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any of various freshwater fish of the family Cyprinidae
the lean flesh of a fish that is often farmed; can be baked or braised
force a way through
a passageway through or under something, usually underground (especially one for trains or cars); "the tunnel reduced congestion at that intersection"
of or relating to the wrist; "Carpal tunnel syndrome"

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『トンネル』,地下道,坑道 / 〈山など〉‘に'トンネルを掘る / 〈トンネルなど〉‘を'掘る / トンネルを掘る
酒根(しゅこん)骨の,腕骨の

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2016/08/20 01:57:21」(JST)

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In the human body, the carpal tunnel or carpal canal is the passageway on the palmar side of the wrist that connects the forearm to the middle compartment of the deep plane of the palm.^[1] The tunnel consists of bones and connective tissue. Several tendons and the median nerve pass through it.

The canal is narrow, and when any of the nine long flexor tendons passing through it swell or degenerate, the narrowing of the canal often results in the median nerve becoming entrapped or compressed, a common medical condition known as carpal tunnel syndrome.^[2]

Structure

The carpus, the bony elements of the wrist, form an arch which is convex on the dorsal side of the hand and concave on the palmar side. The groove on the palmar side, the sulcus carpi, is covered by the flexor retinaculum, a sheath of tough connective tissue, thus forming the carpal tunnel. The flexor retinaculum is attached radially to the scaphoid tubercle and the ridge of trapezium, and on the ulna side to the pisiform and hook of hamate.^[3]

The narrowest section of the tunnel is located a centimetre beyond the mid-line of the distal row of carpal bones where the sectional area is limited to 1.6 cm².^[2]

The tendons of the flexor digitorum superficialis and profundus pass through a common ulnar sheath, while the tendon of the flexor pollicis longus passes through a separate radial sheath. The mesotendon shared by these tendons is attached to the radial and palmar walls of the carpal tunnel.^[3]

Superficial to the carpal tunnel and the flexor retinaculum, the ulnar artery and ulnar nerve pass through the ulnar tunnel.^[3]

Function

Transverse section across the wrist and carpals; the palm is at the top (carpal tunnel not labeled but visible at centre)

A total of nine flexor tendons^[2] (not the muscles themselves) pass through the carpal tunnel:

flexor digitorum profundus (four tendons)
flexor digitorum superficialis (four tendons)
flexor pollicis longus (one tendon)
flexor carpi radialis (one tendon), considered by some as part of the carpal tunnel although it is more precise to state that it travels in the flexor retinaculum which covers the carpal tunnel, rather than running in the tunnel itself.

A single nerve passes through the tunnel: the median nerve between tendons of flexor digitorum profundus and flexor digitorum superficialis

Effect of wrist movements

carpal tunnel symptoms

Movements in the wrist affect the shape and width of the carpal tunnel. The width decreases considerably during normal range of motion in the wrist and because the carpal bones move in relation to each other with every motion of the hand the bony walls of the tunnel are not rigid. Both flexion and extension increase compression in the carpal tunnel.

Flexing the wrist causes the flexor retinaculum to move closer to the radius which considerably decreases the cross section of the proximal opening of the tunnel. Additionally, the distal end of the capitate presses into the opening.
In extreme extension, the lunate constricts the passage as it is pressed toward the interior of the tunnel.^[1]

Clinical significance

Carpal tunnel syndrome is a syndrome characterised by tingling burning and pain (needle, pin),through the course of median nerve particularly over the outer fingers and radiating up the arm, that is caused by compression of the carpal tunnel contents. It is associated with repetitive use, rheumatoid arthritis, and a number of other states. It can be detected using Tinel's sign and the Phalen maneuver. It may be treated non-surgically by splinting and/or corticosteroid injection, though definitive management often requires surgical division of the flexor retinaculum which forms the roof of the carpal tunnel.

