Anatomy of the Hand and Wrist - PowerPoint Presentation

Slide1

Anatomy of the Hand and Wrist

Jane Fedorczyk, PT, PhD, CHTDirector, Center for Hand and Upper Limb Health and PerformanceClinical Professor, Physical TherapyClinical Professor, Occupational TherapyJane.Fedorczyk@Jefferson.edu

Slide2

Objectives

Review primary anatomical structures of the hand and wrist.Apply knowledge of neuromusculoskeletal anatomy to normal wrist and hand movements and functional use of the hand/wrist.Discuss the clinical significance of anatomical structures.Acquaint student to relevant clinical information as it relates to anatomy

Slide3

The Hand: Complex Motor Tasks,

Interaction/Perception with Environment

Slide4

Components of Prehension

StrengthExtrinsic and IntrinsicROM; pain freeTendon GlidingLymphatic FunctionMotor Control

Motor plan

Timing

Recruitment

Coordination

Stable Base especially wrist and thumb

Load Transfer

Quality of bone and articular cartilage

Innervation

SensationVascularitySkin Integrity

Hand of Mountain Gorilla, Rwanda

Slide5

Prehension – two types

Grasp/Grip Pinch/Prehension

Slide6

Grips/Grasp:

uses all digits and palm

Slide7

Pinch/Prehension

Uses radial side of the hand – thumb, index, long fingersOpposition enables thumb to hold against stable post of index and long fingersImmobility of CMC for index and long provides stability

Slide8

Hand Osteology

19 bones distal to the carpus5 Metacarpals (I-V)3 Phalanges (II-V)2 Phalanges (I)

I

II

RAY

III

V

IV

Slide9

Wrist Complex: Osteology

Distal Radius and UlnaRadius extends moredistally than ulna in AP and lateral views

8 Carpal Bones

Proximal Row

Distal Row

Slide10

Proximal Row

ScaphoidMost commonly FxProximal pole has poor blood supplyForms floor of radial snuffbox

Lunate

Most commonly dislocated

Triquetrum

Pisiform

Sesamoid

for FCU

No tendons insert onto to

scaphoid, lunate, & triquetrum

Slide11

The Problematic Scaphoid –Blood Flow Impacts Healing Rates

Tubercle

Slide12

Distal Row

TrapeziumTrapezoidCapitateCenter of rotationHamateUlnar nerve passes beneath hook of hamate

Slide13

Bo

ny Anatomy Hand/Wrist: Radiograph

Slide14

Palm

of Hand

1

s

t

L

a

y

e

rPa

lmar

Ap

o

n

e

u

r

o

s

i

s

Dupuytren

Disease

Slide15

Comp

artments of the Hand

Slide16

Muscles of the Hand: Extrinsic vs. Intrinsic

Extrinsic: originate in the forearm and insert in the hand Intrinsic: originate in the hand and insert in the hand

Slide17

Palm

o

f

H

a

nd

A

bdu

c

t

or

Pollici

s

B

r

e

vi

s

Origi

n

:

Scaphoi

d

&

T

r

ap

e

zium

Inse

r

tio

n

:

Base

o

f

1

s

t

P

r

o

x

.

Phala

n

x

Actio

n

:

Abd

uct

s

thumb

at CMCInnervation: Recurrent Branch of Median NerveFlexor Pollicis Brevis

Origin: TrapeziumInsertion: Base of 1st Prox. PhalanxAction: Flexes CMC, PIP of thumb•

Innervation: Recurrent Branch of Median Nerve

1

s

t Muscular Layer: Thenar Muscles

Slide18

Palm

of Hand

Opp

o

nen

s

P

o

llici

sOrigi

n: Trap

e

zium

In

s

ertion

:

Shaf

t

o

f

1

s

t

me

t

a

c

arpal

Actio

n

:

O

p

p

o

se

s thumb

a

t

CMC

Inne

r

v

a

tio

n

:

R

e

c

ur

r

e

n

t

B

r

anch of Median Nerve2nd Muscular Layer: Thenar Muscles

Slide19

Palm

of HandA

dduc

t

o

r

P

o

llici

sOrigin: Obliqu

e head:

bas

e

o

f

the

2nd

and

3

r

d

me

t

a

c

arpals;

T

r

an

s

v

e

r

se

he

a

d

:

sh

a

f

t

o

f

the

3

r

d

me

t

a

c

arpal

In

s

ertion: Base of Proximal phalanxAction: Adducts thumbInnervation: Ulnar nerve

Slide20

Mechanics for Pinch

Thenar Muscles (median nerve)Abductor Pollicis BrevisFlexor Pollicis Brevis

Opponens

Pollicis

Involved in placement and stabilization for prehension

Adductor

Pollicis

(ulnar nerve)

responsible for power/strength

Thenar

Adductor

Pollicis

ABP

FBP

OP deep to FBP and ABP

Slide21

Hand

Intrinsics: Hypothenar Hypothenar Eminence (Ulnar)Abductor Digiti Minimi

Flexor

Digiti

Minimi

Opponens

Digiti

MinimiAllow independent function of the small finger allowing opposition towards thumb.

