Balance Flashcards
(22 cards)
Define balance
The study of how movement is controlled
Regulation of a functional Action maintaining an upright posture
What is human balance?
Active control of the physical shape of the limbs
Compensative active stability for passive insufficiencies
Humans are possibly unstable
Active process only three muscles
Define stability
The tendency of a body to remain a return to its initial position following the application of a force
Can be passive or active
What factors the passive stability depend on?
Weight
Area of the base size
Horizontal distance of the centre of gravity to the pivot point
Height of centre of gravity above the base

Why does the height of the centre of gravity matter?
Makes it harder to move outside of the body
What is the area of baseboard matter?
Heart of centre of mass to move outside the body
What is equilibrium?
The sum of forces equal zero
What is stable equilibrium?
If a force is applied, will return back to starting point 
What is unstable equilibrium?
Easy percent of mass to move outside of the base support 
Human
What is neutral equilibrium?
Centre of mass does not rise or fall, a circle
What controls the human inverted pendulum
Rotational force from muscles
Ankle strategy mainly 
Explain perturbations
When there is an unexpected perturbation
Elasticity, muscles stretch
Stretch reflexes (spinal chord)
Pre programmed actions
Read!!
What are the reflex balance mechanisms?
Ankle strategy
Hip strategy (horizontal force into ground)
Stepping
Arm swings 
What are the three sensory feedback mechanisms used in balance?
Vision
Vestibula
Proprioreception
Explain the vestibular systems role
Acts as an accelerometer
Picture + book
Explain the vestibulo ocular reflexes
When move head, eye twists within the socket

How is vision used in balance?
Peripheral vision a main component of balance
No, whether we are moving forward or backwards

How much does each part contribute to balance?
Proprio 70% - pressure sensors in feet
Vestibular 20%
Vision 10%
What is centre of pressure?
Some of all the forces through your body into your feet
Point on the force place that the resultant force arises from
How is centre of pressure analysed?
Picture
We’re 95% of the date points lie 
What is the gravity line?
Line passing vertically through the centre of gravity
Centre of pressure moves around it 
Book
Determine control strategy
Book
