Finger joints are connected by a combination of bones, ligaments, and tendons. These structures work together to provide stability, flexibility, and range of motion.
Bone Structure
Fingers are composed of three bones called phalanges (except for the thumb, which has two). These phalanges are connected by two types of joints:
- Interphalangeal (IP) joints: These joints connect the phalanges to each other. The proximal interphalangeal (PIP) joint connects the proximal and middle phalanges, while the distal interphalangeal (DIP) joint connects the middle and distal phalanges. The thumb only has one IP joint.
- Metacarpophalangeal (MCP) joints: These joints connect the phalanges to the metacarpal bones in the palm of the hand.
Ligaments and Tendons
- Ligaments: These strong, fibrous tissues connect bones to other bones. In the fingers, collateral ligaments are crucial for preventing sideways movement at each joint. [Reference: Ligaments and Tendons, The Hand Society] The ligaments provide stability and limit excessive joint movement. [Reference: Hand and Wrist Anatomy | Arthritis Foundation]
- Tendons: These strong cords of tissue connect muscles to bones. Tendons in the fingers allow for movement. [Reference: Hand and Wrist Anatomy | Arthritis Foundation] They transmit the force of muscle contraction to bend and straighten the fingers. [Reference: In brief: How do hands work? - InformedHealth.org - NCBI Bookshelf]
Joint Stability and Function
The combined action of bones, ligaments, and tendons provides the fingers with their remarkable flexibility and strength, enabling a wide range of movements essential for fine motor control and gripping. The specific arrangement and strength of these tissues vary slightly across different finger joints and individuals. [Reference: Hand Anatomy Video | Medical Video Library, Anatomy of the Hand | Johns Hopkins Medicine]
