Discussion Neurobiological Clinical Aspects Postural Control...

NEURAL PLASTICITY VOLUME 12, NO. 2-3, 2005

Discussion on Neurobiological and Clinical Aspects ofPostural Control in Motor Behavior

A. Gramsbergen and M. Hadders-Algra

University ofGroningen, 9713 A V Groningen, the Netherlands

Albert Gramsbergen (Groningen, the Netherlands) REFERENCE FRAMES

This special issue contains the contributions ofthe invited speakers to the international meeting on"Posture in the Picture, on the relevance ofpostural control in children with developmentaldisorders". During the meeting typical develop-ment of postural control was discussed from birthuntil adolescence, biodynamical aspects wereconsidered, as well as phylogenetical aspects ofpostural control during erect gait. Physiologists,movement scientists, and anatomists discussed theroles of the corticospinal system in man, thecerebellum, and the basal ganglia in the develop-ment of postural control. During the meeting, vividdiscussions emerged between these scientists andthose who are involved in analyzing the problemsin postural control in children with motorimpairments, and scientists involved in designingeffective therapies for children with dysfunctionalpostural control. The meeting was concluded by anorganized and structured discussion in which a fewof the most important issues were reconsidered.This discussion made it clear that strong cooperationis urgently needed between those involved in theanalysis and therapy of motor impairments inchildren and basic scientists studying posturalcontrol from a theoretical perspective or performingexperimental research in animals.

The questions from the audience during thismeeting were collected and organized into clustersand brought forward to a panel of the invitedspeakers. The discussion was taped, edited, andauthorized by the speakers.

Mijna Hadders-Algra (Groningen, the Netherlands)

One of the recurring issues in this workshop onpostural control was the concept of referenceframes. The question is do we need a referenceframe in order to control our posture? Do we haveone reference frame or a repertoire of referenceframes? A related question is what actually is thegoal in postural control? Is the goal to prevent usfrom falling or is it used to stabilize our heads inspace? Nowadays the trend in physical therapy isfunctional goal setting. So what is the goal as far aspostural control is concerned?

Marjorie Woollacott (Eugene, Oregon, USA):

We have to realize that basically there are twogoals in postural control. One is the orientation inspace which relates to the head position directingtowards a specific target or to the horizon. Theother is maintaining the center of mass within thebasis of support or moving effectively towards anew basis of support. So within the scope ofphysical therapy, clearly we have to look at thegoal in a specific task and make sure that we applya therapy to have the child reach that goal within atask.


Eva Brogren Carlberg showed us a film of agirl with cerebral palsy (CP), throwing a bean-bag.

(C) 2005 Freund Publishing House Ltd. 263

264 A. GRAMSBERGEN AND M. HADDERS-ALGRA

We clearly saw in the film that her head was notstabilized while she threw the bean-bag. Wouldthat mean that there is a priority in goals and thatthe girl only was able to successfully accomplishthe task of throwing the bean-bag when she did notpay too much attention to the position of the head?Could there be a priority in postural goals: the firstbeing ’not to fall’ and the second ’head stabili-zation in space’?

Eva Brogren Carlberg (Stockholm, Sweden)

reference, movements are performed and posturaladjustments are organized. Reference control iseffected by the stabilization of the body segmentsin relation to each other. When standing, a frameof support is organized and then the segmentalcontrol is relatively simple, but during movementspostural control has to be maintained during themovement. Then, the pelvis, the head, and also thetrunk and shoulders should be controlled in orderto making a movement possible (Assaiante, thisissue).

think you may be right. Her goal was to hitthe pole with the bean-bag: one could say that sheused an allocentric reference frame and all motorabilities to accomplish that task. She clearlyshowed a symmetric tonic neck reflex and that wasthe way for her to stabilize the trunk and thus to beable to make a movement at the same time.

Susan Harris (Vancouver, Canada)

When was a young clinician taking theNeuroDevelopmental Treatment (NDT) course, theinstructors explained that lack of adequate posturalcontrol mechanisms in children with CP, e.g. whilesitting in a seat and working on their schoolwork,meant that they--unlike other childrennwouldhave to think about maintaining their balance ontheir seat, as well as on concentrating on theirschoolwork. Obviously, these are two sets ofthings to think about. would think that when it isimportant for the child to do her schoolwork thateither you might change the environment by givinghim an adapted seat, or else train her to have betterpostural control during the task.

