KInematics (M1) Flashcards
if you speeding you to the right what does this mean for the velocity, change in motion and acceleration direction
all positive
if your travelling to the right and you speed is NOT changing what does this mean for the velocity, change in motion and acceleration direction
velocity is positive
change in motion 0- constant
direction of acceleration 0
if your slowing down but travelling to the right what does this mean for the velocity, change in motion and acceleration direction
velocity Positive
change in motion negative
direction of acceleration negative
if your speeding up but travelling to the left what does this mean for the velocity, change in motion and acceleration direction
velocity negative
change in motion positive
acceleration direction negative
if your travelling to the left and you speed is not changing what does this mean for the velocity, change in motion and acceleration direction
velocity negative
change in motion 0 - constant
acceleration 0
if your travelling to the left but slowing down what does this mean for the velocity, change in motion and acceleration direction
velocity negative
change in motion negative
acceleration positive( because its moving back to the right)
how is stride defined
distance between consecutive ground strikes on the same leg
what is a step length
distance between consecutive ground strikes, going from right foot to left
what is an absolute reference frame describe
used to describe landmarks (CoM) or segment positions (angles
the other angle that is not the inside angle and is often measured is called
supplementary angle
if inside angle is greater then the supplementary angle will be less or greater
less
sin is what sides over which
opposite over hypothesis
what is the calculation when finding an angle
e.g. theta = tan^-1 (O/A)
when do use the pythagorean theorem and what is it
when you trying to find the sides - and have the angle
c^2 =a^2+b^2
what do vectors have (2 things)
magnitude and direction
if forces are parallel and act along the same line do we multiple or add them
add them
if forces are in opposite direction e.g. force going up and force pushing down what do we use to solve this
trig
what is the difference between quantitative and qualitative analysis
quantitative - measurement of movement
qualitative - judgement of the quality of movement are made
what are 3 measurement of quantitive approach
- motion capture
- forces
- muscle activity
what are 3 advantages to quantitative (measurement)
- accurate measurements
- numerical comparisons
- data basing
what are 3 disadvantages to quantitative
- expensive
- time consuming
- lacks ecologically validity - often unable to do it in real field environment
what are 3 advantages to qualitative analysis
- cheap
- field base
- less technical skills required
what are 3 disadvantages to qualitative approach (judging quality of movement)
- observer bias
- reliability often overlooked
- findings not quantified
what are the 4 stages for a qualitative analysis structured approach
- preparation stage
- observation stage
- evaluations and diagnosis stage
- intervention
what occurs in the prep phase
- gather understanding of movement
- need analysis
- build model
what occurs ing observation phase
- use observation strategy that was made in prep phase
- reconsider focus of observation, location number
what occurs in evaluation and diagnosis stage
- evaluate strengths and weaknesses
- address validity and reliability
what occurs in intervention phase
- use feedback to improve
- review analysis
for fast events e.g. golf swing do you need a high or low frame rate and what speed should shutter speed be at
high frame rate wth low shutter speed
what are the 3 components to exposure
- aperture
- shutter
- ISO
what is aperture and what is it measured in
size of lens opening and measured in f-stops
if have large aperture what does this increase and what does this reduces
increase more light to come in
reduces depth of field (background is more blurred)
what does shutter speed do
open and close with exposer to light
if a slow shutter speed what does this allow increase of but also reduces
increase light buts also reduces motion blur
t/f do slow movements need a fast shutter speed
no - fast movements do
out of sunlight an flood light which is better for shutter speed
sunlight
what is ISO
sensitivity to light
what does ISO do to dark pictures but what does it risk
lightens dark pictures but risk graininess
how do you get the best quality ISO but what does this also need
low ISO = best
but needs lots of light
how should a camera be set up (3 things)
camera level
lens height at centre of image
perpendicular to plane
what lens shouldd you zoom in to remove perspective error
telophoto lens
what does video calibration help to achieve (what type does it measurements)
linear measurements
puts it into real world setting
the purpose of measurement tech is to answer questions about performance movement- what are the three can you questions
- can you modify tech
- can you gain further understanding
- can movement be modified to reduce risk of injury
what are high speed cameras needed for
- specialised analysis
- high speed impact
what does 3D motion capture require
- at least two cameras
- calibration object (DLT)
what should 3D motion have
- markers to improve accuracy
- lots of patience
what do strain gauge of force plates detect
change in electrical resistance
what does IMUs stand for
inertial measurement units
what are the three IMUs sensors
- accelerometer
- gyroscope
- magnetometer
what out of the IMUS detect static and dynamic forces and measures linear kinematics
accelerometer
what out of the IMUS detect rate of angular motion and measures angular kinematics
gyroscope
what out of the IMUs detect heading according to magnetic south and orient acceleration and gyro readings
magnetometer
what is a reference frame
a coordinate system that allows us to interpret measurements
what does relative reference frames determine
- used for determing realtive segment position and joint angle
what does the middle finger represent in the right handed rule
z axis
the x axis (thumb) explains what orientation
mediolateral
the y axis (1st finger) explains what orientation
anteroposterior
the z axis (middle finger) explains what direction
longitudinal
if you curl your fingers into palm during the right hand rule is this positive or negative
positive
what are three exceptions to the right hand rule
- knee flexion
- left side ab/adduction
- left side internal/external rotation
what is a movement example for rotating around the z axis
doing a pirouette
what is a movement example for rotating around the x axis
doing a forward flip
- would be negative direction
what is a movement example for rotating around the y axis
cartwheel
(adducting)
having a low launch angle with pos projection height and higher launch angle with neg projection height will increase or decrease range
increase
what stage of the gait cycle - hip and knee are flexing
early swing
what stage of the gait cycle - foot swing under pelvis, max knee flexion - hip still flexing
mid stance
what stage of the gait cycle - knee extending, hip stops flexing and laterally rotates
late swing
why is balance more important in running
no double stance
what in the gait cycle influences amount of pronation and windlass mechanism
fot angle
describe swing or flight time
time one or both legs are not in contact with ground
vertical force greater than body weight after about _%
10%
what force is used until mid stand and what after
before - breaking force
after - propulsion force
when is velocity highest in running
highest during flight
lowest mid stance
when is energy absorbed in what stage of gait cycle and when is it released
absorbed in early stance
released in late stance
what are the three events of a golf swing
- address
- top backswing
- impact
what can linear movement only be achieved through
multi-joint coordination
Short change in muscle length produces a large or short movement at the end of limb
large
to find the vertical component what is the equation
velocity SIN (theta)
to find the horizontal component what is the equation
velocity COS (theta)
what is a resultant
sum of two vectors or more
what is the difference in speed and velocity
speed - rate change in distance
velocity - rate change in position
position, speed and direction, energy (TME)
are all forms of vectors or scalar quantities
scalar
these are all forms of scalar or vectors:
Displacement
Velocity
Force
Momentum
vectors
when something is travelling at a constant velocity what will the acceleration be
zero
