frans bosch - motor learning in athletics(1)
TRANSCRIPT
2012
Motor learning in athletics, the great unknownFrans Bosch• automated control specific and universal• intention action model and intrinsic KR• the need for variation• preflexes compensate errors
Biomechanical analysis: modeling by the expert combined with objective data
Coach Athlete
no translation success as coincidence
Psychology of movement planning and control; goalsetting and actions
translation controlablesuccess
automated control
specific and universal
For ad hoc design for new movement.
Slow processing and fast forgotten
For routine movement patterns.
Under time pressure and long time memory
conscious incidental control “working memory”
automated unconcious control“hard disk”
Conscious control
Learning
conscious incidental control “working memory”
automated unconcious control“hard disk”
conscious incidental control “working memory”
Why skip the working memory???
automated unconcious control“hard disk”
Subconscious control
Wulf ea.
simple task.like lifting?
Motor learning
Practice performance
0
12,5
25,0
practice (oefenen) retention (terugloop)
permanent feedback feedback na 1 p feedback na 5 p
fout
Winstein 1996(physical therapy)
9
retention
How is information transferred to the hard drive?
conscious incidental control “working memory”
automated unconcious control“hard disk”
skill acquisition
motor learning AND
sensory learning
learning new motor and sensory
patterns
using existing
motor and sensory patterns
Specificity as requirement for
transferautomated unconcience control
“hard disk”
Structure of the hard disk?specific and universal
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Bosch & Klomp (2001-7): ‘Specific’ training must meet four criteria:
1) The types of muscle action must be similar to those used during competition (intra and inter-muscular).
2) The structure of the movement must resemble that present during competition (motion of the limbs).
3) The sensory information must resemble that present during competition
4) The dominant energy system used during competition must be called upon.
5) The movement result must resemble that present during competition
2 important properties of the hard drive1) specificity
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Bosch & Klomp (2001-7): ‘Specific’ training must meet four criteria:
1) The types of muscle action must be similar to those used during competition (intra and inter-muscular).
2) The structure of the movement must resemble that present during competition (motion of the limbs).
3) The sensory information must resemble that present during competition
4) The dominant energy system used during competition must be called upon.
5) The movement result must resemble that present during competition
The usual suspects
14
Bosch & Klomp (2001-7): ‘Specific’ training must meet four criteria:
1) The types of muscle action must be similar to those used during competition (intra and inter-muscular).
2) The structure of the movement must resemble that present during competition (motion of the limbs).
3) The sensory information must resemble that present during competition
4) The dominant energy system used during competition must be called upon.
5) The movement result must resemble that present during competition
15
augmented feedback (coach)
intrinsic feedback(athlete)
posture
rhythmcomplex environmental information
simpleenvironmental information
part practice
whole practice
conscious incidental control “working memory” automated unconcious control
“hard disk”
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Bosch & Klomp (2001-7): ‘Specific’ training must meet four criteria:
1) The types of muscle action must be similar to those used during competition (intra and inter-muscular).
2) The structure of the movement must resemble that present during competition (motion of the limbs).
3) The sensory information must resemble that present during competition4) The dominant energy system used during competition must be called upon.
5) The movement result must resemble that present during competition
intention (future state) of the movement
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Wulf & Prinz;2001 Psychomotoric Bulletin & Review
Action effect hypothesisfocussing on movement outcome gives a better learning effect that focussing on performance (knowledge of result versus knowledge of result)
=> external versus internal focus of attention=> external focus is more effective with better retention
KP (knowledge of performance)feedback from elite coach)
KR (knowledge of result)feedback from measuring tape)
imitation without vision on score
The body shows remarkable little interest in what the coach has to say!
task; copy the technique of a model as precise as possible
imitation with vision on score
effector motor equivalence
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The cerebellum makes it fluent?
Spinal relays make it rhythmical?
Synergies absorb errors?
Cocontractions influence ROM?
