Gilles Dietrich

Paris Descartes, CPSC | Paris 5 · UFR de Sciences et Techniques des Activités Physiques et Sportives de Paris (STAPS)

Résumé Objectif Il s’agit, à partir des dessins de conscience de ses sensations internes réalisés par les circassiens du Centre National des Arts du Cirque (CNAC) et de leurs verbatims, de décrire comment des sensations internes produites dans le corps vivant parviennent involontairement, par émersion, dans la conscience du corps vécu. Méthodolog...

Bergson's philosophy marked a turning point in Western understanding of time by differentiating quantitative time-apprehended by intelligence-from qualitative time-duration, embedded in consciousness and provided by intuition. Even if by unveiling those two modalities, he could beneficially reconsider the very nature of, altogether, movement, perce...

De nombreux courants de l’écologique questionnent les rapports entre le corps et son environnement. Il convient aujourd’hui de mettre en exergue leur complémentarité. À travers l’analyse de l’émersion des sensibles du vivant dans la conscience du corps vécu, l’émersiologie est mise en perspective des travaux de Varela sur l’énaction. L’émersion et...

Bergson’s philosophy marked a turning point in Western understanding of time by differentiating quantitative time—apprehended by intelligence—from qualitative time—duration, embedded in consciousness and provided by intuition. Even if by unveiling those two modalities, he could beneficially reconsider the very nature of, altogether, movement, perce...

The robotic-assisted gait training therapy (RAGT), based on intensity and repetition of movement, presents beneficial effects on recovery and improvement of postural and locomotor functions of the patient. This study sought to highlight the effect of this RAGT on the dynamic equilibrium control during walking in children with Cerebral Palsy (CP) by...

L'artisan est bien souvent admiré pour sa production, mais peut-être surtout pour son tour de main. Sa gestualité fascine pour sa "justesse" et son "efficacité" qui lui confèrera aussi une dimension esthétique, tant que l'on est tenté parfois d'y voir une forme de "surfait", de théâtralisation qui transforme l'action efficace en un acte signifiant...

1. La posture : généralités La posture représente l'attitude fondamentale d'une espèce, chaque espèce possédant sa posture propre de référence. Elle se traduit par « la stabilisation automatique du corps dans le champ des forces de gravité dans une position standard caractéristique de l'espèce » (Paillard, 1980). Si l'on considère le corps comme un...

D 'un point de vue général, la rééducation constitue, selon l'Organisation mondiale de la Santé (2001), « l'ensemble des mesures/moyens ayant pour objet majeur de conserver et d'améliorer, si possible, les capacités physiques et/ou mentales du patient, lui permettant d'occuper par ses propres moyens une place aussi normale que possible dans la soci...

Various authors have suggested similarities between tool use in early hominins and chimpanzees. This has been particularly evident in studies of nutcracking which is considered to be the most complex skill exhibited by wild apes, and has also been interpreted as a precursor of more complex stoneflaking abilities. It has been argued that there is no...

Hemiplegia is a more or less complete loss of hemibody voluntary motricity following a brain injury, usually resulting in alterations of the locomotor system with persistent disorders of movement and posture. We were interested in studying the gait pattern called “stiff knee gait” with the main objective to highlight the role of a robotic rehabilit...

This study examines the process of learning to walk from a functional perspective. To move forward, one must generate and control propulsive forces. To achieve this, it is necessary to create and tune a distance between the centre of mass (CoM) and the centre of pressure (CoP) along the antero-posterior axis. We hypothesize that learning to walk co...

Researchers in cognitive neuroscience have become increasingly interested in how different aspects of tool use are integrated and represented by the brain. Comparatively less attention has been directed toward tool use actions themselves and how effective tool use behaviors are coordinated. In response, we take this opportunity to consider the mech...

Understanding the human aging of postural control and how physical or motor activity improves balance and gait is challenging for both clinicians and researchers. Previous studies have evidenced that physical and sporting activity focusing on cardiovascular and strength conditioning help older adults develop their balance and gait and/or decrease t...

Objective: The objective of the present study was to highlight the role of head stabilization and to analyze multisegment head-trunk coordination during gait in children with cerebral palsy (CP). Material and method: Postural control was measured and compared in a group of 16 CP subjects and a control group of 16 healthy subjects. The subjects h...

It is well known that adopting a posture required by the central nervous system takes into account a frame of reference. This frame of reference is built on sensory information and, more particularly, on vision, which is often considered to be the main input. The contribution of vision varies by participant and defines their cognitive style. This s...

Various authors have suggested behavioural similarities between tool use in early hominins and chimpanzee nut cracking, where nut cracking might be interpreted as a precursor of more complex stone flaking. In this paper, we bring together and review two separate strands of research on chimpanzee and human tool use and cognitive abilities. Firstly,...

As society ages and the frequency of falls increases, counteracting gait and posture decline is a challenging issue for countries of the developed world. Previous studies have shown that exercise and hazard management help to improve balance and/or decrease the risks for falling in normal aging. Motor activity based on motor-skill learning, particu...

Vision contributes fundamentally to the control of the standing posture. The illusion of self motion falsely perceived (vection) increases postural sway while standing. In this paper we examine the effect of vection on both standing and deep squatting with the hypothesis that the squatting posture should not be disturbed by the conflict of sensory...

Learning to walk is viewed here from a functional point of view. To move forward it is necessary to produce propulsive forces that necessitate creating and tuning a distance between the center of mass (CoM) and the center of pressure (CoP) along the anteroposterior axis .We hypothesize that learning to walk consists in learning to produce these pro...

