How Older and Young Adults Balance Competing Lateral Stepping Objectives During Walking Maneuvers
Restricted (Penn State Only)
- Author:
- Desmet, David
- Graduate Program:
- Kinesiology
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- June 09, 2023
- Committee Members:
- Jonathan Dingwell, Professor in Charge/Director of Graduate Studies
Joseph Cusumano, Outside Unit & Field Member
Tarkeshwar Singh, Major Field Member
Jonas Rubenson, Major Field Member
Jonathan Dingwell, Chair & Dissertation Advisor - Keywords:
- walking
lateral maneuvers
aging
balance
multi-objective regulation - Abstract:
- Humans must frequently maneuver to traverse their environments, and many falls among older adults occur while doing so. Humans perform maneuvers and enact other walking objectives (e.g., remain balanced) by modulating their foot placement. It has been proposed that humans trade off stability to enact maneuvers, but how they enact this trade-off remains unclear. This dissertation aimed to determine how healthy aging contributes to goal-directed stepping adaptations during walking maneuvers. In the first experiment, we applied the Goal Equivalent Manifold (GEM) framework to a lateral lane-change maneuver task. This quantified how humans adapt lateral stepping to achieve competing step width (w) and lateral position (zB) goals. Both older and young adults exhibited similar w- for zB-regulation trade-offs during the lateral transition itself, although older adults chose to enact this trade-off more gradually. In the second experiment, we aimed to directly relate these stepping adaptations to age-related declines in maneuver performance and decision-making. Older and young adults chose between simultaneously presented narrow and lateral paths of varying difficulties in a virtual environment. Older and young adults were similarly able to traverse most paths. However, older adults chose to traverse the lateral paths more frequently, supporting our hypothesis that older adults select more conservative stepping strategies that prioritize stability. We then quantified these differing strategies using our GEM framework. Together, these results suggest that older adults prioritize lateral stability to enact maneuvers, despite trade-offs in competing walking objectives. This work will inform earlier fall-risk assessments and intervention efforts to improve walking performance.