Wrist

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"Carpus" redirects here. Wrist_sentence_0

For other uses, see Carpus (disambiguation). Wrist_sentence_1

For the municipality in Germany, see Wrist, Germany. Wrist_sentence_2

Wrist_table_infobox_0

WristWrist_header_cell_0_0_0
DetailsWrist_header_cell_0_1_0
IdentifiersWrist_header_cell_0_2_0
LatinWrist_header_cell_0_3_0 articulatio radiocarpalisWrist_cell_0_3_1
MeSHWrist_header_cell_0_4_0 Wrist_cell_0_4_1
TA98Wrist_header_cell_0_5_0 Wrist_cell_0_5_1
TA2Wrist_header_cell_0_6_0 Wrist_cell_0_6_1
FMAWrist_header_cell_0_7_0 Wrist_cell_0_7_1

In human anatomy, the wrist is variously defined as 1) the carpus or carpal bones, the complex of eight bones forming the proximal skeletal segment of the hand; (2) the wrist joint or radiocarpal joint, the joint between the radius and the carpus and; (3) the anatomical region surrounding the carpus including the distal parts of the bones of the forearm and the proximal parts of the metacarpus or five metacarpal bones and the series of joints between these bones, thus referred to as wrist joints. Wrist_sentence_3

This region also includes the carpal tunnel, the anatomical snuff box, bracelet lines, the flexor retinaculum, and the extensor retinaculum. Wrist_sentence_4

As a consequence of these various definitions, fractures to the carpal bones are referred to as carpal fractures, while fractures such as distal radius fracture are often considered fractures to the wrist. Wrist_sentence_5

Structure Wrist_section_0

The distal radioulnar joint is a pivot joint located between the bones of the forearm, the radius and ulna. Wrist_sentence_6

Formed by the head of the ulna and the ulnar notch of the radius, this joint is separated from the radiocarpal joint by an articular disk lying between the radius and the styloid process of the ulna. Wrist_sentence_7

The capsule of the joint is lax and extends from the inferior sacciform recess to the ulnar shaft. Wrist_sentence_8

Together with the proximal radioulnar joint, the distal radioulnar joint permits pronation and supination. Wrist_sentence_9

The radiocarpal joint or wrist joint is an ellipsoid joint formed by the radius and the articular disc proximally and the proximal row of carpal bones distally. Wrist_sentence_10

The carpal bones on the ulnar side only make intermittent contact with the proximal side — the triquetrum only makes contact during ulnar abduction. Wrist_sentence_11

The capsule, lax and un-branched, is thin on the dorsal side and can contain synovial folds. Wrist_sentence_12

The capsule is continuous with the midcarpal joint and strengthened by numerous ligaments, including the palmar and dorsal radiocarpal ligaments, and the ulnar and radial collateral ligaments. Wrist_sentence_13

The parts forming the radiocarpal joint are the lower end of the radius and under surface of the articular disk above; and the scaphoid, lunate, and triquetral bones below. Wrist_sentence_14

The articular surface of the radius and the under surface of the articular disk form together a transversely elliptical concave surface, the receiving cavity. Wrist_sentence_15

The superior articular surfaces of the scaphoid, lunate, and triquetrum form a smooth convex surface, the condyle, which is received into the concavity. Wrist_sentence_16

Carpal bones of the hand: Wrist_sentence_17

Wrist_unordered_list_0

In the hand proper a total of 13 bones form part of the wrist: eight carpal bonesscaphoid, lunate, triquetral, pisiform, trapezium, trapezoid, capitate, and hamate— and five metacarpal bones—the first, second, third, fourth, and fifth metacarpal bones. Wrist_sentence_18

The midcarpal joint is the S-shaped joint space separating the proximal and distal rows of carpal bones. Wrist_sentence_19

The intercarpal joints, between the bones of each row, are strengthened by the radiate carpal and pisohamate ligaments and the palmar, interosseous, and dorsal intercarpal ligaments. Wrist_sentence_20

