An interventional study of Model-Predictive Controller (MPC) Functional Electrical Stimulation (FES) and Conventional Functional Electrical Stimulation (FES) in Post-stroke Hemiparesis, sponsored by Emory University. Recruiting at 1 site in United States. Open to participants aged 40 Years to 90 Years. Per ClinicalTrials.gov, last updated 2026-07-16.
Sponsored by Emory University · Not applicable, Interventional, and Treatment
This study will compare the performance of a novel data-driven model-predictive controller (MPC) based functional electrical stimulation (FES) system versus a conventional FES system for footdrop correction during treadmill and overground walking tasks in people post-stroke.
Functional electrical stimulation (FES) is a common rehabilitation tool that incorporates electrical stimulation timed with a functional task to augment paretic muscle function in people with neuro-pathologies such as stroke and spinal cord injury. The rigor of previous research has established the safety, as well as both neuro-prosthetic and therapeutic effects of FES systems for standing, walking, and grasping. Stroke is the leading cause of disability, and footdrop is a highly prevalent post-stroke gait deficit, leading to insufficient ankle dorsiflexion during the swing phase of gait, and contributing to reduced mobility. FES systems that correct footdrop to improve gait function and reduce fall risk are gaining popularity, with commercial systems such as enhancing translation potential. Despite their promising functional value, accessibility, and positive neuroplasticity effects, current FES systems have some fundamental limitations, which limit their clinical prescription.
The goal of this project is to overcome two major limitations and technical gaps in FES: rapid onset of muscle fatigue during FES and lack of sophisticated closed-loop control of FES intensity. Most existing FES systems do not automatically modulate stimulation intensity in response to muscle fatigue, and may overstimulate the muscles if fixed (open-loop) stimulation or a pure feedback-based stimulation strategy is used to control FES intensity. To address this limitation, the researchers aim to develop and clinically test FES for improving stroke gait using data-driven FES control systems.
Footdrop is a highly prevalent post-stroke gait deficit, leading to insufficient ankle dorsiflexion during the swing phase of gait, and reducing functional mobility. FES, which is an external application of stimulation to generate muscle contractions during a functional motor task, can achieve muscle force demands during standing and walking, and help persons with stroke and spinal cord injury recover mobility. FES for the correction of footdrop is one of the most popular gait applications of FES, which has been shown to improve mobility and reduce falls.
Although FES has positive effects on walking function, elicits active muscle contractions, and enhances corticomotor excitability, FES is not used as commonly as passive orthotics. Most current FES systems incorporate motion sensors to control the timing of FES during the gait cycle (paretic leg swing phase). However, none of these systems provide automatic closed-loop control of FES intensity, so that optimal stimulation can be delivered for each step, preventing over-stimulation, reducing fatigue, and maintaining optimal muscle performance for a greater number of steps. Additionally, rapid onset of muscle fatigue during FES is caused by synchronous, non-selective, repeated recruitment of largely fatigable muscle fibers.
The researchers will implement an innovative model-predictive controller (MPC) combined with real-time ultrasound-based feedback to deliver optimal FES intensities and minimize fatigue.
Emory University is the lead sponsor of 1,386 studies on the registry; 236 are open to participants now.
Of its 229 completed or terminated interventional studies of FDA-regulated products, 174 (76%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Post-stroke participants participating in both treadmill and overground walking trials with the novel model-predictive controller (MPC) functional electrical stimulation (FES) system first and with a conventional functional electrical stimulation (FES) system second.
Device: Model-Predictive Controller (MPC) Functional Electrical Stimulation (FES) · Device: Conventional Functional Electrical Stimulation (FES)
Post-stroke participants participating in both treadmill and overground walking trials with a conventional functional electrical stimulation (FES) system first and the novel model-predictive controller (MPC) functional electrical stimulation (FES) system second.
Device: Model-Predictive Controller (MPC) Functional Electrical Stimulation (FES) · Device: Conventional Functional Electrical Stimulation (FES)
The model-predictive controller (MPC) determines the timing and intensity of electrical stimulation delivered for FES. MPC combined with real-time ultrasound-based feedback delivers optimal FES intensities and minimizes fatigue. FES is delivered to the ankle dorsiflexor muscles using a commercially available FDA-approved electrical stimulator.
For functional electrical stimulation, surface electrodes are placed on the paretic leg on skin overlying the tibialis anterior (TA) muscle, with intensity pre-set to elicit dorsiflexion to neutral against gravity. FES will be delivered to the ankle dorsiflexor muscles using a commercially available FDA-approved electrical stimulator.
Number of Adverse Events
Safety is assessed as the number of adverse events experienced by study participants.
Time frame: Day 1
Count of Risks
Safety is assessed as the count of risks, including falling, discomfort, pain, skin problems, fatigue, and soreness.
Time frame: Day 1
Participant Perception of Comfort
Participant perception of comfort is measured on an 10-point Likert scale ranging from 1 to 10, where 10 is the most comfortable.
Time frame: Day 1
Participant Perception of Acceptability
Participant perception of acceptability is measured on an 10-point Likert scale ranging from 1 to 10, where 10 is the most acceptable.
Time frame: Day 1
Percent of Gait Cycles with Footdrop Correction
Feasibility of the FES control system is assessed as the percentage of gait cycles with footdrop correction. The FES control system is considered effective if greater than 80% of gait cycles have footdrop correction.
Time frame: Day 1
Number of Participants Completing Gait Bouts
Feasibility of the FES control system is assessed as the number of participants who are able to complete gait bouts with the MPC FES system. The FES control system is considered effective if greater than 80% of participants are able to complete gait bouts.
Time frame: Day 1
Peak Ankle Dorsiflexion Angle During Swing
Gait biomechanics performance is assessed as the peak ankle dorsiflexion angle during swing. The normal range for peak ankle dorsiflexion is 0 to 5 degrees.
Time frame: Day 1
Overground Walking Distance
Gait performance is assessed as overground walking distance traveled, in meters, during a 6-minute walk test.
Time frame: Day 1
FES Intensity
FES system performance is assessed as FES intensity. FES intensity is measured during a treadmill walking bout. Intensity is measured by milliamps (mA) or millivolts (mV).
Time frame: Day 1
Plan to share: Yes — De-identified individual participant data for primary dependent variables that underlie the results reported in publications from this study (such as text, tables, appendices) will be made available for sharing with other researchers.
Supporting information: Study protocol, Sap
No publications or documents are linked to this record.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Emory University