Week 1 Flashcards
(199 cards)
1
Q
The human movement system comprises the ____ and ____ that interact to ____
A
The human movement system comprises the anatomic structures and physiologic functions that interact to move the body or its components
2
Q
___ is the core of physical therapy practice, and research
A
The human movement system is the core of physical therapy practice, and research
3
Q
What are the basic requirements of a human movement system practitioner?
A
- An in depth, integrative knowledge of the human movement system and its component elements (anatomical structures and physiological functions)
- The ability to evaluate and diagnose in the clinical setting through skilled observation and instrumentation.
- The ability to identify physical impairments across various body systems that may be contributing to dysfunctional movement
- The ability to design an intervention program to address underlying impairments and directly address movement dysfunction
4
Q
What are the 3 primary ways the PTs function in the management of the movement system of the patient?
A
- Distinctive knowledge and expertise
- Examination, evaluation, and integration
- Optimization through intervention
5
Q
___ and ___ come together to form biomechanics
A
The human movement system and movement science come together to form biomechanics
6
Q
What is biomechanics?
A
The study of biological systems using principle physics.
7
Q
What are the newton’s law of motion?
A
- Law of inertia
- Law of acceleration
- Law of action-reaction
8
Q
What does the law of inertia state?
A
An object will remain at rest or in uniform motion unless acted upon by an unbalanced force
9
Q
What does the law of acceleration state?
A
Acceleration of an object is proportional to the unbalanced forces acting upon it and inversely proportional to the mass of the object
10
Q
What does the law of action-reaction state?
A
For every action, there is an equal and opposite reaction
11
Q
The 3 newton’s laws form the foundations for ___
A
The 3 newton’s laws form the foundations for classical mechanics
12
Q
Classical mechanics is concerned with ___
A
Classical mechanics is concerned with *describing the motions of bodies under the action of a system of forces
13
Q
What are the two main branches of classical mechanics?
A
- Kinematics
- Kinetics
14
Q
What is kinematics?
A
Set of concepts that allows for description of the displacement or motion of the body and/or its segments without regard to the
forces that cause the movement
15
Q
What is displacement?
A
Changes in position over time
16
Q
What is kinetics?
A
Set of concepts that deals with forces that produce, stop or
modify motion of either the body as a whole or the individual body segments
17
Q
What is force?
A
A push or pull exerted by one object or substance on another
18
Q
What are the kinematic variables used in describing displacement?
A
- Type
- Rate
- Magnitude
- Direction
- Location
19
Q
What are the types of displacement?
A
- Translatory motion
- Rotatory motion
20
Q
___ occurs as movement of a body segment in a straight line. Here, each point on the segment moves through the same distance, at the same time, in parallel paths
A
Translatory motion occurs as movement of a body segment in a straight line. Here, each point on the segment moves through the same distance, at the same time, in parallel paths
21
Q
___ occurs as movement of a body segment around a fixed axis in a curved path
A
Rotatory motion/ center of rotation on a curved path occurs as movement of a body segment around a fixed axis in a curved path
22
Q
What is an example of a translatory motion?
A
The anterior translation of the tibia on the femur when doing an anterior drawer test
23
Q
____ is motion occurring as a combination of rotation and translation
A
General motion is motion occurring as a combination of rotation and translation
24
Q
Motions of body segments are
rarely sufficiently constrained
to produce pure ___
A
Motions of body segments are
rarely sufficiently constrained
to produce pure rotatory
motion
25
Most joint rotations take place
| around a series of ___
Most joint rotations take place
around a series of
*instantaneous centers of
rotation*
26
____ is general motion occurring as a combination of
translation and rotation in
two dimensions
*Curvilinear motion* is general motion occurring as a combination of translation and rotation in two dimensions
27
____ is the general motion in
which a body segment moves
across all three dimensions
*3-dimensional motion* is the general motion in which a body segment moves across all three dimensions
28
What is an example of curvilinear motion?
The motion that occurs in the elbow when picking up a glass to drink
29
How is the location of displacement in space described?
- Coronal axis (x-axis)
- Vertical axis (y-axis)
- Anteroposterior axis (z-axis)
30
Movement in the coronal axis occurs in which direction?
