Effect of Combining Central and Peripheral Cutaneous Electrical Stimulation on Lower Limb Motor Function in People With Stroke

A Randomized Controlled Trial of Anodal Transcranial Direct Current Stimulation and Transcutaneous Electrical Nerve Stimulation for Improving Lower Limb Function in Stroke Patients

This study aims to evaluate the effectiveness of transcranial direct current stimulation (tDCS) and transcutaneous electrical nerve stimulation (TENS) in augmenting the efficacy of the lower limb task-oriented training in people with stroke. It is hypothesize that lower limb motor function can be best improved by combining anodal tDCS with TENS, when compared with sham-tDCS with TENS, anodal tDCS with placebo-TENS, or control training at improving ankle muscle strength, motor control of lower limbs, walking performance, functional mobility and community integration in people with stroke.

Study Overview

• Status: Recruiting
• Conditions: Stroke
• Intervention / Treatment: Device: Transcranial direct current stimulation (tDCS); Device: Bilateral Transcutaneous electrical nerve stimulation (Bi-TENS); Behavioral: Lower-limb task-oriented training; Device: Sham transcranial direct current stimulation (Sham-tDCS); Device: Placebo transcutaneous electrical nerve stimulation (Placebo-TENS)

Detailed Description

The application of transcutaneous electrical nerve stimulation (TENS) over a paretic lower limb could augment the effects of task-oriented exercise therapy on lower limb motor function in people with stroke, possibly through increased excitability of sensorimotor cortex.

In transcranial direct current stimulation (tDCS), a weak electrical current is applied through electrodes placed on the scalp to modulate cortical excitability and neural activity in targeted brain regions. Anodal tDCS, specifically, involves positioning the positively charged electrode over the targeted cortical area, which facilitates neuronal depolarization and increases cortical excitability in the underlying brain tissue. The enhanced neural excitability induced by anodal tDCS could promote neuroplasticity and optimize motor learning processes, potentially through the modulation of N-methyl-D-aspartic acid (NMDA) receptor -dependent mechanisms and alterations in GABAergic activity, leading to improved motor function and rehabilitation outcomes in various neurological conditions.

The next question concerns whether anodal tDCS could be combined with TENS and whether their synergetic effects could maximise the motor output of paretic limbs in people with stroke.

• Study Type: Interventional
• Enrollment (Estimated): 92
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Shamay NG, PhD; Phone Number: +852 27664889; Email: shamay.ng@polyu.edu.hk

Study Locations

• Hong Kong
  • Hong Kong, Hong Kong
    • Recruiting
    • The Hong Kong Polytechnic University
    • Contact: Shamay NG, PhD; Phone Number: +852 27664889; Email: shamay.ng@polyu.edu.hk
    • Principal Investigator: Shamay Ng, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. are between 50 and 85 years of age;
2. have had a single stroke more than 6 months and less than 15 years;
3. have at least 5 degrees of active ankle dorsiflexion in the antigravity position;
4. are able to walk 10 m independently, with or without a walking aid;
5. are able to score 6 or higher out of 10 on the abbreviated mental test;
6. have no skin allergies (e.g. redness or itchiness after application of the electrical stimulation pads) to electrical stimulation or electrodes;
7. are able to follow instructions and give informed consent.

Exclusion Criteria:

