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Lumbricals of hand
Other Terms:
Lumbricals of hand,
Lumbrical muscle group of hand,
Musculi lumbricales manus
Muscle parts
None
Latin name
Musculi lumbricales (manus)
Latin muscle parts
None
Group
Hand muscle – intermetacarpal group
Etymology
This muscle’s name in English is the worm muscle. The word lumbrical comes from the Latin lumbricus meaning “worm.”
Origin
First lumbrical from the radial side of the flexor digitorum profundus tendon of the index finger, second lumbrical from the radial side of the flexor digitorum profundus tendon of the middle finger, third lumbrical from the ulnar side of the flexor digitorum profundus tendon of the middle finger and the radial side of the flexor digitorum profundus tendon of the ring finger, fourth lumbrical from the ulnar side of the flexor digitorum profundus tendon of the ring finger and the radial side of the flexor digitorum profundus tendon of the little finger.
Insertion
Radial side of extensor expansion of digits 2,3,4,5
Action
Weak flexion of the metacarpo-phalangeal joints; extension of the interphalangeal joints; contain numerous muscle spindle receptors and play a important role in proprioceptive sense in the hand.
Nerve supply
Median nerve (C8 and T1) to first and second lumbricals; Ulnar nerve (C8 and T1) to third and fourth lumbricals
Blood supply
The supply to the first two lumbricals is, from proximal to distal, via the radialis indicis artery, the first common palmar digital artery, the first and second dorsal metacarpal and dorsal digital arteries. The third and fourth lumbricals are supplied by the common palmar digital arteries and the dorsal digital arteries.
Latin
Musculi lumbricales manus