Christine Assaiante (Marseille, France)

Coming back to the question, think that forthe control of balance it is important to consider aframe of reference. On the basis of such frames of

Hans Forssberg (Stockholm, Sweden)

For the sake of the discussion, want toadvocate another opinion. Reference frames just fitinto a way of thinking. You could consider it a setof words with which we try to understand thenature of po stural control. And then, obviously,reference frames do not apply exclusively topostural stability but to all parts of the body andthe extremities including the fingers. So talking ofreference frames reflects a way of thinking of theprocessing in the CNS rather than that suchmechanisms really exist in the CNS.

Luba Zuk (Tel-Aviv, Israel)

agree only to some extent with Dr. Forssbergas still, think, the brain needs a sort of a referenceframe in order to make, what you might call thetransformations from the visual system to theproprioceptive system in order to plan amovement. When throwing a ball, we have toknow how far we should throw it, in what directionwe should throw it and then we should recruit theforce to accomplish that. So think we not onlyneed to control the head position, trunk, and in factall the parts of our body but we also need thevisual perception and the transformations to

orderly and adequately plan the movement, inorder to achieve what we want to.

GENERAL DISCUSSION 265

Marjorie Woollacott (Eugene, Oregon, USA)

Here would like to add that noticed that inthe studies on postural control performed so far,little attention has been paid to somatosensoryimpairments including visual and vestibularimpairments. As the sensory impairments might becrucial underlying factors to the actual motorimpairments, assessment of the sensory problemswould be a most important thing to add to ourfuture studies.

CLINICAL ASSESSMENT OF QUALITY OFPOSTURAL CONTROL


Another question which has been raised by theaudience is the following. Is there actually aclinical tool with which we can assess the qualityof postural control?

Laila de Groot (Amsterdam, the Netherlands)

think it will tum out to be extremely difficultto design an effective method to assess the qualityof postural control. In the past, mainly the staticcomponent of posture has been considered and itseems relatively easy to score deviations in thatsort of control. However, the dynamic aspect ofpostural control probably is far more important anddisentangling the movement as such from thedynamic component of postural control will bevery difficult.

Tatjana Veliekovic (Ljubljana, Slovenia)

It might well be that a variety of postures andmovement patterns, perhaps in a stylized setting,and recorded on video tape might lend to a

qualitative assessment, in a what we call a GestaltPerception-type of approach.


The Berg Balance Scale (1995) that has beenadapted for children could be of some help. But,indeed, there are only few other instruments toassess postural control and think what we coulddo is to pick out some of the items of the GrossMotor Function Measure (GMFM; Russell et al.2002) which are more balance oriented. Obviously,for children with milder motor disorders, e.g.children who are classified as level and II in theGross Motor Function Classification System(GMFCS, Palisano et al. 1997), you could use partsof the Movement ABC (Henderson & Sugden,1992) or the Bruininks-Oseretsky-test (Bruininks,1978).. But in general, I think it really would beworthwhile to develop a new instrument to assesspostural control that might include some measuresfrom existing methods and some new tests.

Andrew Gordon (New York, USA)

What has come across in this panel is that thereare not only static aspects in postural control, butalso dynamic aspects, and guess, there is not onemeasuring instrument that covers these differentaspects, although that is what we need. could

imagine that an instrument is devised that not onlyincludes some clinical measures, analogous tothose in the Berg Balance Scale but also to look atpostural control during standing or sitting andsway during those static postures. In addition,some active control tasks should be included, muchlike those that Marjorie Woollacott has describedin her contribution (Woollacott, this issue) andperhaps also some destabilization tests, e.g. inwhich children reach forward and where you lookat anticipatory postural adjustments.

Beatrijs Vereijken (Trondheim, Norway)

There are several clinical instruments availableto assess postural control but the problem is that


the results of different postural control tests do notcorrelate well with each other. That actually is themain problem. Each of these tests measuresdifferent aspects, and we do not know well enoughwhat we are looking at or how these differentaspects are related to each other.


