OPPOSING MUSCLE OF THE LITTLE TOE: IRRIGATION AND INNERVATION - ANATOMY AND PHYSIOLOGY - 2024

The opposing muscle of the little toe is an intrinsic muscle of the foot located deep in the plantar aspect of the foot. It is in direct relation to the short flexor of the little or fifth finger.

This muscle shares functions with the flexor brevis of the fifth finger and is frequently confused with it. In fact, in some texts it is described as a bundle of that muscle and not as a separate structure.

By modified by Uwe Gille - Gray445.png, Public Domain, The opponent of the little finger, or fifth toe, is a fickle muscle that takes care of flexing the fifth toe. It is involved in both walking and standing. It also has an atrophied function, which is to adduct or move the fifth finger towards the midline. This movement is important in primates but has evolved in the human foot.

Its route is short. It runs over the fifth metatarsal bone and reaches the first phalanx of the fifth toe, closely related to the flexor brevis muscle of the fifth toe.

Opposing muscle of the little toe

The opponent of the little finger of the foot, is an intrinsic muscle located in the third plane of the sole of the foot.

It is located exactly on the fifth metatarsal bone, often surrounded by the flexor brevis muscle of the fifth finger.

It is a fickle muscle so it is often confused with that flexor. In fact, there are authors who do not consider the opponent of the little toe a muscle by itself, but rather a bundle of the flexor brevis muscle of the fifth toe.

It originates at the level of the cuboid bone, behind the fifth metatarsal. It runs through the bone until it ends on the first joint of the fifth finger, or little finger.

When contracted, it fulfills, together with the short flexor, the function of flexing the fifth finger. It has a second atrophied function, which is to bring the fifth finger closer to the midline, an important movement in primates but which humans are unable to perform.

Irrigation and innervation

The opposing muscle of the fifth toe is supplied by the lateral or lateral lateral plantar artery, originating from the posterior tibialis. This artery is extremely important in the nutrition of the muscles and bones of the plant, as well as the toes.

From Henry Vandyke Carter - Henry Gray (1918) Anatomy of the Human Body (See "Book" section below) Bartleby.com: Gray's Anatomy, Plate 555, Public Domain, https://commons.wikimedia.org/w/index. php? curid = 541420

As for innervation, it is ensured by the lateral plantar nerve, which is a branch of the tibial nerve.

This nerve not only takes care of the motor part of some of the muscles of the sole of the foot, but it also takes care of carrying the sensitive information of the skin of the lateral two thirds of the plantar face.

Foot anatomy

The foot is the terminal organ of the lower limbs. It is a complex biomechanical structure that consists of 33 joints and 26 bones joined by muscles and tendons that move in a coordinated manner, allowing balance and locomotion.

The anatomical beginning of the foot is at the ankle joint, which is the last joint of the leg and the one that joins it.

By AndreasHeinemann at Zeppelinzentrum Karlsruhe, Germany http://www.rad-zep.de - http://www.rad-zep.de, own image, CC BY 2.5, https://commons.wikimedia.org/w/ index.php? curid = 445799

The foot supports the weight of the body, literally behaving like a platform that is responsible for absorbing impacts during walking and maintaining balance during standing.

It consists of two faces, a dorsal and a plantar. The plantar face is the one that is in contact with the walking terrain and the one that directly supports the weight of the body, so the skin on this surface is thicker than that on the back.

It also has an important muscle-tendon system that is in charge of coordinating the movements of all the joints efficiently, to guarantee locomotion.

Foot muscles

In the foot there are a total of 29 muscles responsible for the movement of the bones and joints. These are joined by tendons from the ankle and heel to the toes.

10 of these muscles originate in the leg and strengthen the ankle joint reaching the foot, for this reason they are called extrinsic muscles.

The extrinsic muscles of the foot are responsible for maintaining the position of the ankle and heel for balance.

From Henry Vandyke Carter - Henry Gray (1918) Anatomy of the Human Body (See "Book" section below) Bartleby.com: Gray's Anatomy, Plate 437, Public Domain, https://commons.wikimedia.org/w/index. php? curid = 527206

The remaining 19 muscles are called intrinsic muscles. They originate within the limits of the foot, that is, from the ankle to the toes.

These muscles contribute to supporting functions and work by assisting the extrinsic muscles and the plantar and dorsal aponeuroses, in supporting and distributing body weight as well as in gait control.

By OpenStax - https://cnx.org/contents/:/Preface, CC BY 4.0, The intrinsic muscles are divided into muscles of the sole and muscles of the dorsum of the foot. The muscles of the back of the foot are two extensors; the extensor digitorum brevis and the extensor digitorum brevis.

The muscular system of the sole of the foot is much more complicated and is subdivided into four layers, from superficial to deep, depending on the plane in which the muscle group is located.

Evolution of the intrinsic muscles of the foot

During the evolutionary process from quadruped primates to bipedal hominids and finally man, the muscles of the foot have undergone various modifications in strength, shape and functions.

There are important changes in the intrinsic muscles of the foot that support the theory of evolution towards standing. That is, anatomical variations have occurred over the years that allow the human to walk and maintain a standing position.

In primates the toes are longer and the foot more arched, which allows this species to climb trees and perform specialized movements necessary for its subsistence.

By Walter Heubach (German, 1865–1923) - Upload: User: Jarlhelm, Public Domain, However, many of the functions of these muscles have been atrophied in humans because they are not necessary.

In the case of the opposing muscle of the fifth toe, in primates it fulfills the function indicated by its name. Its contraction makes a movement of the fifth finger towards the first, identical to the pincer movement of the hands.

By Carine06 from UK - Silvestre's foot, CC BY-SA 2.0, However, since pre-human species, this movement is useless and with the shape that the foot has acquired over time it is impossible to perform.

References

1. Card, RK; Bordoni, B. (2019). Anatomy, Bony Pelvis and Lower Limb, Foot Muscles. StatPearls. Treasure Island (FL). Taken from: ncbi.nlm.nih.gov
2. Ficke, J; Byerly, DW. (2019). Anatomy, Bony Pelvis and Lower Limb, Foot. StatPearls. Treasure Island (FL). Taken from: ncbi.nlm.nih.gov
3. Soysa, A; Hiller, C; Refshauge, K; Burns, J. (2012). Importance and challenges of measuring intrinsic foot muscle strength. Journal of foot and ankle research. Taken from: ncbi.nlm.nih.gov
4. Farris, D. J; Kelly, L. A; Cresswell, A. G; Lichtwark, GA (2019). The functional importance of human foot muscles for bipedal locomotion. Proceedings of the National Academy of Sciences of the United States of America. Taken from: ncbi.nlm.nih.gov
5. Crompton, R. H; Vereecke, E. E; Thorpe, SK (2008). Locomotion and posture from the common hominoid ancestor to fully modern hominins, with special reference to the last common panin / hominin ancestor. Journal of anatomy. Taken from: ncbi.nlm.nih.gov