Midterm #1 Flashcards
(148 cards)
1
Q
biomechanics
A
science concerned with effects of forcs in human body
2
Q
topics in biomechanics
A
rigid body mechanics
tissue mechanics
fluid mechanics
3
Q
what is the perspective of biomechanics
A
description of motion
cause of motion
effects of motion on musculo skeletal tissue
4
Q
steps of motion analysis
A
description
observation
evaluation
instruction
5
Q
phases of an activity description
A
preperation
execution
follow-through
6
Q
elements of observation
A
best viewing angle # of viewing angles distance equipment location equipment
7
Q
evaluation of an activity
A
identify errors evaluate errors (cause, impact, safety)
8
Q
instruction
A
feedback
keep, stop, start
9
Q
different types of planes to desxribe motion
A
sagittal plane
frontal plane
transverse plane
10
Q
where does movement occur
A
inside planes and around axes
11
Q
three axes around which motion occurs
A
mediolateral axis
anterior-posterior axis
vertical/longitudinal/superior - inferior axis
12
Q
what motions occur in the sagittal plane
A
flexion - extension
thumb abduction adduction
foot plantar flexion and dorsiflexion
13
Q
which axis is related to sagittal plane motion
A
mediolateral axis
14
Q
what motions occure in the frontal plane
A
abduction - adduction
trunk and head lateral flexion
hand - ulnar and radial deviation
15
Q
which axis is related to frontal plane motion
A
anterior-posterior axis
16
Q
abduction
A
movement away from the midline
17
Q
adduction
A
movement towards the midline
18
Q
what motion occurs in the transverse plane?
A
internal - external rotation
right - left rotation
pronation - supination
19
Q
what axis is related to motion in the transverse plane
A
logitudinal/inferion - posterior axis
20
Q
internal rotation
A
limb rotates towards midline of body
21
Q
external rotation
A
limb rotates towards outside of body
22
Q
what motion is in the hip/coxafemoral joint possible
A
flexion - extension
abdution - adduction
internal - external rotation
23
Q
what motion is in the knee/tibiofemoral joint available
A
flexion - extension
internal - external rotation (only in flexed mosition)
24
Q
what motion is in the ankle/talocrural joint available
A
plantarflexion
dorsiflexion
25
what motion is in the subtalar joint available
inversion - eversion
| abduction - adduction
26
what motion is in the Metatarsophalangeal Joints available
flexion - extention
| abduction - adduction
27
what motion is in the interphalangeal joint available
flexion - extenion
28
what motion is in the shoulder/glenohumeral joint available
flexion - extension
abduction - adduction
internal - external rotation
29
what motion is in the elbow/humeroulnar joint available
flexion - extenion
30
radio - ulnar joint
pronation - supination
31
what motion is in the wrist/radiocarpal joint available
flexion - extension
| radial deviation - ulnar deviation
32
what motion is in the metacarpophalangeal joint available
flexion - extension
| abduction - adduction
33
what are motions in the vertebra
flexion - extension
lateral flexion
right - left rotation
34
what is circumdauction
a combination of motions
| not rotation
35
what are dorsal and ventral
dorsal: towards the back
ventral: towards the abdomen
same as anterior and posterior for humans
36
what does linear kinematics describe
linear movements
37
what are movements in a straight line called
linear or translatory
38
subdivisions of translatory motion
rectilinear - motion in a straight line
| curvilinear - not circles, but curved line
39
what is rotary motion called
angular
40
definition of angular motion
movement in circular manner, maintains distance around a fixed point
41
what kind of motion is human movement predominantly known as
joints: angular
center of gravity: curvilinear
head: linear
42
general motion
combination of rotary and translatory motion
43
how is motion described
distance
speed
acceleration
44
what needs to be taken into consideration when describing movement
entire body or one system
| frame of reference
45
what does a frame of reference include
origin
direction
position (where is body located)
46
defintions of quantities
scalar
| vector
47
scalar
size of magnitude only
| temperature, time, weight...
48
vector
magnitude and direction of motion
| running, throwing, swimming...
