Forearm & Hand Anatomy PDF

Forearm and Hand (to see my pointer on select slides, convert to video or use presentation mode) Natascha Heise, PhD [email protected] Forearm Objectives At the end of this lecture, students will be able to: Describe the major features of the radius and ulna. Identify bony landmar...

Forearm and Hand (to see my pointer on select slides, convert to video or use presentation mode) Natascha Heise, PhD [email protected] Forearm Objectives At the end of this lecture, students will be able to: Describe the major features of the radius and ulna. Identify bony landmarks of the humerus, radius, ulna and hand that serve as points of attachment for the muscles of the forearm. Explain how the forearm is organized into two fascial compartments. Name the muscles of the forearm, and describe their general attachments, actions and innervations. Describe the course and principal branches of the radial and ulnar arteries in the forearm and at the wrist. Describe the course of the radial and ulnar veins. Describe the course of the median, ulnar and radial nerves in the forearm and name the structures it innervates. Identify the radius and ulna and their major features on radiographs of the upper extremity. Identify the ulnar and radial arteries on angiograms of the upper extremity. Explain various clinical correlates associated with the forearm. Hand Objectives At the end of this lecture, students will be able to: Identify the bones of the hand (carpals, metacarpals, phalanges). Describe the anatomy of the joints of the hand and their movements (e.g. wrist, midcarpal, carpometacarpal, metacarpophalangeal and interphalangeal joints). Describe specializations of deep fascia in the wrist and hand (flexor and extensor retinacula, palmar aponeurosis, fibrous digital sheaths, extensor hoods) and discuss their functions. Describe the course and principal branches of the ulnar and radial arteries in the hand. Explain the distribution of dermatomes on the hand. Describe the cutaneous innervation of the hand and name the autogenous zones for the median, radial and ulnar nerves. Describe the course of the median, ulnar, and radial nerves in the hand and name the structures it innervates. Name the intrinsic muscles of the hand, and describe their general attachments, actions and innervations. Describe the borders and contents of the anatomical snuff box. Describe the structure and contents of the carpal tunnel. Explain various clinical correlates associated with the hand. Outline FOREARM HAND Created using Movements of the Wrist and Forearm Wrist movements: Flexion & Extension Abduction & Adduction Radial & Ulnar deviation Other movements: Supination & Pronation Movements of the Digits Movements of Digits 2-5: Abduction & Adduction (midline is digit 3) Flexion & Extension Movements of Thumb: Abduction & Adduction Flexion & Extension Opposition (& Circumduction)  Posterior R Bones & Bony LandmarksMedial epicondyle Humerus Lateral epicondyle Elbow Joint Olecranon Process Medial epicondyle Radial Head Lateral epicondyle Radial notch Radial Neck Elbow Joint Radial Head Radial Neck Coronoid process Supinator Crest Ulnar Tuberosity Ulna Radial Tuberosity Ulna Radius Radius Ulnar notch Styloid Process Styloid Process Styloid Process Styloid Process Wrist joint Wrist joint Carpals L Carpals M Anterior R Source: Essential Clinical Anatomy, 5th edition  D3 D4 D2 12 Bones & Bony Landmarks D5 12 12 11 Word bank: 11 11 12 __Capitate, __Hamate, 11 10 10 10 __ Lunate, __ Metacarpal, D1 __Pisiform, __ Scaphoid, 10 12 __ Trapezium, __Trapezoid, M L __Triquetrum, 10 9 9 __Proximal phalanges, 9 9 __Middle phalanges, 9 __Distal phalanges 8 6 3 7 