Effects of a Powered Lower-Limb Exoskeleton on Walking Performance in Older Adults

Age-related decline in mobility is associated with reduced independence, lower quality of life, and increased risk of disability and adverse health outcomes. Walking performance is a clinically meaningful indicator of functional status in older adults, and preservation of mobility is a major goal of healthy aging. Although exercise and rehabilitation interventions can improve mobility, their benefits typically require repeated training and sustained adherence. Technologies that provide immediate assistance during walking may offer a complementary approach to supporting mobility in older adults.

Powered wearable lower-limb exoskeletons are designed to provide external mechanical assistance during locomotion. Previous studies have shown that lower-limb exoskeletons can reduce the metabolic cost of walking and improve walking performance under laboratory conditions. However, less is known about the acute effects of commercially available exoskeleton systems on clinically relevant walking outcomes in independently ambulatory older adults.

This study will evaluate the acute effects of a commercially available powered lower-limb exoskeleton on walking performance in community-dwelling older adults. The primary outcomes are comfortable gait speed during a 10-meter walk test and average walking speed during a 400-meter walk test. Secondary outcomes include lower-extremity physical performance, physiological responses during walking, perceived exertion, balance confidence, fear of falling, device usability, participant satisfaction, and safety outcomes.

The study uses a randomized crossover design. Older adult participants will complete two experimental conditions in randomized order: walking without the exoskeleton and walking with the powered exoskeleton. Participants will attend a screening and familiarization visit followed by two trial visits separated by at least 48 hours. During the familiarization visit, participants will receive device fitting and supervised practice with the exoskeleton. At each trial visit, participants will complete standardized walking and physical performance assessments under the assigned condition.

A young-adult reference group will complete no-device walking assessments to provide reference values for walking performance. Exploratory analyses will examine whether exoskeleton-assisted walking reduces the performance gap between older adults and young adults.

The study hypothesis is that use of the powered exoskeleton will improve both short-distance and sustained walking performance in older adults and partially reduce the mobility performance gap between older and young adults.

• Short Physical Performance Battery Score [Time frame: During each trial visit following the assigned study condition, up to 5 days.]
• Mean Heart Rate During the 400-Meter Walk [Time frame: During each trial visit following the assigned study condition, up to 5 days.]
• Borg Rating of Perceived Exertion [Time frame: Immediately after the 400-meter walk test during each trial visit, up to 5 days.]
• Fear of Falling 10-Rating Scale Score [Time frame: After physical performance testing during each trial visit, up to 5 days.]
• Activities-specific Balance Confidence Scale Score [Time frame: After physical performance testing during each trial visit, up to 5 days.]
• System Usability Scale Score [Time frame: After completion of the powered-device trial visit, up to 5 days.]
• Quebec User Evaluation of Satisfaction With Assistive Technology 2.0 Device Subscale Score [Time frame: After completion of the powered-device trial visit, up to 5 days.]