Side to side
31
Movement in the vertical axis occurs in which direction?
Up and down
32
Movement in the anteroposterior axis occurs in which direction?
Front to back
33
The number of axis about which a joint moves is referred to as ___
The number of axis about which a joint moves is referred to as *degrees of freedom*
34
What is the maximum possible degrees of freedom with rotation and translation occurring around each of the 3 axis?
6 degrees
35
Rotation moves in or parallel to ___
Rotation moves in or parallel to *cardinal planes*
36
What are the 3 cardinal planes?
- Sagittal plane
- Coronal plane
- Transverse plane
37
True or false
Rotation and translation of body segments are not limited to motion along or around cardinal axis or within cardinal planes
True
38
____ deals with the quantity of motion through which a body segment moves or is able to move
*Magnitude of displacement* deals with the quantity of motion through which a body segment moves or is able to move
39
____ results in angular displacement and is commonly measured in degrees through goniometry
*Rotatory motion* results in angular displacement and is commonly measured in degrees through goniometry
40
____ results in linear displacement and is measured in units of distance
*Translatory motion* results in linear displacement and is measured in units of distance
41
___ is the rate of change in position of a body segment
*Rate of displacement* is the rate of change in position of a body segment
42
___ is the displacement per unit time regardless of direction
*Speed* is the displacement per unit time regardless of direction
43
___ is the displacement per unit time in a given direction
*Velocity* is the displacement per unit time in a given direction
44
___ is a change in velocity per unit time
*Acceleration* is a change in velocity per unit time
45
___ is the velocity of a rotating segment and is expressed as ___
*Angular velocity* is the velocity of a rotating segment and is expressed as *degrees/sec*
46
___ help PTs define and describe the qualitative and quantitative motions
*Kinematic concepts* help PTs define and describe the qualitative and quantitative motions
47
What is range of motion?
The amount of motion available
to a joint (aka. magnitude of displacement) within the
anatomic limits of the joint structure
48
____ is excessive range of motion compared to normal limits
*Hypermobility* is excessive range of motion compared to normal limits
49
Hypermobility at its extreme can be associated with ___ and ____
Hypermobility at its extreme can be associated with *instability and dislocation*
50
Hypomobility is ___
Hypomobility is limited ROM compared to normal limits
51
What are the potential causes of hypomobility?
- Joint contraction
| - Muscle shortness
52
What are the positional consideration in joints and joint function?
- Loose packed position
| - Close-packed position
53
____ is the position of minimum congruency between joint surfaces, where there is the greatest slack between the ligaments and capsules of the joint.
*Loose packed position* is the position of minimum congruency between joint surfaces, where there is the greatest slack between the ligaments and capsules of the joint.
54
The joint surfaces of a loose packed position are ____. The intra articular volume is ___
The joint surfaces of a loose packed position are *unlocked*. The intra articular volume is *maximized*
55
The loose packed position is statically ____ for load bearing as it requires maximum muscular activity to maintain, and dynamically ___ due to the ability to accommodate unexpected perturbations without joint injury
The loose packed position is statically *inefficient* for load bearing as it requires maximum muscular activity to maintain and dynamically *Safe* due to the ability to accommodate unexpected perturbations without joint injury
56
____ is the position of maximum congruency between joint surfaces, where there is the greatest tension between the ligaments and capsules of the joint.
*Close-packed position* is the position of maximum congruency between joint surfaces, where there is the greatest tension between the ligaments and capsules of the joint.
57
The joint surfaces of a close packed position are ____, via
| phenomenon called ___. The intra articular volume is ___
The joint surfaces of a close packed position are *locked*, via phenomenon called *conjunct rotation*.The intra articular volume is *minimized*
58
The close packed position is statically ____ for load bearing as it requires minimal muscular activity to maintain and dynamically ___ due to the limited ability to accommodate unexpected perturbations without joint injury
The close packed position is statically *efficient* for load bearing as it requires minimal muscular activity to maintain and dynamically *dangerous* due to the limited ability to accommodate unexpected perturbations without joint injury
59
_____ refers to movement of bones in space during physiologic joint motion. This is observable and able to be described with respect to plane, axis, and direction
*Osteokinematics* refers to movement of bones in space during physiologic joint motion. This is observable and able to be described with respect to plane, axis, and direction
60
What is arthrokinematics, what does it accompany and what is it also known as?
