StrokeNCT07179627
Ankle Exoskeleton for Stroke Gait Enhancement
A study testing Ankle exoskeleton and Baseline (no ankle exoskeleton) in people with Stroke, run by Georgia Institute of Technology at 1 site in United States.
Trial summary
This work will focus on new algorithms for robotic ankle exoskeletons and testing these in human subject tests. Individuals who have previously had a stroke will walk while wearing a robotic exoskeleton on a specialized treadmill as well as during other movement tasks (e.g., overground, stairs, ramps). Read more about this study
- Who is it for?
- Ages 18 to 85 years
- Conditions the study is for
- Stroke
- What is being tested?
- Ankle exoskeleton and Baseline (no ankle exoskeleton)
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 10 participants
- Where
- 1 siteUnited States
- Study dates
- 9 Feb 2026to 23 Jun 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 85 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Between 18-85 years of age
- Had a stroke at least 6 months prior to study involvement
- Are community dwelling, which means you do not live in an assisted living facility
- Are able to provide informed consent to participate in the study activities
- Can safely participate in the study activities (per self-report)
- Must have a Functional Ambulation Category (FAC) score of 3 or above, which means you can walk without the assistance of another person
Who cannot join
- Require a walker to walk independently
- Have a shuffling gait pattern overground
- Have a Functional Ambulation Category (FAC) score of 2 or lower, which means you require the assistance of another person in order to walk
- Have a significant secondary deficit beyond stroke (e.g. amputation, legal blindness or other severe impairment or condition) that in the opinion of the Principal Investigator (PI), would likely affect the study outcome or confound the results
- For exoskeleton-only studies, the exoskeleton device does not fit appropriately or safely, as determined by the research team during the fitting assessment.
Trial locations and contacts
1 site in 1 country.
United States1 site
Georgia Institute of Technology
Atlanta, Georgia, 30332
About this study
Official title: Powered Ankle Exoskeleton for Stroke Survivors With Gait Impairment
This work will focus on new algorithms for robotic ankle exoskeletons and testing these in human subject tests. Individuals who have previously had a stroke will walk while wearing a robotic exoskeleton on a specialized treadmill as well as during other movement tasks (e.g., overground, stairs, ramps). The study will compare the performance of the advanced algorithm with not using the device to determine the clinical benefit.
Read the detailed description
The focus of this work is on a proposed novel artificial intelligence (AI) system that self-adapts control policy in powered exoskeletons to aid deployment systems that personalize to individual patient gait. Individuals post-stroke have a broad range of mobility challenges, including asymmetric gait, substantially decreased SSWS, and reduced stability, and therefore have greatly impaired overall mobility independence in the community. The investigators expect the proposed novel controller, capable of personalization to such variable and asymmetric gait patterns, will have significant benefits towards increasing community independence and mobility for patients post stroke. Stroke survivor participants will be fitted with an ankle exoskeleton and proceed to walk on a treadmill or perform various movement tasks. The same tasks will be performed by the participants without wearing the ankle exoskeleton to serve as a baseline. The investigators expect improved outcomes in the powered ankle exoskeleton compared to baseline conditions.
- Conditions
- Stroke
- Being tested
- Ankle exoskeleton, Baseline (no ankle exoskeleton)
- Medical subject headings
- Stroke
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Ankle exoskeletonDevice
Also called Powered ankle exoskeleton
The ankle exoskeleton provides bilateral torque assistance at the ankle joints during common functional tasks such as level-ground walking, stair and ramp ascent, and other daily activities, thereby reducing the mechanical workload and supporting more effective community ambulation. In particular, the device is designed to address drop-foot on the paretic side by delivering bidirectional assistance, which helps improve toe clearance during swing as well as push-off during stance. As a wearable assistive device, assistance is applied only while the device is worn.
Baseline (no ankle exoskeleton)Other
The intervention will serve as a baseline where participants will be asked to perform the tasks without wearing an ankle exoskeleton.
| Study group | Role | What they receive |
|---|---|---|
| Ankle exoskeleton for stroke gait assistance | Experimental | This study will be conducted on a sample population of stroke subjects (single arm). Subjects will be tested with the powered ankle exoskeleton and baseline conditions. Receives: Device: Ankle exoskeleton; Other: Baseline (no ankle exoskeleton) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Temporal Convolutional Network (TCN) model performance (Joint moment estimation accuracy)
This outcome represents the error with which the deep learning model embedded into our ankle exoskeleton's microprocessor predicts ankle joint moments in stroke patients. Specifically, the coefficient of determination (R²) is computed between the predicted ankle joint moments and the ground truth measurements. Ground truth measurements are obtained from a laboratory-grade force plate system and inverse dynamics calculations. Ankle joint moment predictions are made at a frequency of 200 Hz and compared to the laboratory-measured values. For these measures, higher R² values (closer to 1.0) indicate better correlation between predicted and actual ankle joint moments. This metric provides a comprehensive assessment of the exoskeleton's ability to accurately estimate ankle joint moments in stroke patients during tasks, with improved outcomes representing better assistive capabilities for the user.
