Lumbricals of the foot

Lumbricals of the foot

The lumbricals of the foot are four small muscles located in the foot. They are analogous to the lumbricals of the hand and play a crucial role in the movement and stabilization of the toes.

Anatomy

The lumbricals of the foot originate from the tendons of the flexor digitorum longus muscle. Each lumbrical muscle inserts into the extensor expansion on the dorsal surface of the proximal phalanges of the second to fifth toes.

Origin

The lumbricals arise from the tendons of the flexor digitorum longus:

• The first lumbrical originates from the medial side of the tendon to the second toe.
• The second, third, and fourth lumbricals originate from the adjacent sides of the tendons to the second, third, fourth, and fifth toes.

Insertion

The lumbricals insert into the extensor expansion on the dorsal aspect of the proximal phalanges of the second to fifth toes.

Innervation

The innervation of the lumbricals of the foot is divided between the medial plantar nerve and the lateral plantar nerve:

• The first lumbrical is innervated by the medial plantar nerve.
• The second, third, and fourth lumbricals are innervated by the lateral plantar nerve.

Blood Supply

The blood supply to the lumbricals of the foot is provided by branches of the plantar arteries.

Function

The primary function of the lumbricals of the foot is to flex the metatarsophalangeal joints and extend the interphalangeal joints of the second to fifth toes. This action is essential for maintaining balance and proper gait during walking and running.

Clinical Significance

Dysfunction or injury to the lumbricals of the foot can lead to various foot deformities and impairments in gait. Conditions such as hammer toe and claw toe can be associated with lumbrical muscle imbalance.

See Also

• Lumbricals of the hand
• Flexor digitorum longus
• Medial plantar nerve
• Lateral plantar nerve
• Extensor expansion