Week 2 Flashcards
Define coordination…?
The process of organising degrees of freedom into an efficient movement pattern to achieve a specific goal
Define control…?
Manipulation of variables within a movement to meet the demands of a given situation
Define degrees of freedom…?
- The human body’s numerous independent elements that produce abundant action possibilities
What is the problem with degrees of freedom?
- How we coordinate and control the available degrees of freedom to produce a particular movement?
Define Motor program theories…?
Command centre in the brain thought to make all decision regarding movement
Define the dynamic interaction theories…?
- A command centre could not account for all variations and adjustments in skilled movement
- Movement results from interaction of body, environment and skill
Early Motor Program Theories proposal –> for each movement…?
- Separate motor program existed and was stored in memory
- When a specific action was required, the program was retrieved from memory and executed
Early Motor Program Theories problem –> ???
- Storage requirements of all the new plans
- Production of new plans
Generalised Motor Program (EXAM) = ??
A class of actions or movement patterns that can be modified to yield various outcomes
Define the invariable features of the generalised motor program?
- they define the program itself (holding the pen, writing)
- they are relatively fixed
Define the parameters features of the generalised motor program?
- things we adjust (how tight we hold the pen etc)
- more flexbile
- defines the programs execution
Invariant features =
Some underlying features of a movement remain constant
Parameters =
Some features of a movement are flexible and are easily modified from one performance to the next
What are the 4 possible parameters?
- Overall duration
- Overall force
- Movement direction
- Muscle selection (forced to use different muscles due to injuries, or choosing to select different muscles to improve technique)
What are the three possible invariant features ?
- Sequence of actions
- Relative timing
- Relative force
Schema (3) =
- Directs decision making
- Develops as result of accumulated experiences
- Each movement attempt gives the learner information to guide future attempts
Recall schema =
Responsible for organising the motor program
Recognition schema =
Responsible for evaluating the movement attempt
Explain the difference between and open and closed loop in control systems?
Open loop -> Input, process, then output. Your brain doesn’t require constant feedback because the object is stationary
Closed loop -> Input, process, output, input again. Your brain keeps collecting more feedback as object is constantly moving.
Dynamic Interaction Theories =
Movement patterns emerge, or self organise, as a function of interactions among various constraints:
- Learner
- Environment
- Task
Constraints =
All of the factors - limiting and enabling - within the practice environment that influence skill acquisition and performance
Types of constraints (3)?
- Individual (varies between people)
- Environmental (surface, ground etc)
- Task (its complexity, duration, rules)
Emergence of movement patterns: Movement =
a function of a system self-organising and compressing available degrees of freedom into a single unit designed to carry out a specific task
Emergence of movement patterns: Movement pattern =
the result of the constraints imposed by a given situation
Stability and movement: Attractor =
Preferred state of stability in a system (what movement feels most comfortable or is most attractive to achieve this goal)
Stability and movement: Control parameter =
Variable that, when changed, leads to corresponding changes (speed, incline etc)
Stability and movement: Rate limiter =
an individual constraint that holds back or slows the emergence of a motor skill (when individual potentially holds back, doesn’t move into run, etc)
The depth of the attractors is an indicator if what?
indication of stability of the system
Shallow vs deep attractors
Deep: stable systems, difficult to change (more stable, situation dictates what you have to do –> treadmill faster = running faster)
Shallow: less stable, more susceptible to change (get into a habit, it doesn’t feel that great but continue –> treadmill at 7km, run or walk?)
Shallow attractor state: a phase shift can occur _____
abruptly
Deep attractor state: intervention strategies have to cause instability, which leads to an increase in movement _____
variability
Over time, the pattern will reorganise, the new technique will take over, and a ___ -____ will occur to a new attractor state.
phase shift
Non-linear pedagogy =
- Learner searches through a range of potential movement solutions for the optimum strategy
- Perceptual-motor workspace
Constraints-led approach =
- Purposeful manipulation of key constraints in an effort to acquire movement skills and decision-making behaviours
- Hands-off practitioner
