Upper Limb Muscles
All muscles of upper limb body with their Origin, Insertion, Nerve Supply and Action
Arm Muscles:-
Anterior Side
(A) Biceps brachii:-
Origin – Short head: The tip of the coracoid process of scapula. Long head: Supraglenoid tubercle of the scapula.
Insertion – Tuberosity of radius.
Nerve Supply – Musculocutaneous Nerve (C5, C6).
Action – Flexion of Elbow, Supination of Forearm.
(B) Coracobrachialis:-
Origin – The tip of the coracoid process of scapula.
Insertion – Anteromedial surface of the humerus.
Nerve Supply – Musculocutaneous Nerve (C5-C7).
Action – Flexion and Adduction of the arm at the shoulder joint.
(C) Brachialis:-
Origin – Distal half of the anterior aspect of the shaft of humerus.
Insertion – Coronoid process and tuberosity of ulna.
Nerve Supply – Musculocutaneous Nerve (C5, C6) and Radial nerve (C7).
Action – Flexion of Forearm at elbow joint.
Posterior Side
(A) Triceps:-
Origin – Long head: Infraglenoid tubercle of the scapula. Lateral head: Posterior surfaces of humerus, superior to the radial groove. Medial head: Posterior surfaces of humerus, inferior to the radial groove.
Insertion – Posterior aspect of the olecranon process of the ulna.
Nerve Supply – Radial Nerve (C7, C8).
Action – Extension of Elbow.
Forearm Muscles:-
Anterior Side
(Superficial Muscles)
(A) Pronator teres:-
Origin – Medial epicondyle of the humerus.
Insertion – Middle convexity of the lateral surface of the radius.
Nerve Supply – Median Nerve.
Action – Pronation of Forearm.
(B) Flexor carpi radialis:-
Origin – Medial epicondyle of the humerus.
Insertion – Bases of 2nd and 3rd metacarpal bones.
Nerve Supply – Median Nerve.
Action – Flexion and abduction of hand at the wrist joint.
(C) Palmaris longus:-
Origin – Medial epicondyle of the humerus.
Insertion – Distal half of flexor retinaculum and apex of the palmar aponeurosis.
Nerve Supply – Median Nerve.
Action – Flexion of hand at the wrist joint.
(D) Flexor digitorum superficialis:-
Origin – Medial epicondyle of the humerus.
Insertion – Sides of the middle phalanges of digits 2-5.
Nerve Supply – Median Nerve.
Action – Flexion of Fingers.
(E) Flexor carpi ulnaris:-
Origin – Medial epicondyle of the humerus.
Insertion – Base of pisiform bone, the hook of hamate and base of the fifth metacarpal.
Nerve Supply – Ulnar Nerve.
Action – Flexion and adduction of hand at the wrist joint.
Anterior Side
(Deep Muscles)
(A) Flexor digitorum profundus:-
Origin – Proximal three-quarters of the medial and interosseous membrane.
Insertion – Base of distal phalanges of digits 2-5.
Nerve Supply – Digit 2-3 by Median Nerve and Digit 4-5 by Ulnar Nerve.
Action – Flexion of fingers.
(B) Flexor pollicis longus:-
Origin – Anterior surface of the radius.
Insertion – Base of distal phalanx of thumb.
Nerve Supply – Anterior interosseous Nerve (branch of median nerve).
Action – Flexion of Thumb.
(C) Pronator quadratus:-
Origin – Distal anterior surface of the shaft of ulna.
Insertion – Distal anterior surface and border of radius.
Nerve Supply – Anterior interosseous Nerve (C8, T1).
Action – Pronation of Forearm.
Posterior Side
(Superficial Muscles)
(A) Anconeus:-
Origin – Lateral epicondyle of the humerus.
Insertion – Lateral surface of the olecranon process of ulna.
Nerve Supply – Radial Nerve.
Action – Extension of Elbow.
(B) Brachioradialis:-
Origin – Upper 2/3rd of lateral supracondylar ridge of the humerus.
Insertion – Distal end of the styloid process of radius.
Nerve Supply – Radial Nerve.
Action – Flexion of forearm at the elbow joint.
(C) Extensor carpi radialis longus:-
Origin – Lower 1/3rd of lateral supracondylar ridge of the humerus.
Insertion – Posterior aspect of the base of second metacarpal.
Nerve Supply – Radial Nerve.
Action – Extends and abducts hand at the wrist joint.
(D) Extensor carpi radialis longus:-
Origin – Lateral epicondyle of the humerus.
Insertion – Posterior aspect of the base of third metacarpal.
Nerve Supply – Radial Nerve.
Action – Extends and abducts hand at the wrist joint.
(E) Extensor digitorum:-
Origin – Lateral epicondyle of the humerus.
Insertion – Bases of the middle phalanges of the 2nd-5th digits. .
