Development of Postural Control in Healthy Children: A Functional Approach

From a set of experimental studies showing how intersegmental coordination develops during childhood in various posturokinetic tasks, we have established a repertoire of equilibrium strategies in the course of ontogenesis. The experimental data demonstrate that the first reference frame used for the organization of balance control during locomotion is the pelvis, especially in young children. Head stabilization during posturokinetic activities, particularly locomotion, constitutes a complex motor skill requiring a long time to develop during childhood. When studying the emergence of postural strategies, it is essential to distinguish between results that can be explained by biomechanical reasons strictly and those reflecting the maturation of the central nervous system (CNS). To address this problem, we have studied our young subjects in situations requiring various types of adaptation. The studies dealing with adaptation of postural strategies aimed at testing short and long-term adaptation capacity of the CNS during imposed transient external biomechanical constraints in healthy children, and during chronic internal constraints in children with skeletal pathologies. In addition to maintenance of balance, another function of posture is to ensure the orientation of a body segment. It appears that the control of orientation and the control of balance both require the trunk as an initial reference frame involving a development from egocentric to exocentric postural control. It is concluded that the first step for children consists in building a repertoire of postural strategies, and the second step consists in learning to select the most appropriate postural strategy, depending on the ability to anticipate the consequence of the movement in order to maintain balance control and the efficiency of the task

Anticipatory postural adjustments in a bimanual load-lifting task in children with developmental coordination disorder

International audienceAIM Postural control is a fundamental component of action in which deficits have been shown to contribute to motor difficulties in children with developmental coordination disorder (DCD). The purpose of this study was to examine anticipatory postural adjustments (APAs) in children with DCD in a bimanual load-lifting task. METHOD Sixteen children with reported motor problems (two females, 14 males; mean age 9y; SD 2y) and 16 typically developing, age-matched children (six females, 10 males; mean age 9y; SD 2y) took part in the study. The task required the children to maintain a stable elbow angle, despite imposed or voluntary unloading of the forearm. APAs were assessed using electromyography and kinematics analysis. RESULTS Although children with DCD could compensate for the consequences of unloading, the results demonstrated that APAs were less efficient in children with DCD than in typically developing children. A positive and significant coefficient of regression between the flexor inhibition latency and the postural stabilization was only found in typically developing children. INTERPRETATION The impaired fine-tuning of the muscle contribution and the poor stabilization performances demonstrate poor predictive modelling in DCD

Concept de handicap. Définitions, classifications et utilisations

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Perspectives actuelles sur le développement du tonus et de la posture

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Development of motor planning for dexterity tasks in trisomy 21

International audienceWe examinedthemacroscopicaspectsofmotorplanningintwomanualdexteritytasks,comparingchildren,adolescents,andyoungadultswithtrisomy21(T21)withtypicallydevelopingcontrolsfromadevelopmentalperspective.Weanalyzedtheorderinwhichobjects werepickedupfromatableduringtwomanualtasksoftheMovementAssessmentBattery forChildren(M-ABC).ParticipantswithT21werealwaysslowerthancontrols.Task completiontimesdependedonthestrategyusedbyparticipantstogatherupthepegs orcoins.Astructuredstrategy,inwhichtheparticipantspickedtheitemsupmovingmethodicallyalongeachrow/column,contributedtorapidtaskcompletionbyyoungerchildren andparticipantswithT21.ThisstudyhighlightstheabilityofchildrenwithT21toselect andmaintainanefficientstrategythattakesaccountoftheirmotordifficulties.DevelopmentaltrajectorieshelptoexplainT21functioninginthesedexteritytasks

Trouble de l'acquisition de la coordination et troubles de l'écriture : peut-on parler de comorbidité ?

International audienceComorbidity in developmental disorders has theoretical significance but also clinical. The term comorbidity refers to any distinct additional clinical entity that has existed or that may occur during the clinical course of a patient (Feinstein, 1970). This acceptance, however, requires to be clarified in the context of diagnostic classifications of mental disorders. Indeed, we must determine whether relationships exist between the two comorbidities. With regard to dysgraphia and developmental coordination disorder (DCD), several facts contribute to answer the title’s question. Firstly, classifications usually do not include "dysgraphia", which is not a diagnostic entity itself. Then, many researches show that dysgraphia and DCD are frequently present at the same time, suggesting the existence of a common dysfunction. Finally, most of the models that are related to dysgraphia consider different origins of the disorder, ipso facto dismissing the assumption of a single disease entity. Therefore, it seems inappropriate to use the term comorbidity to account for the presence of dysgraphia in a child having been diagnosed DCD.La comorbidité dans les troubles développementaux a une importance théorique mais aussi clinique, il est cependant important de définir ce qu’on entend par « comorbidité ». Le terme de comorbidité désigne toute entité diagnostique additionnelle qui apparait ou existe durant l’histoire clinique d’un patient (Feinstein, 1970). Cette acception nécessite toutefois d’être précisée dans le contexte des classifications diagnostiques des troubles mentaux. Il s’agit en effet de définir si des liens existent entre les deux pathologies concomitantes. Pour ce qui concerne la dysgraphie et le trouble de l’acquisition de la coordination (TAC), plusieurs éléments permettent de répondre à la question posée dans le titre. Tout d’abord, les classifications usuelles ne comportent pas la catégorie « dysgraphie », qui n’est donc pas une entité diagnostique à proprement parler. Ensuite, un certain nombre de recherches montre que dysgraphie et TAC sont très fréquemment présents en même temps, ce qui suggère l’existence d’un dysfonctionnement commun. Enfin, les modèles d’explication de la dysgraphie envisagent, dans leur très grande majorité, diverses origines à ce trouble, écartant ipso facto l’hypothèse d’une entité morbide unique. En conséquence, il nous paraît inapproprié d’utiliser le terme de comorbidité pour rendre compte de la présence d’une dysgraphie chez un enfant présentant un TAC

Déficience auditive précoce et attention conjointe : apport de la psychologie du développement

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Dépendance-Indépendance au champ et rééducation psychomotrice

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Approche dimensionnelle de la comorbidité entre trouble développemental de la coordination et trouble spécifique de l’apprentissage de la lecture : étude sur la graphomotricité / A Dimensional Approach to Comorbidity Between Developmental Coordination Disorder and Dyslexia: A Study of Graphomotor Abilities

International audienceThe present study examined the comorbidity between developmental coordination disorder and dyslexia, adopting a dimensional approach. Participants were 120 children aged 8 12 years, with or without developmental disorders. After assessment with a reading test (Alouette) and motor test (MABC), children performed handwriting and graphomotor tasks on a graphic tablet. GAM analyses were used to test the contribution of the children’s reading and motor test scores to their handwriting and graphomotor performances. Results revealed a correlation between reading and motor scores, despite considerable heterogeneity within the groups. The variables measured during the handwriting and graphomotor tasks often depended on the children's scores on the motor and reading tests. Results support the hypothesis of shared risk factors for DCD and dyslexia, and confirm the relevance of adopting a dimensional approach to neurodevelopmental disorders

Le développement typique et atypique des actions: théories, recherches et pratiques

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