Synovial Joints

Types of Synovial Joints

1. Plane Joints

   • Non-axial, slipping or gliding movements.
   • Found in carpals, tarsals, and articular surfaces of vertebrae.
   • Movement: Sliding/gliding against each other without rotation.

2. Hinge Joints

   • Shaped like a hinge; one cylindrical and one trough-like articular surface.
   • Examples: Elbow joint (trochlea of humerus and trochlear notch of ulna), interphalangeal joints.
   • Movement: Uniaxial, moves in the sagittal plane (flexion and extension).

3. Pivot Joints

   • Allows rotational movement around a single axis.
   • Example: Proximal articulation of ulna and radius, the head of the radius rotates around the ulna.
   • Movement: Supination and pronation of the forearm.

4. Condylar Joints

   • One concave and one convex oval articular surface.
   • Examples: Metacarpophalangeal (knuckle) joints, wrist joint.
   • Movement: Biaxial, allowing movement in multiple directions.

5. Saddle Joints

   • Resemble a saddle; both surfaces are concave and convex.
   • Example: Carpometacarpal joint of the thumb.
   • Movement: Biaxial, allowing flexion, extension, abduction, and adduction.

6. Ball and Socket Joints

   • Consist of a ball fitting into a socket.
   • Examples: Shoulder (glenohumeral joint), hip joint.
   • Movement: Multiaxial, allowing rotation, abduction, adduction, flexion, extension, and circumduction.
   • Trade-off: Highly mobile but less stable, prone to dislocations (e.g., shoulder joint).

Key Points

• Movement and Stability: Greater mobility often results in lesser stability.
• Examples and Movements: Each joint type is characterized by unique movements and examples from the human body.