Slide22

Palm

o

f

H

a

nd

A

bduc

t

o

r

D

i

g

it

i

M

ini

m

i

Origi

n

:

Pi

s

i

f

orm

In

s

ertion

:

Base

o

f 5th

P

r

o

x

.

Phala

n

x

Actio

n

:

Abducts

5

t

h

Digit

Inne

r

v

a

tio

n

: Ulnar NerveDon’t worry about palmaris brevis1st Muscular

Layer: Hypothenar Muscles

Slide23

Palm

of Hand

2n

d

Mus

c

ul

a

r

Layer

:

H

y

p

o

th

e

n

a

r

Mus

c

l

e

s

F

l

e

x

o

r

D

i

g

it

i

M

ini

m

i

B

r

e

v

i

s

Origin

:

H

a

m

at

e

In

s

ertio

n

:

Base

of 5th Prox. PhalanxAction: Flexes 5th CMC, MCPInnervation: Ulnar Nerv

eOpponens Digiti MinimiOrigin: HamateInsertion: Shaft of 5th metacarpalAction: Opposes 5

th digitInnervation: Ulnar Nerve

Slide24

Carpal Tunnel

Median Nerve

Slide25

Transverse Carpal Ligament (TLC) serves as point of attachment of hypothenar and thenar muscles

Thenar

Eminence

Hypothenar

Eminence

When ligament is cut during carpal tunnel surgery, focal pain may develop at the attachment points called pillar pain

Slide26

Hand

Intrinsics: Lumbricals Originate from FDP tendons and insert into lateral bands and dorsal hoodContribute to MCP Flexion and IP ExtensionMedian – II,IIIUlnar – IV, V

Slide27

Palm

of Hand3

r

d

Mus

c

ul

a

r

Layer

Lum

b

r

i

c

al

s

Origi

n

:

FD

P

t

endons

–

r

adial

sid

e

f

o

r

1

&

2

;

r

adial

&

ulna

r

s

ide

f

o

r

3

and

4

In

s

ertion

: Radial side of proximal phalanges 2-5, on extensor hoodAction: Flexes MCPs, e

xtends PIPs and DIPs 2-5Innervation: Median nerve (1-2) Ulnar nerve (3-4)

Slide28

Hand

Intrinsics: Interossei (Dorsal and Palmar)With MCPs extended primarily abd/addWith MCPs flexed primarily MCP flexors

All ulnar innervated

Contribute power to grip and pinch

Slide29

Palm

of HandP

al

m

a

r

I

n

t

erossei

– 3 m

uscle

s

Origi

n

:

Shaft

s

o

f

me

t

a

c

arpals

2

,

4

,

&

5

In

s

ertion

:

Base

o

f

the

p

r

o

xi

m

al

phala

n

x

and

e

x

t

ensor

e

xpansi

on of the ulnar side of digit 2, and radial side of digits 4 & 5Action: ADDucts fingers;

Flexes MCPs, extends PIPsand DIPs 2,4,5Innervation: Ulnar Nerve

Slide30

Palm

of HandD

o

r

sa

l

I

n

t

erossei

– 4 m

uscle

s

Origi

n

:

Adja

c

e

n

t

me

t

a

c

arpal

sh

a

ft

s

o

f

1

-

5

In

s

ertio

n

:

Base

o

f the

p

r

o

xima

l

phala

n

x and

e

x

t

ensor

e

xp

ansion on radial side of the 2nd digit, radial & ulnar sides of the 3rd digit, and ulnar side of the

4th digitAction: ABDucts fingers; Flexes MCPs, extends PIPs and DIPs 2 - 4Innervation:

Ulnar nerve

Slide31

Slide32

Forces in Key Pinch:

Thumb Flx/Opp Opposed by 1st DI

Slide33

Intrinsic

Muscles

The 3 “i

n

tr

i

ns

i

c”

hand muscle gr

oups (lum

bri

c

als

and i

n

t

e

r

osse

i)

all

o

w

y

o

u

t

o

d

o this:

