posterior)

supraspinous fossa, scapular spine, infraspinous fossa, suprascapular notch, coracoid process, acromion process, glenoid cavity, lateral border

humerus review (anterior)

lateral epicondyle, capitulum, radial fossa, coronoid fossa, trochlea, medial epicondyle, shaft, deltoid tuberosity, intertubercular groove, surgical neck, lesser tubercle, greater tubercle, neck, head

humerus review (posterior)

head, neck, surgical neck, greater tubercle, shaft, radial groove, medial epicondyle, olecranon fossa, trochlea, lateral epicondyle

shoulder movers

pectoral major (2 heads)

• clavicular head: “upper chest”

- action: humeral flexion

- origin: medial portion of clavicle

- insertion: intertubercular groove of humerus

• sternocostal head: “middle and lower chest”

- action: adduction, medial rotation, shoulder girdle depression

- origin: sternum and costal cartilage of true ribs

- insertion: intertubercular groove of humerus

shoulder mover: latissimus dorsi (lats)

• action: humeral extension, adduction & internal rotation, shoulder girdle depression and adduction (retraction)

• origin: spinous process of T7-T12 & L1-L5, sacrum, iliac crest, 9-12 ribs

• insertion: intertubercular groove of humerus

shoulder mover: Deltoid (3 heads)

deltoid (3 heads)

• action:

- anterior: shoulder flexion, transverse adduction, internal rotation

- medial: shoulder abduction

- posterior: shoulder extension, transverse abduction, external rotation

• origin: lateral clavicle, acromion, spine of scapula

• insertion: deltoid tuberosity of humerus

arm movement synergists/fixators (muscles of the rotator cuff)

• supraspinatus

- action: shoulder abduction

- origin: supraspinous fossa

- insertion: greater tubercle

• infraspinatus

- action: shoulder external rotation, transverse abduction

- origin: infraspinous fossa

- insertion: greater tubercle

• subscapularis

- action: shoulder internal rotation

- origin: subscapular fossa

- insertion: lesser tubercle

• teres minor

- 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: intertubercular groove of humerus

arm movers + synergists

• Biceps brachii (two heads)

- action: elbow flexion, shoulder flexion, supination

- origin: supraglenoid tubercle (long head), coracoid process (short head)

- insertion: radial tuberosity

• brachialis

- action: elbow flexion

- origin: distal anterior portion of humerus

- insertion: anterior surface of the coronoid process

• brachioradialis

- action: elbow flexion

- origin: proximal to lateral epicondyle of humerus

- insertion: styloid process of radius

• triceps brachii (three heads)

- action: elbow extension (all heads), shoulder extension and adduction (long head)

- origin: infraglenoid tubercle (long head), proximal posterior humerus

- insertion: olecranon process

SALT (shoulder medial rotators)

S: subscapularis

A: anterior pectoralis fibres

L: latissimus dorsi

T: teres major

Peters Dad Bought Coffee (shoulder flexors)

P: pectoralis major

D: deltoid

B: biceps brachii

C: coracobrachialis

Forearm: wrist flexors and extensors

• flexor carpi radialis

• - action: wrist flexion and abduction, pronation

  - origin: medial epicondyle of humerus

  - insertion: base of metacarpal 2/3

• palmaris longus

• - action: wrist flexion

  - origin: medial epicondyle of humerus

  - insertion: palmar aponeurosis

• extensor carpi radialis

• - 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: wrist extension, extension pf phalanges 2-5

  - origin: lateral epicondyle

  - insertion: dorsal metacarpals 2-5

forearm: pronators and supinators

• pronator teres

• - action: forearm pronation and flexion

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

  - insertion: lateral radius

• pronator quadratus

• - action: forearm pronation

  - origin: distal anterior ulna

  - insertion: distal anterior radius

• supinator

• - action: forearm supination

  - origin: lateral epicondyle of humerus, lateral ulna

  - insertion: lateral aspect of radius

intrinsic muscles of hand (all for one and one for all)

• abductor pollicis brevis

• flexor pollicis brevis

• opponens pollicis

• adductor pollicis

• opponens digiti minimi

• flexor digiti minimi

• abductor digiti minimi