Measured: 1 year
Metabolic cost for level ground walking
Metabolic energy expenditure will be quantified using an indirect calorimetry system (Parvo Medics, UT) that measures oxygen consumption (VO₂) and carbon dioxide production (VCO₂) during experimental tasks. Measurements will be collected from each participant during a 5-minute baseline standing period followed by level ground walking trials under two conditions: without the exoskeleton, with the exoskeleton in a powered state. Metabolic cost will be calculated from respiratory gas exchange data (VO₂ and VCO₂) using Brockway equations [1] for energy expenditure. Comparisons between the two conditions will be conducted to assess the effectiveness of the exoskeleton with respect to metabolic cost.
Energy expenditure (kilojoule/minute) = 16.58 VO₂ (Liters/minute) +4.51VCO₂ (Liters/minute)
[1] Brockway, J. M. "Derivation of formulae used to calculate energy expenditure in man." Human nutrition. Clinical nutrition 41.6 (1987): 463-471.
Measured: 1 year
Biological Joint Work
Mechanical work performed by the lower limb joints will be quantified through biomechanical analysis of motion capture data. Joint moments and angular velocities will be derived through inverse dynamics and kinematics, respectively. Joint power, calculated as the product of joint moment and angular velocity, will be integrated with respect to time using trapezoidal integration to determine mechanical work. Positive and negative work will be calculated by separately integrating positive and negative joint powers, providing comprehensive quantification of joint energy generation and absorption at each joint during the movement tasks.
Measured: 1 year
Secondary outcomes (11)
Single limb stance time asymmetry (temporal)
This will be measured as the participant walks across a gait mat and/or via motion capture as the time spent on the right and left leg is calculated. The index will be calculated as the difference between the time spent in single-limb support for the right and left legs during walking and expressed as a percentage with a value of 0 indicating perfect symmetry and greater values indicating larger asymmetry.
Measured: 1 year
Step length asymmetry (spatial)
This will be measured as the participant walks across a gait mat and/or via motion capture as the distance traversed by the right and left leg for each step. The index will be calculated as the difference between the step lengths of the right and left legs during walking and expressed as a percentage with a value of 0 indicating perfect symmetry and greater values indicating larger asymmetry.
Measured: 1 year
Interlimb propulsion asymmetry (kinetic)
This will be measured as the participant walks on an instrumented treadmill with force plates, by calculating the peak anterior-posterior propulsive impulse generated by the paretic and non-paretic limbs during late stance. A propulsion symmetry index will then be calculated using the difference between the propulsive impulses of the two limbs, expressed as a percentage. A value of 0 indicates perfect symmetry, while greater values reflect larger propulsion asymmetry between limbs, with lower paretic propulsion indicating impaired forward progression capacity.
Measured: 1 year
Trailing limb angle (kinematic)
This will be measured as the participant walks on an instrumented treadmill via motion capture, by calculating the sagittal-plane angle between the vertical axis and the line connecting the hip joint center to the ankle joint center at the moment of contralateral initial contact. Values will be reported in degrees, with larger angles indicating greater trailing-limb extension and push-off capacity during gait.
Measured: 1 year
Anterior ground reaction force
This will be measured as the participant walks on an instrumented treadmill with force plates, by extracting the peak anterior component of the ground reaction force during late stance. The peak value will be expressed as a percentage of body weight, with higher values reflecting stronger forward propulsion generated by the limb.
Measured: 1 year
Paretic ankle dorsiflexion angle
This will be measured as the participant walks on an instrumented treadmill via motion capture, by calculating the sagittal-plane angle of the paretic ankle joint between the foot and shank segments during swing and stance phases. The peak dorsiflexion angle during swing will be extracted to assess foot clearance. Values will be reported in degrees, with larger dorsiflexion angles indicating greater ankle mobility and reduced risk of foot drop.
Measured: 1 year
Ten Meter Walk test (10 mwt)
This will be measured as the participant walks a distance of 10 meters across a gait mat at their self-selected (or comfortable) walking speed. This measure will be recorded in seconds with lower values indicating faster speed and higher values indicating slower speeds. Self-selected walking speed is highly correlated with functional ability and dependence.
