The knuckle joint is called the metacarpophalangeal joint (MCP joint).
Understanding the Metacarpophalangeal (MCP) Joint
The MCP joint is where the metacarpal bones in your hand connect to the phalanges (finger bones). It's the prominent joint you see and feel at the base of your fingers, often referred to as the knuckle.
Components of the MCP Joint
- Metacarpal Bone: The long bones of your hand.
- Phalanx: The bones that make up your fingers and thumb.
- Ligaments: Strong tissues that connect the bones and provide stability.
- Joint Capsule: A fluid-filled sac that surrounds the joint and helps to lubricate it.
Function of the MCP Joint
The MCP joint allows for a wide range of motion, including:
- Flexion: Bending your fingers towards your palm.
- Extension: Straightening your fingers.
- Abduction: Spreading your fingers apart.
- Adduction: Bringing your fingers back together.
- Circumduction: A circular motion combining flexion, extension, abduction, and adduction.
Common Issues Affecting the MCP Joint
Several conditions can affect the MCP joint, including:
- Arthritis: Inflammation of the joint, causing pain, stiffness, and swelling.
- Sprains: Injuries to the ligaments that support the joint.
- Dislocations: Displacement of the bones from their normal position.
- De Quervain's Tenosynovitis: Affects the tendons in the thumb, causing pain near the thumb knuckle.
Therefore, while commonly referred to as the knuckle, the correct anatomical term for the joint is the metacarpophalangeal joint (MCP joint).
