Kinesiology-Intro Lecture And Biomechanics

Front 1

Biomechanics

Back 1

Application of mechanical principles to human and animal bodies in movement and in rest

Front 2

Kinematics

Back 2

description of motion without regard to the forces

time, acceleration, displacement, velocity, position

Front 3

kinetics

Back 3

describing moving bodies and the forces that produce motion

Front 4

statics

Back 4

study of forces acting on a body in equilibrium

no acceleration-at rest, moving with a constant velocity,

F=ma

Front 5

Dynamics

Back 5

Study of forces acting on a body not in equilibrium

acceleration

unbalanced forces

Front 6

Arthrology

Back 6

study of joints of the body

articulation
osteokinematics
arthrokinematics

Front 7

Arthrology-Articulation

Back 7

arthrology-articulation

joint
union of adjacent bones, whether they enjoy movement or not

Front 8

Arthrology

Osteokinematics

Back 8

osteokinematics

direction of movement of the distal segment of the joint

Front 9

arthrology

Arthrokinematics

Back 9

arthrokinematics-
Direction of movement of articular joint surfaces
-roll
-spin
-slide

Front 10

Anatomic body position

Back 10

stand erect with feet together
look forward
arms held at side
elbows extended
forearms supinated
wrist and fingers extended

Front 11

Planes-Frontal

Back 11

Frontal
aka-coronal or lateral
Divides body into anterior (ventral) and posterior (dorsal) parts

Front 12

Axis-Anteroposterior Axis

Back 12

Sagital
perpendicular to frontal plane
horizontal front to back

Front 13

Sagital Plane
coronal axis

Back 13

sagital plane- anteroposterior or median
divides body into right and left parts

Coronal-horizontal or lateral
perpendicular to sagital plane
horizontal side to side

Front 14

Transverse Plane
Longitudinal Axis

Back 14

Transverse Plane-horzontal
divides body into superior (cranial) and inferior(caudal) parts

Longitudinal Axis- vertical
perpendicular to transverse plane
perpendicular to ground

Front 15

Describing Anatomical Motion-Rule of Three

Back 15

Rule of three-
1.segment, moving on a
2.segment, moving on a
3.joint

eg. (action)- tibia flexing on the femur at the knee

Position- Tibia flexed on the femur at the knee

Front 16

Measurements
English
metric
english gravitational
SI

Back 16

English-foot,pound mass, second, poundal

Metric gravitational- meter, metric slug, second, kilogram force

English Gravitational-foot, slug, second, pound force

International system of units:SI
Meter, kilo, second, kelvin, radian

Front 17

Kinematics- Geometry of Motion

Back 17

Geometry of Motion
whole body motion
component lever motion

Front 18

Kinematics-Translatory Motion

Back 18

Translatory Motion- linear displacement
velocity
acceleration

Front 19

Kinematics- Rotary motion

Back 19

Rotary Motion
angular displacement
angular velocity
angular acceleration

Front 20

Kinematics- Linear Displacement

Back 20

Linear Displacement-
Vector quantity
-magnitude
-direction
---positive or negative

-meters, inches, etc.
Differs from distance
-distance is magnitude without direction

d=x(over time)- x(initial) ??

Front 21

Kinematics- Linear Velocity

Back 21

linear velocity
-rate of displacement
-vector quantity
---magnitude
---direction(positive or negative)

Differs from speed
-speed is a function of distance

As time approaches zero, velocity approaches instantaneous velocity

Front 22

Kinematics- Linear Acceleration

Back 22

Linear Acceleration
Rate of change in velocity (positive or negative-not deceleration)
can be... zero, constant, changing

Average acceleration- a=change in velocity divided by time

Front 23

Kinematics-Angular Displacement

Back 23

Angular Displacement
-magnitude of rotation
measured in...radians, degrees, revolutions

Theta
look on slide (page 3) (biomechanics)

