Effects of a Powered Lower-Limb Exoskeleton on Walking Performance in Older Adults (E-WALK)

Acute Effects of a Powered Lower-Limb Exoskeleton on Walking Performance in Community-Dwelling Older Adults: A Randomized Crossover Trial

The goal of this clinical trial is to learn whether a powered wearable lower-limb exoskeleton can improve walking performance in independently ambulatory older adults aged 65 to 75 years.

The main questions it aims to answer are:

• Does use of a powered lower-limb exoskeleton increase comfortable walking speed over 10 meters?
• Does use of a powered lower-limb exoskeleton increase average walking speed during a 400-meter walk?

Researchers will compare walking performance in older adults during walking with the powered exoskeleton and walking without the device to determine whether the exoskeleton improves mobility. Young-adult reference participants will also complete walking assessments to provide reference values for walking performance.

Participants will:

• Attend a screening and familiarization visit.
• Complete walking assessments with and without the powered exoskeleton in randomized order (older adults only).
• Perform a 10-meter walk test, a 400-meter walk test, and other physical performance assessments.
• Complete questionnaires about balance confidence, fear of falling, and device usability.
• Be monitored for safety events during testing.

Study Overview

• Status: Not yet recruiting
• Conditions: Aging; Mobility Limitation; Walking; Physical Function
• Intervention / Treatment: Device: Powered Lower-Limb Exoskeleton

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Yang Zhang, PhD; Phone Number: 727-251-9431; Email: yzhang68@crimson.ua.edu
• Study Contact Backup: Name: Bo Liu, MS; Phone Number: 8613217485573; Email: 202110150267@hunnu.edu.cn

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Older adults aged 65 to 75 years who are community-dwelling, independently ambulatory, able to walk independently on level ground, able to maintain standing balance without personal assistance, and able to understand study instructions.
• Young-adult reference participants aged 18 to 22 years who are healthy university students without known conditions affecting walking or balance.

Exclusion Criteria:

