BONES OF THE HAND & WRIST

 

 

 WRIST BONES

 

The wrist is comprised of a cluster of 8 carpal bones aligned in 2 rows that articulate with the distal end of the radius to create the radiocarpal joint. These bones join to form a condyloid hinge.

 

CARPAL BONE

ROW

ARTICULATION

SPECIAL FEATURE
Trapezium Distal 1st metacarpal under the thumb
Trapezoid Distal 2nd metacarpal under the index finger
Capitulum Distal 3rd metacarpal largest, in the center
Hamate Distal 4th and 5th metacarpal hooked on palmar surface
Triquetral Proximal between hamate and lunate triangular
Lunate Proximal between capitate and triquetral moon shaped
Scaphoid Proximal radius boat shaped
Pisiform floater on triquetral smallest, pea like

 

 

 

HAND BONES

 

The hand is comprised of metacarpals and phalanges that run along the palmar/dorsal surface, the fingers and thumb.

 

*http://en.wikipedia.org/wiki/Image:Human_hand_bones_simple.svg

Metacarpals These bones are numbered from I (the thumb) to 5 (the little finger) and run the length of the hand. The distal ends are convex to accept the concave surface of the phalanges while the proximal ends are concave to accept the convex surface of the carpals.
Phalanges Each finger of the hand is made up of a proximal, middle and distal phalanx (except for the thumb which only has a proximal and distal phalanx) named for their location in the finger. The base of the distal phalange articulates with the head of the corresponding metacarpal for the digit.
Sesamoid There are two small sesamoid bonds located on palmar surface of the distal end of the first metacarpal. These bones aid in the pull of the flexor pollicis brevis, abductor pollicis brevis and adductor pollicis muscle.

 

 

MUSCLES OF THE HAND & WRIST

 

EXTENSORS

 

SUPERFICIAL LAYER

 

 

*http://www2.ma.psu.edu/~pt/Wrstpost.gif

 

 

MUSCLES ACTION ORIGIN INSERTION INNERVATION

Extensor carpi radialis longus
  • Wrist extension
  • Radial deviation
 Supracondylar ridge of humerus Radial side of the 2nd metacarpal Radial nerve

Extensor carpi radialis brevis
  • Wrist extension
  • Radial deviation

Lateral condyle via the common extensor tendon

Radial collateral ligament

 Base of the 3rd metacarpal Radial nerve

Extensor carpi ulnaris
  • Wrist extension
  • Ulnar deviation
 Lateral epicondyle via the common extensor tendon Ulnar side of the base of the 5th metacarpal Deep radial nerve

Extensor digitorum communis
  • Wrist extension
  • MCP extension
  • IP extension
  • Radial deviation of the wrist
 Lateral epicondyle via the common extensor tendon The dorsal surface of the proximal base of the middle and distal phalanges of each of the four fingers Deep radial nerve

 Images:

Master Muscle List. July 15, 2007

 

 

DEEP LAYER

 

 

 

 *http://www2.ma.psu.edu/~pt/Wrstpost.gif

 

MUSCLE
 ACTION
 ORIGIN
 INSERTION
 INNERVATION 

Extensor pollicis longus

1st IP joint extension

1st CMC joint extension

1st CMC joint extension

Assist in wrist extension

Assist in wrist radial deviation

Posterior surface of the middle 1/3 of the ulna

Adjoining interosseous membrane

 Dorsal surface of the base of the distal phlanx of the thumb Deep radial nerve

Extensor pollicis brevis

  

1st MCP joint extension

1st CMC joint extension

1st CMC joint abduction

Assist in wrist extension

Assist in wrist radial deviation

Posterior surface of the distal radius

Adjoining interosseous membrane  

 Dorsal surface of the base of the proximal phalanx of the thumb Deep radial nerve

Abductor pollicis longus

1st CMC joint abduction

1st CMC joint extension

Assist in radial deviation of the wrist

Posterior surface of the distal ulna

Posterior surface of the distal radius

Adjoining interosseous membrane

 Radial side of the base of the 1st metacarpal Median nerve

Extensor indicis

Extension of index finger

Assist in wrist extension

  Posterior surface of the middle 1/3 of the ulna  Join ulnar side of the extensor digitorum communis to the index finger Deep radial nerve

 Images:

Master Muscle List. July 15, 2007

 

 

FLEXOR MUSCLES

 

SUPERFICIAL LAYER

 

*http://www2.ma.psu.edu/~pt/Wrstflx.gif

 

 

