Final Flashcards
(108 cards)
1
Q
What is a dynamic fluid force
A
a force caused by movement through a fluid
2
Q
what are the two kinds of dynamic fluid force
A
Drag force and lift force
3
Q
What is Drag force?
A
The part of dynamic fluid force that acts in the direction opposite to the movement of the object through the fluid
4
Q
What are the two components of drag force
A
Form drag and surface drag
5
Q
what is form drag?
A
the portion of drag force that is due to the molecules of the fluid hitting the object
6
Q
What is surface drag
A
The portion of drag force that is due to the friction between the object and the fluid moving past it
7
Q
How do you find terminal velocity
A
When the force of gravity is equal to the drag force
8
Q
What is lift force
A
it’s the force applied on the object that is perpendicular to the direction of travel
9
Q
How is lift force caused
A
the object hits the fluid down at a certain angle and the fluid pushes back in the same direction.
It is also caused by bernoulli’s principle
10
Q
What is bernoullis principle
A
Faster moving fluids exert less pressure than slower moving fluids.
So when molecules on one side of an object move faster than the molecules on the other side the object feels the lift force to the side with the faster moving molecules
11
Q
What is the magnus affect
A
It talks about lift force that occurs with a spinning object. If an object is rotating, one side will be spinning against the direction of fluid flow and the other side will be spinning with the fluid flow. the side that spins against the fluid flow will have greater pressure than the side spinning with the fluid flow. So the object will move toward the low pressure side
12
Q
What are the four facts about buoyant force
A
- It results from immersion in a fluid
- Acts upward on the object
- Acts at the center of volume
4, Magnitude is equal to the weight of the fluid displaced
13
Q
What is the specific gravity
A
The ratio between an objects weight, and the weight of the same volume of water
14
Q
What does the C, p, A, and v stand for in the drag force equation
A
C = coefficient of drag p = density of the fliud A = area of the object v = relative velocity
15
Q
What are the densities of Water and Air
A
Air = 1 Kg per meter cubed Water = 1000 Kg per meter cubed
16
Q
What is the most important variable in the drag force equation
A
Relative velocity
17
Q
What determines the coefficient of drag
A
surface (smooth or rough ( rough increases it))
Shape of the object
18
Q
What is laminar flow
A
Flow that travels in parallel lines, this is what people try to get for better velocity
19
Q
What is turbulent flow
A
Flow that is all kind of messed up. This can be created behind an unaerodynamic object, creating low pressure behind the object which pulls it backward.
20
Q
how do you find the force of GraPlastvity
A
Mass * Gravity * sin angle
21
Q
Understand how a tail wind and a head wind matter
A
it its a head wind you take if off of the total force, if it is a tailwind you add it to the total force
22
Q
What are the specific gravities of bone water muscle and fat
A
Bone = 1.15 Water = 1 Muscle = 1.05 Fat = .9
23
Q
What does laminar and turbulent flow impact
A
form drag
24
Q
What are the three primary functions of the skeletal system
A
- Leverage
- Support
- Protection
25
What is the purpose of the load deformation curve
It shows how much an object deforms with an increasing load
26
What are the important parts of the load deformation curve
Elastic Region
Yield point
Plastic region
Failure point
27
What is the elastic region of the load deformation curve
its the area in the graph during which if the load is removed the object will return back to its original shape without any deformation
28
What is the yield point of the load deformation curve
its the point at which the load is too high and the object becomes to deformed to return to its original shape
29
What is the plastic region of the load deformation curve
The area in the graph for which any increased load leads to deformation that can't be undone
30
What is the failure point
the point at which the load is too great and the object can't bear any more load
31
What does the slope of the slope deformation curve represent
the stifness of the object
32
What is compliance
the opposite of stiffness
33
What is the integral of the load deformation curve
Change in energy
34
What is stress
the normalized version of load (normalized to cross sectional area)
35
What is strain
The normalized version of deformation ( normalized to original length)
36
How is stifness measured
stress over strain
37
What is strentgh
the peak load a structure can bear
38
what is anisotropic character of bone
The fact that certain structures respond differently to loads in different directions
39
What are the three principle stresses
Tension
Compression
Shear
40
What is tension
A stress that acts on the long axis of the bone, tends to elongate the bone
41
What is compression
a stress that acts on the long axis of the bone, tends to shorten the bone
42
What is Shear
a stress that is perpendicular to the long axis of the bone
43
What is the viscoelastic property of bone
The fact that bone responds to loads of equal magnitude of different rates.
