Brainscape's Knowledge GenomeTM

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


See full index

Human Biosciences > foundation of biomechanics > Flashcards

foundation of biomechanics Flashcards

1
Q

Pythagoras theorem?

A

A^2 + B^2 = C^2

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

Formula for finding out angles and lengths in a right angled triangle?

A

SOH CAH TOA

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

How to label a triangle?

A

Hypotenuse will be the diagonal
Adjacent will be side next to angle which isn’t the hypotenuse
Opposite will be side opposite from angle you are looking at?

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

How can triangle formulas be used to find distance traveled by ball?

A

Draw right angle triangle, will be given angle and vertical velocity or horizontal velocity and just work it out using formula

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

Qualitative analysis is?

A

Description of movement

Requires experienced coach

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

Quantitative analysis?

A

Numerical evaluation based on data collected during motion

Allows assessment of aspects which can’t be observed eg. force

Removes subjectivity

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

What is kinesiology?

A

Scientific study of human movement

Mainly qualitative

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

What is biomechanics?

A

Considered to be more quantitive

Derived from mechanics, involves motion and effect of forces on living organisms

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

2 types of motion present in human movement or object propelled by a human?

A

Linear (translational) - motion along a straight or curved pathway in which all points on a body/object move the same distance in the same amount of time

Angular - motion about a given point so that different regions of the same body part/region do not move through the same distance in a given time.

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

What is kinematics?

A

Characteristics of motion from a spatial and temporal perspective

Without references to forces causing the motion

Variables of interest are therefore position, velocity and acceleration

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

What is kinetics?

A

Area of study that examines forces acting on a system (human body or an object)

The forces can be external (ground reaction force)

Internal (muscle and bones)

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

What’s a static system?

A

Systems that aren’t moving, or moving at a constant speed

So it’s in equilibrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What’s a dynamic system?

A

Systems that are being accelerated

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

What’s sagittal plane?

A

Cut through the middle of pecs

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

What’s transverse plane?

A

Cut through belly button (rubber ring around you)

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

What’s frontal plane?

A

Cut across shoulders

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What’s rectilinear translation?

A

Body travels in a straight path

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What’s curvilinear translation?

A

Body travels in a curved path

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the sampling frequency?

A

Number of pictures per second (frames/fields)

Units = Hz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is digitisation?

A

Giving selected points numerical values allowing linear and angular displacements of joints and anatomical landmarks to be determined

This allows the calculation of velocities and accelerations

Effectively turns a qualitative video into a quantitative one

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is scaling?

A

Conversion of measured distance into real units

To work this out from screen to reality

Find out what 1mm is on the screen in metres by dividing in reality by mm on screen

Then multiply what your value is by the amount of mm if you asked a different length

Always make sure answer is in metres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Difference between distance and displacement?

A

Distance is the length of the path that it follows

Where as displacement is the length of a straight line joining its initial and final positions, taking note of the direction of this line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is speed?

A

speed = distance / time

Scalar quantity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is velocity?

A

How fast an object moves and in which direction

Velocity = displacement / time

So velocity = change in position / change in time

Vector quantity ( magnitude and direction)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Equation for the first central difference method?

A

Vx2 = (x3 - x1) / (t3 - t1)

Essentially velocity = (Final x position - starting x position) / (final time - initial time)

units of velocity is m/s or m.s^-1

Use values either side of the one your trying to find at a specific time point

With new values for velocity can do this again to find out acceleration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is acceleration?

A

a = change in velocity / change in time

So basically = (final velocity - initial velocity) / (final time - initial time)

Units are m.s^-2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is uniform acceleration?

A

Rate of change of velocity is constant

So acceleration is constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Value of gravity?

A

9.81 m.s^-2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Equations for uniform acceleration?

A 
u= initial velocity 
v = final velocity
s = displacement of the object
a = acceleration 
t = time
v = u + at
v^2 = u^2 + 2as
s = ut + 0.5at^2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Does mass influence motion in flight?

A

NO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

If an object is moving upwards it’s acceleration is and if it’s moving downwards?

A

a = -g = -9.81 m.s^-2

Air resistance assumed to be negligible

a = g = 9.81 m.s^-2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Theory on motion of flight?

A

An object will take the same amount of time to reach max height to then reach floor again

Time up = time down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

When an abject is in flight do we consider the vertical and horizontal components separately?

A

Yes

Equations apply to both

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

How to answer a question when you need to use horizontal and vertical velocity?

A

Work out flight time, using vertical component

Work out with acceleration, initial velocity and the final velocity being 0, but remember need to multiply the flight time by 2 to find full value

Now can work out the unknown you want

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the resultant velocity composed of?

A

Vertical and horizontal velocity

Worked out with Pythagorus and SOH CAH TOA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What angle in theory gives optimum range in a projectile?

A

45 degrees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What does a greater vertical velocity component consist of?

A

Greater Height
Greater flight time
Greater range

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What does a greater horizontal velocity consist of?

A

Same height
Same flight time
Greater range

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is inertia?

A

The resistance of a body to motion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is mass?

A

The amount of matter makes up a body

Greater mass = greater inertia

Standard unit is kg

41
Q

What is force?

