Pierre-Marie GAGEY

     Posturology is a new medical discipline. It studies disorders of the central nervous system thanks to the categories of space AND TIME.
     Indeed, at the end of the XIXth century, Jean-Marie CHARCOT and the Salpetriêre's French school suggested to isolate the disorders of the central nervous system that were caused by a lesion - i.e. that belonged to a spatial, anatomic category. That fertile suggestion led to the foundation of Neurology. But the first neurologists themselves suffered the dialectic effect of their suggestion: they did not know what to say anymore on the disorders of the central nervous system that did not belong to the categories of Neurology because they did not correspond to any lesion.
     The failure of BABINSKI's works on pithiatism at the end of the XIXth century is well known. His interrogations, together with FROMENT, on the functional disorders are less known - they could not find any answer because fundamental mathematical notions were lacking at the time. In the early XXth century, POINCARÉ's thoughts on recalcitrant differential equations opened the way to topology, a basic tool for non-linear dynamic analysis, that only truly developed at the end of the XXth century thanks to Russian mathematicians and calculators.
     That kind of analysis allows doctors to introduce the category of TIME in their approach to the central nervous system. Indeed, that system controls many functions, as the postural one, thanks to retroaction loops during which what happens at instant t depends on what happened at instant t-1. Now, the mathematical functions that express that logic of chained temporal series (as the "logistic" equation, for instance) are not linear, there is no proportionality between the effect and the causes: a minor variation of a factor can lead to the appearance of very important consequences, whereas an important variation will not necessarily have major consequences - what we call "the butterfly effect" since LORENTZ.
     Jean-Bernard BARON was the first doctor, as far as we know, to observe the "butterfly effect" during his experiences (1955) on the regulation of the postural tonic activity. Following and continuing those works, many doctors in southern Europe started to study disorders of the central nervous system whose logical structure is based, not on an anatomical lesion, but on the chaotic logic of chained temporal series. Such studies - particularly vigorous in the field of postural control - constitute Posturology.
     The fundamental concepts of posturology being essentially Latin, that discipline still finds it hard to develop outside southern Europe.

    There is an international Society: the International Society for Postural and Gait Reseach, which was founded in 1969 at Amsterdam (its name was: «International Society of Posturography», at this time), its current secretary is: Doctor Herman KINGMA, ENT Dpt, university Hospital of Maastricht, Holland, <secr@kno.azm.nl>.

    There is also local associations in some countries (Japan, Italy, Canada, Argentina, France).

    The actual president of the «Association Posture et Équilibre» is Michel LACOUR, <lacour@newsup.univ-mrs.fr> (please do not to disturb him)
    The current president of the Italian Association of clinical Posturology is Alfredo MARINO <postur@tin.it>
    The current president of the «Association de Posturopodie Internationale» is Philippe VILLENEUVE, <phvilleneuve@compuserve.com>.