The movement of
joint surfaces relative to one
another. Accompanies voluntary osteokinematic movement, but cannot be voluntarily isolated under normal conditions. Also known as accessory mobility or joint play
61
____ is an arthrokinematic motion where one point of one surface comes in contact with many points on another surface. It is also known as translation
*Slide* is an arthrokinematic motion where one point of one surface comes in contact with many points on another surface. It is also known as translation
62
What is spin? it may also be referred to as ___
An arthrokinematic motion that occurs when one point of one surface is in contact with one point on another surface. it may also be referred to as *rotation*
63
___ is an arthrokinematic motion where various points on one surface comes in contact with many points on another surface. This occurs as a combination of ___ and ___
*Roll* is an arthrokinematic motion where various points on one surface comes in contact with many points on another surface. This occurs as a combination of *rotation and translation*
64
Combinations of rolling and sliding occur in order to maintain ____
Combinations of rolling and sliding occur in order to maintain *joint integrity*
65
The combination of arthrokinematic motions occurring at a particular joint depends on the ___
The combination of arthrokinematic motions occurring at a particular joint depends on the *shape of the articulating surfaces*
66
___ joint surfaces moving on ___ joint surfaces generally roll and slide in opposite directions
*Convex* joint surfaces moving on *concave* joint surfaces generally roll and slide in opposite directions
67
Concave joint surfaces moving on convex joint surfaces generally roll and slide in the ___ direction
Concave joint surfaces moving on convex joint surfaces generally roll and slide in the *same* direction
68
Convex-concave rules merely
describe the _____ pattern that minimizes the inherent migration of the center of the convex member in the direction of the roll
```
Convex-concave rules merely
describe the *arthrokinematic*
pattern that minimizes the
inherent migration of the center
of the convex member in the
direction of the roll
```
69
___ is characterized by magnitude and lacks direction
*Scalar* is characterized by magnitude and lacks direction
70
___ is characterized by magnitude and direction
*Vector* is characterized by magnitude and direction
71
Force is a ___ quantity
Force is a *vector* quantity
72
What are the 3 components considered for a force vector?
- Point of application
- Direction
- Magnitude
73
Where a force acts on the body or a body segment is the ___
Where a force acts on the body or a body segment is the *point of application*
74
The action line or arrow head represents the ___ of force
The action line or arrow head represents the *direction* of force
75
The length of vector represents the ___ of force
The length of vector represents the *magnitude* of force
76
What are the primary rule of forces?
- All forces on a body segment must come from something that is contacting that body segment
- Although magnitude may be small enough to disregard, anything that contacts a segment must create a force on that segment
- Gravity can be considered to be “touching” all objects
77
What are external forces? They can either ___ or ___ movement
Pushes or pulls on the body that arise from sources outside the body. They can either *facilitate or restrict* movement
78
____ are pushes or pulls on structures of the body that arise from the body’s own structures. Muscles ____ movement and ___ restricts movement
*Internal forces* are pushes or pulls on structures of the body that arise from the body’s own structures. Muscles *facilitate* movement and *ligaments* restricts movement
79
___ is the attraction of the
| mass of the earth for the mass of other objects
*Gravity* is the attraction of the
| mass of the earth for the mass of other objects
80
What is the center of gravity (CoG)/ center of mass (CoM)?
The hypothetical point at which all mass appears to be concentrated. The point at which gravity appears to act on an object
81
What is the line of gravity (LoG)?
