Age-related changes in open-loop and closed-loop postural control mechanisms

Collins, James J.; Luca, Carlo J. De; Burrows, Adam B.; Lipsitz, Lewis A.

doi:10.1007/bf00231982

Cited by 281 publications

(271 citation statements)

References 39 publications

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“…the body equilibrium. In these studies, older adults exhibited a greater tendency to overshoot the body equilibrium over short-term intervals which are supposed to reflect an open-loop mode of control (Collins et al 1995). This correspondence between results in ankle proprioceptive control and postural control was consistent with the observed correlation between ankle proprioception and postural balance performance (Goble et al 2011).…”

Section: End-point Performancessupporting

confidence: 77%

Ageing of internal models: from a continuous to an intermittent proprioceptive control of movement

Boisgontier

Nougier

2012

AGE

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To control the sensory-motor system, internal models mimic the transformations between motor commands and sensory signals. The present study proposed to assess the effects of physiological adult ageing on the proprioceptive control of movement and the related internal models. To this aim, one group of young adults and one group of older adults performed an ankle contralateral concurrent matching task in two speed conditions (self-selected and fast). Error, temporal and kinematic variables were used to assess the matching performance. The results demonstrated that older adults used a different mode of control as compared to the young adults and suggested that the internal models of proprioceptive control were altered with ageing. Behavioural expressions of these alterations were dependent upon the considered condition of speed. In the self-selected speed condition, this alteration was expressed through an increased number of corrective sub-movements in older adults as compared to their young peers. This strategy enabled them to reach a level of end-point performance comparable to the young adults' performance. In the fast speed condition, older adults were no more able to compensate for their impaired internal models through additional corrective sub-movements and therefore decreased their proprioceptive control performance. These results provided the basis for a model of proprioceptive control of movement integrating the internal models theory and the continuous and intermittent modes of control. This study also suggested that motor control was affected by the frailty syndrome, i.e. a decreased resistance to stressors, which characterises older adults.

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Section: End-point Performancessupporting

confidence: 77%

Ageing of internal models: from a continuous to an intermittent proprioceptive control of movement

Boisgontier

Nougier

2012

AGE

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“…The stochastic properties of the center-of-pressure dynamics were assessed using both a two-process, random-walk model of Collins and De Luca [35,36] and an Ornstein-Uhlenbeck model that is linear and has displacement governed only by a single stiffness term in the random walk. The two-process, open-and closed-loop model accounted for about 96% and the Ornstein-Uhlenbeck model 92% of the variance of the diffusion term.…”

Section: Aging and The Time To Instability In Postural Controlmentioning

confidence: 99%

Aging-related temporal constraints to stability and instability in postural control

Slobounov

Haibach

Newell

2006

Eur. Rev. Aging.Phys. Act.

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In this study, we review the evidence that older adults tend to have both a shorter time to lose stability in the maintenance of standing posture and the functionally related but inverse problem of needing more time to reacquire stability in transitioning to a postural state. These age-related time limitations to processes of stability are hypothesized to enhance the probability of falling with aging and the problems that can occur in the transition between activities, such as sitting to standing and standing to walking. The potential role of fitness and health variables in mediating the temporal constraints on the acquisition and loss of postural stability in aging is discussed.Keywords Aging . Posture . StabilityThe conduct of daily life involves the engagement in a variety of physical activities that have been historically categorized into subgroups, such as activities of daily living, work, sport, music, and play. These activities in all contexts are manifestations of the fundamental physical activities of posture, locomotion, and manipulation. Thus, even in a single day in the lifetime of an individual, that person switches from the execution of one action to another in a sequence and time course that is determined by many environmental and individual factors. This time course of the change in behavior over time implies that an individual in switching activities is also caught in the continually evolving dynamical spiral of moving from stability to instability to stability and so on. The temporal limitations in acquiring or moving away from stability in standing posture as a function of aging is the focus of this review.It is well established that aging tends to lead in most individuals to a number of limitations and problems in the conduct of perceptual motor skills. The information processing [1-4], neurophysiological [5,6] and fitness [7][8][9] perspectives to aging and physical activity have all revealed age-related trends including: poorer performance (no matter how it is measured), slowness of thought and action, and loss of fitness properties such as strength, flexibility, and endurance. The more recent emphasis on dynamical processes of aging through the metaphor of selforganization has opened up new approaches and findings to aging-related limitations in physical activity [10][11][12][13][14][15]. A particular thrust has been the investigation of age-related changes in the complexity of behavior through a consideration of the evolving dynamics of movement in action [12,16], with emphasis on the health outcomes of dynamical stability and instability. Glass and Mackey [10] have viewed some processes of aging and movement disorders as an example of a dynamical disease in which behavioral and physiological systems change as a consequence of aberrations in the temporal organization of the evolving dynamics.The role and consequences of dynamical stability and instability are magnified in whole body physical activities such as standing posture and locomotion because of the potential severe negati...

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“…They showed that COP trajectories in humans exhibit persistent (long-range) correlations over short time scales and anti-persistent (short-range) correlations over longer time scales. These fractal-like structures changed with variations in visual input [14], touch and vision [15], age [16], and disease [17]. Collins and his colleagues thus proposed a "pinned polymer model" of postural control to explain these seemingly complex correlation structures [18][19][20].…”

Section: Introductionmentioning

confidence: 99%

Possible biomechanical origins of the long-range correlations in stride intervals of walking

Gates

Dingwell

2007

Physica A: Statistical Mechanics and its Applications

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When humans walk, the time duration of each stride varies from one stride to the next. These temporal fluctuations exhibit long-range correlations. It has been suggested that these correlations stem from higher nervous system centers in the brain that control gait cycle timing. Existing proposed models of this phenomenon have focused on neurophysiological mechanisms that might give rise to these long-range correlations, and generally ignored potential alternative mechanical explanations. We hypothesized that a simple mechanical system could also generate similar long-range correlations in stride times. We modified a very simple passive dynamic model of bipedal walking to incorporate forward propulsion through an impulsive force applied to the trailing leg at each push-off. Push-off forces were varied from step to step by incorporating both "sensory" and "motor" noise terms that were regulated by a simple proportional feedback controller. We generated 400 simulations of walking, with different combinations of sensory noise, motor noise, and feedback gain. The stride time data from each simulation were analyzed using detrended fluctuation analysis to compute a scaling exponent, a. This exponent quantified how each stride interval was correlated with previous and subsequent stride intervals over different time scales. For different variations of the noise terms and feedback gain, we obtained short-range correlations (α < 0.5), uncorrelated time series (α = 0.5), long-range correlations (0.5 < α < 1.0), or Brownian motion (α > 1.0). Our results indicate that a simple biomechanical model of walking can generate long-range correlations and thus perhaps these correlations are not a complex result of higher level neuronal control, as has been previously suggested.

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Age-related changes in open-loop and closed-loop postural control mechanisms

Cited by 281 publications

References 39 publications

Ageing of internal models: from a continuous to an intermittent proprioceptive control of movement

Ageing of internal models: from a continuous to an intermittent proprioceptive control of movement

Aging-related temporal constraints to stability and instability in postural control

Possible biomechanical origins of the long-range correlations in stride intervals of walking

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