DIFFERENT KINDS OF JOINTS
5.4
Joints are where two or more bones meet. They are
divided into three types depending on how freely the bones
can move. Movement would not be possible without the
three joint types.
1. Fixed or immovable joints
Eg. Joints between cranium plates.
2. Slightly moveable joints
Eg. Between vertebrae and ribs
3. Freely moveable (synovial) joints
Eg. Knee, shoulder and elbow joints
Fixed or immovable joints
• Bones cannot move at all.
• They interlock/overlap-held together by tough
fibre.
• Present in areas requiring great strength. The
joints in the cranium and sacrum (base of the
spine) are good examples.
Sacrum
Slightly moveable joints
• Limited movement.
• Held together by strong, white straps called
ligaments and joined by cartilage. This acts
as a cushion and stops bones rubbing together.
• Eg. Joints between your vertebrae and ribs. In
the vertebrae the cartilage acts as shock
absorbers when running and jumping.
• The joints between your ribs and sternum move
slightly when you breath in and out.
Remember- Ligaments: Join bone to bone
Tendons: Join muscle to bone
Freely moveable joints
Also called synovial joints. They all have these parts:
Joint capsule: Holds together and protects
Synovial membrane: Lines the capsule and contains
synovial fluid
Joint cavity: Small gap between the bones
Cartilage: Covers end of bones
Ligaments: Holds bones together and keeps them in
place
Eg.
Freely moveable joints (cont)
Divided into four types:
1) Ball/socket, 2) Hinge, 3) Pivot 4) Gliding
Ball and Socket Joint
• Most moveable joint
• One bone has a ball that
fits into a socket on the
Hip joint
other one.
• Can turn in many directions.
• Eg. Hip and shoulder joint.
Shoulder joint
The hinge joint
• Works like a hinge on a door.
• The bone can swing backwards and forwards.
• Cotton reel shaped bone fits into a hollow on the
other.
• The joint will open until it is straight, but no
further.
• Eg. The elbow and knee joints
The pivot joint
One bone has a bit that juts out, like a peg. This
fits into a ring or notch on the other bone.
• Limited movement (Only rotation).
• Eg. Joint between atlas and axisThe top two bones of your vertebrae.
• The joint between the radius and the ulna
(Bones in your lower elbow)
The gliding joint
• The ends of the bone are flat enough to glide
over each other.
• There is a little movement in all directions.
• Least movement of all synovial joints.
• Eg. Joints between carpals (hand) and tarsals
(foot).
carpals