49
how can the distance between two points be described as
displacement
distance
measured in meters, miles, feet or yards
50
distance
can be a curved path
| scalar quantity
51
displacement
shortest path between two points
| vector quantity
52
rate of changed
how quickly a value is increasing or decreasing with time
53
quatity of time
scalar
54
what is valocity (geschwindigkeit)
vector
| displacement per unit of time
55
what is acceleration
change in velocity over time
speeding up, slowing down or changing directions
scalar and vector
56
3 different types of aacceleration
positive
negative
zero
57
when is acceleration positive
when motion is positiv from starting point and speed increases
when motion negative from starting point and speed decreases
58
when is acceleration negative
slwoing down in positive direction
| speeding up in negative direction
59
which kinematic variables are scalar
distance
speed
acceleration
60
which kinematic variables are verctor
displacement
velocity
acceleration
61
what is a projectile
an airborne body
| only subjected to gravity and wind after leaving the ground
62
trajectory
path of a projectile
63
apex
highest point of a trajectory
64
range
horizontal displacement of a projectile
65
what is the velocity of a vertical throw
decreasing from bottom to apex
increases from apex to bottom
0 at apex
66
acceleration of a vertical throw
when ball is travelling up - acceleration -9.81
| when travelling down acceleration is also -9.81
67
what causes acceleration in vertical direction
gravity
68
acceleration for a constant motion after leaving the hand
1
| motion in horizontal direction is constant
69
realtion between motion in vertical and horizntal motion
both motions are independent of each other but form together a parabola
70
what determines the motion of a projectile to make the trajectory predictable
initial position/height
initial velocity
angle at takeoff
71
what can the angle of takeoff be used for
to predict the behavior of projectile that has a parabolic trajectory
72
what kind of technique is used to measure the angle of take-off
trigonometric technique
| SOH, CAH. TOA
73
what is important regarding a max time in air for athletetic performance
large initial vertical velocity compred to horizontal
above 45 angle, ideal 90
highest vertical position
74
what is important regarding the minimum time in air for athletic performance
initial upward vertical velocity of ball is minimized
| projection angle less than 45 somtimes less than 0 degrees
75
what is important regarding the peak hight of an objectt in athletic performance
max initial height
max initial vertical verlocity
angle of projection above 45
76
what is important regardign max horizontal displacement
max time in air
combine horizontal and vertical verlocity
angle between 0 and 90
the higher the hgiht of release, and the more air resistance upward force, the lower the projection angle can be
77
what is angular displacement
change in absolute angular position experienced by a rotating line
angle formed between t´final and intial postion
78
what is angular displacment measured with
radian theta
79
how do you convert degrees to radians and vis versa
degrees to radians: multiplay# of dregrres by pie/180
| radians to degrees: multiply # of radians by 180/pie
80
what does l, r and d represent in angular and linear displacement
l: distance travelled by point of rotating object
r: radius
d: linear displacement
81
what is angular velocity
how fast an object changes its angular position
=angular displacement/time
expressed as radians/degrees per sec
a vector quantity
82
angular acceleration
rate of change of angular velocity
83
what is used to determine the direction of angular acceleration
right hand thumb rule
84
list of linear kinematics
displacement
velocity
acceleration
85
list of angular kinematics
displacement
velocity
acceleration
86
general rules regarding angular kinematics
max velocity occures mid movement
zero velocity at change of direction
max acceleration occurs to initial movement
zero acceleration at point of constant velocity (max velocity)
87
what is force
push or pull
can cause an object to start moving, stop, speed up, slow down, or chnage direction
comes in pairs: action - reaction
88
what unit is used to measure force
newton (N)
89
what is 1 N
force require to accelerate 1kg mass by 1M/s(square)
90
how much newton is 1 pound
4.448N
91
what rules does force follow
point of application
direction (line of action)
sense (push or pull)
magnitude
92
different classifications of force
internal- and external force
93
internal forces
act within the system
| muscles, tendons, bones, cartilage
94
external forces
interaction with environment
contact - ground reaction force
noncontact - gravity
95
point of application, direction, sense, and magnitude for muscle force
muscle attachement
along fibers
pulling on distal attachement
muscle length
96
what is gravity
force hat pulls to objects (weight towards center of earth) towards each other
