Dependence of joint stiffness on the conditions of visual control in upright undisturbed stance in humans

  title={Dependence of joint stiffness on the conditions of visual control in upright undisturbed stance in humans},
  author={Boris Smetanin and K. E. Popov and G. V. Kozhina},
We recorded the sagittal and frontal components of the stabilogram of healthy humans in upright undisturbed stance under five conditions of visual control: (i) open eyes (OE); (ii) closed eyes (CE); (iii) visual inversion (VI); (iv) central vision (CV), and (v) diffused light (DL). Through a low-pass filter of trajectories of the center of pressure of feet (CPF), the vertical projection of the center of gravity (CG) and, consequently, the difference CPF-CG were estimated. The former represents… 
Human upright posture control in a virtual visual environment
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The findings show that, under VVE conditions, visual sensory afferentation is ignored by cerebral structures controlling postural adjustments if standing occurs on a motionless support but is effectively used at the maintenance of upright stance on an oscillating support.
Postural reactions of humans in upright stance: Dependence on different visual conditions and the level of stiffness in the ankle joints
The findings demonstrate that the correlation between the characteristics of postural reactions in the upright stance and the level of ankle joint stiffness is not single-valued.


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The use of stabilogram-diffusion analysis to examine how visual input affects the operational characteristics of open-loop and closed-loop postural control mechanisms and reflex-based feedback systems of healthy, young individuals suggests that they are organized in functionally equivalent ways.
Center of Gravity Motions and Ankle Joint Stiffness Control in Upright Undisturbed Stance Modeled Through a Fractional Brownian Motion Framework
Results deduced from both input (CG,) and muscular stiffness (CP - CGV) thus provide insight into the way the central nervous system regulates stance control and in particular how CG and CP - CG are controlled.
Adaptational Modifications of the Vestibular Postural Response in Humans under Conditions of Horizontal Visual Reversal
The effect of short-term adaptation to visual reversal on the system controlling vertical posture resulted in simple rejection of the information coming via the visual input, which can be interpreted as a result of adaptational transformation of the visual-vestibular relation directed toward minimization of theVisual- vestibular conflict.
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A relatively simple control scheme for regulation of upright posture that provides almost instantaneous corrective response and reduces the operating demands on the CNS is proposed.
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Examination of the function of the pre-gait weight shifts in generating the dynamic forces needed to start walking at different speeds suggested that dynamic phenomena prior to stepping are essential to walking as far as they contribute to the creation of convenient conditions for progression.
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