44
Were humans built for high loading rates or low loading rates
high
45
what kind of loads do we bear best and worst
Compression best
| shear worst
46
What is the approximate composition of bone and what does it do
50% minerals - provides compressive strength and stiffness (Mostly calcium)
25% collagen - provides tensile strength and stiffness
25% water - compressive strength and help it heal
47
What are the two types of bone
cortical (hard)
| cancellus (soft)
48
What are the types of bone cells and what do they do
osteocyte - Bone cell
osteoblast - Bone builder
osteoclast - Bone destroyer
49
What is the normal balance of osteoblasts and osteoclasts
They equally work under normal condition. They are always going. bone Growth = bone resorption
50
What is wolffs law
Bone mass will replace itself in the direction and magnitude of the forces on the bone
51
What kinds of exercises help build strong bones
workouts with high loads and high frequency
52
What is osteopenia
Reduces bone mineral density (less severe)
53
What is osteoporosis
Reduced bone mineral density (more severe)
54
Who is more likely to suffer from osteoporosis
Women
55
What is muscle force
The amount of force a muscle contraction creates
56
What is human strength
The ability to produce torque
57
What influences a muscles ability to produce muscle force
1. Cross Sectional Area
2. Muscle design
3. Fiber length
4. Contraction velocity
5. Fiber type
6. Neural factors
58
What is hypertrophy and hyperplasia
Hypertrophy is muscle fibers get bigger
| Hyperplasia is getting more muscle fibers (humans don't do this)
59
how can muscle design affect force
1. In series or parralel
- Series - greater ROM , less force
- Parallel - Less Range of motion , greater force
2. Pennation angle
- the greater the pennation angle, the greater the force and the less ROM.
60
What is Excursion
how much motion the muscle gets
61
Why does pennation increase force
you can fit more muscle fibers in,
62
How does fiber length affect force
The right amount of myosin actin overlap gives more force than too far stretched or too compressed
63
At what length does tension usually peak out
resting length or 120% of resting length
64
How does contraction velocity affect muscle strength
faster eccentric contractions produce the greatest force
65
How does fiber type affect muscle strength
fast twitch fibers lead to more force
66
How do neural factors affect muscle strength
higher firing rate = higher force
| more muscle fibers recruited = more force
67
What can EMG do for us
1. Help us understand when muscles are active
2. help us determine how active muscles are
3. can help us determine contraction type (eccentric or concentric)
4. can help us learn about muscle fatigue
68
what is passive muscle tension
the tension caused by the strecthing of connective tissue
69
what are the two EMG types
surface
| indwelling
70
What are the two types of gait analysis
Qualitative and quantitative
71
What are the advantages to the different types of gait analysis
```
Qualitative
- Easy, Fast, cheap
- Easier to interpret
Quantitative
- Very precise
- Easier to compare
```
72
What makes up a gait cycle
Heel strike to the next heel strike of the same foot
73
What are the phases of the gait cycle
Stance phase - From heel strike to toe off (60%)
Swing phase - From toe off to heel strike (40%)
Wait acceptace = 0-10%
Single limb support = 10-50%
Double limb support = 50-60%
Swing = 60 - 100%
74
What is a stride
left heel strike to left heel strike
75
What is a step
left heel strike to right heel strike
76
What are the four parts of a qualitative biomechanical analysis
1. Description
2. Observation
3. Evaluation
4. Instruction
77
What do we need to be able to do to do a qualitative biomechanical analysis
1. Choose a skill
2. Describe the purpose using everyday terms
3, Describe the purpose using biomechanical terms
4. List what must be done to perform most effectively
78
From what angle is it generally best to observe from
perpendicular to the plane of motion
79
What needs to be considered when observing
1. level of athelete to observe
2. competition or practice
3. what to look for
80
What needs to be considered when evaluating
1. Does the error lead to injury
2. how correctable is the error
3. is the error the result of another error
4. how impactful is the error
5. is the error due to the equipment
6. is the error due to inadequate strength
81
What needs to be considered when instructing
1. Be positive, simple, and specific
2. focus on one error at a time
3. Recognize that a decrease in performance will occur
82
What is the principle of specificity
The best way to improve an action is by doing it
83
How can one best improve a specific action
by doing it, and chosing exercises that mimic the activity
1. angular displacement
2. angular velocity
3. muscle action type
4. external force magnitude
