Unit 1: Factors Affecting Performance
Ningbo International School
IGCSE Physical Education
Functions of the Skeleton
There are four major functions of the skeleton:
• Shape and support
• Movement
• Protection
• Blood cell production
The bones of the skeleton also have storage capabilities for vital
minerals such as calcium and phosphorus, which can be
distributed to other parts of the body when required.
Functions of the Skeleton
Shape and support
• The skeleton provides a rigid framework
to the body to give it shape. The muscles
and other vital organs are kept in place
by the skeleton. The skeleton supports
the soft tissues of the body as it forms a
rigid framework to which our muscles,
tendons, ligaments etc attach.
Functions of the Skeleton
Movement
• Movement happens where bones meet
at joints. The long bones in particular
provide a system of levers against which
the muscles can pull, causing movement.
Functions of the Skeleton
Protection
• Our bones are very strong and provide
protection for the internal organs. For
example: the vertebral column protects
the spinal cord, the skull protects the
brain, the ribs protect the heart and
lungs.
Functions of the Skeleton
Blood Production
• Inside long bones is a substance called bone
marrow, which makes new blood cells. Bone
marrow produces both red and white blood
cells. Red blood cells are generally produced
at the ends of long bones such as the
humerus and femur. White blood cells are
usually produced in the shafts of long bones.
Bones
• You should know the major bones in the body
and be able to give examples of them to
highlight the four major functions.
• You should be able to discuss the relevance of
this to performance and participation in
physical activity.
HINT: Use the spaces in your handouts to record
notes as you go ------>
Types of Bones
Long Bones – Cylindrical in shape and are found
in the limbs of the body.
i. Femur
ii. Tibia
iii. Humerus
The function of the ‘Long bones’ are:
• Act as levers – essential in movement
• Production of blood cells which occurs deep
inside the bone.
Types of Bones
Short Bones – are small and compact, often
equal in length and width.
i. The bones of the wrist (carpals)
ii. The ankle (tarsals) and calcaneum
The function of the ‘Short bones’ are:
• To support as they are designed for strength
and weight bearing.
Types of Bones
Flat Bones – offer protection to the internal organs.
i. The sternum
ii. The bones of the cranium
iii. The bones of the pelvis
iv. Scapula
v. Upon close inspection the ribs would come
under this category
The function of the ‘Flat bones’ are:
• To provide suitable sites for muscle attachment,
with origins of muscles often attaching to them
• The pelvis, sternum and cranium also produce
blood cells.
Flat Bones
Types of Bones
Irregular Bones – Complex and individuality in
their shape and have a variety of functions
which include protection.
i. The vertebra
(protect the spinal cord and help to absorb
shock when running and jumping)
ii. The bones of the face
Irregular Bones
Bones of the Spine
(Vertebrae)
TEST YOURSELF…
-Name each bone
TEST YOURSELF…
-Give the type of each bone
Classification of Joints
There are 3 main classifications of joints:
• Fibrous Joints – fixed or immovable
• Cartilaginous Joints – Slightly movable
• Synovial Joints – Freely movable.
Fibrous Joints
• Where bones are
connected by fibrous
tissue so that they are
fixed or immovable.
• An example of this is
between the bones in
the skull.
Cartilaginous Joints
• Where bones are
connected by cartilage
so that there is very
little movement.
• Examples of this are
between the vertebrae
or connecting the ribs to
the sternum.
• Ligaments also restrict
movement at these
joints.
Synovial Joints
• Where bones require a
movable point of
connection.
• These form the majority
of joints in our limbs and
are essential for our
body to move freely.
• There are 6 main types.
Characteristics of a Synovial Joint
Characteristics of a Synovial Joint
This is the
outside layer
of a Synovial
Joint &
surrounds the
entire joint
area.
Characteristics of a Synovial Joint
The Synovial
Capsule is lined
on the inside
with a
“Membrane”
which produces
Synovial Fluid.
Characteristics of a Synovial Joint
Synovial Fluid is a
super-slippery
lubricant which
eases the movement
of a joint to stop
bones & cartilage
wearing away due to
the friction of
movement.
Types of Synovial Joints
There are six main types of synovial joints:
• Ball and Socket
• Saddle
• Condyloid
• Pivot
• Hinge
• Gliding
Ball and Socket Joint
• Movements:
– Allows flexion, extension, adduction, abduction
and rotation.
• Example:
– hip/shoulder
Saddle Joint
• Movements:
– Flexion, extension, abduction, adduction.
– No rotation.
• Example:
– thumb
Condyloid Joint
• Movements:
– Flexion, extension, abduction, adduction.
– No rotation.
• Example:
– Wrist, ankle,
Fingers.
Pivot Joint
• Movements:
– This type of joint only allows rotation.
• Example:
– Between the atlas
and axis vertebrae,
between the radius
ulna at the elbow.
