frans bosch - motor learning in athletics(1)

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

12

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

13

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”

17

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

18

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

21

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

36

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?

39

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.

49

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

50

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)

53

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