Saddle joints are shaped with a unique interlocking design, resembling a saddle and a rider.
Understanding Saddle Joint Shape
Saddle joints are a type of synovial joint characterized by their distinctive shape, which allows for movement in multiple planes. The shapes of the bones that form the joint are key to its functionality.
- Concave-Convex Configuration: As the reference states, "the bone forming one part of the joint is concave (turned inward) at one end and looks like a saddle." This concave surface receives the other bone. The second bone has a "convex (turned outward)" shape that fits into the saddle-shaped bone, "and looks like a rider in a saddle." (04-Apr-2018)
Key Characteristics of Saddle Joint Shapes
| Feature | Description |
|---|---|
| Bone 1 | Concave shape, like a saddle. Provides a curved surface for articulation. |
| Bone 2 | Convex shape, like a rider sitting in a saddle. Fits snugly into the concave surface of the other bone. |
| Interlocking | The concave and convex shapes interlock, creating a stable yet mobile joint. |
Functionality Derived from Shape
This unique shape enables the saddle joint to allow movement in two planes: flexion/extension and abduction/adduction. A limited amount of rotation is also possible. This makes the saddle joint highly versatile.
