Effect of age on postural performance and control strategies during changes in visual input and dual-tasking stances
Authors: Hui-Ya Chen 1, Han-Yu Chen 2, Bing-Hong Chen 3, Shu-Zon Lou 4, Li-Yuan Chen 3, Chun-Ling Lin 5
- Department of Adapted Physical Education, National Taiwan Sport University, Taoyuan, Taiwan
- Department of Physical Therapy, Hung Kuang University, Taichung, Taiwan
- Department of Physical Therapy, Chung Shan Medical University, Taichung, Taiwan
- Department of Occupational Therapy, Chung Shan Medical University, Taichung, Taiwan
- Department of Electrical Engineering, Ming Chi University of Technology, New Taipei City, Taiwan
Journal: Heliyon - August 2023, Volume 9, Issue 8, Article no. e18472 (DOI: 10.1016/j.heliyon.2023.e18472)
Background: With age, people begin to experience deterioration in standing balance, especially when sensory input is suddenly removed or added. Here, we sought to explore the effects of age on postural performance and postural control strategies.
Methods: The convenience sample consisted of 15 young, 10 middle-aged, and 14 elderly healthy adults. They were instructed to stand with their feet together in four randomly administered conditions involving visual input removal/addition and single-/dual-tasking. Dual-tasking involved continuous subtraction by 3s.
Results: Postural sway displacement in the two older groups seemed larger than that in the younger group; however, neither the main effect of group (F2, 36 = 1.152, p = .327) nor the group × time interaction effect (F4, 27 = 0.229, p = .922) was significant. Greater stiffness of the lower leg muscles was observed in the vision-addition condition than in the vision-removal condition in only the elderly group (t13 = −2.755, p = .016). The dual-tasking condition resulted in smaller sway displacement (F1, 36 = 7.690, p = .009) and greater muscle stiffness (F1, 36 = 5.495, p = .025). In the vision-removal condition, the increase in muscle stiffness due to dual-tasking was significantly larger in the middle-aged (t9 = −3.736, p = .005) and elderly groups (t13 = −2.512, p = .026).
Conclusions: In healthy older individuals, age-related changes were observed in control strategies used to maintain standing balance upon changes in visual input. The dual-task paradigm induced the use of an ankle-stiffening strategy in middle-aged and elderly adults.
Keywords: balance, cognition, middle-aged, multisensory reweighting, muscle stiffness
In conclusion, although healthy aging does not lead to obvious decreases in postural performance when challenged with tasks requiring multisensory reweighting, it is associated with different postural control strategies. Elderly adults increase the stiffness of the lower leg muscle when visual information is unavailable, indicating the use of an ankle-stiffening strategy. The dual-task paradigm induced the use of an ankle-stiffening strategy in both middle-aged and elderly adults, suggesting reduced attentional capacity and thereby compensation with the postural strategy. Our results have important real-life implications for everyday sensory transitions. If insufficient attentional resources are allocated to postural tasks in middle-aged and elderly populations, modification of sensory status may lead to an increased risk of accidental falls. Fall prevention programs should include dual-tasking training involving multisensory reweighting, especially for individuals 50 years of age or older.