The vector quantity representing force of gravity on an object at its center of gravity
82
The line of gravity is always directed ___ toward the center of the earth
The line of gravity is always directed *vertically downward* toward the center of the earth
83
Each individual body segment may be considered with respect to ____ segmental CoG
Each individual body segment may be considered with respect to *its own* segmental CoG
84
___ body segments may be combined with a resulting segmental CoG being considered
*Adjacent* body segments may be combined with a resulting segmental CoG being considered
85
Rearranging the segments being considered collectively, results in ___
Rearranging the segments being considered collectively, results in *a shift in the resulting segmental center of gravity*
86
CoG of human body lies approximately anterior to __
CoG of human body lies approximately anterior to *S2*
87
LoG extends vertically toward the center of the earth from the
CoG, with its magnitude being equal to ____
LoG extends vertically toward the center of the earth from the
CoG, with its magnitude being equal to *the weight of the individual*
88
Rearrangement of body segments will change the location of the ___ and ___
Rearrangement of body segments will change the location of the *CoG and LoG*
89
____ is defined by the part or parts of the body that are in contact with the ground
*Base of support *BoS* is defined by the part or parts of the body that are in contact with the ground
90
____ is maintained when the LoG is maintained within the BoS
*Stability* is maintained when the LoG is maintained within the BoS
91
The larger the ___ the greater the stability
The larger the *BoS* the greater the stability
92
The closer the ___ is to the
| BoS, the greater the stability
The closer the *CoG* is to the
| BoS, the greater the stability
93
Stability is compromised if the
| ___ is not located with the BoS
Stability is compromised if the
| *LoG* is not located with the BoS
94
Redistribution of mass shifts the location of the ___within the
___
Redistribution of mass shifts the location of the *CoG within the BoS*
95
Shift in CoG is proportional to the change in __
Shift in CoG is proportional to the change in *mass*
96
CoG shifts ___ mass that is added
CoG shifts *TOWARD* mass that is added
97
CoG shifts ___ from mass that is removed
CoG shifts *AWAY* from mass that is removed
98
Redistribution of mass can occur due to the changes in the internal mass as with ____ or with external mass as with _____
Redistribution of mass can occur due to the changes in the internal mass as with *weight gain/loss or amputation* or with external mass as with *the use of a cast, brace or prosthesis*
99
CoG shifts occur in what dimension?
CoG shifts occur in 3-dimension
100
What are ways to improve stability?
- Expanding the BoS. Ex: AD
- Bringing the LoG closer to the center of BoS
- Training to improve stability
101
How can the size and arrangement of BoS by manipulated?
- Bilateral stance
| - Unilateral stance
102
What are the things that can happen in the bilateral stance of BoS manipulation?
- Feet apart
- Feet together
- Tandem stance: placing one foot directly in front of the other to inc stability in one plane and decrease it in another plane
103
The __ the BoS, the ___ the demands to maintain stability
The *smaller* the BoS, the *greater* the demands to maintain stability
104
A tandem stance may increase stability in the ___ plane but reduce it in the ___ plane
A tandem stance may increase stability in the *sagittal plane* but reduce it in the *frontal plane*
105
What is the primary concern of kinetics?
The understanding of the effects that the forces will have on the body or body segments
106
____ occurs when all forces acting upon the body or body segments are balanced
*Equilibrium* occurs when all forces acting upon the body or body segments are balanced
107
___ occurs when all forces acting upon the body or body segments are not in balance
*Acceleration* occurs when all forces acting upon the body or body segments are not in balance
108
What is statics?
The study of conditions under which objects remain in equilibrium
109
What is dynamics?
The study of conditions under which objects do not remain in equilibrium
110
____ identifies conditions under which objects will be in equilibrium
* The law of inertia* identifies conditions under which objects will be in equilibrium
111
Equilibrium requires ___
Equilibrium requires that the sum of all forces and torques applied to an object be equal to 0
112
What is inertia?
The property of an object that
resists both the initiation of
linear motion and a change in
linear motion
113
Inertia is directly proportional to the ___
Inertia is directly proportional to the *mass of an object*
114
The moment of inertia is the
| ____
The moment of inertia is the
*property of an object that
resists rotatory motion and
changes in rotatory motion*
115
What are the 2 types of equilibrium?
Static and Dynamic equilibrium
116
What is static equilibrium?
The state of an object that is acted upon by balanced forces or torques and remains motionless
117
What is dynamic equilibrium?
