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Skeleton

Bones of the human hand

The skeleton of the human hand consists of 27 bones :[4] the eight short bones of the wrist or carpus organized into a proximal row (scaphoid, lunate, triquetral and pisiform) , whicharticulates with the skeleton of the forearm, and a distal row (trapezium, trapezoid, capitateand hamate) , which articulates with the bases of the metacarpal bones (i.e. the bones of the

palm or "hand proper"). Together with the fourteen phalanx bones of the fingers thesemetacarpal bones form five rays or poly-articulated chains.

Because supination and pronation (rotation about the axis of the forearm) are added to the

two axes of movements of the wrist, the ulna and radius are sometimes considered part of theskeleton of the hand.

There are numerous sesamoid bones in the hand, small ossified nodes embedded in tendons;the exact number varies between different people :[2] whereas a pair of sesamoid bones arefound at virtually all thumb metacarpophalangeal joints, sesamoid bones are also common atthe interphalangeal joint of the thumb (72.9%) and at the metacarpophalangeal joints of thelittle finger (82.5%) and the index finger (48%). In rare cases, sesamoid bones have beenfound in all the metacarpophalangeal joints and all distal interphalangeal joints except that of the long finger.

The articulations are:

interphalangeal articulations of hand (the hinge joints between the finger bones) metacarpophalangeal joints (where the fingers meet the palm) intercarpal articulations (where the palm meets the wrist) wrist (may also be viewed as belonging to the forearm) .

Arches

http://en.wikipedia.org/wiki/Skeletonhttp://en.wikipedia.org/w/index.php?title=Hand&printable=yes#cite_note-4http://en.wikipedia.org/w/index.php?title=Hand&printable=yes#cite_note-4http://en.wikipedia.org/w/index.php?title=Hand&printable=yes#cite_note-4http://en.wikipedia.org/wiki/Short_bonehttp://en.wikipedia.org/wiki/Wristhttp://en.wikipedia.org/wiki/Carpushttp://en.wikipedia.org/wiki/Scaphoidhttp://en.wikipedia.org/wiki/Lunate_bonehttp://en.wikipedia.org/wiki/Triquetralhttp://en.wikipedia.org/wiki/Pisiformhttp://en.wikipedia.org/wiki/Trapezium_(bone)http://en.wikipedia.org/wiki/Trapezoid_bonehttp://en.wikipedia.org/wiki/Capitatehttp://en.wikipedia.org/wiki/Hamatehttp://en.wikipedia.org/wiki/Metacarpushttp://en.wikipedia.org/wiki/Phalanx_boneshttp://en.wikipedia.org/wiki/Supinationhttp://en.wikipedia.org/wiki/Pronationhttp://en.wikipedia.org/wiki/Ulnahttp://en.wikipedia.org/wiki/Radius_(bone)http://en.wikipedia.org/wiki/Sesamoid_bonehttp://en.wikipedia.org/wiki/Ossifiedhttp://en.wikipedia.org/w/index.php?title=Hand&printable=yes#cite_note-Schmidt_2003_105-2http://en.wikipedia.org/w/index.php?title=Hand&printable=yes#cite_note-Schmidt_2003_105-2http://en.wikipedia.org/w/index.php?title=Hand&printable=yes#cite_note-Schmidt_2003_105-2http://en.wikipedia.org/wiki/Interphalangeal_articulations_of_handhttp://en.wikipedia.org/wiki/Hinge_jointhttp://en.wikipedia.org/wiki/Metacarpophalangeal_jointhttp://en.wikipedia.org/wiki/Intercarpal_articulationshttp://en.wikipedia.org/wiki/Wristhttp://en.wikipedia.org/wiki/Forearmhttp://en.wikipedia.org/wiki/File:Scheme_human_hand_bones-en.svghttp://en.wikipedia.org/wiki/File:Scheme_human_hand_bones-en.svghttp://en.wikipedia.org/wiki/Forearmhttp://en.wikipedia.org/wiki/Wristhttp://en.wikipedia.org/wiki/Intercarpal_articulationshttp://en.wikipedia.org/wiki/Metacarpophalangeal_jointhttp://en.wikipedia.org/wiki/Hinge_jointhttp://en.wikipedia.org/wiki/Interphalangeal_articulations_of_handhttp://en.wikipedia.org/w/index.php?title=Hand&printable=yes#cite_note-Schmidt_2003_105-2http://en.wikipedia.org/wiki/Ossifiedhttp://en.wikipedia.org/wiki/Sesamoid_bonehttp://en.wikipedia.org/wiki/Radius_(bone)http://en.wikipedia.org/wiki/Ulnahttp://en.wikipedia.org/wiki/Pronationhttp://en.wikipedia.org/wiki/Supinationhttp://en.wikipedia.org/wiki/Phalanx_boneshttp://en.wikipedia.org/wiki/Metacarpushttp://en.wikipedia.org/wiki/Hamatehttp://en.wikipedia.org/wiki/Capitatehttp://en.wikipedia.org/wiki/Trapezoid_bonehttp://en.wikipedia.org/wiki/Trapezium_(bone)http://en.wikipedia.org/wiki/Pisiformhttp://en.wikipedia.org/wiki/Triquetralhttp://en.wikipedia.org/wiki/Lunate_bonehttp://en.wikipedia.org/wiki/Scaphoidhttp://en.wikipedia.org/wiki/Carpushttp://en.wikipedia.org/wiki/Wristhttp://en.wikipedia.org/wiki/Short_bonehttp://en.wikipedia.org/w/index.php?title=Hand&printable=yes#cite_note-4http://en.wikipedia.org/wiki/Skeleton

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Arches of the hand

Red: one of the oblique archesBrown: one of the longitudinal arches of the digitsDark green: transverse carpal arch

Light green: transverse metacarpal arch

The fixed and mobile parts of the hand adapt to various everyday tasks by forming bonyarches: longitudinal arches (the rays formed by the finger bones and their associatedmetacarpal bones), transverse arches (formed by the carpal bones and distal ends of themetacarpal bones), and oblique arches (between the thumb and four fingers):

Of the longitudinal arches or rays of the hand, that of the thumb is the most mobile (and theleast longitudinal). While the ray formed by the little finger and its associated metacarpal

bone still offers some mobility, the remaining rays are firmly rigid. The phalangeal joints of the index finger, however, offer some independence to its finger, due to the arrangement of its flexor and extension tendons .[5]

http://en.wikipedia.org/w/index.php?title=Hand&printable=yes#cite_note-Tubiana-9-5http://en.wikipedia.org/w/index.php?title=Hand&printable=yes#cite_note-Tubiana-9-5http://en.wikipedia.org/w/index.php?title=Hand&printable=yes#cite_note-Tubiana-9-5http://en.wikipedia.org/wiki/File:Hand-arches.svghttp://en.wikipedia.org/wiki/File:Hand-arches.svghttp://en.wikipedia.org/w/index.php?title=Hand&printable=yes#cite_note-Tubiana-9-5