Types of Joints
Your body contains three main structural types of joints that allow different degrees of movement. Fibrous joints are immovable connections like the coronal suture in your skull, keeping certain bones firmly fixed together. Cartilaginous joints permit slight movement, as found between your vertebrae, providing some flexibility while maintaining stability.
Synovial joints are the most mobile type and come in six varieties based on their function. The ball and socket joints in your hips and shoulders allow extensive multi-directional movement, while pivotal joints (like between the first two vertebrae) enable rotation around a single axis. Hinge joints in your elbows and knees work like door hinges, moving primarily in one plane.
Other synovial joint types include saddle joints at your knuckles that allow movement in two planes, plane joints between your wrist and ankle bones that permit short gliding movements, and condyloid joints which enable movement in two axes with their oval shape.
Quick Fact: Synovial joints contain a fluid-filled cavity that reduces friction and acts like a natural lubricant, allowing for smooth movement without painful bone-on-bone contact!
Each joint has specific supporting structures including ligaments, tendons, cartilage, and a joint capsule that work together to ensure proper function and protect the joint from injury during movement.