A

The cause of motion

Alters, or tends to alter, a body’s state of rest or uniform motion

Unit = Newtons (N)

1 N accelerates a 1 kg mass by 1m.s^-2

42
Q

What is a vector?

A

Provides magnitude and direction

43
Q

What is Newtons law of gravitation?

A

F ∝ (m1 x m2 ) / d^2

F = force acting on each particle

m1 = mass of first object

m2 = mass of second object

d = distance between the mass centres

44
Q

Features of weight?

A

Weight = Mass x gravity

Weight varies slightly depending on location (as distance to centre of earth varies)

Unit is newtons

45
Q

What is Newton’s first law of motion?

A

Everybody continues in a state of rest, or uniform motion in a straight line, unless compelled to change that state by external forces exerted upon it

46
Q

What is Newtons second law of motion?

A

Force = mass x acceleration

47
Q

Newton’s 3rd law of motion?

A

For every force that is exerted by one body on another, there is an equal and opposite force exerted by the second body on the first

48
Q

In a vertical Ground Reaction force graph for running, what’s is the small increase, and the highest point and scalings?

A

Peak impact force is the small increase in bell curve

Peak active force top of bell curve

0.3 seconds on x axis

Around 2500 N on y axis

49
Q

Features of horizontal GRF for running?

A

Symmetrical goes negative then positive (sideways figure of 8)

Peak braking force is smallest value

Peak propulsive force is highest value

It’s the same for walking but obviously time increases

0.3 seconds on x axis

Around 400 N on y axis

50
Q

Features of vertical GRF for walking?

A

“M” shaped

Time has increased

51
Q

What does running with a forefoot stride potentially suggest? (promoted from being barefoot)

A

Reduce risk in injury as there isn’t the peak impact force (it’s not as prominent)

52
Q

Factors that affect GRF?

A 
Speed
Mass
Surface
Type of running technique
Footwear
53
Q

Equation for momentum (P)?

A

Momentum (kg.m.s^-1) = mass (kg) x velocity (m.s^-1)

Vector quantity so has magnitude and direction

54
Q

Total momentum of a system =?

A

Sum of the momenta of all the particle in the system

55
Q

What is newtons law of inertia?

A

An object/system will remain at rest or un uniform motion in a straight line unless acted upon by an external force

56
Q

Law of the conservation of momentum?

A

Doesn’t change unless an external force act upon it

57
Q

2 types of collisions?

A

Elastic collisions - kinetic energy of the system is conserved - very uncommon

Inelastic collisions - kinetic energy is transferred to another form of energy

Total system momentum is conserved during collisions

So momentum before the collision = momentum after collision

58
Q

How to work out the momentum of a system and then the final velocity of the system?

A

Work out Total momentum of system by summing all the individuals momentum’s taking into account direction

Then add all the masses and rearrange for the system velocity

59
Q

Equation for force involving momentum and time?

A

Force (N) = (mass (kg) x change in velocity) / change in time

Force (N) = Change in momentum / Change in time

60
Q

What does impulse equal, therefore how do we increase it?

A

Impulse (N . s) = Change in momentum
= Mass x (v-u)!!!!!!!!!!!!!!!!
= Force x time over which force was applied

Increase force

Increase time over which the force is applied

61
Q

Describe horizontal force and impulse in running?

A

Initially there is a negative horizontal impulse and braking, then mid stance switches to a positive horizontal impulse which is propulsive

Impulse = area under the force-time curve if plotted

So total net impulse = positive + negative impulse (negative horizontal impulse is negative on graph)

If impulse = 0, then there is no change in impulse so the person is moving at a constant speed

Also if positive is larger then speeding up, if negative is larger then we are slowing down

62
Q

Given impulses and mass how do you work out how high someone has jumped?

A

Find net impulse in N.s

Look at second half of jump so time is halved

Use Net impulse = mass x v
(as u will be 0)

Now know u so can input into Suvat to work out s

or if don’t need to use impulse can just imput the second half of the jump into s = ut + 0.5at^2

63
Q

Equation for pressure?

A

Force(N) / Area (m^2)

Units = Pascals = N . m^-2

64
Q

Equation for mechanical work?

A

Work(J) = Force (N) x Displacement (m)

1 joule = 1 Nm

65
Q

What is positive work?

A

When the displacement is in the same in the same direction as the force of interest

66
Q

What is negative work?

A

When the displacement is in the opposite direction of the force of interest

Joules value will be negative as well

67
Q

What is the total system work?

A

= Sum of positive (normally work done by muscle) and negative work (normally work done by gravity)

Can be Simplified to:

W = d(f -mg)

w= total system work
d = displacement
f = force
m = mass
g = gravity
68
Q

What’s the value for mechanical work if an object isn’t moving?

A

0

69
Q

Why is work done not a very accurate measure?

A

It doesn’t consider time

70
Q

Equation for power?

A

It’s the rate at which work is performed

Power = Work / time

Units = J.s^-1 = Watts (W)

Or

Power = Force x velocity

71
Q

Equation for kinetic energy and definition?