97
point of application, direction, sense, and magnitude for force of gravity on earth
center of mass
vertical
towards earth
depends on mass
98
what is normal contact force
force applied by surface on object
| always perpendicular to surface
99
what is friction force
force resisting the motion of two solid surfaces against each other
100
direction of friction force
along the surface and opposite to direction of intended motion
101
ground reaction force
when body contacts ground, ground pushes back
| applied to part that contacts ground
102
point of application of ground reaction force
point of contact body´s center of pressure
103
magnitude and direction or ground reaction force
same as force applied to ground
104
what is ground reaction force a resultant of
2 horzontal, 1 vertical component
| can be desolved into normal contact force (vertical) + friction force (horizontal)
105
sense of ground reaction force
opposite to force applied to ground
106
tension force
pulls on body, e.g. slong a cord
| force away from body
107
what is a free body diagram used for
describes forces acting on body
| narrows used to describe forces
108
what is pressure
force distributed over an area
109
units of pressure
N/m(square)
110
what is torque
tendancy of a force to rotate an object about an axis, fulcrum, or pivot
111
moment arm
distance necessary for torque to rotate an object around a fixed axis
is perpendicular to center of rotation
112
examples of external torque
resistance torque
| gravitational torque
113
examples of internal torque
motive torque
effort torque
muscular torque
114
external torque
force that causes rotation
applied at perpendicular distance from axis
force applied to body from outside
115
calculation of external torque
external force x external moment arm
116
calculation of internal torque
internal force x internal moment arm
117
internal moment arm
perpendicular distance between muscle force and joint center
118
when is a free body diagram in static equilibrium
when the sum of torque = 0
| flexor torque = extensor torque
119
1st class lever
muscle force and external force on opposite sides of the center of rotation
example: neck extensors
120
2nd class lever
external force closer to axis than muscle force
IMA > EMA
example: standing on tip toes
121
3rd class lever
muscle force closer to axis than external force
IMA < EMA
example: most muscles
122
what is inertia
resistance of an object to any change in its state of motion
123
law of inertia
body remains in rest or constant linear velocity force by an external force to change state
124
static equilibrium
linear and rotational velocities = 0
| body not moving
125
dynamic equilibrium
linear and rotational velocities not 0 but constant
| body is moving at constant pace
126
relationship between inertia and mass
inertia is proportional to mass
127
law of acceleration
linear acceleration of body is proportional to force that causes it
inversely prportional to mass of body
128
what does accelerating an object result in
change in velocity
| change in displacement
129
equation for force
```
force = mass x acceleration
F= ma
force = maxx x velocity/time
```
130
what causes the change in the momentum of a body
an impulse
impulse = momentum
(force x time = mass x velocity)
131
what is an impulse
force x time
| force applied over a period of time
132
what is momentum
quantity of motion a body possesses
| momentum = mass x velocity
133
law of reaction
for every force there is an equal and opposite directed force
134
according to the law of reaction when does an object speed up, slow down and is constant
speed up: when impulse that pushes forward is larger
slow down: posterior directed impulse is larger
constant: both impulses are the same
135
what is energy
state of matter that makes things change
| scalar quantity
136
how can energy be conserved
can be transformed
| an be transferred
137
kinetic energy
associated with sate of motion
| 0 when object is stationary
138
potential energy
energy a body has with potential to change something. but doesn´t currently
139
different types of potential energy
gravitational potential energy
| strain potential energy
140
gravitational potential energy
potential energy a body has due to its position
141
strain potential energy
energy body has due to its deformation
142
what is work
process of changing the amount of energy in a system
scalar quantity
only occurs with a displacement
force x displacement
143
unit of energy and work
Joules (J)
144
what is positive work force
force and displacement are in same direction
| energy enters system
145
what is negative work force
force and dispalcement are in opposite directions
| energy leaving system
146
what does the work eneryg relationship describe
change in kinetic energy caused by a force applied of a given displacement
147
what is power
rate of performing work
148
calculation of power
average power = work/time
| instantaneous linear power = force x velocity
