Stabilogram-diffusion analysis was used to examine how prolonged periods in microgravity affect the open-loop and closed-loop postural control mechanisms. It was hypothesized that following spaceflight: (1) the effective stochastic activity of the open-loop postural control schemes in astronauts is increased; (2) the effective stochastic activity and uncorrelated behavior, respectively, of the closed-loop postural control mechanisms in astronauts are increased; and (3) astronauts utilize open-loop postural control schemes for shorter time intervals and smaller displacements. Four crew members and two alternates from the 14-day Spacelab Life Sciences 2 Mission were included in the study. Each subject was tested under eyes-open, quiet-standing conditions on multiple preflight and postflight days. The subjects' center-of-pressure trajectories were measured with a force platform and analyzed according to stabilogram-diffusion analysis. It was found that the effective stochastic activity of the open-loop postural control schemes in three of the four crew members was increased following space-flight. This result is interpreted as an indication that there may be in-flight adaptations to higher-level descending postural control pathways, e.g., a postflight increase in the tonic activation of postural muscles. This change may also be the consequence of a compensatory (e.g., “stiffening”) postural control strategy that is adopted by astronauts to account for general feelings of post-flight unsteadiness. The crew members, as a group, did not exhibit any consistent preflight/postflight differences in the steady-state behavior of their closed-loop postural control mechanisms or in the functional interaction of their open-loop and closed-loop postural control mechanisms. These results are interpreted as indications that although there may be in-flight adaptations to the vestibular system and/or proprioceptive system, input from the visual system can compensate for such changes during undisturbed stance.
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Andersen DJ, Reschke MF, Homick JE, Werness SAS (1986) Dynamic posture analysis of Spacelab-1 crew members. Exp Brain Res 64: 380–391
Collins JJ, De Luca CJ (1993) Open-loop and closed-loop control of posture: a random-walk analysis of center-of-pressure trajectories. Exp Brain Res 95: 308–318
Collins JJ, De Luca CJ (1994) Random walking during quiet standing. Physical Rev Lett 73: 764–767
Collins JJ, De Luca CJ (1995a) The effects of visual input on open-loop and closed-loop postural control mechanisms. Exp Brain Res 103: 151–163
Collins JJ, De Luca CJ (1995b) Upright, correlated random walks: a statistical-biomechanics approach to the human postural control system. CHAOS 5: 57–63
De Luca CJ, LeFever RS, McCue MP, Xenakis AP (1982) Control scheme governing concurrently active human motor units during voluntary contractions. J Physiol (Lond) 329: 129–142
Feder J (1988) Fractals. Plenum, New York
Homick JL, Reschke MF (1977) Postural equilibrium following exposure to weightless space flight. Acta Otolaryngol 83: 455–464
Homick JL, Reschke MF, Miller EF (1977) The effects of prolonged exposure to weightlessness on postural equilibrium. In: Biomedical results from Skylab. NASA SP-377:104–112
Joyce GC, Rack PMH (1974) The effects of load and force on tremor at the normal human elbow joint. J Physiol (Lond) 240: 375–396
Kenyon RV, Young LR (1986) M.I.T./Canadian vestibular experiments on the Spacelab-1 mission. 5. Postural responses following exposure to weightlessness. Exp Brain Res 64: 335–346
Kozlovskaya IB, Kreidich YV, Oganov VS, Koserenko OP (1981a) Pathophysiology of motor functions in prolonged manned space flights. Acta Astronautica 8: 1059–1072
Kozlovskaya IB, Kreidich YV, Rakhmanov AS (1981b) Mechanisms of the effects of weightlessness on the motor system of man. Physiologist [Suppl] 24: 59–64
Kozlovskaya IB, Aslanova IF, Grigorieva LS, Kreidich YV (1982) Experimental analysis of motor effects of weightlessness. Physiologist [Suppl] 25: 49–52
Paloski WH, Reschke MF, Black FO, Doxey DD, Harm DL (1992a) Recovery of postural equilibrium control following spaceflight. Ann NY Acad Sci 656: 747–754
Paloski WH, Reschke MF, Doxey DD, Black FO (1992b) Neurosensory adaptation associated with postural ataxia following spaceflight. In: Woollacott M, Horak F (eds) Posture and gait: control mechanisms, vol I. University of Oregon Books, Oregon, pp 311–314
Reschke MF, Andersen DJ, Homick JL (1984) Vestibulospinal reflexes as a function of microgravity. Science 225: 212–214
Roll JP, Popov K, Gurfinkel V, Lipshits M, André-Deshays C, Gilhodes JC, Quoniam C (1993) Sensorimotor and perceptual function of muscle proprioception in microgravity. J Vestib Res 3: 259–273
Saupe D (1988) Algorithms for random fractals. In: Peitgen H-O, Saupe D (eds) The science of fractal images. Springer, New York, pp 71–136
Shrout PE, Fleiss JL (1979) Intraclass correlations: uses in assessing rater reliability. Psychol Bull 86: 420–428
Watt DGD, Money KE, Tomi LM (1986) M.I.T./Canadian vestibular experiments on the Spacelab-1 mission. 3. Effects of prolonged weightlessness on a human otolith-spinal reflex. Exp Brain Res 64: 308–315
Young LR, Oman CM, Watt DGD, Money KE, Lichtenberg BK (1984) Spatial orientation in weightlessness and readaptation to earth's gravity. Science 225: 205–208
Young LR, Oman CM, Watt DGD, Money KE, Lichtenberg BK, Kenyon RV, Arrott AP (1986) M.I.T./Canadian vestibular experiments on the Spacelab-1 mission. 1. Sensory adaptation to weightlessness and readaptation to one-g: an overview. Exp Brain Res 64: 291–298
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Collins, J.J., De Luca, C.J., Pavlik, A.E. et al. The effects of spaceflight on open-loop and closed-loop postural control mechanisms: human neurovestibular studies on SLS-2. Exp Brain Res 107, 145–150 (1995). https://doi.org/10.1007/BF00228026
- Center of pressure
- Space shuttle