Front 24

Kinematics-Angular Velocity

Back 24

Angular velocity
rate of change of angular displacement

as time approaches zero, w approaches instantaneous velocity

Average angular velocity
omega
w=displacement divided by time

Front 25

Kinematics-Angular Acceleration

Back 25

Angular Acceleration
rate of change in angular velocity (positive or negative, not deceleration)

can be... zero, constant, changing

Average acceleration

Alpha=change in velocity divided by time

Front 26

Kinematics- motion (def)

Back 26

motion- continuous change in position with respect to some reference point

object has been displaced

Front 27

Types of Motion

Back 27

Types of Motion

translatory (linear)
-rectilinear
-curvilinear (some consider this general motion)

Angular

General

Front 28

Translatory motion-rectilinear

Back 28

rectilinear- movement of an object or segment in a straight line
-all points move in parallel lines
-all points move at an equal velocity

Front 29

types of motion-translatory motion- curvilinear

Back 29

curvilinear-translatory motion along a curved path

Front 30

types of motion-Angular motion

Back 30

angular motion- movement of an object around a fixed axis

all points move at an equal angular velocity

all points move at a unique linear velocity

Front 31

types of motion- general ******* motion

Back 31

combination of translatory and angular motion.

rotation around a moving axis

Front 32

Measurement of motion (systems)

Back 32

coordinate and collection

Front 33

Measurement of motion (coordinate system)

Back 33

Coordinate system- descriptive terms
clinical
reference frames
cartesian

Front 34

Coordinate system-clinical

Back 34

clinical coordinate system

movement described in anatomic terms
-elbow flexion
-knee extension
-thoracolumbar rotation

Front 35

Coordinate system-reference frames

Back 35

reference frames-
movement described in relation to an anotomic landmark or an external landmark
-left rotation of L4 on L5
-gait
-flexion of the forearm on the humerous at the elbow

Front 36

Coordinate system (motion measurement)

Cartesian

Back 36

coordinate system-
Cartesian
x,y, and z planes and axes
transverse plane hip rotation
sagital plane knee flexion

Front 37

Collection system (measurement of motion)
Direct

Back 37

Direct-
goniomentry
--reliable
--valid
--high utility

electrogoniometry
--more reliable
--more valid
--lower utility

accelerometry
--measures acceleration of segment

digital camera systems

Front 38

measurement of motion- Collection system

Indirect

Back 38

Indirect
photography
--stop action
--measure off photo

Video Recorders
--multiple trials
--measure off video

Front 39

Goniometry

intratester vs. intertester

validity

Back 39

Gonia=angle
Metron=measure

Used to measure: total joint motion-range of motion

Particular joint angle
-joint position

intratester-same joint by same tester
intertester-same joint by different testers

validity-does the obtained measurement equal the actual angle

Front 40

Kinetics-Force

Back 40

Force-Mass times acceleration
push or pull
produces, or tends to produce, a change in the state of rest or motion of an object

A vector quantity
-units
--si: newton (Kg-m/sec squared)
US: pound

Front 41

Types of Forces: (4)

Back 41

Contact: force exerted by one object in direct contact with another

non-contact- force exerted by one object, without direct contact, on another object

external: forces arising from outside the body

internal: forces arising from within the body

Front 42

vectors

Back 42

need: point of application, action line, magnitude, direction

Front 43

Force systems:

Back 43

linear, concurrent, parallel, general

Front 44

Force systems:Linear

Back 44

Linear force system
forces acting on the same object in the same line

Front 45

Force systems: concurrent

Back 45

Concurrent:
forces acting on the same point but at different angles

three forces are necessary for equilibrium

Front 46

Force system:Parallel

Back 46

Parallel: forces acting on the same object but at different points

Front 47

Force systems: General

Back 47

General- forces acting on the same object across three planes

four forces required for equilibrium

Front 48

Diagramming forces: two specific ways

Back 48

Diagramming Forces:

Free Body Diagram:
Forces are drawn to correct proportion

Space Diagram:
Forces are located, but are not drawn to scale

Front 49

Force Couples

Back 49

Two parallel forces equal in magnitude and opposite in direction

results in rotary motion-pure rotation

(can have more than 2 forces contributing)