In line with what said before (and from a

single subject research perspective), you shouldconsider what it is for each child in his or herpostural control that the therapist hopes to change.Secondly, what is most important to the childshould be considered in developing an individualtherapy objective. From this perspective, measuringthe abilities of a particular child would be far moreimportant than using some scale that might nothave specific applicability to your individual client.Far too infrequently, we look for the most effectiveoutcome measures of individual behaviors. Anapproach with a measurable therapy objectiveseems important in this respect. would think thatwould be more important than a broader scale.


think, the old way of thinking was thatpostural control is one component in movementcontrol and voluntary control of extremitymovements another. To my opinion, that is too

simple. The task of the CNS is to perform a

movement. What you may see in a child with CPbefore treatment is that the child manages toperform a movement with the whole body, whileafter successful treatment, the child stabilizes thebody and performs the motor task in another andmore efficient way. This illustrates that the centralnervous system (CNS) is continuously integratingand stabilizing all the elements of a movement. Inother words, posture and movement are not

organized in a hierarchical way but they areintegrated all the time.

An important research task for the future is tounderstand the relations between the two mainsensory systems, the body centered system or

proprioceptive system if you wish, and the other,which calibrates the body to the outside world, inwhich the visual system plays a dominant role. A.major challenge for the CNS is to make theappropriate transformations from the informationprocessed by the visual system to the informationgathered by the body-centered system in order tomake accurate movements.

Returning to the question of clinical assess-ment ofpostural control, we have to realize that themovement itself cannot be separated from posturalcontrol. But what we could do in our tests is toevaluate the reactive postural reactions when youare stabilizing the body or to test reactions whenyou are moving only one joint. So agree with Dr.Harris, Dr. Gordon and others that we have todevelop goal achievement scales with respect to

postural control. Sterotyped batteries are not reallywhat we are aiming for, though these might beuseful as a basis for further investigations.

Sara Capelovitch (Rehovot, Israel)

agree with Dr. Forssberg. It does not seem to

be possible to differentiate between the actual goal-directed movement and its accompanying posturaladjustment. Wouldn’t the conclusion be that we

cannot test the one without the other? Which meansthat we should not aim at an isolated clinicalevaluation of postural control. Wouldn’t it be betterto assess the way movements are carried out?

CEREBELLAR DEVELOPMENT ANDPOSTURAL CONTROL

Albert Gramsbergen (Groningen, the Netherlands)

Another topic relates to the development of thecerebellum. As known, the cerebellum at adult age


plays a key role in the fine-tuning of posturaladjustments. It has been asked to what extent thedevelopment of the cerebellum is dependent uponfunction. might start answering this question. Animportant part of the cerebellar development is lateindeed (e.g., Swinny, this issue). The Anlage of thedeep cerebellar nuclei and the layer of Purkinjecells is very early in the development of the brain.But, much later, in the human from shortly beforebirth until well after birth and in rodents evenwholly after birth, the precursors of the granularcells, the most numerous neuronal cell type in thebrain, start to proliferate from the extragranularlayer. These neuroblasts then migrate in an inwarddirection through the Purkinje cell-layer. Theestablishment of the connections between thesegranular cells with the Purkinje cells and also theirconnections with the climbing fibers that areimportant in the cerebellar circuitry, occurs largelyafter birth.

Jerome Swinny (Philadelphia, USA)

Going back to the question, am not quite surewhether we could differentiate between morpho-logical development and functional or activity-dependent development, as they are closely inter-linked. think all the evidence, which mainlyderives from experiments in tissue culture, pointsto the importance of synaptic activity beingimportant for the development of circuitry. Whenyou remove the afferents or block them yougrossly retard the development of the cerebellum(Strata et al, 1997).

Laurent Vinay (Marseille, France)

If we consider the contribution of thecerebellum in motor control as a link between theCNS and the periphery and muscle contractionsthan cerebellar functioning obviously requires boththe development of ascending and descending fiber

systems. In rats, where the control of the brain onthe lumbar spinal cord is fully developed by theend of the second postnatal week, it can not beotherwise than that the cerebellum has becomefunctionally important by that time.


