Ankle Robot to Reduce Foot Drop in Stroke

• Sponsor: VA Office of Research and Development (U.S. Fed)
• Overall Status: Completed
• CT.gov ID: NCT02483676
• Collaborator: (none)
• Enrollment: 45
• Location: 1
• Arms: 2
• Actual Duration (Months): 45.9
• Patients Per Site Per Month: 1

Study Details

Study Description

Brief Summary

Deficits in ankle control after stroke can lead to foot drop, resulting in inefficient, aberrant gait and an elevated falls risk. Using a novel ankle robot and newly invented adaptive control system, this study tests whether robotic-assisted treadmill training will improve gait and balance functions in chronic stroke survivors with foot drop impairment. It is hypothesized that, compared to treadmill training alone, integrating adaptive ankle robotics with treadmill training will reduce drop foot during independent overground walking, resulting in greater mobility, improved postural control, and reduced fall risk.

Condition or Disease	Intervention/Treatment	Phase
Stroke; Foot Drop	Device: Treadmill plus anklebot; Behavioral: Treadmill only	N/A

Detailed Description

This proposal investigates a novel ankle robot (anklebot) adaptive control approach integrated with treadmill training to reduce foot drop and improve mobility function in chronic hemiparetic stroke survivors. Currently, stroke survivors with foot drop are trained to live with a cane or other assistive device, and often ankle foot orthotics (AFOs) for safety. Neither mediates task-practice or neuromotor recovery.

The investigators have developed an adaptive anklebot controller that detects gait cycle sub-events for precise timing of graded robotics assistance to enable deficit severity-adjusted ankle motor learning in the context of walking. The investigators' pilot findings show that 6 weeks treadmill training with anklebot (TMR) timed to assist swing phase dorsiflexion only is more effective than treadmill alone (TM) to improve free-walking swing dorsiflexion at foot strike, floor-walking speed, and the benefits are retained at 6 weeks post-training. Notably, swing-phase TMR training improved paretic leg push-off, and reduced center-of-pressure sway on standing balance, indicating potential benefits to other elements of gait and balance, beyond those robotically targeted toward foot drop.

This randomized study investigates the hypothesis that 6 weeks TMR is more effective to improve durably gait biomechanics, static, and dynamic balance, and mobility function in chronic stroke survivors with dorsiflexion deficits, compared to TM alone. Aims are to determine the compare effectiveness of 6 weeks TMR vs. TM alone on:

1. Independent gait function indexed by gait velocity, swing-phase DF (dorsiflexion), terminal stance push-off.

2. Balance function indexed by measures of postural sway (CoP), asymmetric loading in quiet standing, peak paretic A-P forces in non-paretic gait initiation, and standardized scales for balance and fall risk.

3. Long-term mobility outcomes, assessed by repeated measures of all key gait and balance outcomes at 6 weeks and 3 months after formal training cessation.

Study Design

• Study Type: Interventional
• Actual Enrollment: 45 participants
• Allocation: Randomized
• Intervention Model: Parallel Assignment
• Masking: Single (Outcomes Assessor)
• Primary Purpose: Treatment
• Official Title: Adaptive Ankle Robot Control System to Reduce Foot-drop in Chronic Stroke
• Actual Study Start Date: Sep 1, 2015
• Actual Primary Completion Date: Apr 1, 2019
• Actual Study Completion Date: Jun 30, 2019

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Treadmill+anklebot This group will receive gait training on a treadmill while wearing the anklebot with the adaptive control system.	Device: Treadmill plus anklebot; This intervention employs the use of the adaptive anklebot control system to complement treadmill exercise training over a 6-week intervention period.; Other Names: TMR
Active Comparator: Treadmill only This group will receive gait training on a treadmill, without use of the anklebot.	Behavioral: Treadmill only; This intervention employs the use of a treadmill for gait exercise training over a 6-week intervention period; Other Names: TM

Outcome Measures

Primary Outcome Measures

1. Gait Velocity During Self-selected Overground Walking [Change from baseline to: Post 6-week training, 6 weeks after completion, and 3 (or 6) months after completion]