4 5 (D = Digit) 2 1 Anterior R midline Source: Netter’s Atlas of Human Anatomy, 6th edition  D3 D4 D2 12 Bones & Bony Landmarks D5 12 12 11 Word bank: 11 11 12 7 Capitate, 8 Hamate, 11 10 10 10 2 Lunate, 9 Metacarpal, D1 4 Pisiform, 1 Scaphoid, 10 12 5 Trapezium, 6 Trapezoid, M L 3 Triquetrum, 10 9 9 10 Proximal phalanges, 9 9 11Middle phalanges, 9 12 Distal phalanges 8 6 3 7 4 5 (D = Digit) 2 1 Anterior R midline Source: Netter’s Atlas of Human Anatomy, 6th edition  D3 Joints D4 D2 D5 Distal inter-phalangeal joint Prox. inter-phalangeal joint (Flexion, Extension) (Flexion, Extension) D1 Metacarpal-phalangeal joint Inter-phalangeal joint (Flexion, Extension, Abduction, (Flexion, Extension) Adduction, Circumduction, Opposition) Mid-carpal joint Carpo-metacarpal joint (allow augmentation of wrist movements) (Flexion, Extension, Adduction, Abduction) Wrist joint (Radiocarpal) (Flexion, Extension, Abduction, Adduction; Anterior R Synovial between radius and carpals) Source: Clinically Oriented Anatomy, 8th edition; Netter’s Atlas of Human Anatomy, 6th edition Radial Head Dislocation Nursemaid’s elbow: Dislocation = bone slips out of normal position & annular ligament displaces Common in younger children under age 5: Pulling a child up by hands Swinging a toddler Breaking a fall Symptoms: Painful around elbow No swelling or bruising Treatment: Reduction Maneuver Pain medicine Olecranon fracture Causes: Fall directly on elbow Receive direct blow to elbow Symptoms: Painful around elbow Swelling, bruising Numbness and weakness in movement of medial digits Treatment: Wearing a splint until bone heals Surgery (pins and wires “tension band” or screws) Source: https://www.jhandsurg.org/article/S0363-5023(12)01850-3/fulltext  FOOSH (= fall onto an outstretched hand) Colle’s fracture = fracture of radius close to the wrist Scaphoid fracture Which artery may be affected here?  Arterial Supply Anterior R Brachial a. Radial recurrent a. Anterior ulnar recurrent a. (anastomosis w/radial collateral a.) (anastomosis w/inferior ulnar collateral a.) Supplies MOST forearm extensors Posterior ulnar recurrent a. Radial a. (anastomosis w/superior ulnar collateral a.) Anterior R Common interosseous a. Recurrent interosseous a. (anastomosis w/middle collateral a.) Posterior Anterior interosseous a. interosseous a. Supplies MOST forearm flexors Supplies MOST forearm extensors Ulnar a. Supplies MOST forearm flexors Interosseous membrane Source: Netter’s Atlas of Human Anatomy, 6th edition  Superficial Proper palmar Arterial Supply digital aa Radial a Superficial palmar Common palmar brr of radial a digital aa Ulnar a Superficial Deep palmar palmar arch a arch a Deep palmar Radialis indicis a brr of ulnar a Princeps pollicis a Superficial Common palmar palmar arch a digital aa Deep palmar Proper palmar arch a digital aa *notice the relationship between the arches, the carpal bones, Deep Anterior R and the surrounding structures! Source: Netter’s Atlas of Human Anatomy, 6th edition Allen’s Test test vascular perfusion distal to wrist Place thumb on patient’s ulnar and radial arteries → patient makes fist → clinician releases pressure on ulnar artery → patient opens fist Normal: skin will turn pink immediately (normal ulnar blood flow through anastomotic palmar arches) Repeat compressing ulnar artery Source: Netter’s Clinical Anatomy, 3rd edition  Posterior/Anterior R Venous Return Median Median Basilic vein Cephalic vein Basilic vein Median antebrachial vein Basilic vein Cephalic vein MCV = Median Cubital Vein CV = Cephalic Vein BV = Basilic Vein Dorsal venous network M M L Angiogram of arteries in the hand (right, palm) Source: Netter’s Atlas of Human