Some degree of mobility is possible between the bones of the proximal row while the bones of the distal row are connected to each other and to the metacarpal bones —at the carpometacarpal joints— by strong ligaments —the pisometacarpal and palmar and dorsal carpometacarpal ligament— that makes a functional entity of these bones. Wrist_sentence_21

Additionally, the joints between the bases of the metacarpal bones —the intermetacarpal articulations— are strengthened by dorsal, interosseous, and palmar intermetacarpal ligaments. Wrist_sentence_22

Articulations Wrist_section_1

The radiocarpal, intercarpal, midcarpal, carpometacarpal, and intermetacarpal joints often intercommunicate through a common synovial cavity. Wrist_sentence_23

Articular Surfaces Wrist_section_2

It has two articular surfaces named, proximal and distal articular surface. Wrist_sentence_24

The proximal articular surface is made up of lower end of radius and triangular articular disc of the inferior radio-ulnar joint. Wrist_sentence_25

On the other hand, the distal articular surface is made up of proximal surfaces of the scaphoid, triquetral and lunate bones. Wrist_sentence_26

Function Wrist_section_3

Movement Wrist_section_4

The extrinsic hand muscles are located in the forearm where their bellies form the proximal fleshy roundness. Wrist_sentence_27

When contracted, most of the tendons of these muscles are prevented from standing up like taut bowstrings around the wrist by passing under the flexor retinaculum on the palmar side and the extensor retinaculum on the dorsal side. Wrist_sentence_28

On the palmar side the carpal bones form the carpal tunnel, through which some of the flexor tendons pass in tendon sheaths that enable them to slide back and forth through the narrow passageway (see carpal tunnel syndrome). Wrist_sentence_29

Starting from the mid-position of the hand, the movements permitted in the wrist proper are (muscles in order of importance): Wrist_sentence_30

Wrist_unordered_list_1

  • Marginal movements: radial deviation (abduction, movement towards the thumb) and ulnar deviation (adduction, movement towards the little finger). These movements take place about a dorsopalmar axis (back to front) at the radiocarpal and midcarpal joints passing through the capitate bone.Wrist_item_1_2
  • Movements in the plane of the hand: flexion (palmar flexion, tilting towards the palm) and extension (dorsiflexion, tilting towards the back of the hand). These movements take place through a transverse axis passing through the capitate bone. Palmar flexion is the most powerful of these movements because the flexors, especially the finger flexors, are considerably stronger than the extensors.Wrist_item_1_5

Wrist_unordered_list_2

Wrist_unordered_list_3

  • Intermediate or combined movementsWrist_item_3_8

However, movements at the wrist can not be properly described without including movements in the distal radioulnar joint in which the rotary actions of supination and pronation occur and this joint is therefore normally regarded as part of the wrist. Wrist_sentence_31

Clinical significance Wrist_section_5

Wrist pain has a number of causes, including carpal tunnel syndrome, ganglion cyst, tendinitis, and osteoarthritis. Wrist_sentence_32

Tests such as Phalen's test involve palmarflexion at the wrist. Wrist_sentence_33

The hand may be deviated at the wrist in some conditions, such as rheumatoid arthritis. Wrist_sentence_34

Ossification of the bones around the wrist is one indicator used in taking a bone age. Wrist_sentence_35

A wrist fracture usually means a fracture of the distal radius. Wrist_sentence_36

History Wrist_section_6

Etymology Wrist_section_7

The English word "" is etymologically derived from the ancient German word wristiz from which are derived modern German ("", "wrist") and modern Swedish ("instep", ""). Wrist_sentence_37

The base writh- and its variants are associated with Old English words "", "", and "". Wrist_sentence_38

The wr- sound of this base seems originally to have been symbolic of the action of twisting. Wrist_sentence_39

See also Wrist_section_8

Wrist_unordered_list_4

Additional images Wrist_section_9

Wrist_unordered_list_5

  • Wrist_item_5_13
  • Wrist_item_5_14
  • Wrist_item_5_15
  • Wrist_item_5_16


Credits to the contents of this page go to the authors of the corresponding Wikipedia page: en.wikipedia.org/wiki/Wrist.