1. have any additional medical, cardiovascular or orthopedic conditions that would hinder their treatment or assessment;
2. have a cardiac pacemaker;
3. have aphasia or cognitive difficulties that may interfere with their comprehension of instructions;
4. have had one or more epileptic seizures within the year prior to the date of inclusion in the study;
5. have an intracerebral metal clip;
6. have a major somatosensory deficit
7. have any contraindication to tDCS;
8. are currently involved in drug studies or other clinical trials.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Anodal tDCS+Bi-TENS; All subjects will receive eighteen 60-minute sessions of intervention, 3 sessions per week for 6 weeks.	Device: Transcranial direct current stimulation (tDCS); tDCS will be delivered by a constant-current electrical stimulator (DC-stimulator; Eldith, Ilmenau, Germany). Rectangular electrodes covered with a saline-soaked sponge will be used for the anode and cathode. The anode will be placed over the leg area of the motor cortex, on the lesioned side, with the medial border of the electrode placed laterally to Cz on the international electroencephalogram 10-20 system. The cathode will be placed above the contralateral orbit. The stimulation intensity will be set at 2 mA for 30 minutes.; Device: Bilateral Transcutaneous electrical nerve stimulation (Bi-TENS); TENS will be delivered to the common peroneal nerve of both intact and paretic leg for 30 minutes using a 120z Dual-Channel TENS Unit (ITO Physiotherapy & Rehabilittaion, Co, Ltd, Tokyo, Japan). The TENS stimulation will be at 100 Hz, with 0.2 ms square pulses at an intensity of twice the sensory threshold (defined as the minimum intensity at which subject reported feeling a tingling sensation and below the motor threshold as indicated by the absence of muscle twitching.; Behavioral: Lower-limb task-oriented training; The lower-limb task-oriented training comprises 5 exercises for 30 minutes, namely stepping up and down, heel lift a dorsiflexed position, partial squatting, gait re-education and transition training.
Sham Comparator: Sham-tDCS+Bi-TENS; All subjects will receive eighteen 60-minute sessions of intervention, 3 sessions per week for 6 weeks.	Device: Bilateral Transcutaneous electrical nerve stimulation (Bi-TENS); TENS will be delivered to the common peroneal nerve of both intact and paretic leg for 30 minutes using a 120z Dual-Channel TENS Unit (ITO Physiotherapy & Rehabilittaion, Co, Ltd, Tokyo, Japan). The TENS stimulation will be at 100 Hz, with 0.2 ms square pulses at an intensity of twice the sensory threshold (defined as the minimum intensity at which subject reported feeling a tingling sensation and below the motor threshold as indicated by the absence of muscle twitching.; Behavioral: Lower-limb task-oriented training; The lower-limb task-oriented training comprises 5 exercises for 30 minutes, namely stepping up and down, heel lift a dorsiflexed position, partial squatting, gait re-education and transition training.; Device: Sham transcranial direct current stimulation (Sham-tDCS); Sham tDCS will be delivered by a constant-current electrical stimulator (DC-stimulator; Eldith, Ilmenau, Germany). Rectangular electrodes covered with a saline-soaked sponge will be used for the anode and cathode. The anode will be placed over the leg area of the motor cortex, on the lesioned side, with the medial border of the electrode placed laterally to Cz on the international electroencephalogram 10-20 system. The cathode will be placed above the contralateral orbit. The stimulation intensity will The stimulator will only be applied for the first and last 30 seconds.
Placebo Comparator: Anodal tDCS+placebo-TENS; All subjects will receive eighteen 60-minute sessions of intervention, 3 sessions per week for 6 weeks.	Device: Transcranial direct current stimulation (tDCS); tDCS will be delivered by a constant-current electrical stimulator (DC-stimulator; Eldith, Ilmenau, Germany). Rectangular electrodes covered with a saline-soaked sponge will be used for the anode and cathode. The anode will be placed over the leg area of the motor cortex, on the lesioned side, with the medial border of the electrode placed laterally to Cz on the international electroencephalogram 10-20 system. The cathode will be placed above the contralateral orbit. The stimulation intensity will be set at 2 mA for 30 minutes.; Behavioral: Lower-limb task-oriented training; The lower-limb task-oriented training comprises 5 exercises for 30 minutes, namely stepping up and down, heel lift a dorsiflexed position, partial squatting, gait re-education and transition training.; Device: Placebo transcutaneous electrical nerve stimulation (Placebo-TENS); Placebo-TENS will be applied to identical-looking TENS devices, with the electrical circuit disconnected inside the devices. Placebo-TENS will be delivered to the common peroneal nerve of both intact and paretic leg for 30 minutes that set at 100 Hz, with 0.2 ms square pulses.
