Blood Flow Restriction and Transcutaneous Electrical Nerve Stimulation on Motor Function in Stroke

NCT06973590 | Recruiting

• 1 other identifier: 2025_BFR+TENS_STROKE
• Study Type: interventional
• Target: 80
• Locations: 1 country
• Sites: 1

Brief Summary

Stroke commonly results in persistent leg impairments that limit mobility and reduce quality of life. This study investigates whether combining low-intensity resistance training with blood flow restriction (LIRT-BFR) and transcutaneous electrical nerve stimulation (TENS) can effectively improve leg function in stroke survivors. Participants with chronic stroke will be randomly assigned to one of four intervention groups: 1) LIRT with simulated BFR and simulated TENS; 2) LIRT with actual BFR and simulated TENS; 3) LIRT with simulated BFR and actual TENS; 4) LIRT with both actual BFR and actual TENS. The resistance training utilizes 20% of each participant's maximum lifting capacity. For blood flow restriction, an automated pressure cuff (SmartCuffs 4.0) will be placed on the upper portion of the affected leg, inflated to 50% of the individual's occlusion pressure during exercises and deflated during rest periods. TENS therapy delivers controlled electrical impulses through electrodes positioned on the anterior thigh. Each 60-minute session includes a 10-minute warm-up followed by 40 minutes of targeted resistance exercises (leg extensions, leg presses, and weight-bearing squats) and concludes with 10 minutes of stationary cycling. The resistance protocol involves 3 sets of 20 repetitions with standardized rest intervals between sets and exercises. Participants will attend three sessions weekly for six weeks. Assessments will be conducted at baseline, midpoint (3 weeks), completion (6 weeks), and follow-up (1 month post-intervention). The primary outcome measure is the Fugl-Meyer Assessment for Lower Extremity function, with secondary measures including muscle strength, stiffness, balance, mobility, walking capacity, and gait parameters. To understand the underlying mechanisms, we will measure muscle oxygenation using near-infrared spectroscopy, evaluate muscle structure via ultrasound, and monitor physiological responses including heart rate variability and perceived exertion for safety monitoring.

Conditions

Chronic Stroke

Keywords

blood flow restriction; transcutaneous electrical nerve stimulation; stroke; low-intensity resistance training

Outcome Measures

Primary Outcomes (1)

• 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 Outcomes (9)

• Paretic ankle dorsiflexor/plantarflexor strength

  Baseline (0 week), Mid-intervention (3 weeks), Post-intervention (6 weeks), 1-month follow-up (10 weeks)

• Knee extension strength

  Baseline (0 week), Mid-intervention (3 weeks), Post-intervention (6 weeks), 1-month follow-up (10 weeks)

• 10-Meter Walk Test (10MWT)

  Baseline (0 week), Mid-intervention (3 weeks), Post-intervention (6 weeks), 1-month follow-up (10 weeks)

• Timed 'Up and Go' test (TUG)

  Baseline (0 week), Mid-intervention (3 weeks), Post-intervention (6 weeks), 1-month follow-up (10 weeks)

• Gait Parameters (via GAITRite)

  Baseline (0 week), Mid-intervention (3 weeks), Post-intervention (6 weeks), 1-month follow-up (10 weeks)

Study Arms (4)

LIRT + BFR + TENS

EXPERIMENTAL

All subjects will receive 60-minute sessions of LIRT with both actual BFR and actual TENS intervention, 3 sessions per week for 6 weeks.

Device: Blood flow restriction (BFR); Device: Transcutaneous electrical nerve stimulation (TENS); Behavioral: Low-intensity resistance training (LIRT)

LIRT + sham BFR + TENS

SHAM COMPARATOR

All subjects will receive 60-minute sessions of LIRT with simulated BFR and actual TENS, 3 sessions per week for 6 weeks.

Device: Transcutaneous electrical nerve stimulation (TENS); Device: Sham blood flow restriction (Sham-BFR); Behavioral: Low-intensity resistance training (LIRT)

LIRT + BFR + sham TENS

SHAM COMPARATOR

All subjects will receive 60-minute sessions of LIRT with actual BFR and simulated TENS, 3 sessions per week for 6 weeks.

Device: Blood flow restriction (BFR); Device: Sham transcutaneous electrical nerve stimulation (Sham-TENS); Behavioral: Low-intensity resistance training (LIRT)

LIRT + sham BFR + sham TENS

PLACEBO COMPARATOR

All subjects will receive 60-minute sessions of LIRT with simulated BFR and simulated TENS, 3 sessions per week for 6 weeks.

