Lumbricals

Lumbricals are located both in the hands and foot.

Lumbricals of hand

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

Origin

They attach proximally to the tendons of flexor digitorum profundus,

Lumbricals labeled at bottom left. Left hand, palmar view.

Blood supply

Four separate sources supply blood to these muscles: the superficial palmar arch, the common palmar digital artery, the deep palmar arch, and the dorsal digital artery.

Nerve supply

The first and second lumbricals (the most radial two) are innervated by the median nerve. The third and fourth lumbricals (most ulnar two) are innervated by the ulnar nerve.

The lumbrical muscles, with the help of the interosseous muscles, simultaneously flex the metacarpophalangeal joints while extending both interphalangeal joints of the digit on which it inserts.

The lumbricals are used during an upstroke in writing.

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  Tendons of forefinger and vincula tendina
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  Lumbricals of the hand
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  Lumbricals of the hand
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  Lumbricals muscle
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  Lumbricals muscle
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  Lumbricals muscle
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  Lumbricals muscle
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  Lumbricals muscle
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  Muscles of hand, cross section
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  Wrist joint. Deep dissection.Anterior, palmar view
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  Wrist joint. Deep dissection.Anterior, palmar view
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  Wrist joint. Deep dissection.Anterior, palmar view

Lumbricals of the foot

The lumbricals in the foot skeletal muscles located in the deeper layers of the foot - there are a total of about 4 of them in each foot.

Lumbricals

These muscles are accessory to the tendons of the flexor digitorum longus muscle. They are numbered from the medial side of the foot.

Origin

They originate at the tendons of flexor digitorum longus in the foot

Insertion

medial surface of extensor expansion of proximal phalanges of lateral four toes

Blood supply

lateral plantar artery, plantar arch, four plantar metatarsal arteries

Nerve supply

lateral plantar nerve (lateral three lumbricals) and medial plantar nerve (first lumbrical)

Function

They help maintain extension of digits at interphalangeal joints

Additional images

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  Tendons of forefinger and vincula tendina
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  Lumbricals of the hand
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  Lumbricals of the hand
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  Lumbricals muscle
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  Lumbricals muscle
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  Lumbricals muscle
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  Lumbricals muscle
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  Lumbricals muscle
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  Muscles of hand, cross section
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  Wrist joint. Deep dissection.Anterior, palmar view
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  Wrist joint. Deep dissection.Anterior, palmar view
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  Wrist joint. Deep dissection.Anterior, palmar view