BPK326 Upper Limb Muscles

Deltoid (anterior)

Origin: lateral clavicle; Insertion: deltoid tuberosity; Action: abduction of arm, flexion, horizontal flexion, adduction, medial rotation; Innervation: axillary nerve.

Deltoid (middle)

Origin: acromion process of scapula; Insertion: deltoid tuberosity; Action: abduction of arm; Innervation: axillary nerve.

Deltoid (posterior)

Origin: spine of scapula; Insertion: deltoid tuberosity; Action: abduction of arm, extension/hyperextension, horizontal extension/adduction of arm, lateral rotation of arm; Innervation: axillary nerve.

Teres major

Origin: inferior angle, lateral border scapula; Insertion: intertubercular groove of humerus (inserts more anteriorly!); Action: adduction of arm, medial rotation, extension of arm; Innervation: subscapular nerve.

Teres minor

Origin: lateral border scapula; Insertion: greater tuberosity of humerus; Action: lateral rotation arm, stabilize GHJ; Innervation: axillary nerve.

Supraspinatus

Origin: supraspinous fossa scapula; Insertion: greater tuberosity of humerus; Action: abduction of arm, stabilize GHJ; Innervation: suprascapular nerve.

Infraspinatus

Origin: infraspinous fossa scapula; Insertion: greater tuberosity of humerus (posteroinferior to supraspinatus); Action: external rotation of arm, stabilize GHJ; Innervation: suprascapular nerve.

Subscapularis

Origin: subscapular fossa, anterior side; Insertion: lesser tuberosity of humerus; Action: medial rotation, stabilize GHJ; Innervation: subscapular nerve.

Biceps brachii long head

Origin: supraglenoid tubercle of scapula; Insertion: radial tuberosity, bicipital aponeurosis; Action: flexion of forearm, supination of forearm, weak arm flexion; Innervation: musculocutaneous nerve.

Biceps brachii short head

Origin: coracoid process of scapula; Insertion: radial tuberosity, bicipital aponeurosis; Action: flexion of forearm, supination of forearm; Innervation: musculocutaneous nerve.

Coracobrachialis

Origin: coracoid process of scapula; Insertion: body of humerus; Action: flexion of arm, adduction of arm, medial rotation; Innervation: musculocutaneous nerve.

Brachialis

Origin: body of humerus; Insertion: ulnar tuberosity; Action: flexion of forearm; Innervation: musculocutaneous nerve.

Triceps brachii long head

Origin: infraglenoid tubercle of scapula; Insertion: posterior olecranon process of ulna; Action: extension of forearm, extension of arm, adduction of arm; Innervation: radial nerve.

Triceps brachii lateral head

Origin: body of humerus, superior to radial groove; Insertion: posterior olecranon process of ulna; Action: extension of forearm; Innervation: radial nerve.

Triceps brachii medial head

Origin: body of humerus, inferior to radial groove; Insertion: posterior olecranon process of ulna; Action: extension of forearm; Innervation: radial nerve.

Anconeus

Origin: lateral epicondyle of humerus; Insertion: olecranon, superior posterior surface of ulna; Action: extension of forearm, stabilize (in pronation/supination); Innervation: radial nerve.

Brachioradialis

Origin: lateral supracondylar ridge humerus; Insertion: styloid process of radius; Action: flexion, pronation/supination of forearm; Innervation: radial nerve.

Pronator teres

Origin: medial epicondyle of humerus; Insertion: lateral surface of radius; Action: pronation, flexion of forearm; Innervation: median nerve.

Flexor carpi radialis

Origin: medial epicondyle of humerus; Insertion: base of 2nd metacarpal; Action: flexion of hand, abduction/radial deviation of hand; Innervation: median nerve.

Palmaris longus

Origin: medial epicondyle of humerus; Insertion: palmar aponeurosis; Action: flexion of hand, weak forearm flexion, tenses palmar aponeurosis; Innervation: median nerve.

