There are three different types of joint which are classified dependant on the movement available. Fixed joints (fibrous joints), slightly moveable joints (cartilaginous) and freely movable (synovial joints).
- Fixed or immovable joints - also known as fibrous joints. An example is the joints between the different bones of the skull
- Slightly movable joints - also known as cartilaginous joints. There is a small amount of movement permitted at these joints which are separated by cartilage, such as in the joints between the vertebrae.
- Freely movable - also known as synovial joints. These contain synovial fluid inside a synovial membrane which surrounds the joint. An example is the knee joint.
There are different types of movement available at different joints, for example the shoulder moves in far more ways than the knee. Here are the main types of movement:
Reducing the angle at the joint, for example bending the knee or elbow is flexion
Increasing the angle at the joint, for example straightening the knee or elbow is extension
Moving the body part towards the centre of the body, for example bringing one leg in towards the other is adduction
Moving the body part away from the centre of the body, for example taking one leg away from the other is abduction
Turning or twisting a body part, either clockwise (external or lateral) or anti-clockwise (internal or medial), for example turning your leg to point the toes outwards
More information about joint movements with video demonstrations can be seen on our A level revision page.
Freely Movable (Synovial) Joints
There are five types of freely moveable, or synovial joints:
|Joint Type||Movement at joint||Examples|
|Pivot||Rotation of one bone around another||
Top of the neck
|Ball and Socket||
Abduction/Internal & External Rotation
Wrist/MCP & MTP joints
Connective Tissues and Joints
There are three types of connective tissue in and around joints:
Cartilage - This sits on the ends of bones within a joint to stop the two ends from rubbing
Ligaments - These connect bones to bones and help keep the joint together
Tendons - These connect muscle to bone and usually cross a joint so that the associated muscle can cause movement at the joint
The spine consists of lots of small irregular bones called vertebrae. Their function is to allow movement at the spine, provide an attachment for muscles and also to protect the spinal cord which runs through their centres. The spine is split into 5 sections:
The cervical spine is the neck part of the spine and consists of 7 vertebrae
The thoracic spine is the upper back and consists of 12 vertebrae
The lumbar vertebrae forms the lower back and includes 5 vertebrae
The sacrum is the buttocks part of the spine and consists of 5 vertebrae, however they are fused and appear as a triangular bone, inbetween the two hip bones (ilium)
The coccyx is the very end of the spine and used to be our tail bones, although it now doesn't have a function.