The phalanges are small bones that form the bony core of the digits in human hands and feet. They play a fundamental role in the overall structure and function of our extremities, enabling a wide range of movements and providing support to the fingers and toes.
Phalanges in the Hand
The human hand contains 14 phalanges, which are specifically arranged to allow for intricate movements. Each of the four fingers, excluding the thumb, has three phalanges: a proximal phalanx, a middle (or intermediate) phalanx, and a distal phalanx. The thumb, however, is unique, possessing only two phalanges: a proximal and a distal phalanx.
The proximal phalanges are the largest of the three types in the fingers, situated closest to the palm. They connect with the metacarpal bones, which form the main structure of the hand, at joints known as the metacarpophalangeal (MCP) joints. Moving further along the finger, the middle phalanges are positioned between the proximal and distal phalanges. These bones articulate with the proximal phalanges at the proximal interphalangeal (PIP) joints.
The distal phalanges are the outermost bones, located at the very tips of the fingers and thumb. In the four fingers, the distal phalanges connect to the middle phalanges at the distal interphalangeal (DIP) joints. The thumb, having only two phalanges, features a single interphalangeal joint that connects its proximal and distal phalanges. This arrangement allows for the hand’s dexterity.
Phalanges in the Foot
Similar to the hand, each human foot also contains 14 phalanges, forming the skeletal structure of the toes. For each of the lesser four toes, there are three phalanges: a proximal, a middle (or intermediate), and a distal phalanx. The great toe, also known as the hallux, differs by having only two phalanges: a proximal and a distal phalanx.
The phalanges in the foot are generally shorter and more compressed compared to those found in the hand. The proximal phalanges are the longest of the toe bones and are located closest to the main part of the foot. These bones articulate with the metatarsal bones, which extend from the midfoot, at the metatarsophalangeal (MTP) joints.
The middle phalanges are found between the proximal and distal phalanges in the four lesser toes. They form the proximal interphalangeal (PIP) joints with the proximal phalanges. The distal phalanges are positioned at the very ends of the toes, supporting the toenails. These articulate with the middle phalanges at the distal interphalangeal (DIP) joints in the lesser toes. The great toe, with its two-bone structure, has a single interphalangeal joint connecting its proximal and distal phalanges.
Overall Count and Importance
The human body contains a total of 56 phalanges, with 14 in each hand and 14 in each foot. These bones collectively provide structural support to the hands and feet.
The arrangement of the phalanges, along with their associated joints, enables a wide array of movements. These bones facilitate the dexterity required for tasks like grasping and manipulating objects with the hands. In the feet, the phalanges contribute to balance and the ability to bear weight effectively, supporting locomotion and standing.