reinforced thickenings of antebrachial fascia at wrist

tendons of extrinsic muscles prevented from "bowstringing"

tough fibrous sheet covered by superficial fascia, protecting deeper structures of palm, provide attachment for tendon of palmaris longus

a small palmaris brevis attaches at hypothenar aspect

fleshy prominences at bases of thumb and digit 5

consist of abductor, flexor and opponens mm.

8 are present in two rows of 4

form a curve:

proximal row, medial to lateral

• pisiform
• triquetrum
• lunate
• scaphoid

distal row, medial to lateral

• hamate
• capitate
• trapezoid
• trapezium

sesamoid bone in tendon of flexor carpi ulnaris

lies anterior to triquetrum

provides attachment for flexor retinaculum

articulates with radius in radiocarpal joint

anterior tubercle provides attachment for flexor retinaculum

forms floor of anatomical snuffbox

most commonly fractured with fall on outstretched hand

proximal bases and distal heads

heads of metacarpals II-V prominent in flexed MCP joints

total of 14, 2 in thumb (proximal, distal), 3 in other four digits (proximal, middle and distal)

proximal bases and distal heads

flexor carpi radialis tendon occupies seperate compartment deep to flexor retinaculum

tendon of flexor carpi ulnaris passes medial to carpal tunnel, superficial to flexor retinaculum; contains sesamoid bone (pisiform)

tendon of palmaris longus passes superficial to flexor retinaculum to palmar aponeurosis

tendons of digital flexors & flexor pollicis longus pass through the carpal tunnel along with median nerve

tendons of flexor digitorum superficialis split near insertions on middle phalanges to permit tendons of flexor digitorum profundus to pass through; flexor tendons are attached to the phalanges by firbous digital sheaths and the tendons are contained within synovial sheaths in the flexor sheath

tendons of extensor carpi radialis longus & brevis pass in seperate compartments through anatomical snuffbox, deep to tendons of thenar outcrop mm. which form boundaries of the snuffbox (aBductor pollicis longus & extensor pollicis brevis anteriorly & extenssor pollicis longus posteriorly)

tendons of extensor carpi ulnaris, digital extensors & extensor digiti minimi occupy seperate compartments

fibrous hoods (expanded attachments for the tendons) drape posterior aspect of digits 2-5

hoods abut the transverse metacarpal ligaments (during extension of MCP joints) and attach to the proximal, middle, and distal phalange

lumbricals and interosseous muscles attach to the expansions

Digital extensors are effective ar MCP joints only

Lumbricals (supported by interossei) extend the PIP & DIP joints

supplied by recurrent branch of median nerve C8-T1

attachments: flexor retinaculum & adjacent carpals to proximal phalanx of thumb (a.&f.p. brevis) or at lateral side of 1st metacarpal (opponens pollicis)

actions:

• ABduction (movement away from palm)
• flexion (movement across palm)
• opposition (folding palm & medial rotation of metacarpal I to touch thumb to little finger)

attachment: flexor retinaculum & hook of hamate (f.& o.d.m.)' from pisiform (a.d.m) to #V proximal phalanx (a.d.m. & f.d.m.); medial side of 5th metacarpal (o.d.m.)

innervation: ulnar nerve C8-T1

actions: ABduction, flexion, opposition (folding palm & lateral rotation of metacarpal V to touch finger to thumb)

NOTE: the small palmaris brevis m. lies superficial to hypothenar mm. attaching to palmar aponeurosis and skin of hypothenar eminence

attachments: tendons of flexor digitorum profundus to lateral sides of digital extensor expansion of digits II to V

innervation: median nerve C8-T1 (lumbricals 1&2), ulnar nerve (lumbricals 3&4)

actions: extension at PIPs & DIPs, flexion at MCP joints

2 sets: palmar interosseous and dorsal interosseous

attachments: sides of metacarpals to axial surfaces of 2, 4, 5th proximal phalanges (palmars); external surfaces of digits II, III (2), & IV (dorsals)

actions:

• ADDuction of digits II, IV & V (PAD = Palmars adduct)
• ABduction of digits II, III (bilateral) & IV (DAB = Dorsals abduct)

Note: Collateral ligaments of MCP joints restrict ABduction with a tight fist

attachments: 3rd metacarpal (transverse head) & capitate (oblique head) to medial side of proximal phalanx of thumb

innervation: ulnar nerve C8-T1

actions: ADDuction of thumb

• Ulnar Artery
• Radial Artery
• Palmar Arches

enters medial side, deeo to flexor carpi ulnaris tendon & palmaris brevis m., accompanied by ulnar nerve

can be palpated as it passes across the flexor retinaculum next to the pisiform bone

major contributor to the superficial palmar arch

deep branch contributes to deep palmar arch

traverses "anatomical snuffbox" to dorsum of hand, pierves first dorsal interosseous m. to form deep palmar arch

superficial branch feeds to superficial palmar arch

• Ulnar Nerve C8-T1
• Median Nerve C8-T1 (in hand)
• Radial Nerve C5-T1

travels medial to the ulnar artery within a canal to medial side of palm

cutaneous supply to medial one and one half digits & adjacent dorsal & palmar surfaces of hand

deep branch supplies lumbricals 3&4, interossei, ADDuctor pollicis and hypothenar mm.

*C8-T1 (in hand)

passes through carpal tunnel, lateral & deep to tendon of palmaris longus

recurrent branch C8-T1 supplies thenar mm.

muscular branches to lumbricals 1&2

superficial branches (digitals) supply skin of lateral three and one half digits and skin of lateral palm

supplies skin of lateral half of dorsum of hand & back of thumb

no motor branches in hand

• thumb C6
• #2&3 C7
• #4&5 C8

• Radiocarpal joint stabilized by radial and ulnar collateral ligaments
• condyloid type joint mostly between radius & lunate & scaphoid of carpus
• small part of triquetrum articulates with articular disc of ulna head
• permits flexion/extension, ab/adduction (radial & ulnar deviation)
• greater chance on ulnar side permits greater ulnar than radial deviation