Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biomechanics > Week 6 > Flashcards

Week 6 Flashcards

1
Q

Base of Support (BoS)

A

Area defined by straight lines connecting the peripheral
most points in contact with the surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Centre of Mass (COM)

A

Point around which the mass and weight of a body are
balanced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Centre of gravity (COG) or Line of Gravity (LOG)

A

Line of action of the force of gravity

Always acts at the COM and always downwards

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Who has a higher centre of mass, males or females and why?

A

Males have a higher centre of mass generally as they have more muscle mass in the upper body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How can the COM be manipulated in humans?

A

Changing the position of our torso over our legs or moving our arms away or toward the BoS.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a concentric force?

A

A force whose line of action passes through the COM of the body on which it acts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does a concentric force do?

A

Causes a change in linear motion (translation) but no changes in rotational motion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is an eccentric force?

A

A force whose line of action does not pass through the COM of the body on which it acts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does an eccentric force do?

A

causes a change in rotational motion as well as a change in linear motion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a force couple?

A

Equal, opposite directed and parallel forces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Define Torque

A

Tendency of a force to cause rotation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How do you calculate torque?

A

T = F*MA (Nm)

F = applied force (N) 
MA = moment arm (m)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a moment arm?

A

Perpendicular distance from the force to the axis of rotation

Draw a line from the force line of action to the axis of rotation. This will give you the moment arm.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Equilibrium

A

ΣF & ΣT = 0

Σ = sum of

Describes the state of a system that is not changing its speed or direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How do you calculate the COM of the forearm?

A

Work out the length of the forearm and multiply it by the proximal or distal length % from Winter’s table.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How do you calculate the mass and weight of a forearm?

A

Determine body weight of person and multiply it by the forearm represented number in Winter’s Table. = 0.016

17
Q

How would we calculate the COM of a forearm if the length was 35cm?

A

0.35 x 0.43 (winter’s table)
= 0.15 m from elbow as we used the proximal length

18
Q

How would we calculate the mass and weight of the forearm if someone weighed 58kg?

A

58 x 0.016 (winter’s table)
=0.928kg for mass and weight:
0.928 x 9.81 = 9.1N

19
Q

How to calculate the centre of mass with a XY graph?

A

Calculate the coordinate for each segment (body part) and times each by their % BW from Winter’s table. Once all segments or body parts are calculated, we some all of the XY x % BW’s together to come up with COM X and Y coordinate to plot on the graph/picture

20
Q

Define balance

A

A body’s ability to control or maintain its state of equilibrium

21
Q

Define Stability

A

The resistance of a body to change its state of equilibrium

22
Q

What are the factors that affect stability or balance

A
  1. Line of Gravity (LOG) within BOS
  2. Size of Base of Support (BOS)
  3. Height of Centre of gravity (COG) / Centre of Mass (COM)
  4. Principles of moments/torque
23
Q

Types of stability

A

Linear stability and Angular stability

24
Q

Define linear stability and what factors play a role

A

Resistance to being moves in a straight line

Inertia (mass), friction

25
Q

Define angular stability and the factors involved

A

Resistance to being ‘tipped’ over

COM, BOS, LOG

26
Q

How do you increase linear stability

A

Greater inertia/mass or increased friction

27
Q

What is The Principle of Moments

A

When a body is balanced, the total clockwise moment about a point equals the total anticlockwise moment about the same point

ΣT = 0

28
Q

Why is the person on the right more stable?

A

COM is lower, BOS is bigger in an Anterior-Posterior direction, LOG in the middle of BOS

29
Q

Explain how the application of stability can be applied to these three real-world examples:

Teaching balance activities in gymnastics

Assisted chairs

Crutches

A

Teaching balance activities in gymnastics - Floor balances to beam balances, start with lower COM and larger BOS and slowly increase COM and decrease BOS.

Assisted chairs - mechanically move COM over BOS

Crutches - Increase BOS

Biomechanics (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions