Download 1.2.5 Revision – Skeletal System

Joints and Movement
All joints have hyaline cartilage between bones to
prevent pain and damage caused by friction. The
cartilage is then surrounded by synovial fluid and a
membrane.
Joints in upper limbs= Mobility
Joints in lower limbs= Stability
Different joints produce different types of movement
Type of
joint
Hinge
Movement possible
Location
Example
Flexion, Extension
Elbow
Knee
Bicep curl
Kicking a football
Ball and
Socket
Flexion, Extension,
adduction, abduction,
rotation
Shoulder
Hip
Bowling a cricket ball
Driving the leg up on take off
to clear the bar in high jump
Function of the skeleton
Movement
Support
Protection
Where bones meet they form joints. These create
leavers. Tendons attach bone to muscle giving
movement. E.g. throwing a shot put or releasing an
archery bow
Supports the body in a variety of positions e.g.
standing/sitting. Gives the body shape and provides
a framework. Affects an individual’s body
composition.
Reduces chance of injury/protects from damage.
E.g. cranium (skull) protects the brain; ribs protect
the heart and lungs. Important for contact sports
e.g. Rugby when tackling
Types of Movement
Flexion
Angle at the joint becomes smaller
Extension
Angle at the joint becomes larger
Abduction
Movement away from the centre of the body (abduct=
to take away)
Movement towards the centre of the body (adding to
the body)
Movement around a point
Adduction
Rotation
Elbow
Knee Joint
1.2.5 The Skeletal System
Exercise and the Skeletal System
 Increases bone density- heavier bones are stronger bones
 Thicker and stronger ligaments and tendons increases joint
flexibility and allows more power in movements.
Note: Certain activities such as weight training and long distance
running can cause bones to develop unevenly in young people.
Importance of Weight Bearing Exercise
With age bones become lighter and their strength and density
decrease. This can lead to osteoporosis, meaning bones break
easily. Weight bearing exercises, like walking, running and
aerobics can help prevent/delay this.
Injuries
Fracture- a broken or cracked bone
Closed fracture- the bone does not damage the skin
Compound/open fractures- a broken bone that protrudes through the skin
Simple fracture- no displacement (crossing) of the bone e.g. Greenstick (only partly broken)
Stress fractures- overuse injuries, muscles become fatigued and unable to absorb impact, this is then transferred to the bone
causing stress. Common in lower limbs.
Joint injuries
Movement past the joints range will damage the tendons
and ligaments. Common joint injuries include:
Tennis/Golfers elbow: overuse injuries caused by
repetitive strain on a joint.
Dislocations: bone at the joint is forced out of its normal
position. Signs include deformity, pain and swelling.
Sprains: Damage to a ligament e.g. twisted ankle, joint is
forces inwards tearing the ligaments holding the ankle
together. Common in lower limbs. Bruising, swelling,
instability, and painful movement are common
symptoms.
Torn Cartilage: damage to the elastic substance (cartilage)
at the ends of the bone. Common in the knee, the
individual will fall to the floor, with pain on the inside.
Strains: Damage to the tendon which holds the muscle to
the bone. Caused by overstretching. Pain, weakness, and
muscle spasms are common symptoms
Treatment (minor injuries)
R- Rest: cease activity and break from training
I- Ice: apply a cold compress, will reduce
swelling and provide some pain relief
C- Compression: apply pressure, while holding
the ice pack to the injury
E- Elevation: Raise the injury, reducing swelling
Diet- can strengthen bones & prevent some
injuries
1. a calcium rich diet, aids bone growth &
density e.g. milk, cheese and yogurt
2. Vitamin D, essential for growth and
maintenance of bones, helps absorption of
calcium. Made in the body when the skin is
exposed to sunlight
3. Smoking & too much alcohol have a toxic
effect on bones