Flexor digitorum longus

A muscle that plays a crucial role in the movement and function of the toes.

Flexor digitorum longus is a long muscle located in the posterior compartment of the leg. It originates from the tibia and runs down the leg to insert into the distal phalanges of the second to the fifth toes. This muscle is primarily involved in the flexion of the toes, allowing for gripping and pushing off during walking.

Terminologia Anatomica

musculus flexor digitorum longus

System

Muscular system

Function

The flexor digitorum longus is essential for the movement and stability of the toes. Its main function is to flex the distal phalanges of the second, third, fourth, and fifth toes. This action is vital during activities such as walking, running, and jumping, as it contributes to the push-off phase of gait. Additionally, flexing the toes helps maintain balance and stability while standing, supporting the body’s weight. When the toes flex, they assist in gripping the ground, which is particularly useful during activities on uneven surfaces. This muscle also plays a role in the overall mechanics of the foot, helping to facilitate movements that involve the arch, thereby absorbing shock and maintaining the integrity of the foot structure.

Location

The flexor digitorum longus is located in the posterior part of the leg, specifically in the deep layer of the muscles. It starts from the fibrous membrane on the back of the tibia and runs down the leg, passing behind the medial malleolus (the bony prominence on the inside of the ankle) as it travels toward the foot. Once it reaches the foot, it divides into four tendons that insert into the bases of the distal phalanges of the toes. This placement allows the muscle to effectively connect the leg's muscular power to the skeletal movements of the toes.

Did You Know?

Flexor digitorum longus is often recruited during activities that require pushing off against the ground, like sprinting or jumping.
This muscle has a unique ability to contribute to both dynamic and static functions of the foot.
Injury or tension in the flexor digitorum longus can lead to difficulties in toe movement and may impact walking mechanics.