Fl

e

x

y

ou

r

MC

P

s

E

x

t

en

d

s

y

ou

r

I

P

s

This

is

a

lso called the “intrinsic plus” positionIf your patient is able to activ

ely assume this hand position then their ulnar nerve is intact

Slide34

Role of Hand Intrinsic Muscles

Support Arches of the Hand: transverse, longitudinal, obliqueContribute to production of grip & pinch strength about 50% grip (Kozin, 1989)about 80% pinch (

Kozin

, 1989)

Interossei are bipennate muscles with large cross-sectional area; capable of large force production

Slide35

Extrinsic Musculature of the Hand

Extrinsics of the DigitsFlexor Digitorum Superficialis (FDS) Flexor Digitorum Profundus (FDP) Extensor Indicis (EI)

Extensor

Digiti

Minimi

(EDM)

Extensor Digitorum (ED)

Extrinsics

of the Thumb

Extensor Policis Longus (EPL)Extensor Pollicis Brevis (EPB)Abductor Pollicis Longus (APL)Flexor Pollicis Longus (FPL)

Slide36

Extensors: Superficial Layer

Brachioradialis

ECRL

ECRB

ECRL/ECRB tendons

2

nd

compartment

Slide37

Extensors

Deep Layer

Abductor

Pollicis

Longus

Extensor

Pollicis

Brevis

Lister’s Tubercle

Slide38

Extrinsic Extensors:

6 CompartmentsI APL and EPBII ECRL and ECRBIII EPLIV EDC and EIPV EDMVI ECU

Separation occurs at retinaculum.

Slide39

Flexors vs.

ExtensorsExtensor do not have a pulley system“Bow stringing” at extensor retinaculumAll extensor tendons are extrasynovial except for zone 7

Slide40

Extrinsic Extensors

EIP and EDM add independent function not strength

Slide41

Extensor

Pollicis Longus

Lister’s

Tubercle

Slide42

Digital Flexors:

FDP, FDS, FPL☺

Flexor

Digitorum

Profundus

Slide43

Carpal Tunnel

Slide44

Extrinsic Flexors:

FDS and FDPSynovial linings decrease friction in tight places (CT and FDS bifurcation)Function is dependent on intact gliding structures; sheaths and pulley system can enhance or impede gliding

Slide45

Flexor Tendon Pulley System

Maintains tendons and sheath close to bone to prevent bow stringing and enhance mechanical advantage

Slide46

Flexor Tendon Pulley System

Originally thought that A2 and A4 considered most crucial to prevent bowstringing; recent flexor tendon research suggests this may be fake newsLoss will result in decreased flexion ROM and grip strength

Slide47

Vincula

Camper’s Chiasm

Slide48

Flexors vs.

ExtensorsExtensor do not have a pulley system“Bow stringing” at extensor retinaculumAll extensor tendons are extrasynovial except for zone 7

Slide49

Juncturae

TendinaeLink EDC to prevent independent functionMaintain dorsal placement of extensors tendons over MPs during flexion

Slide50

Bet You Can’t

Slide51

Extensor Mechanism

EDC flattens into extensor hood just distal to MCP jointCentral tendon inserts onto base of middle phalanxLateral bands arise at PIP joint and reunite into terminal tendon

MCP

MCP

PIP

PIP

DIP

DIP

Slide52

Oblique Retinacular

Ligament (ORL)ORL arises from the A2 pulley near proximal phalanxORL lies volar to PIP joint and dorsal to DIP joint

Slide53

Extensor Mechanism

Oblique Retinacular Ligaments (ORL)Synchronous IP flexion or extension

Slide54

Slide55

Vasculature

Deep Palmar Arch – continuation of Radial Artery

meets deep branch of Ulnar Artery

Superficial Palmar Arch – continuation of Ulnar Artery

Slide56

Cutaneous

Nerve Supply of the Upper Limb

Slide57

Sensory Distribution in the Hand

Dorsal

Volar

Slide58

Median Nerve Innervation

FDSLumbricals (II, III)AbPBOPFPB (superficial head)Pronator

Teres

(PT)

FCR

Anterior

Interosseous

FDP II (III)

FPL

Pronator

Quadratus

Slide59

Ulnar Nerve Innervation

DI and PILumbricals IV, VAdPFPB (deep head)Hypothenar:AbDMFDM

ODM

FCU

FDP IV, V (III)

Slide60

Radial Nerve Innervation

Posterior InterosseousEDCEPLEPBAPLEIPEDMECU

Supinator

ECRL

ECRB

Slide61