Additional Images

Carpal tunnel
Carpal tunnel
Wrist joint. Deep dissection.Anterior, palmar, view.
Wrist joint. Deep dissection.Anterior, palmar, view.
Wrist joint. Deep dissection.Anterior, palmar, view.
Carpal tunnel and thenar and hypothenar eminences
Carpal tunnel

References

^ ^a ^b Schmidt, Hans-Martin; Lanz, Ulrich (2003). Surgical anatomy of the hand. Thieme. p. 29. ISBN 1-58890-007-X.
^ ^a ^b ^c Thieme Atlas of Anatomy: General Anatomy and Musculoskeletal System. Thieme. 2006. pp. 248–249. ISBN 1-58890-419-9.
^ ^a ^b ^c Thieme Atlas of Anatomy: General Anatomy and Musculoskeletal System. Thieme. 2006. p. 354. ISBN 1-58890-419-9.

External links

Anatomy diagram: 25466.091-1 at Roche Lexicon - illustrated navigator, Elsevier

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. Carpal tunnel syndrome: Treatment and prognosis
2. Carpal tunnel syndrome: Clinical manifestations and diagnosis
3. 手根管症候群に対する外科手術 surgery for carpal tunnel syndrome
4. Carpal tunnel syndrome: Etiology and epidemiology
5. 上肢末梢神経症候群の概要 overview of upper extremity peripheral nerve syndromes

English Journal

Prevalence of carpal tunnel syndrome among employees at a poultry processing plant.

Musolin K1, Ramsey JG2, Wassell JT3, Hard DL4.
Applied ergonomics.Appl Ergon.2014 Nov;45(6):1377-83. doi: 10.1016/j.apergo.2014.03.005. Epub 2014 May 10.
OBJECTIVE: To determine prevalence of carpal tunnel syndrome (CTS) among poultry processing employees while taking into account non-occupational factors and assess any association between CTS prevalence and exposure groups.METHODS: Performed a cross-sectional survey to assess CTS (n = 318). A CTS
PMID 24820549

Underreporting of musculoskeletal disorders in 10 regions in France in 2009.

Rivière S1, Penven E, Cadéac-Birman H, Roquelaure Y, Valenty M.
American journal of industrial medicine.Am J Ind Med.2014 Oct;57(10):1174-80. doi: 10.1002/ajim.22364.
BACKGROUND: Underreporting of occupational diseases (OD) has been quantified, in particular in the United States, but little information is available in other countries. The aim of this study was to evaluate underreporting of musculoskeletal disorders (MSD) in France in 2009.METHODS: We calculated a
PMID 25223517

Using multiple data sets for public health tracking of work-related injuries and illnesses in California.

Joe L1, Roisman R, Beckman S, Jones M, Beckman J, Frederick M, Harrison R.
American journal of industrial medicine.Am J Ind Med.2014 Oct;57(10):1110-9. doi: 10.1002/ajim.22361. Epub 2014 Aug 5.
BACKGROUND: Research suggests the U.S. Bureau of Labor Statistics Survey of Occupational Injuries and Illnesses underestimates the magnitude of workplace injuries and illnesses. Enumerating workplace injuries and illnesses may be improved by utilizing multiple state-based data sources.METHODS: Using
PMID 25099607

Japanese Journal

臨床経験重症手根管症候群に対する電気生理学的評価--手掌部刺激の有用性について

金谷貴子,藤岡宏幸,黒坂昌弘 [他]
臨床整形外科 46(6), 551-555, 2011-06
NAID 40018862579

経験と考察石灰沈着による手根管症候群の治療経験

木村哲也,山崎哲也,明田真樹 [他]
整形外科 62(6), 507-511, 2011-06
NAID 40018849186

Related Pictures

★リンクテーブル★

リンク元	「手根管」
拡張検索	「carpal tunnel syndrome」
関連記事	「carp」「tunneling」「carpal」「tunnel」

「手根管」

Carpal tunnel
	The carpal tunnel
Details
Identifiers
Latin	Canalis carpi
Dorlands; /Elsevier	c_04/12208551
TA	A03.5.11.201
FMA	42352
	Anatomical terminology [edit on Wikidata]