   Gait velocity during self-selected overground walking measured in cm/sec

2. Anterior-posterior Propulsion Forces of Paretic Side During Gait [Change from baseline to: Post 6-weeks training, 6 weeks after completion, and 3 (or 6) months]

   Newtons: anterior-posterior force generated during push-off phase of the gait cycle

3. Peak Dorsiflexion Angle During Swing Phase of Gait [Change from baseline to: Post 6-week training, 6 weeks after completion, and 3 (or 6) months after completion]

   Degrees; extent of ankle dorsiflexion to enable foot clearance

4. Postural Sway Areas During Quiet Standing [Change from baseline to: Post 6-week training, 6 weeks after completion, and 3 (or 6) months]

   cm^2; extent of postural deviations to assess static postural control

5. Ratio of Asymmetric Loading in Quiet Standing [Change from baseline to: Post 6-week training, 6 weeks after completion, and 3 (or 6) months]

   Ratio of Newtons of force per each leg (paretic/nonparetic) while standing quietly

6. Peak Paretic Push Off Forces During Gait Initiation [Change from baseline to: Post 6-week training, 6 weeks after completion, and 3 (or 6) months]

   Newtons; magnitude of forward ground reaction forces

Eligibility Criteria

Criteria

• Ages Eligible for Study: 18 Years and Older
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No

Inclusion Criteria:

• Ischemic or hemorrhagic stroke > 2 months prior in men or women

• Residual hemiparesis of the lower extremity that includes symptoms of foot drop

• Capable of ambulating on a treadmill with handrail support

• Already completed all conventional physical therapy

• Adequate language and cognitive function to provide informed consent and participate in testing and training

Exclusion Criteria:

• Cardiac history of:

• Unstable angina

• Recent (< 3 months) myocardial infarction

• Congestive heart failure (NYHA category II or higher)

• Hemodynamic valvular dysfunction

• Hypertension that is a contraindication for a bout of treadmill training (>160/100 mmHg on two assessments)

• Medical history of:

• Recent hospitalization (< 3 months) for any serious condition leading to significant bed-rest or reduction in mobility function

• Symptomatic peripheral arterial occlusive disease

• Orthopedic or chronic pain conditions restricting exercise

• Pulmonary failure requiring oxygen

• Uncompensated renal failure

• Active cancer

• Neurological history and exam consistent with:

• Dementia

• Receptive or global aphasia that confounds testing and training, operationally defined as unable to follow 2-point commands

• Non-stroke neurological disorder restricting exercise (e.g. Parkinson's Syndrome, myopathy)

• Untreated major depression

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Baltimore VA Medical Center VA Maryland Health Care System, Baltimore, MD	Baltimore	Maryland	United States	21201

Sponsors and Collaborators

• VA Office of Research and Development

Investigators

• Principal Investigator: Steven J Kittner, Baltimore VA Medical Center VA Maryland Health Care System, Baltimore, MD

Study Documents (Full-Text)

• Statistical Analysis Plan - Apr 12, 2019
• Informed Consent Form - Jan 17, 2019
• Study Protocol - May 27, 2015

More Information

Publications

None provided.

• Responsible Party: VA Office of Research and Development
• ClinicalTrials.gov Identifier: NCT02483676
• Other Study ID Numbers: N1699-R
• First Posted: Jun 29, 2015
• Last Update Posted: May 20, 2020
• Last Verified: May 1, 2020

• Individual Participant Data (IPD) Sharing Statement: No
• Plan to Share IPD: No
• Studies a U.S. FDA-regulated Drug Product: No
• Studies a U.S. FDA-regulated Device Product: Yes
• Product Manufactured in and Exported from the U.S.: No
• Keywords provided by VA Office of Research and Development: Rehabilitation; Robotics; Gait
• Additional relevant MeSH terms: Stroke; Peroneal Neuropathies

