Wrist & Hand Anatomy

by Ashley, Jamie, Mollie, & Sabina

Overview

CarpalsMetacarpalsPhalanges

JointsCartilage

LigamentsMusclesNerves

Arteries/veinsReview

Surface Anatomy

•Location of the Pisiform •Site for Ulnar pulse•Site for radial pulse •Hypothenar eminence •Thenar eminence

• Location of the ulnar styloid process

•Site of the median nerve

•Distal Wrist Crease

Tendon of Palmaris longus

Tendon of abductor pollicis longus

•Tendon of the flexor carpi ulnaris

• Tendon of flexor carpi radialis

• Tendons of the extensor digitorum

• Tendon of extensor pollicis longus

• Anatomical snuff box

Bones of Wrist and Hand

Wrist:

Scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, hamate

Carpals acronym

Some Lovers Try Positions That They Can’t Handle

S- Scaphoid

L- Lunate

T- Triquetrium

P- Pisiform

T- Trapezium

T-Trapezoid

C- Capitate

H- Hamate

Metacarpals

Numbered 1-5

Starting at the Pollex (thumb)

Phalangels

Numbered 1-5

Starting at the Pollex (thumb)

Proximal

Middle

Distal

Joints

Metacarpo-phalangeal joint (MCP)

The Interphalangeal (IP) are:

Proximal Interphalangeal Joint (PIP)

Distal Interphalangeal Joint (DIP)

Occurs at joints: specialized, fibrous connective tissue present at bone joints.

Articular Capsule

Synovial membrane

Fibrous layer

Articular cartilage

Ligaments

Palmar aponeurosisCommon flexor sheath

Flexor retinaculumExtensor retinaculum

Connective tissue that connects two bones or cartilages,or holds together a joint.

Palmar aponeurosis: Superfical to Extensor retinaculumAttaches to Tendon of Palmaris Longis

Common flexor sheath Flexor retinaculum

Anterior side of hand

Both are deep to Palmar aponeurosis

Extensor Retinaculum

Posterior side of hand.

Superficial to extensor tendons.

Extensor retinaculum

Muscles

Muscles

Intrinsic muscles: Position grip, originate and insert on wrist/hand.

Extrinsic muscles: Power grip muscles of hand, originate on forearm and insert in hand

Extensorhood: wide flat long triangle shaped tendon on phalanges which some muscles attach

Lumbricals (4)

Extend 2nd-5th fingers at IP joints

Flex 2nd-5th fingers at MCP

Lumbrical plus deformity

Important for handwriting.

Lumbricals originate on Tendons. In hand..Tendon of Flexor digitorum profundus

Palmar side of hand

Interosseous muscles

Dorsal interossei Abduct 2nd, 4th, and 5th fingers at MCP joints4 muscles.

(DAB) Dorsal ABducts

Palmar interossei Adducts thumb 2nd, 4th, and 5th fingers at the MCP joints 3 muscles.

(PAD) Palmar ADducts

Both are important in writing position of hand by flexing the mcp joint and extend PIP joint.

Interosseous muscles originate on metacarpals.

Thenar:

Abductor pollicis brevis

Flexor pollicis brevis

Opponens pollicis brevis

Hypothenar:

Abductor digiti minimi

Flexor digiti minimi

Opponens digiti minimi

opponenspollicis brevis opponens

digiti minimi

Abductor pollicis brevis (#23)N: Median nerve (C8-T1)O: Flexor retinaculum and tubercles of trapezium

and scaphoid bonesI: Base of proximal phalanx of thumb: dorsal digital expansion of thumb

Flexor pollicis brevis (#28)N: Superficial head: median nerveO: Superficial Head: flexor retinaculum

and tubercle of trapeziumI: Radial side of proximal phalanx of thumb

Abductor Pollicis

Flexor pollicis brevis

Abductor digiti minimi

Flexor digiti minimi brevis

Abductor digiti minimi (#34)N: Ulnar, deep branch (C8-T1)O: Pisiform bone and tendon of flexor carpi

ulnarisI: Base of proximal phalanx of little finger

Flexor digiti minimi brevis (# )N: Ulnar, deep branch (C8-T1)

O: Hamulus (hook) of the hamate bone and flexor retinaculum

I: Base of proximal phalanx of the little finger

Opponens pollicis (#31)N: Median nerve (C8-T1)O: Flexor retinaculum and tubercles of the

scaphoid and trapezium bones I: whole length of lateral border of metacarpal bone of the thumb

Opponens digiti minimi (#32)N: Ulnar nerve, deep branch (C8-T1)O: Hamulus (hook) of hamate bone and

flexor retinaculumI: Ulnar side of 5th metacarpal bone

Opponens pollicis

Opponens digiti minimi

Adductor pollicis (#30)N: Deep branch of ulnar nerve (C8-T1)O: Oblique head: Capitate bone and bases

of 2nd and 3rd metacarpal bones

I: Ulnar side of base of proximal phalanx of thumb

https://youtu.be/Rd9lLaXnhzM

There’s a lot of Intrinsic Muscles let’s try a song….

