The term “phalanges” is the anatomical name for the long bones that form the skeletal structure of the body’s most distal extremities. These bones are a foundational part of the human musculoskeletal system, providing the framework for manipulation and locomotion. This article clarifies the common name for these bones, their precise location, structure, and functional importance.
The Everyday Term for Phalanges
The common name for the phalanges is simply fingers and toes. While this non-technical terminology refers to the entire digits, phalanges specifically denotes the individual bones contained within those appendages. The singular form of the term is phalanx. Anatomists use this precise language to differentiate these bones from the metacarpals and metatarsals, which are the bones of the palms and the mid-foot.
Location and Structure in the Body
Phalanges are situated in both the upper and lower limbs, forming the skeleton of the fingers and the toes. The human body contains a total of 56 phalanges: 14 bones located in each hand and 14 in each foot. These bones are classified as long bones, despite their relatively small size.
In the majority of digits, each finger and toe is comprised of three separate phalanges. These are named based on their position relative to the center of the body. The proximal phalanx is closest to the palm or sole, the middle phalanx is positioned between the other two, and the distal phalanx is the bone at the tip.
The thumb and the big toe are exceptions to this three-bone rule. These two digits only contain two phalanges: a proximal phalanx and a distal phalanx. This structural variation contributes to the unique mobility and function of these digits.
Essential Roles and Common Injuries
The mechanical role of the phalanges differs significantly between the hands and the feet. In the hands, these bones provide the flexibility and articulated framework required for grasping objects, performing fine motor tasks, and achieving dexterity. The precise arrangement allows for complex movements like writing and manipulating small tools.
In the feet, the phalanges contribute to the body’s base of support. They assist in weight distribution, maintaining balance, and providing the leverage needed for propulsion during walking and running. They also absorb shock and help stabilize the foot as it transitions from heel strike to toe-off.
Because of their exposed position, these bones are frequently subjected to trauma, making fractures and dislocations common injuries. Distal phalanges, the bones at the tips, are particularly susceptible to crush injuries, often resulting from a direct blow or being slammed in a door. Fractures of the proximal and middle phalanges can also occur, sometimes requiring careful alignment to prevent long-term stiffness or loss of function.