MSK - Upper Limb 2 PDF

Anatomy of Musculoskeletal system 2- Upper Limb - Muscles and joints of arm, forearm and Hand Dr Suresh MBBS MD Objectives At the end of the lecture, students are able to, 1. Describe the proximal and distal attachments, innervation and actions of front and back of arm muscles 2. Describe...

Anatomy of Musculoskeletal system 2- Upper Limb - Muscles and joints of arm, forearm and Hand Dr Suresh MBBS MD Objectives At the end of the lecture, students are able to, 1. Describe the proximal and distal attachments, innervation and actions of front and back of arm muscles 2. Describe boundaries and clinical importance of cubital fossa. 3. Describe the proximal and distal attachments, innervation and actions of front and back of forearm muscles 4. Anatomy of elbow, wrist and radio ulnar joints 5. Describe intrinsic muscles of hand and thumb. Muscles of Scapula- Rotator cuff Muscles of Arm: Cross elbow, Move forearm Anterior Compartment Biceps brachii Brachialis Coraco brachialis Posterior Compartment (Extensors of forearm) Triceps brachii Anconeus  Biceps brachii Origin: Long head-supraglenoid tubercle of scapula; Short head-apex of coracoid process Insertion: Radial tuberosity of radius Nerve supply: Musculocutaneous nerve Action: Flexor of the forearm at the elbow joint Supinator of the forearm Accessory flexor of the arm at shoulder joint Brachialis Origin: Anterior aspect of humerus Insertion: Tuberosity of the ulna Nerve supply: Musculocutaneous nerve Action: Flexor of the forearm at the elbow joint Coracobrachialis Origin: coracoid process of scapula Insertion: mid-shaft of humerus Nerve supply: Musculocutaneous nerve Action: Flexor of the arm at the shoulder joint Nerves – musculocutaneous nerve Branch of lateral cord of brachial plexus Pierces coracobarchialis muscle Supplies: (BBC) Biceps brachii, Brachialis Coraco brachialis  Triceps brachii Origin: Long head- Infraglenoid tubercle of scapula Medial head-posterior surface of humerus lateral head-posterior surface of humerus Insertion: Olecranon process of ulna Nerve supply: Radial nerve Action: Extension of the forearm at the elbow joint. Long head - extend and adduct the arm at the shoulder joint Nerves – radial nerve Branch of posterior cord of brachial plexus Supplies muscles of back of arm and forearm Nerves Median nerve Ulnar nerve Arteries Axillary artery ▪ Commences at the outer border of the first rib ▪ Continuation of the subclavian artery ▪ Divided into three parts by pectoralis minor ▪ Continue as Brachial artery from the lower border of teres major Brachial. artery ▪ Commences at the lower border of teres major ▪ Divided into radial and ulnar artery below the elbow joint Elbow joint- (Hing joint) Articular surfaces Capsule & ligaments Movements Arterial supply Nerve supply Brachial, - Musculocutaneous nerve. Profunda brachii, - Radial nerve. Radial, and ulnar arteries. - Ulnar nerve - Median nerve Cubital fossa Situated in anterior aspect of the elbow Boundaries: 1. Superiorly- an imaginary line connecting the medial and lateral epicondyles. 2. Medially- pronator teres & the mass of flexor muscles of the forearm 3. Laterally- brachioradialis ,mass of extensor muscles Cubital fossa Contents (lateral to medial) tendon of the biceps brachii muscle brachial artery median nerve Muscles of forearm: Cross Wrist : flex, extend, abduct, adduct hand Cross Fingers : flex, extend fingers Anterior Flexor Compartment (Superficial + Deep layers) Most flexors have common tendon on medial epicondyle Contains 2 pronators Innervated by *Median, Ulnar nerves Posterior Extensor Compartment (Superficial + Deep layers) Innervated by Radial nerve Lateral epicondyle origin Flexor & Extensor Retinaculam Collagenous bands keep tendons from bowing thick, deep fascia FOREARM Olecranon Olecranon Trochlear notch Coronoid process Proximal Head of radius Radial notch radio-ulnar Neck of joint radius Ulnar tuberosity Radial tuberosity Ulna Ulna Radius Ulna c Lateral view of ulna, showing Interosseous trochlear notch membrane https://aclandanatomy- com.singaporetech.rem Ulnar