Another question was that in the fMRIs duringmotor tasks, as shown by Dr. Forssberg, no clearindication of any activity in the cerebellum couldbe observed. The question is how should we

interpret this absence of activity or are we dealingwith an artifact?


The fMRIs presented to you were the veryfirst we made, and at that time the cerebellum wasout of view. But actually for the simple squeezingtasks showed you, that does not really matter.Our more recent research has indicated that thecerebellum is not active during such graspingtasks. But from more recent studies we now knowthat the cerebellum is very active during morecomplex motor tasks which need a lot ofprogramming and temporal ordering of themovements which constitute the movement pattern(Bengtsson et al., 2004).

THEORIES ON MOTOR CONTROL:WHAT ABOUT POSTURE?


A question from the audience that is remotelyrelated to the former one is the following. Asscientific theories are continuously changing andreplaced with newer theories, what do practitionersneed to know about theories on motor control andwhy?


Beatrijs Vereijken (Trondheim, Norway)

Theories are important because they condense abody of related findings into a coherent framework,allowing for the subsequent building and testing ofhypotheses. Every theory operates with a set ofassumptions and simplifications that direct furtherresearch enterprises. In other words, a theory guidesthe focus of subsequent research--i.e., whichquestions will be asked and how these questions aresought to be answered. This in turn, heavilyinfluences the data being collected, the knowledgedistilled from it, and the resulting recommendationsfor applications. When practitioners want to applythese recommendations in their daily practice, theyneed to be familiar with the background of thetheorymits departure points and fundamentalassumptionsmin order to be able to give therecommendations a proper place in their work.

TRAINING INTENSITY IN CHILDREN WITH CP


Another point of interest: it has been raisedthat children with CP need intense raining as thesechildren might have problems in learning specificfeatures of motor control. So the question is, doesit really help when the training is intense. Orrather: what is intense?


In Dr. Forssberg’s group, we tested a childwith CP in 1990 when she was 6 years old. Twelveyears later, we reassessed the force coordinationduring grasping in this girl. The reassessmentshowed that little change had occurred in the forcecoordination pattern. am not sure what kind oftherapy this child received over the 12 years butdespite of the therapy, performance had not

changed much. Now do not mean to imply that

this is necessarily completely representative butthink that in general we do not see muchimprovement in children with CP. Therefore,believe that at least in some aspects of motorcoordination or discoordination you indeed mightneed intensive training. For instance, in one of ourstudies on force coordination while lifting anobject, we showed that children with CP couldchange the coordination of anticipation within 25lifting trials (Gordon & Duff, 1999), which meansthat children with CP can learn certain aspects ofmotor behavior quickly.

In regard to the question of whether or notchildren with CP can learn, think that when youlook at simple control tasks, they have a problemwith developing internal models for this controlwhich is perhaps due to the impaired sensation ofthe movements. Apparently, these children do not

develop an appropriate representation of theirmovements.

Frank de Vries (Beetsterzwaag, the Netherlands)

Here would like to add the following. Withrespect to the motor performance of the girl withCP whose basic pattern of coordination did not

change over the years, it might mean that the girlalready at the age of 6 years had adopted the beststrategy. This could mean that even 12 years ofintense therapy would not help her any further inthis particular behavior.


This is a very good point. A lot of themovement patterns we see in children with CP maynot really be impairments but they may well beadaptive strategies or compensations.

Milivoj Velickovic Perat (Ljubljana, Slovenia)

When we are talking about intensity, we shouldconsider two points. First, the child should be


actively and intensely involved in the therapy.Second, it is the quality of training that matters.Intensity, therefore, does not just indicate theduration or the frequency of the therapeuticsessions.

Eugene Rameekers (Valkenburg, the Netherlands)

In response to both Dr. Velickovic and Dr.Gordon, would like to say that to my opinion wedo need intense therapy. We have to realize that achild, untreated and using the wrong strategy usedthis strategy for several years many times a dayand that the child did or did not succeed inaccomplishing a cortain task. When we starttherapy, we practice for half an hour per day withthe child. A very limited amount of practicecompared to the years during which the child usedthe maladaptive strategy and failed to perform thetask. Thus think, we do need very intense therapyto overrule the strategies used for years and years.

