The Hand

The hand is a complex biological tool that

permits a wide range of movements that facilitate

grip, pinch, grasp, and fine precision control of

objects

The hand is a complex biological tool that

permits a wide range of movements that facilitate

grip, pinch, grasp, and fine precision control of

objects

These movements are controlled by a series of

highly specialised muscles that are either extrinsic or

intrinsic

Extrinsic muscles are those which originate at the distal humerus or in the forearm and the tendons insert in

the hand

Extrinsic muscles on the volar (or palmar) aspect

include

Flexor Pollicis Longus

Flexor Digitorum Profundus

Flexor Digitorum Superficialis

Flexor Pollicis Longus

Flexor Digitorum Profundus

Flexor Digitorum Superficialis

The tendons of these muscles pass through

the carpal tunnel,Found at the proximal

part of hand just beyond the wrist joint

The Carpal Tunnel

Region on the volar aspect of the hand

Found at the junction between the forearm and hand

The Flexor Retinaculum is a fibrous band of tissue that forms

the roof of the carpal tunnel

The Flexor Retinaculum is a fibrous band of tissue that forms

the roof of the carpal tunnel

It is attached to the carpal bones

It gives rise to a number of muscles within the hand

CT reconstruction of Right Wrist

Radius

Ulna

CT reconstruction of Right Wrist

Radial attachment of the Flexor Retinaculum

Scaphoid(tubercle)

Radial attachment of the Flexor Retinaculum

Trapezium(ridge)

Ulnar attachment of the Flexor Retinaculum

Pisiform

Ulnar attachment of the Flexor Retinaculum

Hamate(hook)

Bony attachments of Flexor Retinaculum

Bony attachments of Flexor Retinaculum

Tendons of Long Flexors

Tendon of Flexor Digitorum Superficialis splits in two and inserts onto either side of the middle phalanx

Tendon of Flexor Digitorum Superficialis splits in two and inserts onto either side of the middle phalanx

It flexes the proximal interphalangeal joint

Tendon of Flexor Digitorum Profundus inserts onto the distal phalanx

Tendon of Flexor Digitorum Profundus inserts onto the distal phalanx

It flexes the distal interphalageal joint

Intrinsic muscles are those which originate and

insert within the hand itself

Intrinsic muscles may be classified as follows;

Thenar Muscles

Adductor Pollicis

Hypothenar Muscles

Lumbricals

Interossei Muscles

Thenar Muscles

control movements of the thumb

3 Thenar Muscles

Abductor Pollicis Brevis

Flexor Pollicis Brevis

Opponens Pollicis

3 Thenar Muscles

Abductor Pollicis Brevis

Flexor Pollicis Brevis

Opponens Pollicis

All supplied by the median nerve

Thenar Muscles

Opponens Pollicis

Arises fromFlexor RetinaculumTubercle of Trapezium

Rotates CMC & MCP joints of thumb

Opponens Pollicis

Arises fromFlexor RetinaculumTubercle of Trapezium

Supplied by median nerve

Rotates CMC & MCP joints of thumb

Abductor Pollicis Brevis

Arises from Flexor Retinaculum Scaphoid Tubercle

Abductor Pollicis Brevis

Abducts thumb at MCP, CMC joints

Arises from Flexor Retinaculum Scaphoid Tubercle

Flexor Pollicis Brevis

Arises fromFlexor Retinaculum Tubercle of Trapezium

Flexor Pollicis Brevis

Flexes MCP joint of thumb

Arises fromFlexor Retinaculum Tubercle of Trapezium

Adductor Pollicis

Supplied by deep branch of ulnar nerve

Also acts on thumb, but is not part of the thenar muscles

Adductor Pollicis

Arises from Oblique head: bases of 2nd and 3rd metacarpals, capitate, trapezoidTransverse head: anterior surface of body of 3rd metacarpal

Supplied by deep branch of ulnar nerve

Adductor Pollicis

Arises from Oblique head: bases of 2nd and 3rd metacarpals, capitate, trapezoidTransverse head: anterior surface of body of 3rd metacarpal

Adducts CMC joint of thumb

Hypothenar Muscles

control movements of the Little Finger

3 Hypothenar muscles

Abductor Digiti Minimi

Flexor Digiti Minimi Brevis

Opponens Digiti Minimi

3 Hypothenar muscles

Abductor Digiti Minimi

Flexor Digiti Minimi Brevis

Opponens Digiti Minimi

All supplied by the deep branch of the ulnar nerve

Abductor Digiti Minimi

Abducts the little finger

Flexor Digiti Minimi Brevis

Flexes the little finger

Opponens Digiti Minimi Opposes the Carpometacarpophalangeal jointsMetacarpophalangeal joints of the little finger

