xx/xx/1929 - 14 Août 2011

Homage to Jean-Bernard BARON, the "Damned"
Victor Gurfinkel & Pierre-Marie Gagey

(Text refused by Dr Theologis, editor of the journal 'Gait and Posture', official journal of the ISPGR)
( You can find the text published by Gait & Posture at this URL: http://dx.doi.org/10.1016/j.gaitpost.2012.11.023 )

     Long before the birth of Jean-Bernard Baron that curse which was to haunt him throughout his life had been uttered: "A fact, whose determinism is not rational must be rejected from Science." (Bernard C, 1865). Jean-Bernard BARON was rejected indeed from Science until his death, because he highlighted a fact whose rationality did not correspond to what was accepted by the international scientific community, at that time. This fact questioned the principle of proportionality between a cause and its effects that Claude Bernard had however demonstrated so brilliantly about the toad venom (Bernard C, 1865).
     Everything had begun with his thesis of Medicine. Why had Baron chosen the heterophoric dizziness as his thesis topic? Anyway, this thesis strongly aroused his curiosity because it allowed him to realize that the medicine of his time knew almost nothing about this kind of dizziness. He decided to make it the subject of a science thesis (Baron JB, 1950, 1951, 1955).
     For such a new subject, he adopted a very simple protocol. Baron tried to perform an experimental model of heterophoria on his experimental animals, only by cutting a few fibers off an oculomotor muscle. Hard to imagine a simpler procedure. The first observations were totally confusing: sometimes nothing happened, the animal would behave as if nothing had been done, sometimes conversely the animal had a massive hypertonia of its paravertebral muscles, on one side only, so it was completely bent on itself and could not swim straight ahead of it, as soon as it began to move, it would turn on itself and go on moving this way on and on.
     The reason for this disparity in results was quickly suspected, Baron knew that his quick strokes of scalpel were far from accurate: they certainly did not cut exactly the same number of muscle fibers on all animals. A first possibility to confirm this hypothesis was easy to imagine, it was enough to observe the importance of the oculomotor imbalance induced by the operation. And after multiplying his interventions, Baron was, indeed, able to separate the two populations on a simple criterion: "Four degrees". If the operation had been successful, that is to say, if it had brought about a small oculomotor imbalance, less than 4°, then the animal showed the paravertebral hypertonia, otherwise no change happened. The extraordinary point was therefore that the major effect was caused by the minor cause, the less than four degrees oculomotor imbalance, and only by it.
     In 1955, the formal absence of proportionality between the cause and its effects was just inadmissible for the doctor' minds. Therefore, this fact, so new, so surprising, had no recognition. Baron's thesis was not even published; it is still a rough copy typed on an old machine "Underwood", hand illustrated as well as possible, deposited in the library of the Faculty of Medicine. When I photocopied this copy, it was in a library of La Sorbonne (Jussieu).
Tired of all these failures, Baron himself dropped this discovery. He entered the CRNS, worked on posturography and participated in the founding of the International Society of Posturography, now the ISPGR.

     Baron died in August 2011, before HIS discovery was known and recognized... Only a few therapists in Southern Europe have realized that Baron had made the first physiological experiment of a nonlinear dynamic system : the 'upright postural system' ( Martinerie J, Gagey PM, 1992; Gagey PM et al., 1998)).

     If Baron had been interested in celestial mechanics, in the problem of the "three-bodies" to define the orbits of three planets interacting according to Newton's laws, or had tried to solve some difficult differential equations, he would have known that fifty years before his thesis, Henri Poincaré had discovered this very peculiar behavior of non-linear dynamic systems, which has nothing to do with the principle of proportionality (Poincaré, 1908). Poincaré had even imagined a very simple representation, the phase space, which allows an easy understanding of what happens in these time series of chained successive states of the system. "The rationality of the determinism" highlighted by Baron was therefore already known... But Baron did not know it, as all the physicians of that time to whom he spoke of his discovery... without being listened to.
     The lack of proportionality between a cause and its effects led to a complete standstill, while the small rotating fishes of Baron told much more things, and easier to understand, than the nonlinear dynamic systems! ...
For example: they showed that when handling an input of the postural system, it immediately changes the regulation of the postural tonic activity - provided that the handling is very fine, of course - Is it not a simple fact? Moreover, a not surprising one: if we change the relationship of a living body to his outside world, what is more normal than its adaptation to this world?
     One more piece of information drawn from this experience: if the small fish of Baron swim round and round, it is because they are completely curved on themselves before they even get to swim. The kinetic activity, as Jacques Paillard said, is set on a static system on which it depends; the fish cannot swim straight ahead when its body is twisted on itself. A static postural system does exist.
     But the curse that had befallen Baron prevented even these very simple data from being heard. Baron presented facts whose determinism was not rational; he was to be pushed out of Science!

Poor Jean-Bernard, the "Damned", what a life! ...
But now the curse has fallen and, we can gloriously say a frank and warm 'thank you' to Jean-Bernard Baron for everything he taught us.


Bernard Cl. (1865) Introduction à l'étude de la médecine expérimentale. Delagrave, Paris.
Baron JB, Musculature extrinsèque et équilibre des poissons, C.R. Acad. Sc.,1950, 2231-2233.
Baron JB, Relations entre les muscles moteurs oculaires, les nageoires et l'équilibre des poissons, C.R. Acad. Sc., 1951, 1087-1088.
Baron J.B. - Muscles moteurs oculaires, attitude et comportement locomoteur des vertébrés. Thèse de Sciences, Paris, 158 pages, 1955.
Martinerie J., Gagey PM (1992) Chaotic analysis of the stabilometric signal. In M.Woollacott & F. Horace (Eds) Posture and gait: control mechanisms. University of Oregon Books (Portland), Tome I: 404,407.
Gagey P.M. Martinerie J., Pezard L., Benaim Ch. (1998) L'équilibre statique est contrôlé par un système dynamique non linéaire. Ann. Oto-Laryngol., 115: 161-168 Poincaré H. (1908) Science et méthode. Flammarion, Paris