Christine Assaiante (Marseille, France)

Has anyone ever demonstrated a relationbetween the intensity of training and the benefitsfor the child?


Some years ago performed a literature searchand found only nine studies about this issue. Threeof these studies showed that the more intense thetherapy was, the better the outcome, but the othersix studies did not show a difference whatsoever.Happily enough, the performance of the childrenwho had been receiving intense therapy did not getworse either. The person who studied this most isEva Bower (e.g., Bower et al., 1996, 2001).

Another issue that is important in this respectis bursts of therapy. Rather than training once ortwice a week, even when it is for 6 hours, weperhaps should look at specific targeted goals

when working intensively with a child. mean thatwe perhaps should aim at a specific goal and allowthe child to practice and work with that specificgoal during an intense bout oftraining.

Eva Brogren Carlberg (Stockholm, Sweden):

The recent evidence report of the AmericanAcademy for Cerebral Palsy and DevelopmentalMedicine on conductive education and theintensity of different treatments (Darrah et al.,2004) included a study in which children weretrained for 13 hours a day, but even in this study,no effect was found; so something must have beenterribly wrong there.

Another aspect is retention of learning. Here, itis important to differentiate between the differentlevels of the GMFCS. Dr. Gordon, who presentedpilot data of a study on the effect of constraint-induced therapy in children with hemiplegia,showed that in children who function at GMFCSlevels and II, one problem is learned non-use (seeCharles & Gordon, this issue). When these childrenreceive very intense training they catch up veryfast. We see a similar thing in strength training andobviously, there is a good retention (Damiano etal., 2002). So the problem comes when the child hasa larger deficit, and is functioning at GMFCS levelsIII to V. The questions are, ’How much can youlearn’ and ’What are the limits’? These questionsare among the challenges for the future.


There is not something magically taking placewith learning in children with CP. Children withCP have the same mechanisms of learning andtraining as in all people and animals. During mylecture, showed you some studies on the plasticityof cortical maps. These studies showed that thesemaps are very dynamic. For instance, the monkeysin the studies by Merzenich were trained only for 3weeks and then only for half an hour or hour a


day, and this induced quite distinctive reorganiza-tions (e.g., Recanzone et al. 1992). So actually,think it is more a question of quality and thespecificity of the task than the duration or theintensity that makes you learn new movements.think that is important.


agree with Dr. Forssberg. In our constraint-induced therapy study, we chose an intensity oftraining that was analogous with that in adultstudies. The adult studies seemed to be suggestiveat this point that there is an efficacy. That beingsaid, do not think that in young children intensityis required to achieve changes. So it is probably thequality of practice that is more important. Like Dr.Forssberg mentioned, the ability to learn and theplasticity mechanisms are important factors intherapy in children with CP. However, childrenwith CP differ in one important aspect fromtypically developing individuals: they have a lesionof the brain. This might mean that the extent towhich you can accomplish changes is limited.

Marianne Appelman-Kreuzen (Lelystad, theNetherlands)

The quality and intensity of training very wellcould be dependent on the motivation of the childand the family to learn a new skill. We still knowlittle about that, but have the gut feeling thatmotivation is a key issue.

patterning of the upper-limb retraction. In otherwords, is a reclined posture a choice or an obligatoryposture imposed on the child by the condition?


The reclined posture was the posture chosenduring reaching by the children with CP thatdemonstrated in my lecture. Here it is interesting tonote that we perhaps deal with differences betweensitting and standing. Dr. Woollacott and hercolleagues showed in one of their studies that whentypically developing children adopted a crouchedposture during standing their muscle activationpatterns resembled those of children with CP(Burtner et al., 1998). But in sitting it might bewell the other way around. We showed that forchildren with CP the more crouched sittingposition functioned better than the upright sittingposture (Brogren et al., 2001). Thus, would not

say that the reclined position is an obligatoryposition. It is the posture which the child selectsthat matters.

Marjorie Woollacott (Eugene, Oregon, USA)

do not think that what we found is that thetypically developing children looked more likechildren with CP when they crouched. That is notto say that a crouched position is not effective orperhaps functional for children with CP.