MUSCLE ACTION ORIGIN INSERTION INNERVATION

Flexor carpi radialis
  • Wrist flexion
  • Forearm pronation
  • Radial deviation
 Medial epicondyle via the common flexor tendon Bases of the 2nd and 3rd metacarpal bones Median nerve

Palmaris longus
  • Wrist flexion
 Medial epicondyle vis the common flexor tendon

Flexor retinaculum

Palmar aponeurosis 

 Median nerve

Flexor carpi ulnaris
  • Wrist flexion
  • Ulnar deviation  

Humeral head:

Medial epicondyle via the common flexor tendon

Ulnar head:

Medial border of the olecranon

Proximal 2/3 of the posterior ulna

Pisiform

Hamate

5th metacarpal

 Ulnar nerve

Flexor digitorum superficialis
  • PIP flexion
  • MCP flexion
  • Wrist flexion

Humeral head:

Medial epicondyle via the common flexor tendon

Ulnar collateral ligament

Ulnar head:

Coronoid process

Radial head:

Oblique line of radius

 Sides of the middle phalanges of the digits 2-5 Median nerve

 Images:

Master Muscle List. July 15, 2007

 

 

DEEP LAYER

 

 

*http://www2.ma.psu.edu/~pt/Finflex.gif, http://www2.ma.psu.edu/~pt/Finflex1.gif

 

 

MUSCLE ACTION ORIGIN INSERTION INNERVATION

Flexor digitorum profundus
  • DIP flexion
  • PIP flexion
  • Wrist flexion
 Anteromedial proximal 3/4 of the ulna & assoicated interosseous membrane Bases of the medial phalanges of digits 2-5 Palmar interosseous

Flexor pollicis longus
  • 1st IP joint flexion
  • 1st MCP joint flexion
  • Assist in wrist flexion

Anterior surface of the radius

Adjoining interosseous membrane

Coronoid process of the ulna     

 Palmar surface of the base of the distal phalanx of the thumb Palmar interosseous

 Images:

Master Muscle List. July 15, 2007

 

 

  

PALMAR MUSCLES

 

 

*http://www.polands-syndrome.com/media/handmusc.gif

 

 

MUSCLE ACTION ORIGIN INSERTION INNERVATION
 

Abductor pollicis brevis

 
  • 1st CMC joint abduction
  • 1st MCP joint abduction
  • Assist in opposition  

Flexor retinaculum

Trapezium

Scaphoid

Radial surface of the base of the proximal phalanx of the thumb

Via a slip into the extensor expansion  

 Median nerve

Flexor pollicis brevis
  • 1st MCP joint flexion
  • 1st CMC joint flexion
  • Assist in opposition

Flexor retinaculum

Trapezoid

Capitate  

Radial surface of the base of the proximal phalanx

Via a slip into the extensor expansion  

Median nerve

Deep palmar branch

Opponens pollicis
  • Thumb opposition

Flexor retinaculum

Trapezium  

 Length of the 1st metacarpal Median nerve

Abductor digiti minimi
  • Abduction of the 5th finger
  • Assist in opposition        

Tendon of the flexor carpi ulnaris

Pisiform  

By two slips into the 5th finger:

Ulnar side of the base of the proximal phalanx

Ulnar border of the extensor expansion     

 Ulnar nerve

Flexor digiti minimi
  • 5th MCP joint flexion
  • Assists in opposition     

Hook of the hamate bone

Flexor retinaculum  

Ulnar border of the proximal phalanx of the 5th finger

 Ulnar nerve

Opponens digiti minimi
  • Opposition of the 5th finger

Hook of the hamate bone

Flexor retinaculum     

 Ulnar border of the length of the 5th metacarpal Ulnar nerve

Adductor pollicis
  • 1st CMC joint adduction
  • 1st MCP joint adduction
  • 1st MCP joint flexion
  • Assists in opposition

Capitate bone

Bases of 2nd and 3rd metacarpals

Palmar surface of 3rd metacarpal

Ulnar surface of the base of the proximal phalanx of the thumb

Via a slip into the extensor expansion

 Deep palmar branch

Dorsal interossei
  • Abduction of 3rd, 4th, and 5th fingers
  • Assists in MCP flexion
  • Assists in extension of the IP joints  

Thumb:

Ulnar border of 1st metacarpal

Radial border of 2nd metacarpal

2nd, 3rd, and 4th fingers:

Adjacent sides of the metacarpals

Thumb:

Radial border of 2nd finger

2nd:

Radial side of 3rd finger

3th:

Ulnar side of 3rd finger

4th:

