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Flashcards in Chapter 10 Deck (24)
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1

quantitative analysis

using high tech instrumentation
usually intended for researchers
measuring variables to optimize athletic preformance
foot forces on sprinters starting block (force platforms)
muscle contraction sequence during running (EMG)
3-D body segment movements during a high jump (motion capture)

2

qualitative analysis

using sight and hearing
usually done by coaches and teacher
who typically do not have access to complex equipment or specialized knowledge
to identify and correct errors "observe, analyze and correct
requires framework and a set of principals

3

kinematics

describing human motion without its focus
focusing on motion spatial and timing characteristics
measurements:
position
displacement
velocity
acceleration
measured with respect to time
linear or angular

4

kinetics

describing forces leading to motion
internal forces:
-muscles pulling on bones
-bone on bone, inside joints
external forces:
-acting on the body
-without contact
from contact with ground opponent or equipment

5

models of human motion

understanding and observing human movements is complex
all body tissues undergo shape deformation - must make assumptions and qaulifications
most movements occur in three dimensions - but can simplify analysis based on our understanding of the movement
3 models simplify the study of human movement:
particle model
stick figure model
rigid body segment model

6

particle model

dot represents center of mass
used when body or object is airborne and in flight
projectile motion

7

stick figure model

body segments= sticks
used when body in contect with other objects
describe gross motor skills in 2-D

8

rigid body segment model

body segments= irregular 3-D volume
used for sophisticated 3-D analysis
can include shape deformation of body segments

9

mass

reluctance of an object to chnange state of linear motion
a measure of linear inertia

10

moment of inertia

relectance of roatating bpdy to change state of angular motion
depends on mass and its ditrubtion around axis of rotation

11

gravity

force of attraction betwen two bodies
newtons univeral law of gravitation

12

mass is a measure of ? and is measured in

inertia and kg

13

weight is a measure of ? and is measured in

force of gravity and newtons

14

types of motion

linear motion translation
angular motion rotation
general motion

15

linear motion

all body parts move same distance and direction at the same time
translation: linear motion of the whole body
ex) bobsled

16

angular motion

body moves on a circular path and rotates about axis of rotation
body segments rotate about their joints
ex) twisting somersault

17

general motion

body segments move lineraly and rotate at the same time
true for most ahtlete and every
ex)

18

how do levers work

force is applied and if the turning effect if the force is greater than the resistance
then: roatation at the axis/fulcrum occurs
to determine turning effect, consider the length of force arm and resistance arm
when lever rotate around and axis/fuldrum:
movement of force or torque is produced
what movement of force occurs?
torque = force arm x force
therefor: the longer the force arm:
less force is needed
greater torque is produced

19

types of levers

levers preform different functions
three basic types
first class
second class
third class
differ based mechanics and how these compnetns are positioned
-axis
-resistance
-force

20

first class levers

applied force and resistance on opposite side of axis at un/equal distance from one another
ex) crow bar
human: head flexion

21

second class levers

applied force and resistance on same side of axis; resistance closer to axis
ex) wheel barrow
human: rare: toe raise

22

third class levers

applied force and ristsenace on same side os axis; closer to the axis
ex) fishing
human: many: forearm flextion

23

surface drag

laminar flow: small, streamlined, smooth, slow-moving bodies
smooth, layered flow pattern with no disturbances
turbulent flow: most human activities
distured flow pattern that changes flow conditions

24

magnus effect

a rotating body carries boundary kayer that interacts with surrounding air
boundary layer flow opposite to relative airflow
-air is slowed by friction
-zone of increased pressure created
bonadry layer same as realtive airflow
-air is not slowed down
-zone of decreased pressure created
net difference in pressure on opposite sides of roating obect = magnus force
found is ping pong, tennis, soccer, baseball