Reint Geuze (Groningen, the Netherlands):

POSTURE IN CHILDREN WITH CP:DYSFUNCTION OR COMPENSATION?

Melanie Gibbs (Tadworth, UK)

Could someone please comment on theinfluence of a reclined posture to increase extensive

To draw this discussion in a wider sense,would like to ask Dr. Brogren the following. Yousuggested that children with deficits willtenaciously choose a certain sitting position whichwould be an optimal solution for their problems.However, to my opinion, the spontaneously chosensolutions are not always the best solutions for thetasks the child should be able to perform. In some


instances an optimal solution is chosen, but inothers not. For therapy, this distinction might bevery important. So my question is, how could we

distinguish between beneficial adaptations andmaladaptations?


think this question should be explored byevery therapist. So we always need to address thequestions, ’What are good compensations’? ’Whatare compensations that the child needs’? and’What can be changed with intense therapy’. Thebig challenge for the therapist is to analyze thecompensations and to ask why these are adopted.


think you ask for 10 more years of furtherresearch to be done. Latash and Anson (1996) havewritten a controversial paper. They addressedquestions about whether the motor patterns inindividuals with movement disorders are compen-sations that you should try to strengthen or whetherthey are rather impairments. They took the positionthat most often you are dealing with a compen-sation. agree with Dr. Geuze that perhaps not allcompensations necessarily are going to lead to thebest function and in those cases, you should trainother types of compensation and increase capabilities.

Richard Major (Newcastle upon Tyne, UK)

energy costs. That might be a good topic for afuture meeting.

Reint Geuze (Groningen, the Netherlands)

would like to make the suggestion thatvariable practice will enable the system to find itsoptimal solutions. Obviously, in children with amotor disorder this practice is limited. This mightbe the solution to the question just posed.


Coming to the end of this discussion, whichcould have continued for a much longer time andto the end of this workshop, we may conclude thatseveral new perspectives for research, for analysisofmotor problems in children with motor disordersand inspiration for a fresh start on thinking of ourtherapies have emerged during this meeting. Theinterest of basic scientists in the problems whichare encountered by th.e investigators involved inclinical problems and the newly gained knowledgein experimental research which has given way tothink of alternative strategies in clinical researchwere the motivation for organizing this workshop.We feel certain that the contributions of the key-note speakers and the poster presentations, as wellas the lively discussions during this workshop havegiven all of us the inspiration to proceed ourresearch into postural control as a key issue intypical and deviant motor behavior.

To answer the question of what is a goodposture, you need to analyze the biomechanics ofsuch postures to really come to an understanding ofit. If you want to optimize, would suggest you tolook at minimizing the moments and torques whichare present around joints and the reason for that isthat you want to minimize energy costs which areinvolved. think, basically we all are lazy and everygoal we want to achieve should be at minimum

REFERENCES

Assaiante C, Mallau S, Viel S, Jover M, Schmitz. 2005Neural Plast 20:37-46 (this issue).

Bentsson S, Ehrsson HH, Forssberg H, Ull6n F. 2004.Dissociating brain regions controlling the temporaland ordinal structure of learned movement sequencesEur J Neurosci 19:2591-2602.


Berg KO, Wood-Dauphinee S, Williams JI. 1995. Thebalance scale: Reliability assessment with elderlyresidents and patients with an acute stroke Scand JRehab Med 27: 27-36.

Bower E, McLellan DL, Arney J, Campbell MJ. 1996.A randomised controlled trial of different intensitiesof physiotherapy and different goals settingprocedures in 44 children with cerebral palsy. DevMed Child Neurol 38: 226-237.

Bower E, Michell D, Burnett M, Campbell MJ, McLellanDL. 2001. Randomized cont,’oiled trial of physio-therapy in 56 children with cerebral palsy followedfor 18 months. Dev Med Child Neuro143: 4-15.

Brogren E, Forssberg H, Hadders-Algra M. 2001. Theinfluence of two different sitting positions onpostural adjustments in children with spasticdiplegia. Dev Med Child Neurol 43" 534-546.