The state of an object that is acted upon by balanced forces or torques and remains in uniform motion with constant speed and direction
118
___ equilibrium can involve linear, rotatory, or general motion and occurs very infrequently with segments of the human body
*Dynamic* equilibrium can involve linear, rotatory, or general motion and occurs very infrequently with segments of the human body
119
____ defines the magnitude of acceleration of a moving object
*Law of acceleration* defines the magnitude of acceleration of a moving object
120
Acceleration of an object is proportional to ____
Acceleration of an object is proportional to *the net forces or torques acting upon the object*
121
Acceleration of an object is inversely proportional to the ___
Acceleration of an object is inversely proportional to the *mass or moment of inertia of that object*
122
Because an object acted upon by a net unbalanced force
or torque must be accelerating, it is invariably in motion
or in a ____ state
Because an object acted upon by a net unbalanced force
or torque must be accelerating, it is invariably in motion
or in a *dynamic* state
123
The acceleration of an object will be in the direction of the
____
The acceleration of an object will be in the direction of the
*net unbalanced force or torque*
124
A net unbalanced force will
| produce ___ motion
A net unbalanced force will
| produce *translatory* motion
125
A net unbalanced torque will
| produce ___ motion
A net unbalanced torque will
| produce *rotatory* motion
126
What type of motion does a combination of unbalanced
| force and torque will produce?
General motion
127
Which motion is the most common type of motion in movement?
General motion
128
What is the composition of forces?
The process used to determine whether a net unbalanced force or forces exist on a segment
129
The composition of forces determines ___
The composition of forces determines *whether the segment is at rest or in motion*
130
When is the term normal force used?
When contact forces are perpendicular to the forces that produce them
131
____ forces are always in the same line and applied to the different but contacting objects.
*Reaction* forces are always in the same line and applied to the different but contacting objects.
132
The direction of ___ forces are always opposite to each other because the two touching objects either pull on each other or push on each other
The directions of *reaction forces* are always opposite
| to each other because the two touching objects either pull on each other or push on each other
133
___ forces are never part of the same force system and cannot be composed because the two forces are, by definition, applied to different objects
*Reaction* forces are never part of the same force system and cannot be composed because the two forces are, by definition, applied to different objects
134
___ forces are always equal in magnitude, opposite indirection, and applied parallel to the long axis of the object
*Tensile forces* are always equal in magnitude, opposite
| indirection, and applied parallel to the long axis of the object
135
____ forces are co-linear, coplanar, and applied to the same object, and are, therefore, part of the same linear force system
*Tensile forces* are co-linear, coplanar, and applied to the same object, and are, therefore, part of the same
linear force system
136
What is a distraction force?
A net force that moves a bony segment away from its adjacent bony segment
137
Distraction forces are ___ forces that create separation of joint surfaces
Distraction forces are *tensile* forces that create separation of joint surfaces
138
There must be a minimum of ____ distraction force on each joint segment
There must be a minimum of *one resultant* distraction force on each joint segment
139
Each distraction force must be __ to the joint surfaces, opposite in direction to the distraction force on the adjacent segment and directed away from its joint surface
Each distraction force must be *perpendicular* to the joint surfaces, opposite in direction to the distraction force on the adjacent segment and directed away from its joint surface
140
Joint distraction can be ___ through unequal or opposite acceleration of segments
Joint distraction can be *dynamic* through unequal or opposite acceleration of segments
141
Joint distraction can be ___ when the tensile forces in the tissues that join the segments are balanced by distraction forces of equal or greater magnitude
Joint distraction can be *static* when the tensile forces in the tissues that join the segments are balanced by distraction forces of equal or greater magnitude
142
What are joint reaction forces?
Contact forces that result
whenever two or more forces cause contact between
contiguous joint surfaces
143
____ forces create contact between joint surfaces
*Joint compression* forces create contact between joint surfaces
144
The acceleration of the ___ phase of joint distraction is very brief, unless the capsule and ligaments or muscles crossing the joints fail
The acceleration of the *dynamic* phase of joint distraction is very brief, unless the capsule and ligaments or muscles crossing the joints fail
145
What is the ground reaction force?