Front 50

Composition

Back 50

Composition: Combining tow or more forces action in the same plane on the same point

a single resultant force

eg. rotator cuff-combining effects of multiple forces

Front 51

Resolution

Back 51

Replacing a single force by two or more equivalent force components

Front 52

Graphic Composition

Back 52

linear system
two or more vectors (add and subtract them)

Concurrent system; two vectors, triangle method, parallelogram method, polygon method (3+ vectors)

Front 53

Graphic Resolution

Back 53

linear system (2+ vectors)

concurrent systems (2 vectors)

3+ vectors

Algebraic Resolution-find x and y component forces

Front 54

Algebraic resolution and composition

Back 54

look in slides p. 18 and 19-21

Front 55

Angle of Pull (insertion)

Back 55

angle of pull (insertion) changes in the angle of pull (insertion) will vary the magnitude of the component forces.

Front 56

Friction

Back 56

Friction
force that resists motion
-only exists when motion is attempted


--

Front 57

-vector force (friction)

Back 57

line of action is always parallel to the contacting surfaces

Direction is opposite the direction of potential motion

whenever two objects touch

Front 58

Static friction

Back 58

friction force when objects are at rest

static friction must be overcome in order to initiate motion

determined by magnitude of external load

Front 59

Kinetic friction

Back 59

kinetic friction- friction force when objects are in motion

kinetic friction must be overcome in order to maintain motion

remains constant while motion is occuring

Front 60

Friction- refer to slides p. 22-24; 25-27

Back 60

22-24

Front 61

Friction- Clinical Applications

Back 61

angle of placement of crutches changes normal force, frictional force, and sliding force

Front 62

Newton's Laws

Back 62

1st-(law of inertia)- object will remain at rest or in uniform motion unless acted on by an unbalanced force

inertia is the property of an object that makes the object resist both the initiation of movement or a change in motion

Second- (law of acceleration)- acceleration of an object is proportional to the force acting upon it and inversely proportional to the mass.

F=ma
A=F/m

Acceleration may be a change in velocity or a change in direction

3rd- (Law of Reaction)- in order to achieve equilibrium
-for every force (action), there is an equal and opposite reaction force

Front 63

Levers
Simple Machine
Classifications

Back 63

Simple Machine- two forces
--effort: causes the motion
--resistance: resists the motion

fulcrum

Classifications: 1st, 2nd, 3rd.

Front 64

First Class Lever

Back 64

2 forces on either side of fulcrum

>,< or = 1

1st class levers- favor either linear displacement and velocity of resistance or force

Front 65

Second Class Lever- definition and mechanical advantage

Back 65

Resistance force is between effort force and fulcrum

Mechanical advantage- always>1

most mechanically advantageous and efficient


--second class levers-favor less effort force, less linear displacement and velocity of resistance

Front 66

3rd Class Lever-definition and mechanical advantage

Back 66

Effort force is between resistance force and fulcrum
mechanical advantage-Always < 1

always mechanically inefficient, effort arm always shorter than resistance arm

most of our joints are 3rd class levers since it is more advantageous to have movement over force.



3rd Class levers- favor linear displacement and velocity of resistance, requires greater force

Front 67

Mechanical Advantage

Back 67

Ratio of Effort arm length to resistance arm length
measure of efficiency

effort arm/ resistance arm

(always a measure of distance)

Front 68

Angular vs. linear displacement and velocity

Back 68

angular displacement and velocity is the same for all points on the lever

linear displacement and velocity increases further from the axis
reference slide p. 32

Front 69

Anatomic levers

Back 69

Anatomic levers- bones and joints constitute anatomic levers
-most 3rd class levers
-anatomic trade offs

--second class levers-favor less effort force, less linear displacement and velocity of resistance

3rd Class levers- favor linear displacement and velocity of resistance, requires greater force

1st class levers- favor either linear displacement and velocity of resistance or force