Extensor pollicis longus (#21)N: Posterior interosseous nerve (C7-C8)O: Posterior surface of middle ⅓ of ulna and

interosseous membrane

I: Dorsal surface of distal phalanx of thumb

Extensor pollicis brevis (#22)N: Posterior interosseous nerve (C7-C8)O: Posterior surface of distal ⅓ of ulna and

interosseous membrane

I: Dorsal surface of the base proximal phalanx of thumb

Extensor indicis

Abductor pollicis longus (#23)N: Posterior interosseous nerve (C7-C8)O: Posterior surface, proximal ½ of ulna,

radius, and interosseous membraneI: Base of 1st metacarpal

Extensor indicis (deep cant see on model)

N: Radial nerve, posterior interosseous branch (C7-C8)

O: Posterior surface of the ulna and interosseous

membraneI: Into the extensor hood of the index

finger

Extensor indicis

Extensor digiti minimiN: Posterior interosseous nerve (C7-C8)O: Lateral epicondyleI: Extensor tendons of 5th finger

Extensor digitorum N: Posterior interosseous nerve (C7-C8)O: Lateral epicondyleI: Extensor tendons of medial 4 fingers

at distal digits

Flexor pollicis longus

Flexor pollicis longus (#41)N: Median (C8, T1)O: Anterior surface of radius,

interosseous membrane

I: Distal phalanx of the thumb

Flexor digitorum superficialis N: Median (C7 & C8, T1)O: Humero-ulnar head: medial

epicondyle of humerus and coronoid process Radial head: oblique line of radiusI: body of middle phalanges (digits

2-5)

Flexor digitorum profundus N: Lateral fibers: median

(C8, T1) Medial fibers: ulnar

O: Proximal ¾ of medial and anterior surfaces of ulnar, interosseous membraneI: Base of distal phalanges (digits 2-5)

Thumb Actions

● abductor pollicis longus

● Abductor pollicis brevis

● extensor pollicis brevis

● extensor pollicis longus

● abductor pollicis longus

● adductor pollicis

● palmar interossei

● flexor pollicis brevis

● flexor pollicis longus

● adductor pollicis

● opponens pollicis

● abductor pollicis brevis

● flexor pollicis brevis

Finger Abduction● Dorsal interosseous● Abductor digiti minimi● Abductor pollicis longus● Abductor pollicis brevis

Finger Adduction● palmar interosseous

Finger Extension● extensor digiti minimi● extensor digitorum● lumbricals

Finger Flexion● Flexor digiti minimi brevis● flexor digitorum

Arteries of Hand

Ulnar arteryRadial artery

Superficial Palmar arch

Deep Palmar arch

Cephalic veinBrachial veinBasilic vein

Dorsal venous arch

Cephalic Vein

Brachial Vein

Cephalic vein

Veins of the Hand

Basilic Vein

Basilic Vein

Dorsal Venous Arch of the Hand

Median nerveRadial NerveUlnar nerve

Nerves of Hand

Median nerve (71)

Radial Nerve (80)

Ulnar nerve (74)

Activity: Look at your hand and identify the part of your hand that is affected by Ulnar nerve, the Radial nerve, and the Medial nerve.

(#) corresponds with location on model in lab

CARPAL TUNNEL SYNDROME

What Ligament is involved?

What Nerves going through the Carpal Tunnel?

What fingers affected by this?

Making the same hand movements

repeatedly can cause a series of symptoms

such as numbness and tingling in fingers and

hand, due to pressure put on the Nerve.

Carpal Tunnel Syndrome

Transverse Carpal Ligament

Carpal Tunnel

Median Nerve

Pain and Numbness

Digit #4 Digit #3

Digit #2

Digit #1

Pressure on Median nerve causes pain and numbness.

Carpal Tunnel Syndrome