Nut-cracking may be described as the action of choosing a stone with one hand, positioning the nut on an anvil with the other hand, and hitting the nut with a ballistic movement. A functional description of the nut-cracking action will consider the mechanical properties that must be satisfied to succeed in the task at hand, that is, the mechanical...

This paper presents the results of a new approach to investigation of the relationships between stone knapping kinematics (covering motion, speed and kinetic energy of the percussive act), knapping expertise and characteristics of resulting debitage. It introduces wholly new methods of lithic analysis, leading to empirical recognition of knapping s...

The purpose of the present work was to study swimmers' efficiency during the underwater phase of the grab start. Eight high-level swimmers participated in this study. They performed two types of start: a regular grab start (with underwater leg propulsion after the glide) and a grab start with no underwater movement (swimmers had to remain in a stre...

The aim of this article is to elaborate a general framework for modeling dual opposition activities, or more generally, dual interaction. The main hypothesis is that opposition behavior can be measured directly from a global variable and that the relative distance between the two subjects can be this parameter. Moreover, this parameter should be co...

Tool use can be considered a particularly useful model to understand the nature of functional actions. In 3 experiments, tool-use actions typified by stone knapping were investigated. Participants had to detach stone flakes from a flint core through a conchoidal fracture. Successful flake detachment requires controlling various functional parameter...

Since a few years, performance analysis during a sport event became a key point to understand and improve athletes’ performance. Nevertheless, as during football and basketball games, these analyses are often statistical analysis. No kinematic data are collected. Performance analysis during swimming races also follows this trend. The most widely us...

The aim of the present study was to identify the main motor coordination involved during the underwater undulatory swimming phase of the start. Twelve French high-level swimmers took part in this study. Swimmers were filmed during the entire underwater phase of the start (i.e. fifteen meters from the start platform). Specific anatomical landmarks w...

Background. Based on personal experience of ski teaching, ski training and ski competing, we have noticed that some gaps exist between classical models describing body-techniques and actual motor acts made by performing athletes. The evolution of new parabolic shaped skis with new mechanical and geometric characteristics increase these differences...

Tool use in apes has been considered a landmark in cognition. However, while most studies concentrate on mental operations, there are very few studies of apes' cognition as expressed in manual skills. This paper proposes theoretical and methodological considerations on movement analysis as a way of assessing primate cognition. We argue that a privi...

C6 quadriplegic patients lose the ability to use their triceps, but the arm flexors remain intact. However, they are still able to extend the elbow. A previous kinematics study showed that their pointing movements were very similar to those of healthy subjects. We make the hypothesis that the triceps is more likely to be used to ensure elbow stiffn...

Cambay is one of the very rare places in the world where the stone-knapping technique still responds to the principles of the conchoidal fracture. The technique practised is an indirect percussion by counter-blow and is used for making stone beads. This technique is a recent one in the history of techniques. It can provide, however, an appropriate...

Introduction. – In this preliminary study, we introduce a biomechanical model to analyse javelin throw movement in order to determine how the maximal velocity at release time is reached.Fact synthesis. – We calculated many parameters. Only javelin velocity at release time is correlated with the throwing distance. By using this method, we could note...

Maintaining an unstable equilibrium requires that multiple joints be coordinated so that the center of mass is kept above the base of support. The authors' aim in the present study was to discover the underlying dynamics of local (foot, hip, or head) and global (center of mass) components involved in balance control and how those dynamics are affec...

This paper presents a conceptual model for studying the contribution of each leg to sideways stability of a four-link biped. It was assumed that a linear feedback controller maintained balance with torque related to the deviation from a reference value of the angle made by the trunk with the vertical. Predictions for ground reaction forces produced...

Trajectories of the hands and whole-body center of mass were studied during whole-body lifting tasks. The movements of different parts of the body were monitored with the ELITE system. Subjects were instructed to lift to shoulder height an object placed at one of two distances (5-45 cm) before them on the floor. The lifts were performed both with a...

This study deals with the learning of a complex motor task. The example used is rock climbing, where the subject's motricity is highly constrained by the natural environment. The working hypothesis is that the sensorimotor system searches for behavioral solutions characterized by minimal energy expenditure in the dissipation of forces. Harmonic sys...

Skills involved in the knapping of Harappan long carnelian beads are studied in order to assess their value as well as knappers’ socio‐economic status. Skills are studied by reference to present‐day bead knapping in Khambhat, India. They are examined from the way actors are able to handle the complexity of the task and achieve it. They are analyzed...

The study deals with the segmental organization of single- and multi-step walking. Local (segmental) and global (center of gravity) anticipatory movements associated with the initiation of the stepping movement were investigated in 5 normal subjects. Each subject performed a single-step walking task under three conditions of step velocity. Global a...

This study analyzes the movements of the hips, shoulders and of the body center of gravity before and at heel-off, when step execution begins to initiate gait from an upright posture. The heel-off movement was considered as a dynamic perturbation induced by the stepping movement. The experimental paradigm used for studying this perturbation was the...

INTRODUCTION: Motion analysis is a common technique in biomechanics and sport studies. Since Abdel-Aziz and Karara (1971), the direct linear transformation (DLT) is the most widely used method to analyse human movements. More recently, Drenk et al. (1999) proposed a modified DLT method, called DLT double-plane method (DLT DP), which involves two pa...