Anatomy, 6th edition  Innervation (cutaneous - segmental) Anterior R Posterior R DERMATOMES C5 C6 C5 C7 T1 T1 C8 C7 C6 C8 Source: Netter’s Atlas of Human Anatomy, 6th edition  Radial nerve Median nerve Innervation (cutaneous - peripheral) Ulnar nerve Anterior R Posterior R Lateral antebrachial cutaneous n. (musculocutaneous n.) Radial n. (C5-C8) Medial antebrachial cutaneous n. (C8,T1) Lateral antebrachial cutaneous n. (musculocutaneous n.) Ulnar n. Superficial brr of radial n. Median n. Median n. Source: Netter’s Atlas of Human Anatomy, 6th edition  Radial nerve Median nerve Innervation (motor - peripheral) Ulnar nerve Musculocutaneous nerve (sensory only in forearm) Ulnar nerve Radial nerve (medial anterior (ALL extensor muscles in posterior forearm) forearm muscles) Median nerve (lateral anterior forearm muscles) Source: Netter’s Atlas of Human Anatomy, 6th edition  Radial nerve Nerves in the Forearm Posterior R Radial Nerve: Runs anterolateral in forearm before running posteriorly Radial nerve innervates muscles & skin of posterior arm & Brachioradialis & Extensor carpi radialis longus mm Branches into a deep branch to innervate Extensor carpi radialis brevis & Supinator mm Continues as posterior interosseous nerve to innervate rest of extensor muscles of the forearm Superficial branch of radial n (cut; sensory hand) Source: Netter’s Atlas of Human Anatomy, 6th edition  Anterior R Median nerve Median n Ulnar nerve Nerves in the Forearm Median Nerve Runs lateral & then medial to brachial artery Innervates anterolateral forearm muscles Ulnar nerve Branches into anterior interosseous nerve to innervate deep muscles in anterior forearm Rest continues as median nerve to hand Ulnar Nerve Median nerve Runs posterior to elbow through ulnar tunnel In forearm, branches into muscular branches to innervate flexor carpi ulnaris & half of flexor digitorum profundus Anterior R Rest continues to hand Ulnar n Source: Netter’s Atlas of Human Anatomy, 6th edition  Radial nerve Median nerve Nerves in Hand (cutaneous - peripheral) Ulnar nerve Median nerve: Palmar branch: innervates skin of lateral palm Common & Proper palmar digital branches: innervate palmar surface and fingertips of lateral three and half digits Ulnar nerve: Dorsal branch: innervates the dorsal surface of medial one and a half fingers and associated dorsal hand area Palmar branch: innervates skin of medial palm Superficial branch → Common & Proper palmar digital branches: innervates palmar surface and fingertips of medial one and a half digits Superficial branch of radial n Radial nerve: superficial branch: innervates dorsal lateral hand Source: Netter’s Atlas of Human Anatomy, 6th edition  Median nerve Ulnar nerve Nerves in Hand (motor - peripheral) Median nerve: Recurrent branch: innervates Palmar branch thenar muscles of median n (cut, sensory) Palmar digital branch (2): Palmar branch of innervates lateral two ulnar nerve (cut, sensory) lumbricals Ulnar nerve: Deep branch: hypothenar muscles, medial lumbricals, adductor pollicis, interossei Superficial branch: palmaris brevis muscle Proper palmar digital branch of Anterior R median n (sensory) Source: Netter’s Atlas of Human Anatomy, 6th edition  Forearm (Antebrachial fascia) Anterior Posterior Ulnar nerve Radial nerve Median nerve  Median nerve Ulnar nerve At the Gym Climbing/Bouldering Palms-up Wrist Curl Forearm Squeeze  Median nerve Ulnar nerve Musculature Superficial & Deep layer Anterior L  Median nerve Anterior R Ulnar nerve Musculature Flexor carpi radialis Pronator Flexes and abducts hand at teres wrist Pronates forearm Palmaris longus Flexes hand at wrist and tenses palmar aponeurosis Flexor Flexor carpi ulnaris