• Self-reported neurological disease affecting gait or balance.
• Major musculoskeletal injury or surgery affecting walking within the previous 6 months.
• Uncontrolled cardiopulmonary disease.
• Severe visual or vestibular impairment affecting safe walking.
• Current lower-limb pain that limits walking.
• Cognitive impairment that prevents informed consent or protocol adherence.
• Any condition judged by the study team to make participation unsafe.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Older Adults; Community-dwelling older adults aged 65-75 years who complete walking assessments under both no-device and powered-exoskeleton conditions in randomized order using a crossover design. Participants attend a screening and familiarization visit followed by two trial visits.	Device: Powered Lower-Limb Exoskeleton; A commercially available powered wearable lower-limb exoskeleton (VIATRIX; ULS Robotics Co., Ltd., Shanghai, China) designed to provide bilateral lower-limb assistance during walking. The device is worn around the pelvis and lower limbs and provides powered assistance through bilateral actuation. During powered-device assessments, participants use the adaptive assistive walking mode following device fitting and familiarization procedures.
No Intervention: Young Adult Reference Participants; Healthy young adults aged 18-22 years who complete no-device walking assessments to provide reference values for walking performance. Participants are not randomized and do not receive the powered exoskeleton intervention.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
10-Meter Comfortable Gait Speed	Comfortable gait speed (m/s) measured during a 10-meter walk test. Participants walk at their usual comfortable speed along a flat indoor walkway. Two trials are completed, and the mean gait speed is used for analysis.	During each trial visit following completion of the assigned study condition (up to 5 days)
400-Meter Average Walking Speed	Average walking speed (m/s) measured during a 400-meter walk test. Participants walk 400 meters at a self-selected comfortable speed on an indoor walkway. Average walking speed is calculated as total walking distance divided by total completion time.	During each trial visit following completion of the assigned study condition (up to 5 days)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Short Physical Performance Battery Score	Lower-extremity physical performance assessed using the Short Physical Performance Battery. The test includes standing balance, short-distance gait speed, and repeated chair-stand performance. Component scores are summed to produce a total score ranging from 0 to 12, with higher scores indicating better physical performance.	During each trial visit following the assigned study condition, up to 5 days.
Mean Heart Rate During the 400-Meter Walk	Mean heart rate recorded continuously during the 400-meter walk test using a wrist-worn optical heart-rate monitor.	During each trial visit following the assigned study condition, up to 5 days.
Borg Rating of Perceived Exertion	Perceived exertion is assessed immediately after the 400-meter walk test using the Borg Rating of Perceived Exertion Scale. Scores range from 6 to 20, where 6 indicates "no exertion at all" and 20 indicates "maximal exertion." Higher scores indicate greater perceived exertion and a worse outcome.	Immediately after the 400-meter walk test during each trial visit, up to 5 days.
Fear of Falling 10-Rating Scale Score	Immediate fear of falling will be assessed after each trial condition using the single-item Fear of Falling 10-Point Rating Scale. Participants will rate how concerned they were about falling during the walking and physical performance tests completed during that visit. Scores range from 0 to 10, where 0 indicates "not concerned at all" and 10 indicates "extremely concerned." Higher scores indicate greater fear of falling and a worse outcome.	After physical performance testing during each trial visit, up to 5 days.
Activities-specific Balance Confidence Scale Score	Balance confidence will be assessed after each trial condition using the Activities-specific Balance Confidence Scale. The scale includes 16 activities, each rated from 0%, indicating no confidence in maintaining balance, to 100%, indicating complete confidence in maintaining balance. The total score is calculated as the mean of the 16 item scores and ranges from 0 to 100. Higher scores indicate greater balance confidence and a better outcome.	After physical performance testing during each trial visit, up to 5 days.
System Usability Scale Score	Perceived usability of the powered lower-limb exoskeleton will be assessed after the powered-device condition using the 10-item System Usability Scale. Item responses are converted and summed to produce a total score ranging from 0 to 100. Higher scores indicate greater perceived usability of the exoskeleton and a better outcome.	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	Participant satisfaction with the powered lower-limb exoskeleton will be assessed after the powered-device condition using the eight-item device subscale of the Quebec User Evaluation of Satisfaction With Assistive Technology 2.0. Each item is rated from 1, indicating "not satisfied at all," to 5, indicating "very satisfied." The device-subscale score is calculated as the mean of the valid device-item ratings and ranges from 1 to 5. Higher scores indicate greater satisfaction with the exoskeleton and a better outcome.	After completion of the powered-device trial visit, up to 5 days.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Falls	Number of falls occurring during study procedures. A fall is defined as an event in which the participant comes to rest inadvertently on the ground, floor, or another lower level.	From enrollment through completion of the final study visit, up to 5 days.
Number of Near-Loss-of-Balance Events	Number of near-loss-of-balance events occurring during study procedures. A near-loss-of-balance event is defined as an observable unintended balance disturbance requiring a corrective response to prevent a fall.	From enrollment through completion of the final study visit, up to 5 days.
Number of Device-Related Adverse Events	Number of adverse events judged to be caused by, probably caused by, or associated with use of the powered lower-limb exoskeleton.	From enrollment through completion of the final study visit, up to 5 days.

Collaborators and Investigators

• Sponsor: Hunan Normal University
• Investigators: Principal Investigator: Yang Zhang, PhD

Study record dates

Study Major Dates

• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): October 1, 2026
• Study Completion (Estimated): October 1, 2026

Study Registration Dates

• First Submitted: June 2, 2026
• First Submitted That Met QC Criteria: June 2, 2026
• First Posted (Actual): June 8, 2026

Study Record Updates

• Last Update Posted (Actual): June 9, 2026
• Last Update Submitted That Met QC Criteria: June 5, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Gait Speed; Exoskeleton; Assistive Technology; Wearable Robotics; Mobility Assistance
• Additional Relevant MeSH Terms: Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Mobility Limitation
• Other Study ID Numbers: HNU-2026-408

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No