Transcript Document

P
2
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 joint
There are 3 different types of joint:
1. Immovable (or fixed) joints
2. Slightly movable joints
3. Movable (or synovial) joints
1. Fixed or immovable joints
There 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 joints
Slightly movable joints are sometimes called
cartilaginous joints.
bone
The bones are separated by a cushion of
cartilage. The joints between the vertebrae in
the spine are cartilaginous joints.
cartilage
bone
ligaments
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.
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.
Synovial fluid
All the moving parts are held together by
ligaments.
These are highly mobile joints, like the shoulder Synovial
and knee.
membrane
Knee
Connective tissues
Connective tissues are vital to the functioning of joints.
There are 3 types of connective tissue:
Tendons connect muscles to
bones.
Ligaments are tough,
elastic fibres that link
bones 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 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 extreme
physical movements, ligaments can tear and
the 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.
Ligaments and tendons are strengthened by training.
Freely movable (synovial) joints
The 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.
Synovial
fluid
Cartilage
Smooth coverings of cartilage at the ends of the
bones stops them rubbing together and provide
some shock absorption.
Ligaments hold the bones together and keep them in place.
Femur
Tibia
Synovial
membrane
Joint capsule
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 joints
1) Label a Synovial Joint
Copy 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
ball and socket
joints, the rounded end of one bone
In
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.
Atlas
Examples: The joint between the atlas and axis in
the neck which allows you to shake your head.
Axis
Types of synovial joints
saddle joints
In
, 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 joints
Condyloid 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 examples
During 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 Patterns
In 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
When the angle of
the joint decreases
When the angle of the
joint increases
Extension
Adduction
Movement towards the midline of
the body
Abduction
Movement away from the midline of the body (e.g. A star jump
Circumduction
The 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’
Rotation
The structure of the elbow joint
(hinge)
Humerus
Radius
Ligaments
Ulna
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
E.G.
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.