A

Energy resulting from motion

KE = 1/2 x mass x velocity^2

72
Q

Equation gravitational energy and definition?

A

The energy an object posses because of it’s position in a gravitational field. We will usually think of this as an objects height from the ground

PE = mass x gravity x height

73
Q

Equation for strain energy and definition?

A

Stored potential energy in a object which is deformed by a force

SE = 1/2 . k . x^2

(using “.” for multiplication)

k = stiffness (N/m)

x = displacement (m)

74
Q

A way to find total mechanical energy?

A

= KE + PE +SE

75
Q

At the apex of a projectiles flight the potential energy will be?

A

All of the total energy of the system

76
Q

2 types of friction?

A

Sliding

Rolling

77
Q

What’s force applied (P), friction force (F) and reaction force (R)?

A 
P = the force pushing
F = force resisting (limiting friction is the highest value it can take in the circumstance)
R = perpendicular to contact surface (normally straight up)
78
Q

Equation for friction force is equal to?

A

The reaction force (R) multiplied by a constant (u)

F = uR

F/R = u

79
Q

Does mass and surface area affect friction?

A

NO

80
Q

What does the constant (u) equal when you have been given an angle in which something starts to slide?

A

u = tan(x)

81
Q

Equation for friction force in sliding friction?

A

Fs (friction force) = coefficient of sliding friction (us) x R (reaction force)

Coefficient of sliding friction < coefficient of limiting friction

82
Q

What does Fy/Fz equal?

A

u

83
Q

Equation for the coefficient of restitution?

A

Giving you e = square root of (height bounced /height dropped)

84
Q

Other factors that can increase e?

A

Temperature

85
Q

What increases force of attraction?

A

Smaller distance between objects

Larger masses

86
Q

What’s the line of gravity?

A

Is the vertical line through the point at which the object would balance

87
Q

What’s the centre of gravity (means the centre of mass as well)?

A

Where the 2 lines of gravity (horizontal and vertical) meet

= the point about which gravitational force is balance

it is the point through which the resultant force acts

88
Q

3 ways to determine the centre of gravity?

A

Balance method
Suspension
Reaction board

89
Q

5 ways to asses sports performance?

A

Direct observation

Video observation

Video analysis to obtain kinematic data

Force analysis to obtain kinetic data with a force plate

Pressure analysis to obtain kinetic data with a pressure plate

90
Q

How to answer a large study question?

A

Introduction:
What is the question you are trying to answer?
Why would it be beneficial to investigate this?

Population:
How many participants would you use?
How would you determine the inclusion/exclusion criteria?

Equipment:
What equipment would be required?
Can you add extra information such as make/model and recording frequency?

Experimental setup

Testing procedures:
What would happen?
Conditions?
Repeat trials?
Order?
Data collected:
What type (kinematic or kinetic)?
Which variables would be of interest?

Implications:
What does the data tell you?
How does it relate to the question you were trying yo answer

91
Q

How to draw a Standing vertical jump impulse and answer the question about working it out?

A

y axis goes up to 3.5 seconds

x axis goes up to 2500 N

In comparison to BW line, straight line for a bit, small down, big bump little bump, straight down to touch x axis, big gap, massive straight up, down through BW line then up to bw line and wiggle

Take up is on left side of gap on axis, landing is on right side

Peak take off force is top of hump before drop down and peak landing force is top off hump on right side

Negative take-off impulse is area of the dip at the beginning, and positive is the area above the BW line on the next bit

Have force time history printed onto gridded paper from the force plate

Calculate what one mm^2 is in N.s (0.5 N.s)

Net impulse = 100 squares in negative (-50 N.s) + 600 squares (300 N.s) = 250 N.s

Impulse = mass x final velocity

250 = 100v
v = 2.5
2.5 = 9.81t
t = 0.255

s = (0 x 0.255) + (0.5 x 9.81 x 0.255^2) = 0.32 m

92
Q

Different foot arches on a pressure plate?

A

High Arch:
Only visible is toes and ball of foot

Medium Arch:
Just a normal foot toes are visible

Low arch:
Broader foot can only see big toe

93
Q

Software used in digitising?

A

MaxTRAQ

94
Q

Software used when we measured a punch?

A

Codamotion software

95
Q

Describe steps in a friction experiment looking at turning?

A

Use the AMTI Force platform to obtain vertical and anterior-posterior force time histories at 500Hz during turning

From the anterior-posterior need the values of:
Peak Braking force
Time of peak braking force

Then from vertical:
Vertical force at time of peak braking force (N)

The put into the equation:
Coefficient of friction = Fy/Fz = Peak braking force / Vertical force at the time of peak braking

96
Q

Describe steps in working out friction between a shoe and a surface?

A

Place shoe on a surface and slowly raise until find a point in which shoes starts to slide, find just before this point and measure the angle with a goniometer

Then use the equation u = tan(x)

97
Q

When walking instead of walking what does it do to the scaling force?

A

Halves it roughly

108
Q

How do you get mass in vertical jump and what do you call grid?

A

Create scaling factor

Calculate mass from body weight line (/9.81)

Human Biosciences (69 decks)

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