Bruininks RH. 1978. Bruininks-Oseretsky Test of MotorProficiency. Circle Pines: American GuidanceService; 1-153.

Burtner PA, Quails C, Woollacott MH. 1998. Muscleactivation characteristics of stance balance controlin children with spastic cerebral palsy. Gait Posture8:164-174.

Charles J, Gordon AM. 2005. A critical review ofconstraint-induced therapy and forced-use inchildren with hemiplegia. Neural Plast 20:173-189(this issue).

Damiano DL, Dodd K, Taylor NF. 2002. Should we betesting and training muscle strength in cerebralpalsy? Dev Med Child Neurol 44: 68-72.

Darrah J, Watkins B, Chen L, Bonin C. 2004.Conductive education intervention for children withcerebral palsy: an AACPDM evidence report. DevMed Child Neurol 46:187-204.

Gordon AM, Duff SV. 1999. Fingertip forces during

object manipulation in children with hemiplegiccerebral palsy. Anticipatory scaling. Dev MedChild Neurol 41:166-175.

Henderson SE, Sugden DA. 1992. Movement Assess-ment Battery for Children: Manual. Sidcup, Kent,UK: The Psychological Corporation; 128.

Latash ML, Anson JG. 1996. What are ’normal move-ments’ in atypical populations? Behav Brain Sci 19:55-68.

Palisano R, Rosenbaum P, Walter S, Russell D, WoodE, Galuppi B. 1997. Development and reliability ofa system to classify gross motor function inchildren with cerebral palsy. Dev Med Child Neurol39:214-223.

Recanzone GH, Merzenich MM, Jenkins WM, GrajskiKA, Dinse HR. 1992. Topographical reorganizationof the hand representation in cortical area 3b owlmonkeys trained in a frequency-discrimination task.J Neurophysiol 67:1031-1056.

Russell DJ, Rosenbaum P, Avery LM, Lane L. 2002.Gross Motor Function Measure (GMFM-66 &GMFM-88) users manual. Clin Dev Med No. 159.London, UK: MacKeith Press; 234.

Strata P, Tempia F, Zagrebelsky M, Rossi F. Reciprocaltrophic interactions between climbing fibres andPurkinje cells in the rat cerebellum. Prog Brain Res1997; 114:263-282

Swinny JD, Van der Want JJL, Gramsbergen A. 2005.Cerebellar development and plasticity: perspectivesfor motor coordination strategies, for motor skillsand for therapy. Neural Plast 20:81-88 (this issue).

Woollacott MH, Shumway-Cook A. 2005. Posturaldysfunction during standing and walking in childrenwith cerebral palsy: what are the underlying problemsand what new therapies improve balance. Neural Plast12:139-148 (this issue).

Submit your manuscripts athttp://www.hindawi.com

Neurology Research International

Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014

Alzheimer’s DiseaseHindawi Publishing Corporationhttp://www.hindawi.com Volume 2014

International Journal of

ScientificaHindawi Publishing Corporationhttp://www.hindawi.com Volume 2014


BioMed Research International


Research and TreatmentSchizophrenia

The Scientific World JournalHindawi Publishing Corporation http://www.hindawi.com Volume 2014


Neural Plasticity


Parkinson’s Disease


Research and TreatmentAutism

Sleep DisordersHindawi Publishing Corporationhttp://www.hindawi.com Volume 2014


Neuroscience Journal

Epilepsy Research and TreatmentHindawi Publishing Corporationhttp://www.hindawi.com Volume 2014


Psychiatry Journal


Computational and Mathematical Methods in Medicine

Depression Research and TreatmentHindawi Publishing Corporationhttp://www.hindawi.com Volume 2014


Brain ScienceInternational Journal of

StrokeResearch and TreatmentHindawi Publishing Corporationhttp://www.hindawi.com Volume 2014

Neurodegenerative Diseases


Journal of

Cardiovascular Psychiatry and NeurologyHindawi Publishing Corporationhttp://www.hindawi.com Volume 2014

Discussion Neurobiological Clinical Aspects Postural Control...

Documents

Transcript of Discussion Neurobiological Clinical Aspects Postural Control...