digitorum Flexes and adducts hand at superficialis wrist Flexes middle and proximal phalanges of medial four digits Source: Anatomy & Physiology Revealed 4.0  Median nerve Ulnar nerve Musculature Flexor pollicis longus Flexes phalanges of digit 1 Pronator quadratus Pronates Flexor digitorum forearm profundus (Medial part: ulnar n Lateral part: median n) Flexes distal phalanges of medial four digits Anterior R Source: Anatomy & Physiology Revealed 4.0  Summary – Anterior Forearm Muscle Prox. attachment Distal attachment Innervation Blood supply Action Medial epicondyle of Pisiform bone, hook of humerus; olecranon Posterior ulnar Flexes and adducts Flexor carpi ulnaris hamate, base of 5th Ulnar nerve and posterior border recurrent artery hand at wrist metacarpal of ulna Anterior Flexes distal Medial/anterior/pro Medial part: Ulnar Palmar base of distal interosseous artery phalanges of medial Flexor digitorum ximal ulna and nerve phalanges of medial & muscular four digits; assist in profundus interosseous Lateral part: four digits branches of ulnar flexion of hand at membrane Median nerve artery wrist Medial epicondyle of Flexes middle and humerus and Flexor digitorum Middle phalanges of Ulnar and radial proximal phalanges coronoid process of Median nerve superficialis medial four digits arteries of medial four digits; ulna; superior flexes hand at wrist anterior radius Medial epicondyle of Flexes and abducts Flexor carpi radialis Base of 2nd metacarpal Median nerve Radial artery humerus hand at wrist  Summary – Anterior Forearm Muscle Prox. attachment Distal attachment Innervation Blood supply Action Flexes hand at wrist Distal flexor Medial epicondyle of Posterior ulnar and tenses palmar Palmaris longus retinaculum and palmar Median nerve humerus recurrent artery aponeurosis aponeurosis Medial epicondyle of Pronates forearm humerus and Mid-lateral surface of Anterior ulnar Pronator teres Median nerve and assists with coronoid process of radius recurrent artery elbow flexion ulna Median nerve Anterior Pronator quadratus Distal anterior ulna Distal anterior radius (anterior Pronates forearm interosseous artery interosseous) Anterior radius and Median nerve Palmar base of distal Anterior Flexes phalanges of Flexor pollicis longus interosseous (anterior phalanx of digit 1 interosseous artery digit 1 membrane interosseous) Medial epicondylitis Golfer’s/baseball elbow: Caused by: Repetitive microtrauma due to overuse contraction of wrist flexors Pain along medial anterior forearm, weakness in hands/wrist MRI, CT Treatment: Non-surgical: rest, meds, PT, brace, steroid injections Surgical (after 6-12 months): remove diseased muscle and reattach healthy muscle back to bone, splint, PT, athletic activity after 4-6 months after surgery  Forearm (Antebrachial fascia) Anterior Posterior Ulnar nerve Radial nerve Median nerve  Radial nerve At the Gym Barbell wrist extension Reverse curls Dumbbell wrist extension  Radial nerve Musculature Posterior L Posterior R Superficial layer R  Posterior L Radial nerve Musculature Extensor carpi radialis longus Extends and abducts wrist Extensor carpi radialis brevis Superficial layer Extends and abducts wrist Brachioradialis: Weak flexion when arm mid-pronated Extensor carpi ulnaris: Extends and adducts the wrist Extensor digitorum Extends wrist & digits 2-5 Extensor digiti minimi Extends digit 5 & assists in wrist extension Source: NetAnatomy  Radial nerve Posterior L Extensor Digitorum Extensor Carpi Radialis Longus Extensor Extensor Carpi Radialis Digitorum Brevis Source: NetAnatomy  Extensor Radial nerve Extensor Posterior L Carpi Ulnaris Digiti Minimi Extensor retinaculum Extensor Extensor Extensor