notch Distal radio-ulnar joint of radius otexs.co/MultimediaPla Head of ulna yer.aspx?multimediaId= Head of ulna Ulnar styloid process Radial styloid 10528065 process a Posterior view b Anterior © 2018 Pearson Education, Ltd. view  HAND She – Scaphoid Looks– Lunate Too – Triquetral Pretty – Pisiform Try – Trapezium To – Trapezoid Catch – Capitate Her – Hamate https://aclandanatomy- com.singaporetech.remotexs.co/MultimediaPlayer.aspx?multimediaId=10528093  Innervation of Anterior Compartment- Forearm Muscles Muscle Nerve Superficial Muscles Pronator teres Median Flexor carpi radialis Median Palmaris longus Median Flexor carpi ulnaris Ulnar (Intermediate layer) Flexor digitorum superficialis Median Deep Muscles Pronator quadratus Median Flexor pollicis longus Median Flexor digitorum profundus Ulnar (med 1/2) Median (lat 1/2) Anterior Compartment Forearm- Superficial layer Medial Epicondyle Pronator Teres Flexor Carpi Radialis Palmaris longus Flexor Carpi Ulnaris Flexor Digitorum Superficialis is deep to other flexors Anterior Compartment Forearm-Deep layer Flexor dig. profundus Flexor pollicis longus Pronator quadratus Pronator teres Origin: medial epicondyle of humerus Ulnar head-coronoid process Insertion: mid-shaft, of radius Nerve supply: median nerve Action: Pronate and flexes forearm Flexor carpi radialis Origin: medial epicondyle of humerus Insertion: Base of metacarpals II and III Nerve supply: median nerve Action: Flexion and abduction of wrist  Palmaris longus Origin: Medial epicondyle of humerus Insertion: Palmar aponeurosis of hand Nerve supply: median nerve Action: Flexion of wrist joint  Flexor carpi ulnaris Origin: medial epicondyle of humerus Ulnar head: olecranon and posterior border of ulna Insertion: Pisiform bone, hamate and base of metacarpal V Nerve supply: Ulnar nerve Action: Flexion and adduction of wrist  Flexor digitorum superficialis Origin: Medial epicondyle of humerus, coronoid process of ulna head of radius Insertion: Four tendons, which attach to the palmar surfaces of the middle phalanges of the index, middle, ring, and little fingers Nerve supply: median nerve Action: Flexes proximal interphalangeal joints of the index, middle, ring, and little fingers; can also flex metacarpophalangeal joints of the same fingers and the wrist joint  Flexor digitorum profundus Origin: Ulna and interosseous membrane Insertion: Four tendons, which attach to the palmar surfaces of the distal phalanges of the index, middle, ring, and little fingers Nerve supply: Lateral half by median nerve , medial half by ulnar nerve Action: Flexes distal interphalangeal joints of the index, middle, ring, and little fingers; flex metacarpophalangeal joints of the same fingers and the wrist joint Flexor pollicis longus Origin: Anterior surfaces of radius and interosseous membrane Insertion: base of distal phalanx of thumb Nerve supply: median nerve Action: Flexes interphalangeal and metacarpo- phalangeal joint of the thumb Pronator quadratus Origin: Distal anterior surface of ulna Insertion: Distal anterior surface of radius Nerve supply: median nerve Action: pronation Posterior Compartment of Forearm  Forearm Muscles- Posterior Compartment Superficial Brachioradialis Extensor carpi radialis longus Extensor carpi radialis brevis Extensor digitorum Extensor carpi ulnaris Extensor digiti minimi Radial nerve Anconeus Deep Supinator Abductor pollicis longus Extensor pollicis longus + brevis Extensor indicis Brachioradialis Origin: supracondylar ridge of humerus Insertion: Distal end of radius Nerve supply: radial nerve Action: flexor of elbow joint  Muscle Origin Insertion Action Extensor carpi radialis supracondylar ridge of humerus Dorsal surface of base of Extends and abducts longus metacarpal II the wrist Extensor carpi radialis Lateral epicondyle of humerus Dorsal surface of base of Extends and abducts brevis metacarpals II and III the wrist Extensor digitorum Lateral epicondyle of humerus bases of the middle and Extends the index, distal phalanges of the middle, ring, and index, middle, ring, and little fingers; can little fingers also