The reaction of the ground with the foot. As the body exerts its force upon the ground, the ground pushes back
146
Joint reaction forces are dependent on the ____
Joint reaction forces are dependent on the *existence of one force on each of the adjacent joint segments that is perpendicular to and directed towards the joint surface*
147
___ forces are the two forces that cause joint reaction forces. There must be a minimum of one on each contiguous joint surfaces
*Joint compression* forces are the two forces that cause joint reaction forces. There must be a minimum of one on each contiguous joint surfaces
148
___ forces are required to push joint surfaces together to produce joint reaction forces
*Joint compression* forces are required to push joint surfaces together to produce joint reaction forces
149
What happens when there is a net compression of joint surfaces resulting in joint reaction forces?
The capsule and ligaments at the joint are generally not under tension, as long as all forces are perpendicular to contacting surfaces
150
What are the two components that newton's law of inertia can be broken down into?
- Sum of vertical forces (Fv) acting on an object in equilibrium must total 0
- Sum of horizontal forces (Fh) acting on an object in equilibrium must total 0
151
Shear and friction forces exist when ___
Shear and friction forces exist when *two objects touch*
152
What is shear force?
Any force or component of a force that has an action line parallel to contacting surfaces or tangential to curved surfaces
153
___ forces creates or limits movement between surfaces
*Shear forces* forces creates or limits movement between surfaces
154
Shear forces are ___ to the component of the contact force that is perpendicular or normal to the contact surface
Shear forces are *perpendicular* to the component of the contact force that is perpendicular or normal to the contact surface
155
What is friction force?
Friction force is a force that potentially exist on an object whenever there is a contact force on that object, that is always parallel to contacting surfaces or tangential to curved surfaces that have a direction that is opposite to potential movement
156
What needs to happen for friction to have magnitude?
A net shear force that creates or attempts to create movement between objects must exist
157
The magnitude of a friction force on an object is always and only ____
The magnitude of a friction force on an object is always and only *a function of the magnitude of contact forces between the objects and the slipperiness or roughness of the contacting surfaces*
158
The potential friction generated between 2 objects is directly proportional to ____
The potential friction generated between 2 object is directly proportional to *the contact forces*
159
Why can friction forces be considered a special case of shear force?
Both forces are parallel to contacting surfaces and perpendicular to contact forces
160
Friction is the shear force that is __ to movement or potential movement
Friction is the shear force that is *opposite* to movement or potential movement
161
What is static friction?
Friction force occurring between two objects in contact
| that are not moving relative to one another
162
What is kinetic friction?
Friction force occurring between two objects in contact
| that are moving relative to one another
163
The maximum magnitude of static friction on each object is the product of ___
The maximum magnitude of static friction on each object is the product of *the coefficient of static friction and the magnitude of contact force on each object*
164
What happens to the coefficient of static friction as the contacting surfaces become softer or rougher?
It increases
165
Once an object is moving, the magnitude of the force of kinetic friction on the contacting objects is a constant value equal to the product of ___
Once an object is moving, the magnitude of the force of kinetic friction on the contacting objects is a constant value equal to the product of *contact force and the coefficient of kinetic friction*
166
The coefficient of kinetic friction is always ___ than the coefficient of static friction
The coefficient of kinetic friction is always *smaller* than the coefficient of static friction
167
What happens once the shear force has exceeded the maximum value of static friction?
The object will move, because of the net unbalanced force that occurs
168
What are pressure ulcers?
Localized injuries to the skin and/or underlying tissue
usually over a bony prominence, as a result of
pressure, or pressure in combination with shear
169
___ is a risk factor that may
| contribute to or exacerbate pressure ulcer development due to the shear it creates
*Friction* is a risk factor that may contribute to or exacerbate pressure ulcer development due to the shear it creates
170
What are some ways to reduce tissue shear and friction?
- Assist patients in adopting
stable postures using external
support when necessary
- Lower the head of hospital beds to reduce the chances of sliding down
- Assure proper fit, alignment and support when sitting to reduce the chances of sliding within chairs
- When repositioning patients, LIFT rather than DRAG a
patient’s and their body segments
171
What happens when the force applied to an unattached object does not pass through its center of mass?
