Exercise of mechanisms of dynamic stability improves the stability state after an unexpected gait perturbation in elderly

Abstract

Unexpected changes during gait challenge elderly individuals to a greater degree than young adults. However, the adaptive potential of elderly seems to be retained, and therefore, the training of the mechanisms of dynamic stability as well as muscle strength training may improve the dynamic stability after unexpected perturbations. Thirty-eight subjects (65-75 years) participated in the study, divided into two experimental groups (stability training group, ST, n014 and mixed training group, MT, n014) and a control group (CG, n010). Both experimental groups performed exercises which focused on the mechanisms of dynamic stability. Additionally, the MT group executed a training to improve muscle strength. Session volume and duration were equal for both groups (14 weeks, twice a week,~1.5 h per session). Pre-and post-intervention, subjects performed a gait protocol with an induced unexpected perturbation. Post-intervention, the margin of stability was significantly increased after the unexpected perturbation in the ST group, indicating an improvement in stability state (pre, −30.3 ± 5.9 cm; post, −24.1 ± 5.2 cm). Further, both intervention groups increased their base of support after the intervention to regain balance after gait perturbation, whereas only the ST group showed a statistically significant improvement (ST pre , 90.9± 6.6 cm, ST post , 98.2±8.5 cm; MT pre , 91.4±6.2 cm; MT post , 97.9±12.7 cm). The CG showed no differences between pre-and post-measurements. The exercise of the mechanisms of dynamic stability led to a better application of these mechanisms after an unexpected perturbation during gait. We suggest that the repeated exercise of the mechanisms of dynamic stability contributes to significant improvements in postural stability. Additional strength training for healthy elderly individuals, however, shows no further effect on the ability to recover balance after unexpected perturbations during gait.

The effect of crossed reflex responses on dynamic stability during locomotion

“…From a mechanical point of view, the following mechanisms seem to be responsible for dynamic stability after a perturbation: increasing in the base of support, counterrotating segments around the center of mass, and applying an external force such as grasping (Arampatzis et al 2011;Bierbaum et al 2013;Hof et al 2005). At the time the perturbation was delivered, the projection of the center of mass to the ground was outside of the base of support or still inside but directed outside of the base of support.…”

Effects of Exergaming on Balance of Healthy Older Adults: A Systematic Review and Meta-analysis of Randomized Controlled Trials

“…Parameters such as CoP displacement and joint moment reflect stability control in response to the unexpected perturbation. 88 Given the fact that assessments utilized in the included studies are mostly concerned with balance control under self-initiated conditions, it would be meaningful if future research could provide an insight into exergaming-associated effects on reactive balance in older adults.…”

Comparação das inclinações lateral e anteroposterior no equilíbrio estático entre jovens, adultos e idosos

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