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

Abstract

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...

Postural Stability Margins as a Function of Support Surface Slopes

“…The results are consistent with previous findings on the postural stability index in studies of aging [ 23 ], support surface compliance [ 10 ] and vision/no vision with aging [ 30 ]. The CoP area and functional stability boundary area provide evidence on the sensitivity of spatial/temporal margins of postural stability to the sloped base of support and provide a boundary relevant measure for postural stability.…”

Measuring the Reliability of Postural Sway Measurements for a Static Standing Task: The Effect of Age

“…Some studies showed that the mean distance of COP for older adults was greater than the value for young subjects for a balance test (Prieto et al, 1996;Slobounov et al, 2006). Many studies also identified significantly greater postural sway in the older population than in younger cohorts (Prieto et al, 1996;Slobounov et al, 2006).…”

“…Some studies showed that the mean distance of COP for older adults was greater than the value for young subjects for a balance test (Prieto et al, 1996;Slobounov et al, 2006). Many studies also identified significantly greater postural sway in the older population than in younger cohorts (Prieto et al, 1996;Slobounov et al, 2006). The effect of age on the reliability of postural sway measurements determines the variables that are used to evaluate postural sway and the effectiveness of any intervention.…”

Reliability of center of pressure measures of postural stability in healthy older adults: Effects of postural task difficulty and cognitive load

“…Postural instability has been identified as a major intrinsic risk factor of falling which can potentially be influenced with intervention [1,2,5]. It is well documented that even healthy older adults show a marked decline in the ability to control upright posture compared with young adults [6][7][8]. Early detection of balance limitations is required to identify older people who are at risk of falls and adopt effective fall prevention strategies.…”