A combination of translation and rotation results
172
What must happen to produce pure rotatory motion?
A 2nd force that is parallel to the original force must be applied to the object or segment
173
What is a force couple?
Two forces that are equal in magnitude, opposite in direction, parallel and applied to the same object at different points
174
If there are no other forces on an object, a force couple will always produce a ___
If there are no other forces on an object, a force couple will always produce a *pure rotatory motion*
175
Two forces of equal magnitude applied to an object in opposite directions constitute a force couple and will create rotation about a point ___
Two forces of equal magnitude applied to an object in opposite directions constitute a force couple and will create rotation about a point *midway
between the forces if both
points of application are free
to move*
176
Two forces of equal magnitude applied to an object in opposite directions constitute a force couple and will create rotation around the point of ____
Two forces of equal magnitude applied to an object in opposite directions constitute a force couple and will create rotation around the point of *application of one of the
forces if that point is fixed*
177
The strength of rotation produced by a force couple is known as ___/moment of force
The strength of rotation produced by a force couple is known as *torque*/moment of force
178
___ is the perpendicular distance between forces that produce a torque, or moment of force
*Moment arm (MA) is the perpendicular distance between forces that produce a torque, or moment of force
179
Torque is the product of ___
Torque is the product of *the magnitude of one of the forces and the shortest distance*
180
The shortest distance in torque is always the ___ distance
The shortest distance in torque is always the *perpendicular* distance
181
What sign is given to a torque that produces clockwise motion? And vice versa
A negative sign
182
Torque is directly proportional to both the ____ and the ___
Torque is directly proportional to both the *magnitude of the
applied force and the distance
between the force couple*
183
What is the result of an unbalanced torque?
Angular/rotatory acceleration
184
What is the result of a balanced torque?
Angular/rotatory equilibrium
185
What are the 3 conditions independently necessary for an object or segment to be completely at rest?
The sum of the vertical forces, horizontal forces, and torque must all equal 0
186
Whenever two or more forces applied to the same object are parallel to each other ___ exist
Whenever two or more forces applied to the same object are parallel to each other *a parallel force system* exist
187
What determines the torque generated by each force in a parallel force system?
Multiplying the magnitude by its distance/moment arm either from the point of constrain of the segment or an randomly chosen point on the segment as long as point is used in reference to all forces
188
What are considered to be bending moments?
The torques or moment of force applied to a particular point on the object
189
What is a bending moment?
A torque between two forces that compose a force couple
190
Bending moments on a segment that is not rotating are also known as ____
Bending moments on a segment that is not rotating are also known as *three point bending*
191
____ is sometimes considered a special case or subcategory of a torque whereby a so called torsional force creates/tends to create a rotation of the segment around its long axis
*Torsional moment* is sometimes considered a special case or subcategory of a torque whereby a so called torsional force creates/tends to create a rotation of the segment around its long axis
192
When a force creates a rotation of the body segment around its longitudinal joint axis, the resulting torque produces a ____
When a force creates a rotation of the body segment around its longitudinal joint axis, the resulting torque produces a *medial or lateral rotatory moment*
193
Torsion is used to describe a force on ___
Torsion is used to describe a force on *a single object rather than on 2*
194
Excessive torsional forces in long bones generate a particularly severe fracture called a ___
Excessive torsional forces in long bones generate a
| particularly severe fracture called a *spiral fracture*
195
The moment arm of a force is minimum when the _____
The moment arm of a force is minimum when the
*action line of the force passes through the center of
rotation of the segment to which the force is applied*
196
As the moment arm of a force increases, its potential to produce torque ___
As the moment arm of a force increases, its potential to produce torque *increases*
197
The moment arm of a force is maximum when the force is applied at ___
The moment arm of a force is maximum when the force is applied at *90 degrees to its segment*
198
What is the angle of application of a vector?
The angle made by the inner section of the force vector in the segment to which it is applied on the side of the joint axis of consideration
199
Regardless of the magnitude of the angle, the angle of application of force is identified to be on the side of the ___
Regardless of the magnitude of the angle, the angle of application of force is identified to be on the side of the *joint axis relative to the point of which the force is applied*