Carpi Ulnaris Digiti Minimi retinaculum Extensor expansion/hood Source: NetAnatomy  Radial nerve Posterior R Musculature Posterior L Deep layer  Radial nerve Musculature Posterior L Posterior L Supinator Supinates forearm Deep layer Dumbbell wrist rotation Fist Bumps Source: NetAnatomy  Radial nerve Musculature Posterior L Extensor Deep layer digitorum Extensor pollicis longus Interosseous Extends distal phalanx of 1st digit at ip and mp joint membrane Extensor indicis Extends 2nd digit & assists in wrist extension Abductor pollicis longus Abducts and extends digit 1 Extensor pollicis brevis Extends distal phalanx of 1st digit at cm joint Source: NetAnatomy  Summary – Posterior Forearm Muscle Prox. attachment Distal attachment Innervation Blood supply Action Proximal lateral Weak flexion of Lateral distal end of Radial recurrent Brachioradialis supracondylar ridge Radial nerve forearm when mid- radius artery of humerus pronated Extensor carpi Lateral supracondylar Dorsal base of 2nd Radial artery, radial Extends and abducts Radial nerve radialis longus ridge of humerus metacarpal recurrent artery hand at wrist Lateral epicondyle of Radial nerve (deep Radial recurrent Supinator Proximal radius Supinates forearm humerus brr) artery Extensor carpi Lateral epicondyle of Dorsal base of 3rd Radial nerve (deep Radial artery, radial Extends and abducts radialis brevis humerus metacarpal brr) recurrent artery hand at wrist Radial nerve Extensor carpi Lateral epicondyle of Dorsal base of 5th Posterior Extends and adducts (posterior ulnaris humerus metacarpal interosseous artery hand at wrist interosseus)  Summary – Posterior Forearm Muscle Prox. attachment Distal attachment Innervation Blood supply Action Extensor Extends 5th digit & Lateral epicondyle of Radial nerve (posterior Posterior Extensor digiti minimi expansion of 5th assists in wrist humerus interosseous) interosseous artery digit extension Extensor Extends medial 4 Lateral epicondyle of Radial nerve (posterior Posterior Extensor digitorum expansion of digits & assists in humerus interosseous) interosseous artery medial 4 digits wrist extension Extensor Extends 2nd digit & Posterior ulna and Radial nerve (posterior Posterior Extensor indicis expansion of 2nd assists in wrist interosseous membrane interosseous) interosseous artery digit extension Dorsal base of Extends distal Posterior ulna & Radial nerve (posterior Radial artery, radial Extensor pollicis longus distal phalanx of phalanx of 1st digit at interosseous membrane interosseous) recurrent artery digit 1 ip and mp joint Dorsal base of Extends proximal Posterior radius & Radial nerve (posterior Radial artery, radial Extensor pollicis brevis proximal phalanx phalanx of 1st digit at interosseous membrane interosseous) recurrent artery of digit 1 cm joint Posterior ulna, radius, Base of 1st Radial nerve (posterior Posterior Abducts and extends Abductor pollicis longus interosseous membrane metacarpal interosseous) interosseous artery thumb at cm joint Lateral epicondylitis: Tennis elbow: Caused by: Repetitive microtrauma due to overuse contraction of wrist extensors Commonly affected: Extensor carpi radialis brevis m (dominant side) Pain along posterio-lateral side of forearm and weakness of extension and abduction of wrist MRI, CT Treatment: Non-surgical: rest, meds, PT, brace, steroid injections Surgical (after 6-12 months): remove diseased muscle and reattach healthy muscle back to bone, splint, PT, athletic activity after 4-6 months after surgery Fascia of Palm Fascia of palm is continuous with anterior antebrachial fascia and dorsum of hand Thin over thenar and hypothenar eminence Hypothenar mm Thick centrally: palmar