Study Results

Participant Flow

Arm/Group Title	Treadmill+Anklebot	Treadmill Only
Arm/Group Description	This group will receive gait training on a treadmill while wearing the anklebot with the adaptive control system. Treadmill plus anklebot: This intervention employs the use of the adaptive anklebot control system to complement treadmill exercise training over a 6-week intervention period.	This group will receive gait training on a treadmill, without use of the anklebot. Treadmill only: This intervention employs the use of a treadmill for gait exercise training over a 6-week intervention period
Period Title: Overall Study
STARTED	23	22
COMPLETED	17	17
NOT COMPLETED	6	5

Baseline Characteristics

Arm/Group Title	Treadmill+Anklebot	Treadmill Only	Total
Arm/Group Description	This group will receive gait training on a treadmill while wearing the anklebot with the adaptive control system. Treadmill plus anklebot: This intervention employs the use of the adaptive anklebot control system to complement treadmill exercise training over a 6-week intervention period.	This group will receive gait training on a treadmill, without use of the anklebot. Treadmill only: This intervention employs the use of a treadmill for gait exercise training over a 6-week intervention period	Total of all reporting groups
Overall Participants	23	22	45
Age (Count of Participants)
<=18 years	0 0%	0 0%	0 0%
Between 18 and 65 years	8 34.8%	10 45.5%	18 40%
>=65 years	15 65.2%	12 54.5%	27 60%
Age (years) [Mean (Full Range) ]
Mean (Full Range) [years]	64	65	65
Sex: Female, Male (Count of Participants)
Female	9 39.1%	8 36.4%	17 37.8%
Male	14 60.9%	14 63.6%	28 62.2%
Race (NIH/OMB) (Count of Participants)
American Indian or Alaska Native	0 0%	0 0%	0 0%
Asian	2 8.7%	1 4.5%	3 6.7%
Native Hawaiian or Other Pacific Islander	0 0%	0 0%	0 0%
Black or African American	15 65.2%	15 68.2%	30 66.7%
White	6 26.1%	6 27.3%	12 26.7%
More than one race	0 0%	0 0%	0 0%
Unknown or Not Reported	0 0%	0 0%	0 0%
Region of Enrollment (Count of Participants)
United States	23 100%	22 100%	45 100%
Years since stroke (Count of Participants)
<2	4 17.4%	2 9.1%	6 13.3%
2-4	7 30.4%	9 40.9%	16 35.6%
4-6	4 17.4%	7 31.8%	11 24.4%
6+	8 34.8%	4 18.2%	12 26.7%

Outcome Measures

1. Primary Outcome

Title	Gait Velocity During Self-selected Overground Walking
Description	Gait velocity during self-selected overground walking measured in cm/sec
Time Frame	Change from baseline to: Post 6-week training, 6 weeks after completion, and 3 (or 6) months after completion

Outcome Measure Data

Analysis Population Description

Only 38 of patients were included in the intention-to-treat analysis, as we excluded patients who had no baseline or follow-up data on the primary outcomes.

Arm/Group Title	Treadmill+Anklebot	Treadmill Only
Arm/Group Description	This group will receive gait training on a treadmill while wearing the anklebot with the adaptive control system. Treadmill plus anklebot: This intervention employs the use of the adaptive anklebot control system to complement treadmill exercise training over a 6-week intervention period.	This group will receive gait training on a treadmill, without use of the anklebot. Treadmill only: This intervention employs the use of a treadmill for gait exercise training over a 6-week intervention period
Measure Participants	17	21
Baseline	0.48 (0.21)	0.48 (0.34)
Post 6-week training	0.54 (0.24)	0.56 (0.32)
6 weeks after completion	0.53 (0.24)	0.55 (0.33)
3 (or 6) months after completion	0.52 (0.23)	0.55 (0.33)

2. Primary Outcome

Title	Anterior-posterior Propulsion Forces of Paretic Side During Gait
Description	Newtons: anterior-posterior force generated during push-off phase of the gait cycle
Time Frame	Change from baseline to: Post 6-weeks training, 6 weeks after completion, and 3 (or 6) months

Outcome Measure Data

Analysis Population Description

Only 38 are included in the intention-to-treat analysis, as we excluded patients with no baseline or follow-up data on the primary outcomes.

