Coordination and Control

1. degrees of freedom
2. coordination
3. control

Coordination and Control

Degrees of Freedom

• independent elements of each limb
• body => joints (all action possibilities)

Coordination and Control

Coordination

• organizing a system's degrees of freedom
  • into an efficient movement pattern
  • to achieve a desired result
• to provide a skilled mvt
• "Putting ingredients into a soup"

Coordination and Control

Control

• manipulation of variables within a movement to meet the demands of a given situation
  • motor skill into different environments // changing varibles
  • given situation = taken account of degree of freedom

Motor Program Theories

• theory based upon the brain as the "command center" for movement

Generalized motor program

• class of actions or pattern of movement that can be modified to yield a response outcome

Invariant features

• Relatively FIXED // NO CHANGE
  • EX. same letter
  • Fixed in motor skill
• Defines motor program (WHAT)

Parameters

• FLEXIBLE // YES CHANGE
  • different tasks or changes
• defines EXECUTION of program (HOW+PLAYED OUT)

Invariant Features

1. sequence of actions
2. relative timing
3. relative force

Invariant Features

sequence of actions

• order of components = doesn't really change
  • EX: volleyball spike = fixed

Invariant Features

Relative timing

• internal RHYTHM of the skill
  • EX: Swim fast vs. swim slow
    • = same swim technique
• Regardless of speed = component mvt does NOT change
• Cyclical events: hurdling, swimming, ect.

Invariant Features

Relative Force

• tension created in muscles
  • proportionate regardless of resistance
• EX: Air squats vs. 50lb squat
  • muscle use = STILL SAME

Parameters

1. overall duration
2. overall force
3. movement direction
4. muscle selection

Parameters

Overall duration

• duration or speed of the skill is performed // MVT does not change
  • Long vs. short
  • Fast vs. Slow

Parameters

Overall force

• amplitude of the movement
  • strength / power / range
• EX. long vs. short pass
• EX. learn to sit => stand
  • can do same # from high to low surface

Parameters

Movement direction

• directional passes, shots, ect.
  • mvt needing aim (darts, pulling items to grab)

Parameters

Muscle selection

• use different muscels to accomplish the same task
  • EX. different hands
  • EX. writing w/ hands VS. writing w/ mouth

Schema (WIP)

• a rule or relationship that directs decision during a movement pattern
  • develops as a result of accumulated experiences (INFO) within a class of action
  • Already learn to change
• Each attempt = builds bigger schema

Schema

Sources of Information

• initial conditions
  • start info @ start of mvt
• response specifications
  • parameters used for execution (amt of speed/force)
• sensory consequences
  • feedback fr. mvt (what felt during/after mvt)
• response outcome
  • success/fail of mvt

Schema

Recall schema

• organizes the motor program that initiates and controls desired movement
• subconsciously selected based on actual outcomes and response specifications

Schema

Recognition schema (fr. outside info)

• based upon relationship between inital conditions, past outcomes, sensory consequences
• comparison btn sensory feedback + reference of correctness

Motor program execution

• Open-loop control
  • brain general action plans w/o modification
  • feedback present BUT too late
  • EX. after a softball toss when pitching
• Close-loop control
  • for beginners to learn
  • allows adjustments to be made after attempt
  • EX. Golf putting

Evidence for motor program control

• reaction time increases = task complexity increases
  • mvt planned in advance
• deafferentation
  • MONKEY
  • severing of nerves responsible for CNS sensory feedback
• electromyography studies
  • similar activation in muscles for BLOCKED and UNBLOCKED limbs

Dynamic Interaction TheoryDynamic Interaction Theory

• movements occur in response to
  • dynamic interaction of person
  • environment
  • task
• movement patterns = result of constraints
  • IMPOSED by given situation
  • EX. finger movements with metronome // traffic (unexpected // can't explain movements)

Dynamic Interaction Theory

Constraints

1. individual
2. environment
3. task

Dynamic Interaction Theory // Constraints

Individual

• body attributes // personality characteristics // fitness varibles
• EX: playing volleyball on knees

Dynamic Interaction TheoryDynamic Interaction Theory // Constraints

Environment

• gravity // temperature // lighting // presence of spectators

Dynamic Interaction Theory // Constraints

Task (x3)

• Goal: outcome of action
• Rules: physical boundaries, movements, etc.
  • EX: fast pitch softball => don't lift toe off pitch
• Implements: size of ball/goal, length of object, etc.
  • EX. athlete + smt else //

changes in movement

1. control parameter
2. rate limiters
3. phase shifts

changes in movement

Control parameter

• variables that, when changed, lead to changes in the collective behavior of the system
• direction, force, speed, perceptual information

changes in movement

Rate-limiters

• constraints that INHIBIT a system to change
  • DOES NOT CHANGE // when sm1 injuried
• Strength, size, speed, etc.
  • EX. hop flexor gait walking example

changes in movement

Phase shifts

• changes in movement behavior are the result of
  • series of transitions in a system's state of stability
    • EX. log walk // increase or decrease balance // swinging a heavy vs. light bat
  • Implement 3 weeks before big game

Non-linear pedagogy

• learners search through a range of potential movement solutions
  • for an optimal strategy

Perceptual-Motor Workplace

• represents practice content for the learner
  • perception <=> action