Ankle Robot to Reduce Foot Drop in Stroke

NCT ID: NCT02483676

Last Updated: 2020-05-20

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 45 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2015-09-01
• Study Completion Date: 2019-06-30

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.

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.

Conditions

Stroke; Foot Drop

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: SINGLE

Study Groups

Treadmill+anklebot

This group will receive gait training on a treadmill while wearing the anklebot with the adaptive control system.

Group Type: EXPERIMENTAL

Treadmill plus anklebot

Intervention Type: DEVICE

This intervention employs the use of the adaptive anklebot control system to complement treadmill exercise training over a 6-week intervention period.

Treadmill only

This group will receive gait training on a treadmill, without use of the anklebot.

Group Type: ACTIVE_COMPARATOR

Treadmill only

Intervention Type: BEHAVIORAL

This intervention employs the use of a treadmill for gait exercise training over a 6-week intervention period

Interventions

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.

Intervention Type: DEVICE

Treadmill only

This intervention employs the use of a treadmill for gait exercise training over a 6-week intervention period

Intervention Type: BEHAVIORAL

Other Intervention Names

TMR; TM

Eligibility Criteria

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

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

VA Office of Research and Development

FED

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Steven J Kittner

Role: PRINCIPAL_INVESTIGATOR

Baltimore VA Medical Center VA Maryland Health Care System, Baltimore, MD

Locations

Baltimore VA Medical Center VA Maryland Health Care System, Baltimore, MD

Baltimore, Maryland, United States

Countries

United States

Provided Documents

Document Type: Statistical Analysis Plan

View Document

Document Type: Informed Consent Form

View Document

Document Type: Study Protocol

View Document

Other Identifiers

N1699-R

Identifier Type: -

Identifier Source: org_study_id