Lumbricals of the foot

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Lumbrical muscle of the foot
Lumbricales pedis.png
Muscles of the sole of the right foot, viewed from below. Second layer. (Lumbricals visible at bottom.)
Details
Origin Medial borders of long flexor tendons
Insertion Proximal phalanges and extensor tendons of the 4 lateral toes
Artery Medial and Lateral plantar arteries
Nerve medial and lateral plantar nerves (S3)
Actions Flexes metatarsophalangeal joints, extends interphalangeal joints
Identifiers
Latin musculus lumbricalis pedis
TA98 A04.7.02.069
TA2 2685
FMA 37453
Anatomical terms of muscle

The lumbricals are four small skeletal muscles, accessory to the tendons of the flexor digitorum longus muscle. They are numbered from the medial side of the foot. [1]

Contents

Structure

The lumbricals arise from the tendons of the flexor digitorum longus muscle, [1] as far back as their angles of division, each springing from two tendons, except the first. The first lumbrical is unipennate, while the second, third and fourth are bipennate.

The muscles end in tendons, which pass forward on the medial sides of the four lesser toes, and are inserted into the expansions of the tendons of the extensor digitorum longus muscle on the dorsal surfaces of the proximal phalanges. [1] All four lumbricals insert into extensor hoods of the phalanges, thus creating extension at the inter-phalangeal (PIP and DIP) joints. However, as the tendons also pass inferior to the metatarsal phalangeal (MTP) joints it creates flexion at this joint.

Innervation

The most medial lumbrical is innervated by the medial plantar nerve while the remaining three lumbricals are supplied by the lateral plantar nerve.

Variation

Absence of one or more; doubling of the third or fourth even the fifth. Insertion partly or wholly into the first phalanges.

History

The term "lumbrical" comes from the Latin, meaning "worm". [1]

Additional images

Related Research Articles

Foot Anatomical structure found in vertebrates

The foot is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion. In many animals with feet, the foot is a separate organ at the terminal part of the leg made up of one or more segments or bones, generally including claws or nails.

Human leg Lower extremity or limb of the human body (foot, lower leg, thigh and hip)

The human leg, in the general word sense, is the entire lower limb of the human body, including the foot, thigh and even the hip or gluteal region. However, the definition in human anatomy refers only to the section of the lower limb extending from the knee to the ankle, also known as the crus or, especially in non-technical use, the shank. Legs are used for standing, and all forms of locomotion including recreational such as dancing, and constitute a significant portion of a person's mass. Female legs generally have greater hip anteversion and tibiofemoral angles, but shorter femur and tibial lengths than those in males.

Lumbricals of the hand

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

The flexor digitorum profundus is a muscle in the forearm of humans that flexes the fingers. It is considered an extrinsic hand muscle because it acts on the hand while its muscle belly is located in the forearm.

Extensor hallucis longus muscle Thin muscle, situated between the tibialis anterior and the extensor digitorum longus

The extensor hallucis longus muscle is a thin skeletal muscle, situated between the tibialis anterior and the extensor digitorum longus. It extends the big toe and dorsiflects the foot. It also assists with foot eversion and inversion.

Upper limb

The upper limbs or upper extremities are the forelimbs of an upright-postured tetrapod vertebrate, extending from the scapulae and clavicles down to and including the digits, including all the musculatures and ligaments involved with the shoulder, elbow, wrist and knuckle joints. In humans, each upper limb is divided into the arm, forearm and hand, and is primarily used for climbing, lifting and manipulating objects.

Tibial nerve Branch of the sciatic nerve

The tibial nerve is a branch of the sciatic nerve. The tibial nerve passes through the popliteal fossa to pass below the arch of soleus.

Extensor digitorum muscle

The extensor digitorum muscle is a muscle of the posterior forearm present in humans and other animals. It extends the medial four digits of the hand. Extensor digitorum is innervated by the posterior interosseous nerve, which is a branch of the radial nerve.

Dorsal interossei of the foot Four muscles situated between the metatarsal bones

In human anatomy, the dorsal interossei of the foot are four muscles situated between the metatarsal bones.

Palmar interossei muscles

In human anatomy, the palmar or volar interossei are three small, unipennate muscles in the hand that lie between the metacarpal bones and are attached to the index, ring, and little fingers. They are smaller than the dorsal interossei of the hand.

Flexor hallucis longus muscle One of the three deep muscles of the posterior compartment of the leg that attaches to the plantar surface of the distal phalanx of the great toe

The flexor hallucis longus muscle (FHL) is one of the three deep muscles of the posterior compartment of the leg that attaches to the plantar surface of the distal phalanx of the great toe. The other deep muscles are the flexor digitorum longus and tibialis posterior; the tibialis posterior is the most powerful of these deep muscles. All three muscles are innervated by the tibial nerve which comprises half of the sciatic nerve.

Flexor digitorum longus muscle Muscle located on the tibial side of the leg

The flexor digitorum longus muscle is situated on the tibial side of the leg. At its origin it is thin and pointed, but it gradually increases in size as it descends. It serves to flex the second, third, fourth, and fifth toes.

Extensor digitorum longus muscle Pennate muscle, situated at the lateral part of the front of the leg

The extensor digitorum longus is a pennate muscle, situated at the lateral part of the front of the leg.

Extensor digitorum brevis muscle Muscle on the upper surface of the foot that helps extend digits 2 through 4

The extensor digitorum brevis muscle is a muscle on the upper surface of the foot that helps extend digits 2 through 4.

Flexor digitorum brevis muscle Lies in the middle of the sole of the foot

The flexor digitorum brevis is a muscle which lies in the middle of the sole of the foot, immediately above the central part of the plantar aponeurosis, with which it is firmly united.

Quadratus plantae muscle Muscles of the sole of the foot

The quadratus plantae is separated from the muscles of the first layer by the lateral plantar vessels and nerve. It acts to aid in flexing the 2nd to 5th toes and is one of the few muscles in the foot with no homolog in the hand.

Sole (foot) Bottom part of foot

The sole is the bottom of the foot.

Medial plantar nerve Larger of the two terminal divisions of the tibial nerve

The medial plantar nerve is the larger of the two terminal divisions of the tibial nerve, which accompanies the medial plantar artery.

Interphalangeal joints of the foot

The interphalangeal joints of the foot are between the phalanx bones of the toes in the feet.

Extrinsic extensor muscles of the hand

The extrinsic extensor muscles of the hand are located in the back of the forearm and have long tendons connecting them to bones in the hand, where they exert their action. Extrinsic denotes their location outside the hand. Extensor denotes their action which is to extend, or open flat, joints in the hand. They include the extensor carpi radialis longus (ECRL), extensor carpi radialis brevis (ECRB), extensor digitorum (ED), extensor digiti minimi (EDM), extensor carpi ulnaris (ECU), abductor pollicis longus (APL), extensor pollicis brevis (EPB), extensor pollicis longus (EPL), and extensor indicis (EI).

References

PD-icon.svgThis article incorporates text in the public domain from page 493 of the 20th edition of Gray's Anatomy (1918)

  1. 1 2 3 4 Bozer, Cüneyt; Uzmansel, Deniz; Dönmez, Didem; Parlak, Muhammed; Beger, Orhan; Elvan, Özlem (2018-12-01). "The effects of the communicating branch between medial and lateral plantar nerves on the innervations of the foot lumbrical muscles". Journal of the Anatomical Society of India. 67 (2): 130–132. doi:10.1016/j.jasi.2018.11.006. ISSN   0003-2778. S2CID   81678124.