Case Studies in Neuroscience: A dissociation of balance and posture demonstrated by camptocormia

George, Rebecca J. St; Gurfinkel, V. S.; Kraakevik, Jeff; Nutt, John G.; Horak, Fay B.

doi:10.1152/jn.00582.2017

“…More detailed evidence comes from a case study of a patient with camptocormia, and condition where posture becomes 'bent over' whilst standing [86]. This study found that whilst posture was perturbed by camptocormia, balance remained intact, dissociating the balance component from particular states and trajectories of posture.…”

Section: What Happens Next? Post-buoyancy Adaptation and Sensorimotor...mentioning

confidence: 99%

Hanging in there: Uterine Buoyancy Defines Homeostatic Set-Points for Gravity Adaptation in Humans

Wilkinson¹,

Ciaunica²

2023

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0

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Gravity is a fundamental force of nature, to which all biological systems, including human bodies, must adapt to survive. Maintaining bodily and behavioural integrity in the vertical spatial dimension whilst under continuous perturbation from gravity is a universal task for all living systems. However, gravity adaptation in human embodiment in utero and beyond is often overlooked. This paper suggests that prenatal buoyancy (i.e. adaptation to fluid medium) provides foundational set-points for antigravity homeostatic self-regulatory processes in humans. The concepts of homeostasis and allostasis are central to understanding biological self-organisation and adaptivity to the external environment. Organisms must maintain essential variables within certain bounds or ‘set-points’ in order to self-maintain and survive, despite ambient variation and entropic pressures. We propose a novel characterisation of antigravity adaptation as a core homeostatic drive, analogous to body temperature regulation. This proposal is based on a reconceptualization of self-regulation in relation to gravity constraints as a problem of density/buoyancy, not just mass/weight as it is typically considered. Specifically, we suggest a hypothetical foundational set-point for gravity homeostasis in prenatal neutral buoyancy via suspension of the foetus in amniotic fluid. Our proposal provides a principled route to naturalise the strong links between antigravity adaptation and emotionally valenced perceptions as expressions of satisfying core bodily needs. By highlighting the role of prenatal buoyancy in scaffolding self-regulatory processes in development, this paper aims to pave the way towards more accurate picture of how key developmental stages of human embodiment unfold across the sensorimotor lifespan.

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“…If this distinct challenge is met by a distinct homeostatic response, one would expect to observe a dissociation between the pure 'postural control' system (arranging body and limbs), and the 'antigravity balance system' (supporting the weight of body and limbs). There is some evidence for such dissociation from a case study of a patient with camptocormia, a condition where posture becomes bent over whilst standing [112].…”

Section: 𝑀𝑀mentioning

confidence: 99%

Hanging in there: Prenatal origins of antigravity homeostasis in humans

Wilkinson,

Ikegami,

Ciaunica

2023

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0

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All life on Earth must find a way to manage the continuous perturbation of gravity. From birth, and even before, humans exhibit effortful ‘antigravity’ work to enact bodily, postural and behavioural form despite gravity. Indeed, observable antigravity behaviour is a standard diagnostic indicator of neonatal sensorimotor health. Antigravity behaviour has been investigated extensively in its biomechanical details. Yet its motivational structure has not been a focus of research. What drives the human body to expend energy on this effortful behaviour? It is widely understood that thermic homeostasis in humans is organised around conserving core body temperature at a set-point of ~37oC. There is currently no equivalent concept of a general homeostatic set-point driving antigravity effort. In this theoretical paper, we aim to establish such a concept. We make the case that the core developmental set-point for human antigravity homeostasis is “neutral buoyancy” (gravity and buoyant force are balanced), which is afforded to the foetus by its approximately equi-dense amniotic fluid medium in utero. We argue that postnatally, the general task of human antigravity balance is to emulate the conditions of neutral buoyancy, based upon prenatal experience thereof. Our aim in this paper is to sketch a high-level outline of a novel characterisation of ‘antigravity balance’ as conservative homeostasis, and lay out some implications and predictions of this model, with the intention of spurring wider research and discussion on this hitherto little explored topic.

show abstract

“…If this distinct challenge is met by a distinct homeostatic response, one would expect to observe a dissociation between the pure 'postural control' system (arranging body and limbs), and the 'antigravity balance system' (supporting the weight of body and limbs). There is some evidence for such dissociation from a case study of a patient with camptocormia, a condition where posture becomes bent over whilst standing [113].…”

Section: 𝑀𝑀mentioning

confidence: 99%

Prenatal origins of antigravity homeostasis in humans

Wilkinson,

Ikegami,

Ciaunica

2023

Preprint

0

View full text Add to dashboard Cite

All life on Earth must find a way to manage the continuous perturbation of gravity. From birth, and even before, humans exhibit effortful ‘antigravity’ work to enact bodily, postural and behavioural form despite gravity. Indeed, observable antigravity behaviour is a standard diagnostic indicator of neonatal sensorimotor health. Antigravity behaviour has been investigated extensively in its biomechanical details. Yet its motivational structure has not been a focus of research. What drives the human body to expend energy on this effortful behaviour? It is widely understood that thermic homeostasis in humans is organised around conserving core body temperature at a set-point of ~37oC. There is currently no equivalent concept of a general homeostatic set-point driving antigravity effort. In this theoretical paper, we aim to establish such a concept. We make the case that the core developmental set-point for human antigravity homeostasis is “neutral buoyancy” (gravity and buoyant force are balanced), which is afforded to the foetus by its approximately equi-dense amniotic fluid medium in utero. We argue that postnatally, the general task of human antigravity balance is to emulate the conditions of neutral buoyancy, based upon prenatal experience thereof. Our aim in this paper is to sketch a high-level outline of a novel characterisation of ‘antigravity balance’ as conservative homeostasis, and lay out some implications and predictions of this model, with the intention of spurring wider research and discussion on this hitherto little explored topic.

show abstract

Case Studies in Neuroscience: A dissociation of balance and posture demonstrated by camptocormia

Cited by 8 publications

References 32 publications

Hanging in there: Uterine Buoyancy Defines Homeostatic Set-Points for Gravity Adaptation in Humans

Hanging in there: Uterine Buoyancy Defines Homeostatic Set-Points for Gravity Adaptation in Humans

Hanging in there: Prenatal origins of antigravity homeostasis in humans

Prenatal origins of antigravity homeostasis in humans

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