An IP joint, or interphalangeal joint, is a uniaxial hinge joint found in the fingers and toes. These joints allow for flexion and extension, enabling the bending and straightening movements of digits.
Structure and Support
The structure of an IP joint contributes to its stability and function:
- Type: Hinge joint, allowing movement in one plane.
- Location: Present in fingers and toes (not the thumb, which only has one IP joint).
- Support: Supported on the palmar side by a thick volar plate and laterally and medially by the collateral and accessory collateral ligaments.
Key Components and their Roles
| Component | Role |
|---|---|
| Volar Plate | Provides palmar support and prevents hyperextension. |
| Collateral Ligaments | Provides lateral and medial support, ensuring stability. |
| Hinge Joint | Allows for flexion (bending) and extension (straightening) movements. |
Stability
The stability of the IP joint is enhanced by the attachment of the volar plate and collateral ligaments. This design helps to withstand stress and maintain the joint's integrity during movement.