84
Be able to identify whether a skill is more technical or physical
Because that helps know how to train for it
85
how do you train for a technical skill
practice good technique
| break the skill down (small toss)
86
How do you train for a physical skill
Improve your physical condition
- identify what anatomy to work on
- do the skill (long distance running)
87
What are the steps for a qualitative anatomic analysis
1. Temporal phases
2. Joint motions during each phase
3. Muscle action types for each phase
4. High accelerations for each phase
5. Extreme range of motion for each phase
Then design a training program
88
How do you create a training program after having done the qualitative anatomic analysis
1. List the physical and technical requirements
2. Decide which requirement gets priority
3. How to address each requirement
4. Include the actual activity in your training
89
What are the 6 characteristics of force that can influence injury
1. MAGNITUDE
2. Area of force application (pressure)
3. Load rate
4. Force direction
5. Force application location
6. Force frequency
90
What is a good way to cause injury
high stress high frequency activities
91
What is the difference between stress and distress
Stress is when the damaging of the tissue is going slower than the remodeling of that tissue
Distress is when the damaging of the tissue is going faster than the remodeling of that tissue
Distress is bad (you can work someone too hard)
92
What are intrinsic factors that can influence injury risk
1. Body Mass
2. Skeletal (density, alignment, asymmetry)
3. Muscular (strength, endurance, firing patterns)
4. Previous history of injury
5. psychological (motivation and tolerance)
93
What are extrinsic factors that can influence injury risk
1. nature of task (frequency, speed, intensity)
2. Level of participation
3. equipment
4. environment
94
Can you describe some ways to decrease injuries for a sport
manipulate the intrinsic and extrinsic factors
95
What is the kinematics for the hip during a gait cycle
20 degree flexion at heel strike
20 degree hyperextension and toe off
20 degree flexion at heel strike
96
What are the kinetics for the hip during the gait cycle
extension torque during the stance phase
| flexion during the swing phase
97
What are the kinematics for the knee during the gait cycle
Extended at heel strike
flexed slightly throughout stance phase
increase in flexion during first half of swing phase, then it decreases until it is fully extended at heel strike
98
What are the kinetics for the knee during the gait cycle
Extension torque throughout stance phase
| neutral during swing phase
99
What are the kinematics for the ankle during the gait cycle
Neutral at heel strike
Plantar flexes slightly after
transitions to max dorsi flexion slightly before toe off begins
Lots of plantar flexion at toe off
100
What are the kinetics for the ankle during the gait cycle
Dorsiflexion from heel strike to 50% of stance
| plantar flexion from 50% to toe off
101
What are the muscle actions for the hip during the gait cycle
hamstrings and glutes are working concentrically during stance pahse
Quads are working concentrically during swing phase
102
What are the muscle action for the knee during the gait cycle
Quads are working eccentrically from heel strike to just before toe off where it transfers to concentric activity
Muscles are quiet during swing phase
103
What are the muscle actions for the ankle during the gait cycle
Dorsiflexors work eccentrically at heel strike until your foot hits flat, then they work concentrically until 50% of stance, then plantar flexors work eccentrically until your heel leaves the ground just before toe off. then they work concentrically until toe off
104
Rundown of reading 1
Infused hypertonic saline into knee to see how it runners ran when they had knee pain.
They found that it did mimic knee pain and that runners do run different with knee pain.
It's important because running with knee pain may lead to further injury
105
Rundown of reading 2
A cats terminal velocity is much less than a humans because of the way they fall, it increases their surface area for more drag force
I can use this info by creating more surface area if I want to slow down, or decrease it if I want to speed up
106
Rundown of reading 3
There is a push to optimize peak bone mass when you are young because at a certain age (30ish) it will begin to steadily decline. People who just begin to do weight bearing exercise can get more bone growth because it's new for them, and they haven't amassed as much yet.
107
Rundown of Reading 4
cocontraction of the quads and hamstrings were the dependent variables.
The study was done to see the differences in cocontraction between men and women because woman are far more proned to tearing thier ACL than men.
108
What does the big E stand for
Stiffness
