Exoskeleton-Assisted Mobility in Aging and in Parkinson's Disease

Age-related declines in balance and walking ability increase the risk of falls, a leading cause of injury, loss of independence, and reduced quality of life among older adults. These challenges are even more pronounced in people living with Parkinson's disease, a neurological condition that affects movement and further impairs gait and postural stability. Although medications and rehabilitation can provide some benefit, mobility limitations often persist. Wearable exoskeletons have emerged as a promising approach to improve walking and reduce effort; however, their effectiveness and acceptability in individuals with Parkinson's disease remain insufficiently understood, particularly in real-world functional tasks.

The primary objective of this study is to determine the immediate effect of using a mobility-assistive exoskeleton on objective measures of balance and gait in healthy older adults and in individuals living with Parkinson's disease, and to explore user experience and acceptability.

The specific objectives are to: 1) Identify participant profiles (e.g., sex, age, severity of balance and gait impairments, severity of Parkinson's disease) that benefit the most from exoskeleton use, 2) Compare the effects of different levels of exoskeleton assistance on objective mobility measures relative to each participant's preferred assistance level, in order to determine whether this preferred level corresponds to the most effective level of assistance, 3) Determine whether the use of the exoskeleton improves balance and gait parameters, 4) Describe the perceptions of healthy older adults and in individuals with Parkinson's disease regarding the use of an exoskeleton in daily life, with particular attention to their interest, perceived benefits, barriers, and concerns related to its use, and 5) Explore how perceptions of exoskeleton use in daily life may change following a supervised exoskeleton use experience.

The study will be conducted in a laboratory setting and will take place over two separate sessions spaced at least two days and no more than four days apart. The first session will involve fitting and familiarizing participants with the exoskeleton, as well as conducting baseline clinical assessments (general health, mobility, balance, physical activity level, fatigue, mood, and cognitive function). During this session, participants will also undergo two semi-structured interviews, one before and one after using the exoskeleton, to share their perceptions, expectations, and concerns about using an exoskeleton.

During the second session, participants will perform a series of functional mobility tests both with and without the exoskeleton. When testing mobility with the exoskeleton, levels of assistance will manipulated to determine whether more or less support leads to better performance, and whether a participant's preferred level of assistance is also the most effective. Kinematics data will be collected using accelerometers to measure detailed aspects of walking, such as speed, step length, and variability.

For participants with Parkinson's disease, data collection will be conducted during the optimal effect of their usual dopaminergic medication, corresponding to the "ON" state.

The findings from this study will help determine whether exoskeletons are a useful and acceptable tool to support mobility in older adults and people with Parkinson's disease. In the long term, this research could contribute to the development of new strategies to reduce fall risk, improve independence, and enhance quality of life. It may also help guide healthcare professionals and technology developers in designing and implementing mobility aids that better meet the needs of these populations.

• Changes in gait variability [Time frame: Through intervention completion, on average one hour]
• Exoskeleton acceptability (qualitative data, before exoskeleton use) [Time frame: Baseline]
• Changes in exoskeleton acceptability (qualitative data, post exoskeleton use compared to pre) [Time frame: Immediately after the intervention]