Device: Sham blood flow restriction (Sham-BFR); Device: Sham transcutaneous electrical nerve stimulation (Sham-TENS); Behavioral: Low-intensity resistance training (LIRT)

Interventions

Blood flow restriction (BFR) DEVICE

BFR implementation involves an automated restriction band (SmartCuffs 4.0) positioned at the proximal region of the affected lower extremity, calibrated to 50% of the individual's lower limb occlusion pressure (LOP). The pressure system remains inflated throughout active training phases and is systematically deflated during inter-exercise intervals.

LIRT + BFR + TENS; LIRT + BFR + sham TENS

Transcutaneous electrical nerve stimulation (TENS) DEVICE

TENS will be delivered to the anterior thigh region of the paretic leg 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.

LIRT + BFR + TENS; LIRT + sham BFR + TENS

Sham blood flow restriction (Sham-BFR) DEVICE

Sham BFR implementation involves an automated restriction band (SmartCuffs 4.0) positioned at the proximal region of the affected lower extremity, calibrated to 50% of the individual's lower limb occlusion pressure (LOP). But the pressure system remains deflated throughout active training and resting phases.

LIRT + sham BFR + TENS; LIRT + sham BFR + sham TENS

Sham transcutaneous electrical nerve stimulation (Sham-TENS) DEVICE

Sham TENS will be delivered to the anterior thigh region of the paretic leg 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. But the stimulator will only be applied for the first and last 30 seconds.

LIRT + BFR + sham TENS; LIRT + sham BFR + sham TENS

Low-intensity resistance training (LIRT) BEHAVIORAL

The LIRT protocol utilizes 20% of one-repetition maximum (1-RM) as the standardized training load. LIRT including leg extensions, leg presses, and load-bearing squats focused on the affected limb. Each resistance exercise consists of 3 sets of 20 repetitions with rest intervals.

LIRT + BFR + TENS; LIRT + BFR + sham TENS; LIRT + sham BFR + TENS; LIRT + sham BFR + sham TENS

Eligibility Criteria

• Age: 50 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• are between 50 and 80 years of age;
• have had a single stroke more than 6 months and less than 15 years;
• have at least 5 degrees of active ankle dorsiflexion in the antigravity position;
• are able to walk 10 m independently, with or without a walking aid;
• are able to score 6 or higher out of 10 on the abbreviated mental test;
• have no skin allergies (e.g. redness or itchiness after application of the electrical stimulation pads) to electrical stimulation or electrodes;
• are able to follow instructions and give informed consent.

You may not qualify if:

• presence of other comorbidities like varicose veins, peripheral neuropathy, cancer, musculoskeletal injury, lower limb peripheral edema, post-surgical swelling, open wounds, or on a medication that increases blood clotting risk;
• resting blood pressure ≥ 160/100 mmHg even after taking medications, cardiovascular comorbidity, heart failure, unstable angina, by-pass surgery, a pacemaker;
• administration of botulinum toxin in the lower limb at least 6 months prior to training;
• history of epilepsy, cochlear implants, any type of deep brain stimulator and metal implants in the head or neck;
• currently not participating in resistance training or high-intensity or long duration cardiovascular exercise;
• lack the ability to feel pain (because of paralysis), or other subjects who cannot complain of discomfort.

Sponsors & Collaborators

• The Hong Kong Polytechnic University: lead

Study Sites (1)

The Hong Kong Polytechnic University

Hong Kong, Hong Kong

RECRUITING

MeSH Terms

Conditions

Stroke

Interventions

Blood Flow Restriction Therapy; Transcutaneous Electric Nerve Stimulation

Condition Hierarchy (Ancestors)

Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases

Intervention Hierarchy (Ancestors)

Exercise Therapy; Rehabilitation; Aftercare; Continuity of Patient Care; Patient Care; Therapeutics; Physical Therapy Modalities; Electric Stimulation Therapy; Analgesia; Anesthesia and Analgesia

Study Officials

• Shamay NG, PhD

  The Hong Kong Polytechnic University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Shamay NG, PhD

CONTACT

+852 27664889; shamay.ng@polyu.edu.hk

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Prof.

Study Record Dates

• First Submitted: May 7, 2025
• First Posted: May 15, 2025
• Study Start: September 1, 2024
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026
• Last Updated: May 15, 2025

Record last verified: 2025-05

Data Sharing

• IPD Sharing: Will not share

Locations

HK (1)