Measurement Of Motor Skills Flashcards
What is performance measurement essential for
- Performance assessment/evaluation
- Motor learning and control research
What are the two general categories of performance measurements
- Performance outcome measures
- Performance production measures
What are performance outcome measures
- category of motor skill performance that indicates the outcome or result of performing a motor skill
- e.g. how far someone threw a ball
What do performance outcome measures not inform us about
- behaviour of the limbs of the body that led to outcome
- the activity of various muscles involved
What are performance production measures
- measures of motor skill performance that indicate the performance of specific aspects of the motor control system during the performance
- e.g. EMG, EEG, recordings
What are examples measures of measurement devices for performance outcome measures
- time to complete a task
- amount of error in performing criterion movement
- number of successful attempts
- time on/off balance
- distance
- trials or reps to complete
Examples of measures of measurement device for performance production measures
- displacement
- velocity
- acceleration
- joint angle
- Joint torque
- EMG
- EEG
- PET
- fmri
What are error measures
Allow us to evaluate performance for skills that have spatial or temporal accuracy action goals
- show us how well we perform against a criterion/goal
Spatial accuracy
Where something is occurring
Ie) throwing darts, high jump
Temporal accuracy
When something is occurring or the timing of a skill
Ie) ones timer, musical instrument, volleyball spike
What are one-dimension accuracy goals that assess error in skills
Absolute error (size of error)
Constant error (direction of error)
Variable error (consistency/variability)
Absolute error (AE)
- tells us magnitude of error
- how accurate we are
- average of the absolute values
AE = goal - actual
Constant error (CE)
- direction of error
- provides an index of tendency for the performance error to be directionally biased
= (performance - criterion)/ number of trials
Variable error (VE)
- consistency of error
- standard deviation of the constant error scores
- how variable the trials are (how close together)
= SD of CE scores
What are skills assessed by two dimension movement goals
Skills requiring accuracy in the vertical and horizontal directions
I.e) darts, archery, golf
What are 2 types of measuring two-dimensional accuracy
Radial error
Qualitative assessment of bias and consistency
Radial error
- AE for two direction accuracy
- similar to AE in one direction accuracy
- calculate hypotenuse of right angle triangle formed by the intersection of x and y axis
Qualitative assessment of bias and consistency
- general approach to assessing bias and consistency
- look at group of locations
Consistency errors
Difficulty in learning the skill
Bias errors
Difficulty in adapting the skill
What do continuous skills require
Spatial accuracy over a period of time
How do you assess error for continuous skills
Root mean squared error (RMSE)
What is RMSE
Indicated amount of error between performance curve produced and the criterion performance curve for a specific amount of time during which performance is sampled
- AE for continuous task
Kinematics
Description of motion without regards to force or mass
What 3 things does kinematics include
Displacement, velocity, acceleration
Displacement
- spatial position of a limb or joint over a period of time
Velocity
Rate of change in an object with respect to time (speed)
=displacement/time
Acceleration
Change in velocity during movement
= velocity/time
Kinetics
The study of the role of force as a cause of motion
- human movements involve both internal and external sources of force
- Newton’s laws of motion important
Internal force of human movement
Muscles
External force of human movement
Gravity, wind
What are direct force measurements
Force plates, strain gauges, force trasnducers
Indirect force measurements
Calculations to determine force
Ways to measure muscle activity
Surface EMG, fine wire intramuscular EMG, EMG
Electromyography (EMG)
- Measurement of electrical activity of muscle
- insight into neural control of movement (onset, magnitude, duration)
What are brain activity measures
EEG, PET, fMRI, MEG
Electroencephalography (EEG)
Detection of cortical activity via scalp electrodes
Active regions produce electrical activity
What are limitations of EEG
- only records surface activity
- does not show which anatomical structures are active
Brain computer interfaces
- measure brain activity using EEG
- Transform activity into motion (robots, wheelchairs, someone else’s arm)
Positron emission topography (PET)
Detection of metabolic brain activity
- positrons interact with blood and look at glucose levels
- scans detect activity in various locations
What are limitation of PET
- subject must be stationary
- injection of isotope
Functional magnetic resonance imagining (fMRI)
Brain activity detected by changes in blood oxygenation
Limitation of fMRI
Subject must be stationary
Magnetoencephalography (MEG)
Measures magnetic fields created by neuronal activity
- high temporal resolution
- increased accuracy of activity location compared to EEG
Limitations of MEG
- Subject must be stationary
- does not show anatomical structures that are acitve
Transcranial magnetic stimulation (TMS)
Magnetic pulse delivered to brain either excited or inhibits brain activity
- temporary movement caused artificially through stimulation
Limitations of TMS
- must estimate location of stimulus
- may have discomfort at stimulation site
What measures peripheral nerve activity
Microneurography
Microneurography
Measures impulses in peripheral nerves
- used to understand function of various nerves
Examples of peripheral nerve function
- cutaneous responses from feet for balance
- muscle spindle responses
Limitations of microneurography
- fine wire needle must be inserted
- only small movements tested