Flexor carpi ulnaris

Origin: medial epicondyle of humerus, olecranon of ulna; Insertion: base of 5th metacarpal, hook of hamate, pisiform bone; Action: flexion of hand, adduction/ulnar deviation of hand; Innervation: ulnar nerve.

Flexor digitorum superficialis

Origin: medial epicondyle of humerus, coronoid process ulna, upper surface radius; Insertion: middle phalanges (digits 2-5); Action: flexion of proximal+middle phalanges (digits 2-5), flexion of hand (weak), flexion of forearm; Innervation: median nerve.

Flexor digitorum profundus

Origin: Anterior surface of the ulna; interosseous membrane; Insertion: distal phalanges of digits 2-5; Action: flexion of proximal+middle phalanges (digits 2-5), flexion of hand; Innervation: median nerve (lateral), ulnar nerve (medial).

Flexor pollicis longus

Origin: Anterior surface of the radius; Interosseous membrane; Insertion: thumb phalanx; Action: flexion of proximal/distal phalanges digit 1, abduction/radial deviation of hand, flexion of hand; Innervation: median nerve.

Pronator quadratus

Origin: distal ulna; Insertion: distal radius; Action: pronation of arm; Innervation: median nerve.

Extensor carpi radialis longus

Origin: lateral supracondylar ridge humerus; Insertion: dorsal base second metacarpal; Action: extension, abduction/radial deviation of hand; Innervation: radial nerve.

Extensor carpi radialis brevis

Origin: lateral epicondyle of humerus; Insertion: dorsal base third metacarpal; Action: extension, abduction/radial deviation of hand; Innervation: radial nerve.

Extensor digitorum

Origin: lateral epicondyle of humerus; Insertion: dorsal bases digital/middle phalanges (digits 2-5); Action: extension of digits 2-5, abduction of fingers; Innervation: radial nerve.

Extensor digiti minimi

Origin: lateral epicondyle of humerus; Insertion: dorsal aponeurosis (middle/distal phalanges) of 5th digit; Action: extension of 5th digit (pinky), adduction/ulnar deviation, extension of hand; Innervation: radial nerve.

Extensor carpi ulnaris

Origin: lateral epicondyle of humerus, posterior surface of ulna; Insertion: dorsal base of 5th metacarpal; Action: extension, adduction/ulnar deviation of hand; Innervation: radial nerve.

Supinator

Origin: lateral epicondyle of humerus, supinator crest of ulna; Insertion: posterior surface of radius; Action: supination of forearm; Innervation: radial nerve.

Abductor pollicis longus

Origin: dorsal surface of radius/ulna, adjacent interosseus membrane; Insertion: lateral side base of 1st metacarpal; Action: abduction of thumb, abduction/radial deviation of hand; Innervation: radial nerve.

Extensor pollicis brevis

Origin: posterior surface of radius, interosseous membrane; Insertion: dorsal base of 1st proximal phalanx; Action: extension of thumb, abduction/radial deviation of hand; Innervation: radial nerve.

Extensor pollicis longus

Origin: posterior surface of ulna, interosseous membrane; Insertion: dorsal base of 1st distal phalanx; Action: extension of thumb, abduction/radial deviation of hand; Innervation: radial nerve.

Extensor indicis

Origin: posterior distal ulna, interosseous membrane; Insertion: distal aponeurosis of 2nd digit; Action: extension of digit; Innervation: radial nerve.

Abductor pollicis brevis

Action: abduction of digit 1; Innervation: median nerve.

Flexor pollicis brevis

Action: flexion of digit 1 (opposition too); Innervation: median nerve.

Opponens pollicis

Action: opposition of 1st digit; Innervation: median nerve.

Abductor digiti minimi

Action: abduction of digit 5; Innervation: ulnar nerve.

Flexor digiti minimi

Action: flexion of digit 5; Innervation: ulnar nerve.

Opponens digiti minimi

Action: opposition of digit 5; Innervation: ulnar nerve.