Lumbricals of the hand

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The lumbricals are the intrinsic muscles of the hand that flex the metacarpophalangeal joint and extend the interphalangeal joint.

There are also leg muscles that have similar actions, although this is less clinical concern.

Video Lumbricals of the hand

Structure

Lumbricals are four, small, muscle-like worms in each hand. These muscles are unusual because they do not stick to the bone. Instead, they attach proximally to the flexor digitorum profundus tendon and distal to the extensor expansion.

Supply of nerves

The first and second lumbrss (the most radial two) are serviced by median nerves. The third and fourth lumbrs (mostly ulnar two) are treated by deep ulnar nerve branches.

This is the ordinary innervation of lumbricals (occurring in 60% of individuals). However 1: 3 (median: ulnar - 20% of individuals) and 3: 1 (median: ulnar - 20% of individuals) also exist. The innervation of the lumbia always follows the innervation pattern of the associated muscular unit of the flexor digitorum profundus (ie if the muscle unit supplying the tendon to the middle finger is supplied by the median nerve, the second lumbar will also be innervated by the median nerve).

Blood supply

There are four separate sources of blood supply for these muscles: superficial palmar arch, general digital palmar artery, deep palmar arch, and digital dorsal artery.

Maps Lumbricals of the hand

Function

Otot-otot lumbris, dengan bantuan otot interoseus, secara bersamaan melenturkan sendi metacarpophalangeal sambil memperpanjang kedua sendi interphalangeal dari digit yang disisipkan. Lumbricals digunakan selama upstroke secara tertulis.

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Gambar tambahan

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Catatan

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Referensi

• Gosling, J.A.; Harris, P.F.; Humpherson, J.R.; Whitmore, saya.; Willan, P.L.T. (2008). Human Anatomy: Color Atlas and Textbook . phot. oleh A.L. Bentley (edisi ke-5). Philadelphia: Mosby. ISBN: 978-0-7234-3451-1.

Source of the article : Wikipedia