extend the ‘Extensor Hoods' wrist Extensor digiti minimi Lateral epicondyle of humerus Dorsal hood of the little Extends the little finger finger Extensor carpi ulnaris Lateral epicondyle of humerus base of metacarpal V Extends and adducts and ulna the wrist  Deep muscles of Posterior Compartment Muscle Origin Insertion Action Supinator Superficial part-lateral Lateral surface of supination epicondyle of humerus, radius ulna Extensor indicis Ulna Extensor hood of Extends index index finger finger  Deep muscles of Posterior Compartment Muscle Origin Insertion Action Abductor pollicis Posterior surfaces of ulna Lateral side of base of Abducts carpometacarpal longus and radius metacarpal I joint of thumb Extensor pollicis brevis Posterior surface of base of proximal phalanx of Extends radius the thumb metacarpophalangeal and carpometacarpal joint of the thumb Extensor pollicis longus Posterior surface of ulna Dorsal surface of base of Extends interphalangeal distal phalanx of thumb joint of the thumb; can also extend carpometacarpal and metacarpophalangeal joints of the thumb Hand  Intrinsic Muscles of Hand Muscle Nerve little finger All digiti minimi Ulnar (Flexor, Abductor, Opponens) Thumb Abductor pollicis brevis Median Flexor pollicis brevis Median Opponens pollicis Median Adductor pollicis Ulnar Other Intrinsic Muscles Palmar + Dorsal Interossei Ulnar Lumbricals Median, Ulnar  Muscles of Hand Muscle Origin Insertion Nerve supply Action Thenar muscles Opponens Tubercle of Lateral margin and median nerve Medially rotates thumb pollicis trapezium and adjacent palmar flexor surface of retinaculum metacarpal I Abductor Tubercles of Proximal phalanx median nerve Abducts thumb at pollicis brevis scaphoid and and extensor metacarpophalangeal joint trapezium and hood of thumb adjacent flexor Flexor pollicis Tubercle of the Proximal phalanx median nerve flexes the metacarpophalangeal joint brevis trapezium and of the thumb of the thumb flexor retinaculum  Muscles of Hand Muscle Origin Insertion Nerve supply Action Hypothenar muscles Opponens digiti Hook of hamate Medial aspect of Deep branch of ulnar Laterally rotates minimi and flexor metacarpal V nerve [C8,T1] metacarpal V retinaculum Abductor digiti Pisiform, the Proximal phalanx of Deep branch of ulnar Abducts little finger at minimi pisohamate little finger nerve [C8,T1] metacarpophalangeal ligament, and joint tendon of flexor carpi ulnaris Flexor digiti minimi Hook of the Proximal phalanx of Deep branch of ulnar Flexes little finger at brevis hamate and flexor little finger nerve [C8,T1] metacarpophalangeal retinaculum joint Lumbricals 1ST Dorsal interossei Adductor pollicis Flexor pollicis brevis Opponens pollicis Abductor pollicis brevis Palmar interosseus Abductor digiti minimi Flexor digiti minimi brevis Opponens digiti minimi Intrinsic Muscles of Hand Lumbricals Palmar Dorsal Interossei Interossei 3rd ADDuction ABduction 2nd 4th 1st Interossei help the lumbricals to extend IP joints and flex MC-P joints BLOOD SUPPLY Wrist joint synovial joint ARTICULAR SURFACES: Distal end of radius & scaphoid, lunate, triquetral LIGAMENTS: Fibrous capsule with synovial membrane Dorsal & palmar radio-carpal ligaments Radial & ulnar collateral ligaments Movements: adduction- abduction flexion – extension Radio-ulnar joints APPLIED ANATOMY Subluxation or pulled elbow. Preschool children. eg., lifting a child into bus. Nerves Median nerve Ulnar nerve Radial nerve Carpal tunnel syndrome References Richard Drake A. Wayne Vogl Adam 2011. Gray's Anatomy for Students, 3rd edition Churchill Livingstone Standring, 2020 Gray’s Anatomy: The Anatomical Basis of Clinical Practice, 42nd Edition,, Churchill Livingstone Moore, K.L., Dalle,A.F. & Agur, A.M. 2017. Clinically Oriented Anatomy. 8th edition. Philadelphia: Lippincott Williams & Wilkins. Snell, R.S. 2018. Clinical Anatomy by Regions. 10th edition. Philadelphia: Lippincott Williams & Wilkins. Frederic H. Martini. Fundamentals of Anatomy & Physiology, Global Edition, 11th Edition: Pearson (instructor resources) http://anatomediaonline.com/amedia/index.html