Hinge Joint
• Movements:
– Flexion and extension only.
• Example:
– knee/elbow
Gliding Joint
• Movements:
– A small amount in all directions by gliding over
each other
• Example:
– Between
tarsals/carpals
Joint Movements
There are different types of movement available at
different joints, for example the shoulder moves
in far more ways than the knee.
The five kinds of joint movements that you need to
know are:
• Flexion
• Extension
• Abduction
• Adduction
• Rotation
Check out the link joint movements for more information and video demonstrations.
Flexion
• Closing a joint or decreasing the angle of the
joint.
Extension
• Opening a joint or increasing the angle of the
joint.
Adduction
• Moving a limb towards the centre line of your
body.
TIP: Remember – ADDuction is bringing two bits together, kind of like adding them.
Abduction
• Moving a limb away from the centre line of
you body.
TIP: Remember – ABDuction is taking someone away, like being abducted by aliens.
Rotation
• Turning or twisting a body part, either
clockwise (external or lateral) or anticlockwise (internal or medial).
Of the neck (at the atlas and axis)
At the hip
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.
Cartilage protects ends of bones
Tendons join muscle to bone
Lateral View of Knee
(from side)
Ligaments join bone to bone
Joint Problems
There are a variety of problems that can be
associated with the ligaments, tendons, cartilage
and synovial fluid at our joints.
• Many of these problems can be reduced by
having a healthy and active lifestyle.
• If our joints are healthy and efficient, they add
value to our physical performance.
Joint Problems
These can include:
• Soft tissue injuries that damage ligaments,
tendons, cartilage and muscles.
– E.g. sprains, dislocations, torn cartilage
•
•
•
•
Chronic injuries of joints
Deterioration of flexibility
Inflammation of joints (arthritis)
Osteoarthritis (deterioration of bone density)
Sprains
• These occur when ligaments at joints get
stretched and torn. E.g. a sharp twist of the
foot can give you a sprained ankle.
• Sprains can cause considerable pain and loss
of function at the joint.
• Sprains should be treated with ice and rest
and
• A physiotherapist should be consulted if
possible.
Dislocation
• A dislocation occurs when a bone is twisted or
pulled out of place at a joint.
• This damages the connective tissue around the
joint.
• Dislocations are very painful and require hospital
treatment to move the bone back into position.
• The ligaments, muscles, cartilage and tendons
around the joint can take a long time to recover.
Torn Cartilage
• Cartilage aids friction free movement at joints
and provides some shock absorption.
• Cartilage can tear if the joint is twisted
excessively.
• E.g. torn knee cartilage is a common injury for
footballers caused when they change direction
quickly.
• A cartilage tear is a very painful injury.
• Swelling may be reduced by using an ice pack but
surgery is sometimes needed to repair the
damaged cartilage.
Chronic Injuries of Joints
• Chronic injuries are caused by continuous
stress on a joint or body part over a long time.
• E.g. tennis elbow, runners knee.
• Chronic injuries can be caused by training too
hard, not allowing time for recovery, poor
footwear or bad technique.
• It is important to give your body time to adapt
when increasing training demands and ensure
enough recovery time between training
sessions.
Deterioration of Flexibility
• Most people’s flexibility deteriorates as they
get older. This is because the connective
tissues around the joints become less elastic.
• Flexibility exercises and extended warm-ups
before exercise can help, but ultimately, it
becomes harder and harder to maintain the
same levels of flexibility.
Joint Inflammation and Arthritis
• Joint inflammation occurs when the immune
system is trying to fight off unwanted organisms
or unhealthy cells in the area.
• It usually involves pain and swelling (from
increased blood and synovial fluid in the joint).
• Some people, especially older
individuals, may develop arthritis – a disease that
causes pain, stiffness and inflammation around
joints.
• It is usually hereditary, but injured joints that
have not healed properly can be more prone to
arthritis.
Bone Density and Osteoporosis
• After the age of 35, bone tissue begins to be
broken down more quickly than it is replaced.
• This means that bone density and strength
begin to deteriorate.
• Osteoporosis can occur where bones become
very brittle and are more likely to break.
Exercise for Bone and Joint Health
• Exercise has been shown to increase bone
density and strength.
• Stronger, denser bones are better at carrying
weight and more resistant to injury.
• The increase in bone density is specific to the
activity – walking will strengthen your leg
bones but not your arm bones.
• Both anaerobic exercise and weight training
are effective in increasing bone strength but
the activity must be weight bearing.
Exercise for Bone and Joint Health
• Regular exercise including aerobic, anaerobic
and strength training increases blood flow to
connective tissues.
• This helps to regenerate synovial fluid and
connective tissues.
• If joints are mobile they are more likely to
maintain flexibility and continue to work
effectively.
• This will help to reduce strain and injury at
joints.
What happens
when things go
wrong...