Placebo Comparator: Control training; All subjects will receive eighteen 60-minute sessions of intervention, 3 sessions per week for 6 weeks.	Behavioral: Lower-limb task-oriented training; The lower-limb task-oriented training comprises 5 exercises for 30 minutes, namely stepping up and down, heel lift a dorsiflexed position, partial squatting, gait re-education and transition training.; Device: Sham transcranial direct current stimulation (Sham-tDCS); Sham tDCS will be delivered by a constant-current electrical stimulator (DC-stimulator; Eldith, Ilmenau, Germany). Rectangular electrodes covered with a saline-soaked sponge will be used for the anode and cathode. The anode will be placed over the leg area of the motor cortex, on the lesioned side, with the medial border of the electrode placed laterally to Cz on the international electroencephalogram 10-20 system. The cathode will be placed above the contralateral orbit. The stimulation intensity will The stimulator will only be applied for the first and last 30 seconds.; Device: Placebo transcutaneous electrical nerve stimulation (Placebo-TENS); Placebo-TENS will be applied to identical-looking TENS devices, with the electrical circuit disconnected inside the devices. Placebo-TENS will be delivered to the common peroneal nerve of both intact and paretic leg for 30 minutes that set at 100 Hz, with 0.2 ms square pulses.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Paretic ankle dorsiflexor strength	The paretic ankle dorsiflexor strength (in kilograms) is measured with a Nicholas hand-held dynamometer (model 01,160, Lafayette Instrument Company, Lafayette, IN) in supine lying position. The muscle strength will be measured twice. The average strength of the 2 trials will be recorded. A higher value indicated a better paretic ankle dorsiflexor strength.	Baseline (0 week), Mid-intervention (3 weeks), Post-intervention (6 weeks), 1-month follow-up (10 weeks)
Paretic ankle plantarflexor strength	The paretic ankle plantarflexor strength (in kilograms) is measured with a Nicholas hand-held dynamometer (model 01,160, Lafayette Instrument Company, Lafayette, IN) in supine lying position. The muscle strength will be measured twice. The average strength of the 2 trials will be recorded. A higher value indicated a better paretic ankle dorsiflexor strength.	Baseline (0 week), Mid-intervention (3 weeks), Post-intervention (6 weeks), 1-month follow-up (10 weeks)
Fugl-Meyer Assessment of Lower Extremity (FMA-LE)	FMA-LE is used to evaluate the lower extremity motor control, including reflexes, voluntary control of isolated movement and coordination. The scale score ranging from 0 to 34, with 17 items and ordinal scoring from 0 to 2. A higher score indicates a better lower extremity motor control.	Baseline (0 week), Mid-intervention (3 weeks), Post-intervention (6 weeks), 1-month follow-up (10 weeks)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
10-Meter Walk Test (10MWT)	The subject will be asked to walk 10 meter in a comfortable speed. The completion time will be records by stopwatch. The test will be repeated for 2 times. The completion time will be averaged. The shorter the completion time, the better performance is.	Baseline (0 week), Mid-intervention (3 weeks), Post-intervention (6 weeks), 1-month follow-up (10 weeks)
Timed 'Up and Go' test (TUG)	The TUG is used to measure the functional mobility. Each subject will be required to rise from a chair with armrests, walk 3 m forward, turn around, return to the chair and sit down. The time taken to complete this task will be measured in seconds with a stopwatch. Each condition will be repeated for 2 times. The completion time will be averaged.	Baseline (0 week), Mid-intervention (3 weeks), Post-intervention (6 weeks), 1-month follow-up (10 weeks)
Lower-extremity motor co-ordination test	The lower-extremity motor coordination test is used to measure the coordination of both the paretic and intact legs. Two red flat targets will be secured on the floor 30 cm apart. In sitting position with the feet resting flat on the floor and the heels on one of the targets, the participant will be instructed to touch 2 targets alternately with the big toe, as quickly and as accurately as possible, for 20 seconds. The number of times each target is touched will be counted. The more touch times indicated a better performance.	Baseline (0 week), Mid-intervention (3 weeks), Post-intervention (6 weeks), 1-month follow-up (10 weeks)
Gait Parameters (via GAITRite)	Gait parameters will be assessed using the GAITRite system (CIR system, Inc., Havertown, Pennsylvania), a pressure-sensitive mat that automatically captures spatiotemporal gait characteristics. Participants will walk at their self-selected comfortable pace along the instrumented walkway.	Baseline (0 week), Mid-intervention (3 weeks), Post-intervention (6 weeks), 1-month follow-up (10 weeks)
