Simulating Ideal Assistive Devices to Reduce the Metabolic Cost of Walking In the Elderly

Abstract

As the population ages, decreased mobility and loss of independence becomes a concern for many elderly individuals. Walking assist exoskeletons offer a solution for restoring, enhancing, and maintaining mobility. However, as this technology is a growing area of study pertaining to the elderly population, there is not currently a unified standard as to the optimal strategy for assisting elderly gait. The gait patterns of elderly individuals differ from that of the younger population primarily in the ankle and hip joints. This study used musculoskeletal simulations to investigate how hypothetical ankle and hip actuators affected the metabolic cost of elderly participants during gait. Using OpenSim as a modelling tool, simulations were generated of 10 elderly participants walking at a self-selected comfortable speed. Ideal flexion and extension assistive devices were then added to the ankle and hip joints of the musculoskeletal models to simulate the subsequent metabolic savings. The resulting simulations suggest that providing hip assistance to elderly participants results in significantly greater metabolic savings compared to ankle assistance. Compared to the unassisted scenario, the use of an ideal hip actuator resulted in 25.5 ± 7% metabolic savings, whereas use of an ideal ankle actuator resulted in 14.2 ± 2% metabolic savings. Our results can help researchers determine which joint to target when developing WAE for elderly users in the future.