aponeurosis (deep fascia) continuous with flexor retinaculum (fibrous bands of fascia; serves as pulley Thenar mm for flexor muscles and stabilization) and palmaris longus tendon Palmar aponeurosis Fibrous digital sheaths surround flexor tendons (filled with lubricating fluid) Formation of 5 compartments Flexor retinaculum Anterior R Source: Netter’s Atlas of Human Anatomy, 6th edition  Fascia of Palm Palmar aponeurosis Medial fibrous septum (1) Thenar (5) CENTRAL MC1 compartment-3 mm (2) Hypothenar MC5 (3) Adductor compartment-3 mm compartment-1 m Lateral fibrous septum 9 Long flexor tendons (3 mm) 1 nerve (4) Interossei compartment-2 mm Anterior R Source: Clinically Oriented Anatomy, 8th edition; Netter’s Atlas of Human Anatomy, 6th edition Fascia of Dorsum Hand Fascia of dorsum of hand is continuous with posterior antebrachial fascia and palm of hand Extensor expansion Thickening: Extensor retinaculum Extensor expansion/hood: Special connective attachments by which extensor tendons insert into phalanges Surrounds distal metacarpal + proximal Extensor retinaculum phalanges and holds extensor tendons in place Formed by: extensor digitorum, Extensor lumbricals, and interossei mm digitorum mm Source: Netter’s Atlas of Human Anatomy, 6th edition Fascia of Dorsum Hand Extensor expansion Lumbricals Interossei Extensor retinaculum Extensor digitorum mm Extensor digitorum Source: Netter’s Atlas of Human Anatomy, 6th edition  Median nerve Ulnar nerve Musculature - Palm Anterior R Palmar Aponeurosis Palmaris brevis Deepens hollow of hand, assist grip Palmaris Longus Flexes hand at wrist and tenses palmar aponeurosis Flexor Retinaculum Source: Anatomy & Physiology Revealed 4.0  Median nerve Ulnar nerve Musculature - Palm Anterior R Flexor Digitorum Superficialis Flexor Pollicis (FDS) Brevis Flexes prox. phalanx of digit 1 Opponens Pollicis THENAR Draws 1st muscles metacarpal forward and Abductor rotates it Pollicis Brevis medially Abducts digit 1 Anterior L Source: Anatomy & Physiology Revealed 4.0  Median nerve Ulnar nerve Musculature - Palm Anterior R Abductor Digiti Minimi Abducts digit 5 Flexor Digiti Minimi Flexes proximal phalanx of digit 5 HYPOTHENAR Anterior L muscles Source: Anatomy & Physiology Revealed 4.0  Median nerve Ulnar nerve Musculature - Palm Anterior R Flexor Opponens Digitorum Digiti Minimi Profundus Draws 5th (FDP) metacarpal anteriorly and Flexor Pollicis rotates to face Longus digit 1 3 2 1 4 Opponens Pollicis Draws 1st metacarpal forward and rotates it medially Lumbricals Lumbricals (inn. by Extend digits at IP median and ulnar n) joints, flex MP joints Source: Netter’s Atlas of Human Anatomy, 5th edition; Anatomy & Physiology Revealed 4.0  Median nerve Ulnar nerve Musculature - Palm Anterior R Flexor Opponens Digitorum Digiti Minimi Profundus Draws 5th (FDP) metacarpal anteriorly and Flexor Pollicis rotates to face Longus digit 1 Opponens Pollicis Draws 1st Tendons of FDS metacarpal forward split @ proximal and rotates it phalanx to permit medially FDS passage of the Lumbricals (inn. by FDP tendons of FDP median and ulnar n) Source: Netter’s Atlas of Human Anatomy, 5th edition; Anatomy & Physiology Revealed 4.0  Ulnar nerve Musculature - Palm Anterior R Adductor Pollicis Adducts digit 1 Adductor Pollicis Source: Anatomy & Physiology Revealed 4.0  Ulnar nerve Musculature - Palm DAB PAD 2 4 3 1 1 3 2 Dorsal interossei (4 bipennate) Palmar interossei (3 unipennate) Abducts digits from axial line of hand (3rd digit), flex Adducts digits towards axial line (3rd digit), flexes digits at digits at MP joint and extend IP joints MP joints and extends IP joints  Posterior L Radial nerve Musculature Ulnar nerve Extensor