Anatomy and Stability of Joints

Ligamentous Stability

• Definition: Ligamentous stability refers to the ability of ligaments to provide stability to a joint by limiting excessive movement and maintaining joint congruency.
• Functions:
  • Resist excessive joint movement
  • Maintain joint alignment
  • Provide proprioceptive feedback
• Types of Ligamentous Stability:
  • Static stability: Provided by ligaments that are taut in a specific joint position.
  • Dynamic stability: Provided by ligaments that become taut as the joint moves through a range of motion.

Anatomy Of Joints

• Joint Components:
  • Articular cartilage: Hyaline cartilage that covers the ends of bones in a joint.
  • Synovial membrane: A layer of connective tissue that lines the joint capsule and produces synovial fluid.
  • Joint capsule: A fibrous sac that surrounds the joint and attaches to the bones.
  • Ligaments: Fibrous connective tissue that connects bones and provides stability.
• Types of Joints:
  • Synovial joints: Freely movable joints with a space between the bones (e.g., shoulder, elbow, knee).
  • Cartilaginous joints: Joints connected by cartilage (e.g., spine, ribcage).
  • Fibrous joints: Joints connected by fibrous connective tissue (e.g., skull bones).
• Joint Classifications:
  • Monaxial: One degree of freedom (e.g., hinge joints like the elbow).
  • Biaxial: Two degrees of freedom (e.g., condyloid joints like the wrist).
  • Triaxial: Three degrees of freedom (e.g., ball-and-socket joints like the shoulder).