The role of joints and types of synovial joints
A joint is a place where two or more bones meet and is also called an articulation.
Synovial joints (freely movable joints) allow us the free movement to perform skills and techniques during physical activity.
Synovial joints have synovial fluid in the joint cavity that lubricates or 'oils' the joint so it moves smoothly. Synovial fluid is made by the synovial membrane.
In synovial joints, the ends of the bones are covered with cartilage (called articular cartilage) which cushions the joint and prevents friction and wear and tear between the bone ends. Cartilage is a soft, spongy connective tissue.
The bones in a synovial joint are connected by ligaments.
- Ligaments are a type of connective tissue and are tough, fibrous and slightly elastic.
- They connect bone to bone and help keep the joint together.
- They stabilise the joints during movement and prevent dislocation by restricting actions outside the normal joint range.
- They can absorb shock because of their elasticity, which protects the joint.
- They help maintain correct posture and movement.
The movement at a synovial joint is caused by the muscles attached across the joint. Muscles are attached to bone by tendons. Tendons are very strong, inelastic connective tissues that allow a muscle to pull on a bone to move it.