Interossei Muscles

Interossei Muscles

There are two sets of Interossei

Palmar Interossei

Interossei Muscles

There are two sets of Interossei

Palmar Interossei

Dorsal Interossei

Interossei Muscles

Palmar Interossei

ADDuct the fingers

Interossei Muscles

Dorsal Interossei

ABduct the fingers

Useful Pnemonic

PAD and DAB

Useful Pnemonic

PADPalmar InterosseiADDuct the fingers

DABDorsal InterosseiABduct the fingers

PAD and DAB

The lumbricals are interesting muscles as they

arise from the tendons of flexor digitorum profundus

attach to the dorsal expansion of the digits

There are 4 lumbricals

Lumbricals

1st Lumbrical

The lumbricals have a dual nerve supply

Lumbricals

The lumbricals have a dual nerve supply

Lateral two are by Median nerve

Lumbricals

The lumbricals have a dual nerve supply

Lateral two are by Median nerve

Medial two are by Ulnar nerve

Lumbricals

Nerves

All Intrinsic muscles of the hand are supplied

by the Ulnar Nerve

EXCEPT

The lateral 2 lumbricals and thenar muscles

L

O

A

F

Useful pnemonic for muscles in the hand

supplied by the median nerve is

Useful pnemonic for muscles in the hand

supplied by the median nerve is

Lateral 2 lumbricals

O

A

F

Useful pnemonic for muscles in the hand

supplied by the median nerve is

Lateral 2 lumbricals

Opponens Pollicis

A

F

Useful pnemonic for muscles in the hand

supplied by the median nerve is

Lateral 2 lumbricals

Opponens Pollicis

Abductor Pollicis Brevis

F

Useful pnemonic for muscles in the hand

supplied by the median nerve is

Lateral 2 lumbricals

Opponens Pollicis

Abductor Pollicis Brevis

Flexor Pollicis Brevis

Summary of Muscles in the Hand

Abductor Digiti MinimiOrigin Pisiform, pisohamate

ligament, flexor retinaculumInsertion Ulnar aspect base of proximal

phalanx of little fingerAction Abducts little (5th) finger

Nerve Supply Deep branch of ulnar nerve (C8 and T1) (C8, T1)

Blood Supply Ulnar artery

Anterior Hand

Anterior Hand

Abductor Pollicis BrevisOrigin Flexor retinaculum and

scaphoid tubercleInsertion Radial sesamoid of proximal

phalanx of thumb & tendon of extensor pollicis longus

Action Abduction of thumb at MCP, CMC

Nerve Supply Recurrent branch of median nerve (C8 and T1) (C8, T1)

Blood Supply Superficial palmar branch of the radial artery

Anterior Hand

Flexor Digiti MinimiOrigin Hook of hamate and flexor

retinaculumInsertion Ulnar aspect base of proximal

phalanx of little fingerAction Flexes metacarpophangeal

joint little fingerNerve Supply Deep branch of ulnar nerve (C8

and T1) (C8, T1)Blood Supply Ulnar artery

Flexor Pollicis BrevisOrigin Flexor retinaculum and

tubercle of trapeziumInsertion Lateral side of base of

proximal phalanx of thumbAction Flexes MCP joint thumbNerve Supply Recurrent branch of median

nerve (C8 and T1) (C8, T1)Blood Supply Superficial palmar branch of

the radial artery

Anterior Hand

Adductor PollicisOrigin Oblique head: bases of 2nd

and 3rd metacarpals, capitate, trapezoidTransverse head: anterior surface of body of 3rd metacarpal

Insertion Ulnar aspect base of proximal phalanx of thumb and tendon of extensor pollicis longus

Action Adducts CMC joint of thumb

Nerve Supply Deep branch of ulnar nerve (C8 and T1) (C8, T1)

Blood Supply Deep palmar arterial arch

Anterior Hand

Anterior Hand

Opponens Digiti MinimiOrigin Hook of hamate and flexor

retinaculumInsertion Ulnar border 5th metacarpal

Action Opposes CMC and MCP joints of little finger

Nerve Supply Deep branch of ulnar nerve (C8 and T1) (C8, T1)

Blood Supply Ulnar artery

Anterior Hand

Opponens PollicisOrigin Flexor retinaculum and

tubercle of trapeziumInsertion Radial border 1st metacarpalAction Opposes CMC & MCP joints of

thumbNerve Supply Recurrent branch of median

nerve (C8 and T1) (C8, T1)Blood Supply Superficial palmar branch of

the radial artery

Palmar InterosseiOrigin Anterior shaft of 2,4,5

metacarpalsInsertion Proximal phalanges and dorsal

expansion of ulnar side of index and radial side of ring and little fingers

Action Adducts fingers to axis of middle finger

Nerve Supply Deep branch ulnar nerve C8, T1

Blood Supply Branches from deep palmar arch

Anterior Hand

Dorsal InterosseiOrigin Bipennate from shafts of all

metacarpalsInsertion Proximal phalanges and dorsal

expansion of radial side of index and middle fingers and ulnar side of middle and ring fingers

Action Abducts fingers away from axis of middle finger

Nerve Supply Deep branch ulnar nerve C8, T1

Blood Supply Dorsal metacarpal arteries

Posterior Hand

LumbricalsOrigin Four tendons of flexor

digitorum profundus, Radial two are unipennate, Ulnar two are bipennate

Insertion Extensor expansion radial side 2-5 digits

Action Flex MCP joints and extend interphalangeal joints of fingers

Nerve Supply Radial 2; median nerve Ulnar 2; ulnar nerve

Blood Supply Dorsal metacarpal arteries

Anterior Hand