The elbow joint is functionally classified as a uniaxial diarthrosis.
Understanding Joint Classification
Joints, or articulations, are classified based on their structure and function. Functional classification focuses on the type of movement the joint allows. There are three main functional classifications:
- Synarthroses: These are immovable joints, like the sutures in the skull.
- Amphiarthroses: These are slightly movable joints, such as those between vertebrae.
- Diarthroses: These are freely movable joints, also known as synovial joints. The elbow is an example of a diarthrosis.
Diarthroses are further sub-classified based on the number of axes around which movement can occur:
- Uniaxial: Movement occurs around a single axis. The elbow joint is a prime example, primarily allowing flexion and extension.
- Biaxial: Movement occurs around two axes. Examples include the wrist and metacarpophalangeal joints.
- Multiaxial: Movement occurs around three or more axes. The shoulder and hip joints are multiaxial.
The Elbow Joint: A Uniaxial Diarthrosis
As stated in the provided reference, all synovial joints are diarthroses. The elbow, being a synovial joint, falls under this category. Its movement is restricted to a single plane – flexion and extension – making it a uniaxial diarthrosis. This limitation ensures stability, crucial for supporting the forearm and hand during various activities. The hinge-like structure of the elbow joint facilitates this uniaxial movement efficiently.