Ulnar side of 4th finger

 Deep palmar branch

Lumbricals
  • Flexion of the 2nd through 5th MCP joints
  • Extension of the PIP and DIP joints

1st and 2nd:

Radial surface of flexor profundus tendons

3rd:

Adjacent sides of flexor profundus tendons of 3rd and 4th fingers

4th:

Adjacent sides of flexor profundus tendons of the 4th and 5th fingers

 Radial border of the extensor tendons of the respective digits

1st and 2nd: median nerve

3rd and 4th: deep palmar branch

Palmar interossei
  • Adducts fingers towards middle finger

1st:

Ulnar side of 2nd metacarpal

2nd:

Radial side of 4th metacarpal

3rd:

Radial side of 5th metacarpal

1st:

Ulnar side of promximal phalanx and index finger

2nd:

Radial side of 4th

3rd:

Radial side of 5th

 Deep branch of ulnar nerve

Images:

Master Muscle List. July 15, 2007

 

 

 

 JOINTS & LIGAMENTS OF THE WRIST & HAND

 

Overview of Joint Types

JOINTS & LIGAMENTS OF THE WRIST

 

 

 

*http://en.wikipedia.org/wiki/Image:Gray334.png

JOINT

TYPE OF JOINT

LIGAMENT

ARTICULATION

RANGE OF MOTION
Radioulnar condyloid radioulnar head of ulna with unlar notch of radius pronation, supination
Radiocarpal condyloid palmar radiocarpal (3 brances) radius with capitate, triquetral and scahphoid limit hyperextension
    dorsal radiocarpal posterior radial styloid with lunate and triquetrum limit flexion
    radial collateral styloid of radius withscaphoid and trapezium limit ulnar deviation
    ulnar collateral styloid of ulna with triquetrial and pisiform limit radial deviation
Intercarpal gliding intercarpal between each carpal bone gliding
Intermetacarpal gliding intermetacarpal between distal and proximal rows of carpal bones limited gliding, flexion, extention, ulnar/radial deviation

 

 

 

JOINTS & LIGAMENTS OF THE HAND

 

 

 

 

 

 

 

JOINT

TYPE OF JOINT

LIGAMENT

ARTICULATION

RANGE OF MOTION

Carpometacarpal I

 saddle carpometacarpal metacarpal I with trapezium flexion, extension, abduction, adduction, opposition, reposition

Carpometacarpal II

 plane synovial carpometacarpal metacarpal II with trapezoid, metacarpal III with capitate, metacarpal IV and V with hamate

joints II - IV: flexion, extension

joint V: flexion, extension, abduction, adduction

Metacarpophalangeal

 condyloid metacarpophalangeal metacarpal to proximal phalange flexion, extension, abduction, adduction

Interphalangeal

 hinge palmar interphalangeal, medial/lateral collateral distal phalange with intermediate phalange, intermediate with proximal phalange, distal phalange with proximal phalange (thumb only) flexion, extension

 

 

 

 

NERVES OF THE HAND & WRIST

 

The wrist and hand are innervated by 3 main nerves: the radial nerve, median nerve and ulnar nerve and their branches.

 

*http://en.wikipedia.org/wiki/Image:Gray817.png

 

 

 

Radial nerve The radial nerve originates at the posterior cord of the brachial plexus. It then travels down the dorsal side of the arm where it innervates the dorsal side of the hand.
Median nerve The median nerve originates from the lateral and medial cords of the brachial plexus. It travels down the medial side of the arm along with the brachial artery innervating the lateral portion of the palmar side of the hand.

Ulnar nerve

 The ulnar nerve originates from the medial cord of the brachial plexus and travels down the lateral side of the arm innervating the medial portion of the palmar side of the hand, as well as the dorsal side of the hand.

 

 

 

 

REFERENCES

 

 

Starkey C, Ryan J.  Evaluation of Orthopedic and Athletic Injuries 2nd Edition. F.A. Davis Company 2002.

 

 

Moore, K.L, DalleyA.F. Clinically Oriented Anatomy 5th Edition. Lippincott Williams & Wilkins 2005.

 

 

 

 

 

 


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  • Recent comments:
    ian metzler:I reformatted the tables with color, bulleting and positioning to make them easier to follow. I increased the text size because it was too small to read. I made headings more visible and consistent throughout. To make it more concise, I transferred the review information about joint types to another page and added a link instead of having it in the body of the text.
    Lucy Yeo:I added some tables to organize some information. My main contribution to this page was additional images of individual muscles. They had already included overall images of the muscles all together, but sometimes it's easier to see a muscle all by itself to get a better idea of its location.
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