Abstract
In an earlier posturographic investigation (Collins and De Luca 1993) it was proposed that open-loop and closed-loop control mechanisms are involved in the regulation of undisturbed, upright stance. In this study, stabilogram-diffusion analysis was used to examine how the natural aging process affects the operational characteristics of these control mechanisms. Stabilogram-diffusion analysis leads to the extraction of repeatable center-of-pressure (COP) parameters that can be directly related to the steady-state behavior and functional interaction of the neuromuscular mechanisms underlying the maintenance of erect posture. Twenty-five healthy young males (aged 19–30 years) and twenty-five elderly males (aged 71–80 years) who were free of major gait and postural disorders were included in the study. An instrumented force platform was used to measure the time-varying displacements of the COP under each subject's feet during quiet standing. The COP trajectories were analyzed as one-dimensional and two-dimensional random walks, according to stabilogram-diffusion analysis. Using this technique, it was demonstrated cross-sectionally that healthy aging is associated with significant changes in the ‘quasi-static’ dynamics of the postural control system. (It was also shown that more traditional posturographic analyses, i.e., summary statistics, were not sensitive enough to detect these age-related differences.) It was found that the steady-state behavior of the open-loop postural control mechanisms in the elderly is more positively correlated and therefore perhaps more unstable, i.e., the output of the overall system has a greater tendency to move or drift away from a relative equilibrium point over the short term. In contrast with this result, it was also found that the steady-state behavior of the closed-loop postural control mechanisms in the elderly is more negatively correlated and therefore perhaps more stable, i.e., over the longer term, there is an increased probability that movements away from a relative equilibrium point will be offset by corrective adjustments back towards the equilibrium position. In addition, it was demonstrated that the elderly utilize open-loop control schemes for longer time intervals and correspondingly larger COP displacements during periods of undisturbed stance. This result suggests that in the elderly there is a greater delay, on average, before closed-loop feedback mechanisms are called into play. Finally, it was shown that there is an increased heterogeneity of postural control abilities in healthy older adults.
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References
Alexander NB (1994) Postural control in older adults. J Am Geriatr Soc 42:93–108
Alexander NB, Shepard N, Gu MJ, Schultz A (1992) Postural control in young and elderly adults when stance is perturbed: kinematics. J Gerontol 47:M79–87
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. Phys 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
Dorfman LJ, Bosley TM (1979) Age-related changes in peripheral and central nerve conduction in man. Neurology 29:38–44
Dornan J, Fernie GR, Holliday PJ (1978) Visual input: its importance in the control of postural sway. Arch Phys Med Rehab 59:586–591
Era P, Heikkinen E (1985) Postural sway during standing and unexpected disturbance of balance in random samples of men of different age groups. J Gerontol 40:287–295
Faulkner JA, Brooks SV, Zerba E (1990) Skeletal muscle weakness and fatigue in old age: underlying mechanisms. Annu Rev Gerontol Geriatr 10:147–166
Feder J (1988) Fractals. Plenum Press, New York
Fernie GR, Gryfe CI, Holliday PJ, Llewellyn A (1982) The relationship of postural sway in standing to the incidence of falls in geriatric subjects. Age Ageing 11:11–16
Folstein MF, Folstein S, McHugh PR (1975) Mini-mental state. J Psychiatr Res 12:189–196
Hasan SS, Lichtenstein MJ, Shiavi RG (1990) Effects of loss of balance on biomechanics platform measures of sway: influence of stance and a method for adjustment. J Biomech 23:783–789
Hasselkus BR, Shambes GM (1975) Aging and postural sway in women. J Gerontol 30:661–667
Horak FB, Shupert CL, Mirka A (1989) Components of postural dyscontrol in the elderly: a review. Neurobiol Aging 10:727–738
Hytönen M, Pyykkö I, Aalto H, Starck J (1993) Postural control and age. Acta Otolaryngol (Stockh) 113:119–122
Inglin B, Woollacott M (1988) Age-related changes in anticipatory postural adjustments associated with arm movements. J Gerontol 43:M105–113
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
Lipsitz LA, Jonsson PV, Kelley MM, Koestner JS (1991) Causes and correlates of recurrent falls in ambulatory frail elderly. J Gerontol 46:M114–122
Lord SR, Clark RD, Webster IW (1991) Postural stability and associated physiological factors in a population of aged persons. J Gerontol 46:M69–76
Maki BE, Holliday PJ, Fernie GR (1987) A posture control model and balance test for the prediction of relative postural stability. IEEE Trans Biomed Eng 34:797–810
Maki BE, Holliday PJ, Topper AK (1991) Fear of falling and postural performance in the elderly. J Gerontol 46:M123–131
Manchester D, Woollacott M, Zederbauer-Hylton N, Marin O (1989) Visual, vestibular and somatosensory contributions to balance control in the older adult. J Gerontol 44:M118–127
Overstall PW, Exton-Smith AN, Imms FJ, Johnson AL (1977) Falls in the elderly related to postural imbalance. Br Med J 1:261–264
Prieto TE, Myklebust JB, Myklebust BM (1993) Characterization and modeling of postural steadiness in the elderly: a review. IEEE Trans Rehab Eng 1:26–34
Pyykkö I, Jäntti P, Aalto H (1990) Postural control in elderly subjects. Age Ageing 19:215–221
Ring C, Nayak USL, Isaacs B (1989) The effect of visual deprivation and proprioceptive change on postural sway in healthy adults. J Am Geriatr Soc 37:745–749
Saupe D (1988) Algorithms for random fractals. In: Peitgen H-O, Saupe D (eds) The science of fractal images. Springer, New York Berlin Heidelberg, pp 71–136
Sheldon JH (1963) The effect of age on the control of sway. Gerontol Clin 5:129–138
Skinner HB, Barrack RL, Cook SD (1984) Age-related decline in proprioception. Clin Orthop 184:208–211
Stelmach GE, Phillips J, DiFabio RP, Teasdale N (1989) Age, functional postural reflexes, and voluntary sway. J Gerontol 44:B100–106
Stelmach GE, Populin L, Müller F (1990) Postural muscle onset and voluntary movement in the elderly. Neurosci Lett 117:188–193
Tinetti ME, Speechley M (1989) Prevention of falls among the elderly. N Engl J Med 320:1055–1059
Tinetti ME, Speechley M, Ginter SF (1988) Risk factors for falls among elderly persons living in the community. N Engl J Med 319:1701–1707
Whanger AD, Wang HS (1974) Clinical correlates of the vibratory sense in elderly psychiatric patients. J Gerontol 29:39–45
Winters J, Stark L, Seif-Naraghi A-H (1988) An analysis of the sources of musculoskeletal system impedance. J Biomech 21:1011–1025
Woollacott MH, Shumway-Cook A, Nashner LM (1986) Aging and postural control: changes in sensory organization and muscular organization. Int J Aging Hum Dev 23:97–114
Yesavage JA, Sheikh JI (1986) Geriatric depression scale. Clin Gerontol 5:165–172
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Collins, J.J., De Luca, C.J., Burrows, A. et al. Age-related changes in open-loop and closed-loop postural control mechanisms. Exp Brain Res 104, 480–492 (1995). https://doi.org/10.1007/BF00231982
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DOI: https://doi.org/10.1007/BF00231982