The brain controls intetions?
problem
problem
problem
problem
problem
problem
problem
problem
solution
solution
solution
solution
solution
solution
solution
solution
control
control
control
control
control
2 important properties of the hard drive2) universal
storage problemretrieval problem
beweeg-probleem
beweeg-probleem
beweeg-probleem
beweeg-probleembeweeg-oplossingbesturing
problem
problem
problem
problemsolutioncontrol
Alexander (1992) Exploring Biomechanics
“Equivalent speeds” means equal Froude numbers:
(Speed)2
Gravity × leg length
If a rhino’s legs are 4 times as long as a cat’s legs, a cat will move (more or less) like a rhino going twice as fast.
stride length <> stride frequency
Movement is organised along mathematical rules
2 important properties of the hard drive2) universal
general control
force procuction << thresholdand joint angle velocity >> threshold
concious incidental control “working memory”
Learning
automated unconcious control“hard disk”
Structure of the hard disk?specific and universal
Structure of the working memory?simple sensory informationbrain gives all motor commands
minimal transfer
Protocol;hitting height follows tone height
group in top shape
group in slump
which group is performing best?
Gray 2004
intention action model and intrinsic
KR
KRknowledge of result
cause
effect
cause
effect
KPknowledge of performance
muscle synergy
tendon compliance
KR feedback
KR outside the movementKR within the movement
A new look at KR feedback
KR augmented
movement KR intrinsic
movement KR intrinsic
the organisme
The shorter the loop, the better we learn?
6
Lockposition of the free hip
the most important intrinsic result in running and jumping?
Lockposition of the free hip and no residual rotations at toe off as a result of a good push off
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6
intrinsic KR beaconsfor motor control
sagittal plane amortisation
frontal plane amortisation
useful in high speed running?useful in hurdling?useful in tripple-jump?useful in long-jump?
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high pull<>clean
high pullmovement resultunclear>>no intrinsic feedback
cleanmovement resulttotal balance>>good intrinsic feedback
minimal transfer
maximal transfer
what does this mean for traditional training
like in strength training?
conclusions
• specificity is not understood well enough.
• sensory specificity may be crucial for learning, but in coaching we have no good idea how to augment sensory information processing.
• the intention (goal / future state) of the movement planning is a crucial aspect of specificity
conclusions
• technical internal focus cues activate the working memory and reduce the learning process.
• coaching the movement outcome (intention, result) is more successful than coaching the movement process.
the need for variation
4 degrees of freedom 2 degrees of freedom 1 degrees of freedom
sternoclaviculare 4 dofscapula 6 dof schoulder 6 dofelbow 2 dofforearm 2 dofwrist 4 dofmuscles x dof
}impossible to control
degrees of freedom
attractorsstable elements
fluctuationsunstable elements
elements can be temporal and spatial spreaded
acquiring the ideal technique(controlled by the brain)
eliminate all redundant options(controlled by the body)
schema: hiërarchic model If control structure is hiërarchic, the CNS needs to make an precise estimation of the forces inside and outside of the body.
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demands1) sensory information must be precise and in time
signal delayed
muscle length difficult to measure because of tendon compliance and muscle slack
sensory information is vague and old
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demands1) the motor information must be precise and in time
the motor program is shaky
the bigger the signal, the bigger the noise+/-
51force dependent on tendon compliance, F/v, F/L, fatigue, PAP
muscle react different each time
demands1) the motor information must be precise and in time
signal delayed
52no precise muscle contractionsmuscles can not be trusted
teh signal from the brainwhat do I want to achief
motor control is crude and delayed(100-150ms supraspinal)
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The cerebellum makes it fluent?
Spinal relays make it rhythmical?
Synergies absorb errors?
Cocontractions influence ROM?
The brain controls intetions and crude motor signals?
The cerebellum makes it fluent?
Spinal relays make it rhythmical?
Synergies absorb errors?
Cocontractions influence ROM?
The brain controls intetions and crude motor signals?
movement result movement process
speed <> variability
fluctuationattractor
attractors in outside mechanics
movement result movement process
speed <> variability
fluctuationattractor
movement result movement process
train for adaptive fluctuations
train for deeper attractor wells
The learning process is non-linear, because learning is not just about getting the technique right, but also (mainly) to build in the error compensation mechanism
preflexes compensate
errors
schema: hiërarchisch model dynamic systems
Preflexen;muscle properties > influences outside the CNS
Preflexes, the role of cocontractions
F
v0
AB
A B
B
A
elastic elements
contractile elements
Conclusions
• Also in a perfect technique some elements are variable (fluctuations).
• Intrinsic results of movement are linked to (invariable) attractors. Precise feedback on movement outcome is useful.
• And train variables (fluctuations) with the aim to learn the skill to vary
2012
thanks for listening/IFACScotland
@IFAC_SCOTLAND