Discrepancy in the involution of the different neural loops with age

Abstract

The purpose of the study was to compare the effects of sensory manipulations on postural control for subjects of different ages. A young group of subjects (n = 17; 20.0 ± 1.3 years) and an old group of subjects (n = 17; 74.7 ± 6.3 years) were compared in 14 postural conditions [2 reference conditions and 12 sensory manipulation conditions: eyes closed, cervical collar, tendon vibration, electromyostimulation, galvanic vestibular stimulation (2 designs), foam surface] on a force platform. Spatio-temporal parameters of the center of foot pressure displacement were analyzed. When vestibular or proprioceptive afferences were manipulated, the old group was more disturbed than the young group. In addition, when myo-articular proprioceptive afferences were the only non-manipulated information source, the old group was also more disturbed than the young group. Hence, the inability to correctly interpret proprioceptive information and/or the impairment of myo-articular information would appear to be the major factor causing postural control deterioration. Moreover, concerning the vestibular system, it may be that aging alters the central integration of vestibular afferences. These results suggest that aging differently affects the functional ability of the different neural loops in postural control.

Vestibular Adaptations Induced by Gentle Physical Activity Are Reduced Among Older Women

“…These adaptive neural mechanisms render older individuals more sensitive to electrical vestibular stimuli than younger individuals (Peters et al, 2016). Previous studies (Deshpande and Patla, 2007; Maitre et al, 2013a) have indicated greater effects of GVS on the postural control of older individuals than on that of younger individuals. Unlike other studies involving young participants (Balter et al, 2004b; Yang et al, 2015; Maitre and Paillard, 2016), the greater effect of GVS on older individuals could have reduced the difference between the active and non-active older groups in the present study.…”

“…Indeed, to some extent, physical activity performed on a regular basis may be able to protect the postural system from aging effects. To understand how aging and physical activity affect postural control, external perturbation techniques, more precisely sensory manipulation techniques (i.e., mechanical, electrical, chemical, optical) have been widely used (Gauchard et al, 2001, 2003; Hue et al, 2004; Jeka et al, 2006; Deshpande and Patla, 2007; Maitre et al, 2013a,b, 2015; Eikema et al, 2014; Maitre and Paillard, 2016). The main objective of these techniques was to alter or manipulate sensory information (i.e., afferents emanating from the visual, vestibular and somatosensory systems) in order to analyze postural compensatory strategies, and to understand how individuals cope so that they can reorganize their posture in a challenging sensory context.…”

“…The artificial alteration of the vestibular afferent signal induces an erroneous perception of head movement (i.e., illusion of motion), which generates an inadequate motor response (Fitzpatrick and Day, 2004; St George and Fitzpatrick, 2011). To analyze postural compensatory strategies in a context of a vestibular sensory manipulation, galvanic vestibular stimulation (GVS) has been widely used (Wardman and Fitzpatrick, 2002; Wardman et al, 2003; Balter et al, 2004a; Fitzpatrick and Day, 2004; Cenciarini and Peterka, 2006; Deshpande and Patla, 2007; Fransson et al, 2007; St George and Fitzpatrick, 2011; Maitre et al, 2013a, 2015; Eikema et al, 2014; Héroux et al, 2015; Yang et al, 2015; Maitre and Paillard, 2016). The GVS delivered a transmastoid electrical current to modulate the continuous firing level of vestibular afferents in order to generate a fictitious vestibular signal of head movement (Wardman and Fitzpatrick, 2002; St George and Fitzpatrick, 2011).…”

“…Among these previous studies about GVS, few have focused on how older individuals reorganize their posture (Balter et al, 2004b; Deshpande and Patla, 2007; Maitre et al, 2013a, 2015; Eikema et al, 2014) and how the effects of regular physical activity alter the individuals’ postural response to GVS (Balter et al, 2004b; Yang et al, 2015; Maitre and Paillard, 2016). In addition, only one study discussed the way older individuals adapt their postural control to the effects of GVS, in relation to their physical activity status (Maitre et al, 2015).…”

Evaluation of the Dynamical Structures of Postural Control: New Insights into Motor Adaptation in Ageing and Pain

“…This might be because the studies that used muscle vibration had small participant numbers, and /or the response to muscle vibration is more complicated to interpret as it reflects the peripheral function, the weighting applied by CNS to the proprioceptive information during a functional task, and the capacity of the postural muscles to respond. When comparing the postural response to vibration between young and elderly individuals, some studies observed no difference (Abrahámová et al, 2009;Brumagne et al, 2004), a lower response (Hay et al, 1996;Pyykko et al, 1990;Quoniam et al, 1995), or a greater response in postural sway (Maitre et al, 2013) in elderly than young.…”