The Hand (Analysis)- Exam 2

What's the hand?

Key point of function for the upper extremity

What does the hand consist of?

5 digits, the thumb and four fingers

What're the fingers made up of?

Phalanges (3) and Metacarpals (1)

How many joints does the thumb consist of?

3

Name the three joints of the thumb

1.Carpometacarpal (CMC)

2.Metacarpophalangeal (MCP)

3.Interphalangeal (IP)

From an anatomical position, the 1st metacarpal (thumb's) is in a __________ _____ from the other digits? (CMC joint of thumb)

Different plane

What does the thumb being in a different plane than the other digits allow for? (CMC joint of thumb)

More mobility

What's the carpometacarpal joint of of thumb made up of?

Trapezium (carpal) and base of the 1st metacarpal

What type of joint is the CMC joint of the thumb?

Saddle joint- convex/concave

What does the CMC joint of thumb allow compared to the CMC joint of fingers?

Much more movement

What motions occur at the CMC joint of the thumb?

-Flexion/extension (frontal)

-Ab/adduction (sagittal)

-Opposition/reposition

What type of joint is the metacarapophalangeal joint (MCP) of the thumb?

Unaxial hinge joint

What motions occur at the MCP joint of the thumb?

-Flexion

-Extension

What type of joint is the Interphalangeal (IP) joint of the thumb?

Unaxial hinge joint

What motions occur at the IP joint of the thumb?

-Flexion

-Extension

What's the name and joints of the 1st digit?

Thumb; CMC, MP, IP

What's the name and joints of the 2nd digit?

Index; CMC, MCP, PIP, DIP

What's the name and joints of the 3rd digit?

Middle; CMC, MCP, PIP, DIP

What's the name and the joints of the 4th digit?

Ring; CMC, MCP, PIP, DIP

What's the name and joints of the 5th digit?

Little; CMC, MCP, PIP, DIP

What do the CMC joints of the 2nd-5th digit provide?

More stability than mobility - uniaxial

What does the CMC joint of the 2nd-4th digits have?

Very little mobility - gliding

What does the CMC joint of the 5th digit allow?

A small amount of opposition

What motions occur at the metacarpophalangeal joints of the fingers?

-Flexion

-Extension

-Abduction

-Adduction

How many interphalangeal joints does the thumb have?

One

How many interphalangeal joints do the 2nd-5th digits have? Names?

Two; Proximal Interphalangeal (PIP)

Distal Interphalangeal (DIP)

What does PIP stand for?

Proximal Interphalangeal Joint

What type of joint is a PIP joint?

Uniaxial hinge joints

What motions occur at the PIP joint?

-Flexion

-Extension

What does DIP stand for?

Distal Interphalangeal Joint

What type of joint is a DIP joint?

Unaxial hinge joint

What motions occur at the DIP joint?

-Flexion

-Extension

List the ligaments of the hand

•Flexor Retinaculum

-aka Transverse Carpal Ligament

•Extensor Retinaculum

•Extensor Hood

•Volar Plate

•Collateral Ligaments

What does the Transverse Carpal Ligament span?

The volar (anterior) surface of the wrist

What's the primary purpose of the transverse carpal ligament?

Is to cover and hold the flexor tendons in place during wrist flexion

What does the transverse carpal ligament form?

Tunnel through which flexor tendons and median nerve passes

Define Carpal Tuneel

Bony floor of carpals and fibrous ceiling of ligament

What does the Extensor Retinaculum span?

The dorsal (posterior) side of the wrist

What's the primary purpose of the extensor retinaculum?

Is to cover and hold the extensor tendons in place during wrist extension

Define the Extensor Hood

•Triangular aponeuorsis that covers the dorsal side of each proximal phalanx

What motion does the extensor hood perform?

Extends the fingers

Define Volar Plate

Thick ligament anterior side of each IP joint

What motion does the Volar Plate limit?

Extension

What's injury to the Volar Plate commonly referred to as?

A "jammed" finger (hyperextension)

Where're the collateral ligaments found?

Each side of MCP, PIP, DIP joints (medial and lateral)

What're the collateral ligaments when the finger is fully extended?

Loose

What're the collateral ligaments when the finger is flexed?

Taunt (tight)

Define Intrinsic Muscles

•In hand

-Origin and insertion within hand

What're Intrinsic Muscles responsible for?

Dexterity

Define Extrinsic Muscles

•outside of hand

-Origin located proximal to wrist (FA, elbow)

-Insertion within hand

What're Extrinsic Muscles responsible for?

Gross grasping

List the extrinsic muscles of the fingers

) Flexor Digitorum Profundus

Flexor Digitorum Superficialis

Extensor Digitorum

Extensor Indicis

Extensor Digiti Minimi

What motion does the Flexor Digitorum Superficialis perform?