Measured: 1 year
6 minute walk test (6MWT)
This is a measurement of endurance and functional ability that assesses the participants ability to walk a distance over a time period of 6 minutes. It is measured in distance with greater distances indicating improved levels of endurance and functional ability.
Measured: 1 year
Maximum walking speed test
This will be measured as the fastest treadmill walking speed that the participant can sustain for approximately one minute. The maximum speed will be recorded under conditions with and without the exoskeleton. This test assesses functional capability and physical performance when higher exertion is required over a short duration.
Measured: 1 year
Modified Stroke Impact Scale
This self-report questionnaire is designed specifically for individuals post-stroke to assess the impact of stroke on multiple domains of health and function, including strength, hand function, mobility, activities of daily living, emotion, memory, communication, and participation. Scores are standardized from 0 to 100, with higher scores indicating less impact of stroke and better functional outcomes.
Measured: 1 year
The Activities-specific Balance Confidence (ABC) Scale
This survey measures the participant's confidence in performing various ambulatory activities without losing balance or becoming unsteady. Participants rate their confidence on a scale from 0% (no confidence) to 100% (complete confidence) across 16 daily activities. Higher scores indicate greater balance confidence and reduced perceived fall risk.
Measured: 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Sep 2025
- Study start9 Feb 2026
- Primary completion23 Jun 2026
- Study completion23 Jun 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for StrokeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- The model used is a repeated measures single arm study
- Masking
- None (open label)
- Enrolment
- 10 participants (actual)
Sponsor and investigators
- Lead sponsor
- Georgia Institute of Technology
- Sponsor type
- University, hospital or other
- Collaborators
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
- Responsible party
- Sponsor
- Investigators
- Aaron Young, PhD, Principal investigator, Georgia Institute of Technology
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07179627
- Sponsor's protocol ID
- IRB2025-962
- Other IDs
- R01HD113598-01
- Status last verified
- Sep 2025
- First submitted
- 11 Sep 2025
- Last updated
- 28 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 28 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Powered Ankle Exoskeleton for Stroke Survivors With Gait Impairment
- ClinicalTrials.gov ID
- NCT07179627
- Acronym / sponsor ID
- IRB2025-962
- Conditions
- Stroke
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 10 participants (actual)
- Lead sponsor
- Georgia Institute of TechnologyUniversity, hospital or other
- Collaborators
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
- Study start
- 9 Feb 2026 (actual)
- Primary completion
- 23 Jun 2026 (actual)
- Study completion
- 23 Jun 2026 (actual)
- First posted
- 18 Sep 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This work will focus on new algorithms for robotic ankle exoskeletons and testing these in human subject tests. Individuals who have previously had a stroke will walk while wearing a robotic exoskeleton on a specialized treadmill as well as during other movement tasks (e.g., overground, stairs, ramps). The study will compare the performance of the advanced algorithm with not using the device to determine the clinical benefit.
Detailed description
The focus of this work is on a proposed novel artificial intelligence (AI) system that self-adapts control policy in powered exoskeletons to aid deployment systems that personalize to individual patient gait. Individuals post-stroke have a broad range of mobility challenges, including asymmetric gait, substantially decreased SSWS, and reduced stability, and therefore have greatly impaired overall mobility independence in the community. The investigators expect the proposed novel controller, capable of personalization to such variable and asymmetric gait patterns, will have significant benefits towards increasing community independence and mobility for patients post stroke. Stroke survivor participants will be fitted with an ankle exoskeleton and proceed to walk on a treadmill or perform various movement tasks. The same tasks will be performed by the participants without wearing the ankle exoskeleton to serve as a baseline. The investigators expect improved outcomes in the powered ankle exoskeleton compared to baseline conditions.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- The model used is a repeated measures single arm study
| Arm | Type | Receives |
|---|---|---|
| Ankle exoskeleton for stroke gait assistance | Experimental | Device: Ankle exoskeleton, Other: Baseline (no ankle exoskeleton)This study will be conducted on a sample population of stroke subjects (single arm). Subjects will be tested with the powered ankle exoskeleton and baseline conditions. |
Who may qualify
- Ages
- 18 to 85 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Between 18-85 years of age
- Had a stroke at least 6 months prior to study involvement
- Are community dwelling, which means you do not live in an assisted living facility
- Are able to provide informed consent to participate in the study activities
- Can safely participate in the study activities (per self-report)
Key exclusion criteria (5 listed)