Nerve Supply – Radial Nerve.
Action – Extension of fingers.
(E) Extensor digiti minimi:-
Origin – Lateral epicondyle of the humerus.
Insertion – Extensor expansion of the fifth digit.
Nerve Supply – Radial Nerve.
Action – Extends MCP joint of fifth digit.
(F) Extensor carpi ulnaris:-
Origin – Lateral epicondyle of the humerus.
Insertion – Base of 5th metacarpal bone.
Nerve Supply – Radial Nerve.
Action – Extends and adducts hand at the wrist joint.
Posterior Side
(Deep Muscles)
(A) Supinator:-
Origin – Lateral epicondyle of the humerus.
Insertion – Neck and whole shaft of the upper 1/3rd of radius.
Nerve Supply – Radial Nerve.
Action – Supination of Forearm.
(B) Abductor pollicis longus:-
Origin – Dorsal aspect of the shaft of radius and ulna.
Insertion – Base of 1st metacarpal bone.
Nerve Supply – Radial Nerve.
Action – Abducts and extends thumb.
(C) Extensor pollicis brevis:-
Origin – Dorsal aspect of the shaft of radius.
Insertion – Base of the proximal phalanx of thumb.
Nerve Supply – Radial Nerve.
Action – Extends MCP joint of thumb.
(D) Extensor pollicis longus:-
Origin – Dorsal aspect of the shaft of ulna.
Insertion – Base of the distal phalanx of thumb.
Nerve Supply – Radial Nerve.
Action – Extends distal phalanx of the thumb.
(E) Extensor indicis:-
Origin – Dorsal aspect of the shaft of ulna.
Insertion – Extensor expansion of the second digit.
Nerve Supply – Radial Nerve.
Action – Extends MCP joint of the second digit.
Hand Muscles:-
Thenar
(A) Abductor pollicis brevis:-
Origin – Tubercle of scaphoid, trapezium and flexor retinaculum.
Insertion – Base of proximal phalanx of the thumb.
Nerve Supply – Median Nerve.
Action – Abduction of thumb.
(B) Flexor pollicis brevis:-
Origin – Trapezoid, capitate and flexor retinaculum.
Insertion – Base of distal phalanx of thumb.
Nerve Supply – Median Nerve.
Action – Flexes MCP joint of Thumb.
(C) Opponens pollicis:-
Origin – Flexor retinaculum.
Insertion – Lateral side of the shaft of metacarpal bone of thumb.
Nerve Supply – Median Nerve.
Action – Opposes thumb towards the fingers.
(D) Adductor pollicis:-
Origin – Oblique head – Bases of 2nd and 3rd metacarpals and capitate bone. Tranverse head – Anterior aspect of the shaft of 3rd metacarpal.
Insertion – Medial side of base of proximal phalanx of the thumb.
Nerve Supply – Ulnar Nerve.
Action – Adduction of thumb.
Hypothenar
(A) Abductor digiti minimi:-
Origin – Pisiform bone.
Insertion – Medial side base of proximal phalanx of the little finger.
Nerve Supply – Ulnar Nerve.
Action – Abduction of little fingers.
(B) Flexor digiti minimi:-
Origin – Flexor retinaculum.
Insertion – Medial side base of proximal phalanx of the little finger.
Nerve Supply – Ulnar Nerve.
Action – Flexion of little fingers.
(C) Opponens digiti minimi:-
Origin – Flexor retinaculum and the hook of hamate bone.
Insertion – Medial border of the fifth metacarpal.
Nerve Supply – Ulnar Nerve.
Action – Pull 5th metacarpal forward as in cupping the palmer sider.
(D) Palmaris brevis:-
Origin – Palmar aponeurosis and flexor retinaculum.
Insertion – Medial side of the palmar skin.
Nerve Supply – Ulnar Nerve.
Action – Wrinkles skin to improve the grip of palm.
Lumbricals
Origin – Tendons of flexor digitorum profundus muscles.
Insertion – Extensor expansion into dorsum of bases of the distal phalanges.
Nerve Supply – Lumbricals 1-2: Median Nerve. Lumbricals 3-4: Ulnar Nerve.
Action – Flexion of MCP joints and extension of interphalangeal joint of 2-5 fingers.
Palmar interossei
Origin – Palmar surface of 2nd, 4th and 5th metacarpal bones.
Insertion – Bases of proximal phalanges and extensor expansions of 2nd, 4th and 5th digits.
Nerve Supply –Ulnar Nerve.
Action – Adduction of fingers towards centre of third digit or middle finger.
Dorsal interossei
Origin – Adjacent sides of two metacarpals
Insertion – Bases of proximal phalanges and extensor expansions of 2nd-4th digits..
Nerve Supply –Ulnar Nerve.
Action – Abduction of fingers towards centre of third digit or middle finger.