Berg Balance Scale (BBS)	BBS is a 14-item objective measure that assesses static balance and fall risk in adult patients. Items include tasks such as sitting to standing, standing unsupported, transfers, reaching, turning 360 degrees, and single-leg stance. Each item is scored from 0-4 points (0=unable to perform, 4=independent), with a maximum total score of 56 points. Higher scores indicate better balance.	Baseline (0 week), Mid-intervention (3 weeks), Post-intervention (6 weeks), 1-month follow-up (10 weeks)
Limits of Stability (LOS) Test	The Limits of Stability (LOS) test quantifies participants' ability to intentionally shift their center of gravity (COG) to their stability limits without losing balance using Bertec Balance Advantage System (Bertec Corporation, Columbus, OH, USA). Participants stand on a force plate and shift their weight to move a cursor on a screen toward 8 targets arranged in a circular pattern at their theoretical limits of stability (100% LOS). Key parameters measured reaction time (RT) , movement velocity (MVL), directional control (DCL), endpoint excursion (EPE), maximum excursion (MXE). Higher scores indicate better dynamic balance control, except for reaction time where lower scores are better.	Baseline (0 week), Mid-intervention (3 weeks), Post-intervention (6 weeks), 1-month follow-up (10 weeks)
Sensory Organization Test (SOT)	SOT assesses the participant's ability to maintain postural stability by evaluating the integration of visual, vestibular, and somatosensory inputs using Bertec Balance Advantage System (Bertec Corporation, Columbus, OH, USA). The test systematically disrupts sensory information while measuring postural sway. Outcome measures include composite equilibrium score and sensory analysis ratios (somatosensory, visual, vestibular, and preference ratios). Higher scores indicate better postural stability and sensory integration.	Baseline (0 week), Mid-intervention (3 weeks), Post-intervention (6 weeks), 1-month follow-up (10 weeks)
Cantonese version of Community Integration Measures (CIM-C)	The level of community integration will be assessed by the Cantonese version of Community Integration Measures (CIM-C). The CIM is a client-centred questionnaire with 10 items; each item rating from 1 to 5 with a total score from 10 to 50. A higher CIM-C score indicates a higher level of community integration.	Baseline (0 week), Mid-intervention (3 weeks), Post-intervention (6 weeks), 1-month follow-up (10 weeks)
Foot & Ankle Disability Index Score (FADI)	FADI is a 26-item patient-reported outcome measure that assesses functional limitations related to foot and ankle conditions. The questionnaire consists of 22 items assessing activities of daily living and 4 items specific to pain. Each item is scored on a 5-point Likert scale from 0 (unable to do) to 4 (no difficulty at all). Total scores are converted to percentages, with 100% representing no dysfunction. The FADI includes activities such as walking on even/uneven ground, climbing stairs, squatting, and recreational activities.	Baseline (0 week), Mid-intervention (3 weeks), Post-intervention (6 weeks), 1-month follow-up (10 weeks)
EQ-5D Visual Analogue Scale (EQ-5D VAS)	The EQ-5D VAS is a standardized vertical visual analog scale (thermometer-like scale) that measures self-rated health status. Participants rate their overall health state on a scale from 0 (worst imaginable health state) to 100 (best imaginable health state). This scale is part of the EQ-5D instrument but specifically captures the respondent's overall self-rated health status on the day of assessment. The VAS provides a quantitative measure of health outcome that reflects the participant's own judgment.	Baseline (0 week), Mid-intervention (3 weeks), Post-intervention (6 weeks), 1-month follow-up (10 weeks)

Collaborators and Investigators

• Sponsor: The Hong Kong Polytechnic University
• Investigators: Principal Investigator: Shamay NG, PhD, The Hong Kong Polytechnic University

Study record dates

Study Major Dates

• Study Start (Actual): June 17, 2024
• Primary Completion (Estimated): August 31, 2026
• Study Completion (Estimated): August 31, 2026

Study Registration Dates

• First Submitted: February 16, 2025
• First Submitted That Met QC Criteria: February 16, 2025
• First Posted (Actual): February 20, 2025

Study Record Updates

• Last Update Posted (Actual): July 9, 2025
• Last Update Submitted That Met QC Criteria: July 3, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Keywords: transcranial direct current stimulation; stroke; rehabilitation; transcutaneous electric nerve stimulation
• Additional Relevant MeSH Terms: Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Stroke
• Other Study ID Numbers: 2023_GRF_Ng

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
• product manufactured in and exported from the U.S.: No