Assessing the Long-term Effects of Wearing a Lower-limb Exoskeleton on Physical Activity and Quality of Life in Pre-frail Adults - a Feasibility Study

Despite the high benefits of performing physical activity in terms of physical and cognitive function, between 27-38% of Danish older adults do not meet the required physical activity recommendations. Due to the longer life expectancy, the increasingly older population will face gait disorders. These gait disorders will affect their motor and cognitive functions, and impair the performance of daily physical activity and overall quality of life. Frailty is one of the most frequent aging-related deficits observed in older adults, often characterized by three of the following criteria: unintentional weight loss >4.5 kg within the last year, exhaustion, loss or slower mobility, loss of grip strength, and low physical activity. However, pre-frail adults may present some of the aforementioned criteria and a score of ≤5 on the Tilburg Frailty Indicator. Therefore, there is an increasing need to provide the aging population with devices capable of promoting physical activity and independent living. Exoskeletons have been shown to facilitate physical activity in the older adult population by improving metabolic costs, increasing walking speed, and preventing falls. However, whether these benefits are only temporary, or can be maintained over a longer period, remains to be determined. Therefore, it is of pivotal importance to assess the long-term effects of exoskeletons, in terms of mobility, within the older adult population.

The use of external mechanical walking devices started in the late 1890s. However, only in the past two decades have gait-assisting exoskeletons, with increased human performance capability, gained popularity. Exoskeletons have been shown to reduce metabolic cost, and fatigue onset and increase walking velocity. Currently on the market, there are several lower-limb exoskeletons that target older populations and people with gait and neurological disabilities which are designed to enhance walking performance and reduce the muscle activation required during walking activities. Wearing gait-assisting exoskeletons can provide instant ease, delay fatigue onset, increase social engagement, and support rehabilitation to recover normal walking capabilities. The effects of hip exoskeletons have been previously investigated in terms of quality of life and improvement of gait performance. However, the effect of long-term use has yet to be assessed. Hence, this study aims to evaluate the impact of extended usage of a non-invasive passive hip exoskeleton on the quality of life of older adults. This will be achieved by analyzing the spatiotemporal gait characteristics in a feasibility study conducted over a 12-week period of consistent device usage. Additionally, the study aims to ascertain the persistence of these effects for a duration of 6 weeks post-usage.