Arm/Group Title	Treadmill+Anklebot	Treadmill Only
Arm/Group Description	This group will receive gait training on a treadmill while wearing the anklebot with the adaptive control system. Treadmill plus anklebot: This intervention employs the use of the adaptive anklebot control system to complement treadmill exercise training over a 6-week intervention period.	This group will receive gait training on a treadmill, without use of the anklebot. Treadmill only: This intervention employs the use of a treadmill for gait exercise training over a 6-week intervention period
Measure Participants	17	21
Baseline	2.22 (12.37)	2.22 (12.37)
Post 6-week training	4.92 (10.99)	3.03 (10.99)
6 weeks after completion	6.06 (8.92)	4.14 (8.92)
3 (or 6) months after completion	4.88 (10.74)	3.98 (10.74)

3. Primary Outcome

Title	Peak Dorsiflexion Angle During Swing Phase of Gait
Description	Degrees; extent of ankle dorsiflexion to enable foot clearance
Time Frame	Change from baseline to: Post 6-week training, 6 weeks after completion, and 3 (or 6) months after completion

Outcome Measure Data

Analysis Population Description

Only 38 are included in the intention-to-treat analysis, as we excluded patients who had no baseline or follow-up data on the primary outcomes.

Arm/Group Title	Treadmill+Anklebot	Treadmill Only
Arm/Group Description	This group will receive gait training on a treadmill while wearing the anklebot with the adaptive control system. Treadmill plus anklebot: This intervention employs the use of the adaptive anklebot control system to complement treadmill exercise training over a 6-week intervention period.	This group will receive gait training on a treadmill, without use of the anklebot. Treadmill only: This intervention employs the use of a treadmill for gait exercise training over a 6-week intervention period
Measure Participants	17	21
Baseline	3.95 (6.83)	3.95 (6.83)
Post 6-week training	4.84 (6.83)	4.24 (6.83)
6 weeks after completion	4.34 (6.26)	3.27 (6.26)
3 (or 6) months after completion	3.33 (6.72)	3.43 (6.72)

4. Primary Outcome

Title	Postural Sway Areas During Quiet Standing
Description	cm^2; extent of postural deviations to assess static postural control
Time Frame	Change from baseline to: Post 6-week training, 6 weeks after completion, and 3 (or 6) months

Outcome Measure Data

Analysis Population Description

Only 38 are included in the intention-to-treat analysis, as we excluded patients who had no baseline or follow-up data on the primary outcomes.

Arm/Group Title	Treadmill+Anklebot	Treadmill Only
Arm/Group Description	This group will receive gait training on a treadmill while wearing the anklebot with the adaptive control system. Treadmill plus anklebot: This intervention employs the use of the adaptive anklebot control system to complement treadmill exercise training over a 6-week intervention period.	This group will receive gait training on a treadmill, without use of the anklebot. Treadmill only: This intervention employs the use of a treadmill for gait exercise training over a 6-week intervention period
Measure Participants	17	21
Baseline	1.16 (0.64)	1.16 (0.64)
Post 6-week training	1.51 (0.82)	1.33 (0.82)
6 weeks after completion	1.44 (0.57)	1.13 (0.52)
3 (or 6) months after completion	1.59 (0.52)	1.14 (0.52)

5. Primary Outcome

Title	Ratio of Asymmetric Loading in Quiet Standing
Description	Ratio of Newtons of force per each leg (paretic/nonparetic) while standing quietly
Time Frame	Change from baseline to: Post 6-week training, 6 weeks after completion, and 3 (or 6) months

Outcome Measure Data

Analysis Population Description

This data was not recorded during the study nor calculated as part of the analysis.

