# Balance Flashcards Preview

## Biomechanics Exam 1 > Balance > Flashcards

Flashcards in Balance Deck (19)
1
Q

What is does it mean for something to be stable?

A

The forces acting upon an object are equal to the forces the object is acting upon its surroundings?

2
Q

What is a stable equilibrium?

A

Occurs when a disturbance to an object / person will only cause it to gain stability again?

3
Q

What is an unstable equilibrium?

A

It means that when a force is applied to a person or object, it will need to find a new position?

4
Q

What is neutral equilibrium?

A

When an object will move but remain perfectly stable?

5
Q

What is the center of gravity?

A
• Aka “COG” or Center of mass (COM)
• The theoretical point around which the mass of the point is balance
6
Q

Does the center of gravity need to be inside of an object / person?

A

No

7
Q

Where is the center of gravity in humans?

A
• An inch below the belly button
• In front of the S2 vertebrae?
8
Q

What is a line of gravity?

A
• It’s an imaginary vertical line passing through the COG toward the center of the earth
• Demonstrates how exactly the force of gravity is pulling on an object
9
Q

What is the base of support?

A
• The area in contact with the ground AND the area between these contact points
• The contact points don’t need to be body parts (Ex: walkers, crutches)
10
Q

What are the four main factors that influence stability?

A
• Height of the center of gravity
• The base of support
• The location of the line of gravity relative to the base of support
• The weight of the body
11
Q

How does the height of the center of gravity affect stability?

A
• The higher the height, the more unstable the person is (and vise versa)
• Ex: stilts would be less stable then just standing on the ground
12
Q

How does the base of support affect stability?

A
• The size of the base of support affects stability
• As the size decreases, the stability decreases (and vise versa)
• Direction of depth of the base of support affects stability
• The greater surface area in the direction of the force applied, the greater the stability (and vise versa)
^ Think of the tightrope pushing we did in class
13
Q

How does the location of the line of gravity relative to the base of support affect stability?

A
• If the center of gravity is no longer over the base of support, the person will fall
• Think about when we tried to grab the pencil with our heals on the wall
14
Q

How does the weight of the body affect stability?

A

More mass = more stable (and vise versa)

15
Q

In general, who is more stable, men or women? Why?

A
• Women
• They have a lower center of gravity as they carry more weight in their hips and lower extremities than men do
16
Q

How does friction affect stability?

A

More friction = more stability (and vise versa)

17
Q

How does muscular effort affect stability?

A

When someone is in an unstable position, they require more muscular effort to remain there

18
Q

How does mobility affect stability?

A
• The more mobile someone is, the less stable they are (and vise versa)
• Fast movements = less stable (and vise versa)
19
Q

What are the three sensory components that affect stability?

A
• Vision
• Vestibular (inner ear)
• Proprioception / somatosensory