Pollicis - Dorsum Brevis Extends proximal phalanx of 1st digit at cm joint Extensor Pollicis Longus Extends distal Abductor phalanx of 1st digit Pollicis Longus at ip and mp joint Abducts and extends digit 1 at cm joint longus First Dorsal interosseous brevis longus Source: NetAnatomy  Posterior L Radial nerve Anat. Snuffbox Anatomical Snuffbox EPB & APL Triangular depression on dorsum of hand at the base of the thumb: Borders: Medial: EPL EPL Lateral: APL, EPB Superior: Head of radius Contents: Radial artery Brr of radial nerve Cephalic vein CLINICAL: tenderness, pain, swelling may indicate scaphoid fracture Source: NetAnatomy Carpal Tunnel = passageway from wrist to hand Borders: Flexor retinaculum & carpal bones Contents: 1 x Flexor pollicis longus tendon 4 x Flexor digitorum profundus tendons 4 x Flexor digitorum superficialis tendons 1 x Median nerve  Summary – Hand Highlighted = thenar muscles Muscle Prox. attachment Distal attachment Innervation Blood supply Action Flexor retinaculum, Lateral proximal Median nerve Superficial palmar brrr Abductor pollicis brevis Abducts digit 1 scaphoid and trapezium phalanx of digit 1 (recurrent brr) of radial artery Flexor retinaculum and Lateral proximal Median nerve Superficial palmar Flexes proximal phalanx Flexor pollicis brevis trapezium phalanx of digit 1 (recurrent brr) branch of radial artery of digit 1 Draws 1st metacarpal Flexor retinaculum and Lateral side of 1st Median nerve Superficial palmar brr Opponens pollicis forward and rotates it trapezium metacarpal (recurrent brr) of radial artery medially Lateral two tendons of Lateral sides of Median nerve Superficial and deep Extends digits at IP Lumbrical 1-2 flexor digitorum extensor expansion (digital brr) palmar arches joints, flexes MP joints profundus of digits 2 and 3 Medial three tendons of Lateral sides of Ulnar nerve (deep Superficial and deep Extends digits at IP Lumbrical 3-4 flexor digitorum extensor expansion brr) palmar arches joints, flexes MP joints profundus of digits 4 and 5 Proximal phalanx Adducts digits towards Palmar interosseous Sides of metacarpal 2, and extensor Ulnar nerve (deep axial line (3rd digit), Deep palmar arch muscles 4, and 5 expansion of digits brr) flexes digits at MP joints 2,4, and 5 and extends IP joints  Summary – Hand Highlighted = hypothenar muscles Muscle Prox. attachment Distal attachment Innervation Blood supply Action Palmar aponeurosis and Skin of medial Ulnar nerve Superficial Deepens hollow of hand, Palmaris brevis flexor retinaculum border of palm (superficial brr) palmar arch assist grip 2nd/3rd metacarpal, capitate, and adjacent Medial proximal Adductor pollicis Ulnar nerve (deep brr) Deep palmar arc Adducts digit 1 bones + anterior 3rd phalanx of digit 1 metacarpal Proximal Abducts digits from axial Dorsal interosseous Adjacent sides of two phalanges, extensor Deep palmar line of hand (3rd digit), Ulnar nerve (deep brr) muscles metacarpal bones expansion of digit arch flex digits at MP joint 2-4 and extend IP joints Pisiform and tendon of Medial proximal Deep palmar brr Abductor digiti minimi Ulnar nerve (deep brr) Abducts digit 5 flexor carpi ulnaris phalanx of digit 5 of ulnar artery Flexor digiti minimi Flexor retinaculum, Medial proximal Deep palmar brr Flexes proximal phalanx Ulnar nerve (deep brr) brevis hook of hamate phalanx of digit 1 of ulnar artery of digit 5 Draws 5th metacarpal Flexor retinaculum and Palmar surface of Deep palmar brr Opponens digiti minimi Ulnar nerve (deep brr) anteriorly and rotates to hamate 5th metacarpal of ulnar artery face digit 1 Quiz 1 1 3 2 4 5 6 Anterior L  Questions? Feel free to email me Natascha Heise, PhD [email protected]