Flexes MCP, PIP

Where's the origin of the Flexor Digitorum Superficialis?

medial epicondyle (part of common flexor tendon)

What does the FDS pass under?

Flexor retinaculum (transverse carpal ligament/carpal tunnel)

Where does the FDS insert?

On sides of middle

phalanx

What motion does the Flexor Digitorum Profoundus perform?

Flexes MCP, PIP, DIP

Where's the origin of the FDP?

Medially on prox ulna

What does the FDP pass under?

Flexor retinaculum (transverse carpal ligament/carpal tunnel)

Where's the insertion of the FDP?

distal phalanx anteriorly

What motion does the Extensor Digitorum perform?

Extends all fingers (digits 2-5)

Where's the origin of the Extensor Digitorum?

Lateral epicondyle (part of common extensor tendon)

What does the ED pass under?

Extensor retinaculum

Where's the insertion of the ED?

Posterior distal phalanx via extensor hood

What motion does the Extensor Indicis perform?

Extends 2nd digit MCP, PIP, DIP

Where's the origin of the Extensor Indicis?

Distal half of ulna

Where's the insertion for the Extensor Indicis?

Base of the distal phalanx of index finger (2nd digit)

What's the motion of Extensor Digiti Minimi?

Extends 5th digit MCP, PIP, DIP

Where's the origin of the Extensor Digiti Minimi?

From common extensor tendon of lateral epicondyle

Where's the Insertion of the Extensor Digiti Minimi?

Base of the distal phalanx of pinky finger (5th digit)

List the Intrinsic muscle groups of the fingers and how many there're in each one

Lumbricals (4)

Dorsal Interossei (4)

Palmar Interossei (3)

Hypothenar Group (1)

What motions does the Lumbrical group perform?

Flexes MCP

Extends PIP, DIP

What's special about the Lumbrical group?

No bony attachment

Where does the lumbrical group attach proximally?

Anteriorly to tendons of FDP

Where does the lumbrical group cross?

MCPs

Where does the lumbrical group attach distally?

To tendons of ED

What motion does the Dorsal Interossei group perform?

ABDucts fingers at MCP joint

Where's the origin of the dorsal interossei group?

Adjacent metacarpals posteriorly

Where's the insertion of the dorsal interossei group?

Base of proximal phalanx

What motion does the Palmar Interossei group perform?

ADDucts fingers at MCP joint

Where's the origin of the palmar interossei group?

Proximally on metacarpals of digits 2, 4, and 5

Where's the insertion of the palmar interossei group?

Distally to proximal phalanx of same digit

What muscles does the Hypothenar group include?

Flexor Digiti Minimi

Abductor Digiti Minimi

Opponens Digiti Minimi

What digit does the Hypothenar muscle group act on?

5th digit

What motion does the Flexor Digiti Minimi of the Hypothenar group perform?

Flexes CMC and MCP

What motion does the ABDuctor Digiti Minimi of the Hypothenar group perform?

ABDucts MCP

What motion does the Opponens digiti minimi of the Hypothenar group perform?

Opposes CMC

Name Thumb Muscles (flexors) and actions

1) Flexor Pollicis Longus (FPL)

-flexes MCP, IP

*Flexes ALL thumb joints

2) Flexor Pollicis Brevis (FPB)

-Flexes MCP

Name Thumb Muscles (extensors) and actions

3) Extensor Pollicis Longus (EPL)

-Extends MCP, IP

4) Extensor Pollicis Brevis (EPB)

-Extends MCP

Name the other 3 thumb muscles and actions

5) ABDuctor Pollicis

-Abducts thumb at CMC joint

6) ADDuctor Pollicis

-Adducts thumb at CMC joint

7) Opponens Pollicis

-Opposes thumb at CMC joint

How many nerves are in the hand?

3

What do the nerves of the hand provide?

Tactile (touch) sense

Name the nerves of the hand

1) Radial

2) Ulnar

3) Median

What muscle group does the Median nerve innervate?

THENAR group (thumb side)

List the muscles innervated by the median nerve

Lumbricals 1 & 2 (lateral ones)

Opponens pollicis

Abductor pollicis

Flexor pollicis

What muscle group does the ulnar nerve innervate?

HYPOTHENAR group

List the muscles innervated by the ulnar nerve

Lumbricals 3 & 4 (medial ones)

Opponens digiti minimi

Abductor digiti minimi

Flexor digiti minimi

What other muscles are innervated by the ulnar nerve?

-Adductor pollicis

-Dorsal & palmar interossei

What muscle group does the radial nerve innervate?

Extensors dorsally:

List the muscles innervated by the radial nerve

-Extensor digitorum

-Extensor indicis

-Extensor digiti minimi

-Extensor pollicis longus & brevis

-Abductor pollicis longus