Planning movement Flashcards
Fitts law basic concept
the slower you are, the more accurate. more speed = less accuracy
Fitts law 3 concepts of size, speed and distance
the bigger or closer something is the simpler, easier or more eye catching. The quicker something is to do the better
What can fitts law do
predict human behaviour
What is the basic concept of two third power law
Curved movements take longer than straight lines
what relationship does it show
shows a relationship between geometrical and temporal aspects of human movement
two third power law states that an increased velocity is lower in more what movement
curvature
what type of relationship does two third power law show with curvature and anuglar speed when drawing curves
positive
Define kinematics
The study of mechanics of studying movement/ motion of objects /body’s- without referencing forces
Displacement definition
the shortest distance between 2 points
vector definition
a measurable quantity that has magnitude and direction.
scalar definition
a quantity with only magnitude, no direction
distance definition
a length of space between 2 points
velocity definition and equation
rate of change of displacement - v=Distance speed/Time
is velocity a scalar or a vector and why
vector, has direction
speed equation
speed = distance over time
acceleration defintion
increase in velocity (has direction - a vector)
inverse and forward kinematics can do what
calculate motion of a system of joints and bones and robotics
when is inverse kinematics used
when a position of end chain is known
forward kinematics is used when what
the position of the intermediate joints are known and end joint position is known
why is inverse kinematics useful
defining goal position
forward kinematics is
the calculation of position and orientation of an end effector using variables of the joint
forward kinematics can also
calculation position and orientation of end effector
inverse kinematics is the calculation of
the variables of the set of joints and linkages connected to an ed effector
inverse dynamics relies on
motion of subject and a body
what does inverse dynamics do
calculate forces needed to create movement
forwards dynamics uses what to predict what
forces and or torque to predict resultant motions
what can forward dynamics help do
predict orientations of each link in articulated body
what factor may impact movement?
resistance
define torque in 3 ways
force x distance or length
the tendency of a force to turn or twist
torque is a measure of the force that can cause an object to rotate - a vector
what does the brain act as when planning movement
a controller
what are the 2 strategies for planning movement in the brain
feedback and feedforward
define feedforward - both names
open loop , predetermined plan
feedback definition
closed loop , case by case control
feedback is trial and error - true or false
true
what is policy
desire to move
what acts as information gathering of how far muscles will stretch and act to get to desired position
muscle spindles
varability is
when you repeat the same movement and it is different each time
when you repeat the same movement and it is different each time is is called
variability
localisation definition
becoming located or fixed in a particular place:
what is a reference frame
use letters like x y z to determine up down and side to side and right or left to help determine for coordinates
what is extrinsic information
information received from external sources, outside of the body - like visual or auditory cue
what is intrinsic information
kinematic or kinetic information from inside the body
what is kinetics
the study of forces that cause motion
what 3 organs does the body use for information for movement
muscle spindles
Golgi tendons
mechano reactors
define golgi tendons
is a organ receptor loctaed at teh junction of the muscle and tendon
what do golgi tendons do
it is a mechanoreceptor that plays an important role in regulating muscle tone. protects from excessive force and limits risk of injury
what happens when the golgi tendon is stimulated
sends a message to the brain that relaxes the muscle
what does the golgi tendon sense
muscle tension
what is a mechanorepctor
a sensory receptor that responds to mechanical pressure or distortion
what are mechanorepctors innervated by
sensory neurons
where are electrical signals sent from mechanoreceptors
CNS
What are muscle spindles
stretch receptors in the body of a skeletal muscle
what do muscle spindles do
detetc changes in length of the muscle
what do muscle spindles do 2
convey information of muscle length to the CNA via afferent nerve fiber’s
what is a spinal reflex
spinal reflex are involuntary movements initated by sensory receptors
how do spinal reflexes occur
activation of neurons
spinal reflexes are a type of what
involuntary reflex
voluntary movements require what
higher-level cortical control
cortical control is in which part of the brain - 2 part s
cerebral cortex in the frontal lobe
what does cortical control do to help movement planning
generates a plan
sensorimotor transformations definition
process by which sensory stimuli are converted into motor commands - in order to respond to environment or stimuli
how does the nervous system generate motor command
the nervous system compares the current sensory state to the desired state and transforms sensory coordinates into motor system coordinates - generating muscle movement
what are the 4 stages of movement planning
locate, plan movement, find a plan, execute
what is egocentric coordinate system
geometrical orientation linked to a body/object
exteroceptive information example
visual or auditory
2 types of extrinsic coordinate system
allocentric or egocentric and exteroceptive
allocentric coordinate system definition
world or area centered coordinates
