P2P2. Joint movement – what are joints? A joint is a place where two or more bones meet. Without...

P2Joints and their classifications

Joint movement – what are joints?A joint is a place where two or more bones meet.Without joints, our bodies would not be able to move. Joints, along with the skeleton and muscular system, are responsible for the huge range of movement that the human body can produce.There are several different types of joint, each producing different types and amounts of movement.

Different types of jointThere are 3 different types of joint:

1. Immovable (or fixed) joints

3. Movable (or synovial) joints

2. Slightly movable joints

1. Fixed or immovable jointsThere are fewer than 10 immovable joints in the body.They are sometimes called fibrous joints because the bones are held together by tough fibres.

Immovable joints can be found in the skull and pelvis, where several bones have fused together to form a rigid structure.

2. Slightly movable jointsSlightly movable joints are sometimes called cartilaginous joints.The bones are separated by a cushion of cartilage. The joints between the vertebrae in the spine are cartilaginous joints.The bones can move a little bit, but ligaments stop them moving too far. This is why we can bend, straighten and rotate through the back, but not too far.

bone

ligaments

cartilage

bone

3. Freely movable or synovial joints

90% of the joints in the body are synovial joints. They are freely movable.Synovial joints contain synovial fluid which is retained inside a pocket called the synovial membrane. This lubricates or ‘oils’ the joint.All the moving parts are held together by ligaments.These are highly mobile joints, like the shoulder and knee.

Synovial fluid

Knee

Synovial membrane

Connective tissuesConnective tissues are vital to the functioning of joints. There are 3 types of connective tissue:

Ligaments are tough, elastic fibres that link bones to bones.

Tendons connect muscles to bones.

Cartilage prevents the ends of bones rubbing together at joints. Its

slippery surface also helps to lubricate the joint.

Tendons and ligaments

Ligaments and tendons are strengthened by training.

Ligaments are responsible for holding joints together. They prevent bones moving out of position during the stresses of physical activity.

If they are pulled or twisted too far by extremephysical movements, ligaments can tear andthe joint may dislocate.

Tendons anchor muscles to bones, allowing the muscles to move the skeleton. Tendons are not very elastic –

if they were, then the force produced by muscles would be absorbed instead of creating movement.

Tendons can also be torn if subjected to too much force.

Freely movable (synovial) jointsThe joint capsule is an outer sleeve that protects and holds the knee together. The synovial membrane lines the capsule and secretes synovial fluid – an oil like liquid which lubricates the joint, allowing it to move freely.

Femur

Tibia

Joint capsule

Synovial membrane

Synovial fluid

Ligaments hold the bones together and keep them in place.

Cartilage

Smooth coverings of cartilage at the ends of the bones stops them rubbing together and provide some shock absorption.

Task…To achieve P2 you need to describe:• The different types of joint and the movements available at each.(Fixed, slightly moveable, synovial/freely movable)• The different types of synovial joint and movements available at each.

Types of joints1) Label a Synovial JointCopy the picture of the synovial joint from the internet and label/describe it

2) Give a brief description (Up to 50 words each/also picture examples) of each of the following types of joints, and the movement available at each one- Fixed or fibrous- Slightly moveable or cartilaginous- Synovial or freely moveable

Types of synovial joints

In ball and socket joints, the rounded end of one bone fits inside a cup-shaped ending on another bone.

Ball and socket joints allow movement in all directions and also rotation. The most mobile joints in the body are ball and socket joints.Examples: Shoulders and hips.

Hip

Types of synovial joints

Pivot joints have a ring of bone that fits over a bone protrusion, around which it can rotate.These joints only allow rotation.

Examples: The joint between the atlas and axis in the neck which allows you to shake your head.

Axis

Atlas

Types of synovial jointsIn saddle joints, the ends of the two bones fit together in a special way, allowing movement forwards and backwards and left to right, but not rotation.

Examples: The thumb is the only one.

Hinge joints – as their name suggests – only allow forwards and backwards movement.

Examples: The knee and elbow.

Elbow

Types of synovial jointsCondyloid joints have an oval-shaped bone end which fits into a correspondingly shaped bone end.They allow forwards, backwards, left and right movement, but not rotation.Examples: between the metacarpals and phalanges in the hand.

Gliding joints have two flat faces of bone that slide over one another.They allow a tiny bit of movement in all directions.

Examples: between the tarsals in the ankle.

Synovial joints – sporting examplesDuring the butterfly stroke, the ball and socket joint of the shoulder allows the swimmer’s arm to rotate.

You might head a football using the pivot joint in your neck, which allows your head to rotate.

What type of joint allows a handball player’s fingers to spread apart so that they can control the ball with one hand?

Answer:The condyloid joints between the metacarpals and phalanges.

Movement PatternsIn order for us to understand sporting movements, we have to be

able to label the possible movements available at a joint, using specific terms.

Flexion

ExtensionAdduction

Abduction

When the angle of the joint decreases

When the angle of the joint increases

Movement towards the midline of the body

Movement away from the midline of the body (e.g. A star jump

Circumduction

RotationThe limb moves in a Circle. For example this occurs at the shoulder joint during an ‘Overarm bowl in Cricket’

The limb moves in a circular motion towards the midline of the body. For example this occurs in a ‘golf swing when driving the ball’

The structure of the elbow joint (hinge)

The elbow is another complex hinge joint. The hinge between the humerus and ulna allows the arm to bend (Flexion) and straighten (Extension).

The elbow also has a pivot joint between the ulna and radius which allows us to rotate (Rotation) the lower arm while keeping the upper arm still.A gliding action occurs between the humerus and radius.

The whole joint is encased in a synovial capsule and held together by ligaments.

Radius

Humerus

UlnaLigaments

Task…3) Find a picture of a player in action. Paste it into the same document that you have been working on. Use arrows to label the picture with each of the following joint types and what movements (flexion/adduction/ rotation etc.) are available at each Joint:

- 2 Hinge Joints- 2 Ball and Socket Joints- Gliding Joint- Pivot Joint- Saddle Joint- Condyloid Joints

Some suggested answers:

Left elbow – involves the humerus, radius and ulna. It is a hinge joint. It is extended.Left wrist – involves the carpals. This is a gliding joint. There is rotation.Left hand – joint between metacarpals and phalanges. This is a condyloid joint. There is abduction and flexion on the phalanges.Right hip – involves the pelvis and femur. This is a ball and socket joint. There is abduction.Knees – involve the femurs, tibias and fibulas. These are hinge joints. There is flexion.

E.G.