Arm/Group Title	Treadmill+Anklebot	Treadmill Only
Arm/Group Description	This group will receive gait training on a treadmill while wearing the anklebot with the adaptive control system. Treadmill plus anklebot: This intervention employs the use of the adaptive anklebot control system to complement treadmill exercise training over a 6-week intervention period.	This group will receive gait training on a treadmill, without use of the anklebot. Treadmill only: This intervention employs the use of a treadmill for gait exercise training over a 6-week intervention period
Measure Participants	0	0

6. Primary Outcome

Title	Peak Paretic Push Off Forces During Gait Initiation
Description	Newtons; magnitude of forward ground reaction forces
Time Frame	Change from baseline to: Post 6-week training, 6 weeks after completion, and 3 (or 6) months

Outcome Measure Data

Analysis Population Description

Only 38 are included in the intention-to-treat analysis, as we excluded patients who had no baseline or follow-up data on the primary outcomes. The results should be interpreted with extreme caution as there was inconsistent use of AFO's (ankle-foot orthosis) during evaluations and/or the training focus was on dorsiflexion assistance.

Arm/Group Title	Treadmill+Anklebot	Treadmill Only
Arm/Group Description	This group will receive gait training on a treadmill while wearing the anklebot with the adaptive control system. Treadmill plus anklebot: This intervention employs the use of the adaptive anklebot control system to complement treadmill exercise training over a 6-week intervention period.	This group will receive gait training on a treadmill, without use of the anklebot. Treadmill only: This intervention employs the use of a treadmill for gait exercise training over a 6-week intervention period
Measure Participants	17	21
Baseline	64.7 (28.5)	64.7 (28.5)
Post 6-week training	63.5 (27)	62.8 (27)
6 weeks after completion	65.4 (30.6)	69.8 (30.6)
3 (or 6) months after completion	66.1 (29.9)	70.9 (29.9)

7. Post-Hoc Outcome

Title	Dorsiflexion Angle at Foot Strike
Description	Degrees, extent of ankle dorsiflexion at initial foot contact with the floor
Time Frame	Change from baseline to: Post 6-week training, 6 weeks after completion, and 3 (or 6) months after completion

Outcome Measure Data

Analysis Population Description

Only 38 are included in the intention-to-treat analysis, as we excluded patients who had no baseline or follow-up data on the primary outcomes.

Arm/Group Title	Treadmill+Anklebot	Treadmill Only
Arm/Group Description	This group will receive gait training on a treadmill while wearing the anklebot with the adaptive control system. Treadmill plus anklebot: This intervention employs the use of the adaptive anklebot control system to complement treadmill exercise training over a 6-week intervention period.	This group will receive gait training on a treadmill, without use of the anklebot. Treadmill only: This intervention employs the use of a treadmill for gait exercise training over a 6-week intervention period
Measure Participants	17	21
Baseline	-1.83 (5.03)	-1.83 (7.31)
Post 6-week training	-0.70 (6.55)	-0.46 (5.7)
6 weeks after completion	-2.18 (6.27)	-2.15 (6.16)
3 (or 6) months after completion	-2.99 (5.96)	-1.58 (6.71)

Adverse Events

Time Frame	24 to 36 weeks for each subject; 6 week training + 6 weeks post training + 12 or 24 weeks follow up
Arm/Group Title	Treadmill+Anklebot		Treadmill Only
Arm/Group Description	This group will receive gait training on a treadmill while wearing the anklebot with the adaptive control system. Treadmill plus anklebot: This intervention employs the use of the adaptive anklebot control system to complement treadmill exercise training over a 6-week intervention period.		This group will receive gait training on a treadmill, without use of the anklebot. Treadmill only: This intervention employs the use of a treadmill for gait exercise training over a 6-week intervention period
All Cause Mortality
	Treadmill+Anklebot		Treadmill Only
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/23 (0%)		0/22 (0%)
Serious Adverse Events
	Treadmill+Anklebot		Treadmill Only
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/23 (0%)		0/22 (0%)
Other (Not Including Serious) Adverse Events
	Treadmill+Anklebot		Treadmill Only
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	4/23 (17.4%)		2/22 (9.1%)
Cardiac disorders
Weakness	0/23 (0%)	0	2/22 (9.1%)	2
Musculoskeletal and connective tissue disorders
Pre-existing Medical Condition	2/23 (8.7%)	2	0/22 (0%)	0
Pain	2/23 (8.7%)	2	0/22 (0%)	0

Limitations/Caveats

[Not Specified]

More Information

Certain Agreements

Principal Investigators are NOT employed by the organization sponsoring the study.

There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.