Front 70

Pulleys- fixed

Back 70

Fixed Pulleys- pulley remains stationary in space

changes the action line of a force vector

does not change the magnitude of a force vector

Front 71

pulleys- moveable

Back 71

moveable pulleys- move through space

for every moveable pulley divide resistance in 1/2 and you'll have the amount of effort needed.
or- number of strands divides the wieght

efficient for force

inefficient or distance

traction

equipment

Front 72

anatomic pulleys

Back 72

anatomic pulleys- changes the action line of the muscle force vector

increases torque by increasing moment arm.

deflect action line away from axis

increases torque by increasing the rotary component

increases angle of insertion

eg. changes angle of quadraceps- deflects quad tendon away from center of knee --> increases insertion of quad

another example, acromion at shoulder

Front 73

anatomic pulleys- affect on torque, moment arm, action line, rotary component, angle of insertion

Back 73

increases- torque (by increase in moment arm) --> increase rotary component

increases angle of insertion

deflect action line away from axis

Front 74

wheel and axle

Back 74

wheel and axle-
causes or prevents rotation

second class lever-resistance is set, effort arm changes as diameter of wheel changes

Front 75

Torque- moment

Back 75

torque moment- when a force is causing rotation about an axis

Torque= Force times its perpendicular distance

resultant torque is sum of all torques action on the lever= counter clockwise vs. clockwise

resultant torque determines the direction of rotation of the lever

Forces acting through the axis cannot produce torque because distance =0!

Front 76

Work

Back 76

Work= Force x Distance (joules)

Force overcoming a resistance and moving an object through a distance

Front 77

Power

Back 77

Power= work (force x distance) divided by time (watts)

amnt of work performed over time

Front 78

Equilibrium

Back 78

Equilibrium- sum of all forces = 0

Front 79

Equilibrium- Static

Back 79

Equilibrium-static

object is at rest
--velocity=0

Front 80

equilibrium- dynamic

Back 80

Equilibrium- dynamic
object is moving with a constant velocity

Front 81

Equilibrium- rotational

Back 81

Equilibrium- rotational
must consider torque/moment

lever systems

Front 82

Equilibrium- translational
linear and concurrent

Back 82

Equilibrium- translational

linear- add and subtract vectors

concurrent- three or more forces can result in equilibrium
two concurrent forces need a third force to achieve equilibrium

Front 83

Center of Mass

Back 83

Center of Mass
Center of gravity
--point where gravity acts
--line of gravity in the gravity force vector action on the COG

All parts of body or of the part are evenly distributed

Not confined to the physical limits of the part/body

Front 84

Center of Mass

Back 84

Center of Gravity in Humans
-intersection of all three planes
generally anterior to the S-2 spinal segment

Line of gravity in Humans- Vector from COG to earth

Front 85

Center of Mass- segmental parts

Back 85

COG in Humans can be broken into specific parts of the body (limbs, bony segments)--> segmental parts

Front 86

Center of Mass--Relocation of COG

Altering of COG

Back 86

Relocation of COG in humans
-unchanged in rigid parts
-changes with position changes in segmental parts

ALTERING of COG
human COG can shift with changes in
-body weight distribution (fatness, pregnancy)
-lower extremity amputee
-carrying an external load

Front 87

Center of Gravity Stability

Back 87

Line of gravity must pass through the base of support
-whole body
-segments

Front 88

COG- Stability- BASE OF SUPPORT

Back 88

COG- Stability- BASE OF SUPPORT

-Area formed under the object
-Increasing size of base of support increases stability

Front 89

COG- Instability- BASE OF SUPPORT

Back 89

COG- Instability- BASE OF SUPPORT

-Line of gravity is passing outside of Base of Support
--movement toward the line of gravity
--return to starting position
---fall to new position

Front 90

Stability- Height of Center of Gravity

Back 90

As Center of Gravity height increases, stability decreases

As COG height decreases, stability increases

Front 91

Stability- Base of Support Size

Back 91

Stability- Base of Support Size

Increasing size of BOS increases stability

Front 92

Maximizing Stability

Back 92

Low COG over large BOS will result in maximum stability