- Require a walker to walk independently
- Have a shuffling gait pattern overground
- Have a Functional Ambulation Category (FAC) score of 2 or lower, which means you require the assistance of another person in order to walk
- Have a significant secondary deficit beyond stroke (e.g. amputation, legal blindness or other severe impairment or condition) that in the opinion of the Principal Investigator (PI), would likely affect the study outcome or confound the results
- For exoskeleton-only studies, the exoskeleton device does not fit appropriately or safely, as determined by the research team during the fitting assessment.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Ankle exoskeletonAlso: Powered ankle exoskeletonThe ankle exoskeleton provides bilateral torque assistance at the ankle joints during common functional tasks such as level-ground walking, stair and ramp ascent, and other daily activities, thereby reducing the mechanical workload and supporting more effective community ambulation. In particular, the device is designed to address drop-foot on the paretic side by delivering bidirectional assistance, which helps improve toe clearance during swing as well as push-off during stance. As a wearable assistive device, assistance is applied only while the device is worn. | Device | Ankle exoskeleton for stroke gait assistance |
| Baseline (no ankle exoskeleton)The intervention will serve as a baseline where participants will be asked to perform the tasks without wearing an ankle exoskeleton. | Other | Ankle exoskeleton for stroke gait assistance |
Primary outcome
Temporal Convolutional Network (TCN) model performance (Joint moment estimation accuracy)
Time frame: 1 year
This outcome represents the error with which the deep learning model embedded into our ankle exoskeleton's microprocessor predicts ankle joint moments in stroke patients. Specifically, the coefficient of determination (R²) is computed between the predicted ankle joint moments and the ground truth measurements. Ground truth measurements are obtained from a laboratory-grade force plate system and inverse dynamics calculations. Ankle joint moment predictions are made at a frequency of 200 Hz and compared to the laboratory-measured values. For these measures, higher R² values (closer to 1.0) indicate better correlation between predicted and actual ankle joint moments. This metric provides a comprehensive assessment of the exoskeleton's ability to accurately estimate ankle joint moments in stroke patients during tasks, with improved outcomes representing better assistive capabilities for the user.
Metabolic cost for level ground walking
Time frame: 1 year
Metabolic energy expenditure will be quantified using an indirect calorimetry system (Parvo Medics, UT) that measures oxygen consumption (VO₂) and carbon dioxide production (VCO₂) during experimental tasks. Measurements will be collected from each participant during a 5-minute baseline standing period followed by level ground walking trials under two conditions: without the exoskeleton, with the exoskeleton in a powered state. Metabolic cost will be calculated from respiratory gas exchange data (VO₂ and VCO₂) using Brockway equations [1] for energy expenditure. Comparisons between the two conditions will be conducted to assess the effectiveness of the exoskeleton with respect to metabolic cost. Energy expenditure (kilojoule/minute) = 16.58 VO₂ (Liters/minute) +4.51VCO₂ (Liters/minute) [1] Brockway, J. M. "Derivation of formulae used to calculate energy expenditure in man." Human nutrition. Clinical nutrition 41.6 (1987): 463-471.
Biological Joint Work
Time frame: 1 year
Mechanical work performed by the lower limb joints will be quantified through biomechanical analysis of motion capture data. Joint moments and angular velocities will be derived through inverse dynamics and kinematics, respectively. Joint power, calculated as the product of joint moment and angular velocity, will be integrated with respect to time using trapezoidal integration to determine mechanical work. Positive and negative work will be calculated by separately integrating positive and negative joint powers, providing comprehensive quantification of joint energy generation and absorption at each joint during the movement tasks.
11 secondary outcomes
Single limb stance time asymmetry (temporal)
Time frame: 1 year
Step length asymmetry (spatial)
Time frame: 1 year
Interlimb propulsion asymmetry (kinetic)
Time frame: 1 year
Trailing limb angle (kinematic)
Time frame: 1 year
Anterior ground reaction force
Time frame: 1 year
Paretic ankle dorsiflexion angle
Time frame: 1 year
Ten Meter Walk test (10 mwt)
Time frame: 1 year
6 minute walk test (6MWT)
Time frame: 1 year
Maximum walking speed test
Time frame: 1 year
Modified Stroke Impact Scale
Time frame: 1 year
The Activities-specific Balance Confidence (ABC) Scale
Time frame: 1 year
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Jul 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Aaron Young, PhD principal investigator
Georgia Institute of Technology
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Ankle exoskeleton and Baseline (no ankle exoskeleton) in people with Stroke, run by Georgia Institute of Technology at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 28 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Temporal Convolutional Network (TCN) model performance (Joint moment estimation accuracy) (time frame: 1 year). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Jul 2026.