Effects of Blood Flow Restriction Training on Muscle Strength and Physical Function for Stroke-Related Sarcopenia

The Hong Kong Polytechnic University64 enrolled

Overview

Effects of Blood Flow Restriction Walking on Muscle Strength and Physical Function in Chronic Stroke Patients with Sarcopenia: A Randomized, Sham-Controlled Trial Primary Objective: To evaluate the effects of BFR walking on muscle strength and physical function in chronic stroke patients with sarcopenia, compared to sham-BFR walking. Secondary Objective: (1) To explore the potential impact of BFR walking on muscle mass and vascular function in chronic stroke patients with sarcopenia. (2) To assess the influence of BFR walking on quality of life in chronic stroke patients with sarcopenia.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Enrollment

Conditions

Sarcopenia Chronic Stroke Patients

Interventions

Participants in this group will undergo a supervised treadmill walking program with blood flow restriction (BFR) applied using BFR pressure cuffs. The cuffs are applied to the proximal thighs, and the training pressure starts at 50% of the participant's arterial occlusion pressure (AOP), increasing every two weeks up to 200 mmHg. Walking is performed at 60% of the maximum walking speed, 20 minutes per session, 3 sessions per week for 6 weeks.

Sham Blood Flow Restriction (Sham-BFR) WalkingPROCEDURE

Participants in this group will follow the same supervised treadmill walking protocol as the BFR group but with minimal cuff pressure (20 mmHg), which does not restrict blood flow. This simulates the sensation of BFR without physiological impact. The purpose is to serve as a placebo comparator. Walking is performed at 60% of maximum walking speed, 20 minutes per session, 3 sessions per week for 6 weeks.

Eligibility

Sex: ALLMin age: 50 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Diagnosed with chronic stroke (≥6 months post-stroke) * Sarcopenia will be diagnosed using the Asian Working Group for Sarcopenia (AWGS) 2025 criteria, defined as the concurrent presence of low muscle strength and low appendicular skeletal muscle mass. Muscle strength will be assessed using handgrip strength measured on the non-paretic side. Low muscle strength will be defined as handgrip strength \<28 kg for men and \<18 kg for women aged ≥65 years, and \<34 kg for men and \<20 kg for women aged 50-64 years. Appendicular skeletal muscle mass will be measured using bioelectrical impedance analysis, and the appendicular skeletal muscle mass index will be calculated as appendicular skeletal muscle mass divided by height squared. Low muscle mass will be defined as an appendicular skeletal muscle mass index \<7.0 kg/m² for men and \<5.7 kg/m² for women aged ≥65 years, and \<7.6 kg/m² for men and \<5.7 kg/m² for women aged 50-64 years. Exclusion Criteria: * Stroke occurred within the past 6 months * Resting systolic blood pressure \> 200 mmHg * Resting diastolic blood pressure \> 100 mmHg * Presence of implanted electronic or metallic devices that interfere with blood flow restriction cuffs * Contraindication to bioelectrical impedance analysis (e.g., pacemaker, ICD)

Locations (2)

Hong Kong Polytechnic University

Hung Hom, Kowloon, Hong Kong

NOT_YET_RECRUITING

Hong Kong Polytechnic University

Hung Hom, Kowloon, Hong Kong

RECRUITING

Outcomes

Primary Outcomes

Muscle Strength

Isometric knee extensor strength of the paretic limb will be assessed using an isokinetic dynamometer at 60 degrees of knee flexion. The primary variable will be peak torque, recorded in Newton-meters (N·m). Higher values indicate greater knee extensor strength.

Time frame: baseline (prior to intervention), 6 weeks post-intervention (End), and 6 weeks after the end of the intervention (Follow-up)

Secondary Outcomes

Nutritional Status - Mini Nutritional Assessment Short Form (MNA-SF)

Nutritional status will be evaluated using the Mini Nutritional Assessment - Short Form (MNA-SF), a validated screening tool for identifying malnutrition or risk of malnutrition in older adults. The total score ranges from 0 to 14. Scores ≥12 indicate normal nutritional status, 8-11 at risk, and ≤7 malnourished.

Time frame: baseline (prior to intervention), 6 weeks post-intervention (End), and 6 weeks after the end of the intervention (Follow-up)

Quality of Life - Sarcopenia and Quality of Life Questionnaire (SarQoL)

Quality of life related to sarcopenia will be assessed using the Sarcopenia and Quality of Life Questionnaire (SarQoL), a disease-specific instrument for older adults with reduced muscle mass or function. It covers domains such as physical health, mental health, locomotion, and daily activities. Higher scores indicate better quality of life.

Time frame: baseline (prior to intervention), 6 weeks post-intervention (End), and 6 weeks after the end of the intervention (Follow-up)

Appendicular Skeletal Muscle Mass (ASM)

ASM will be assessed using bioelectrical impedance analysis (BIA) and reported in kilograms per square meter (kg/m²). This value is calculated as total limb lean mass divided by height squared, following the AWGS 2019 criteria.

Time frame: Baseline, Week 6, Week 12

Muscle Thickness (MT)

Muscle thickness will be measured using B-mode ultrasonography with a high-frequency linear probe. Values will be reported in millimeters (mm). The average of three measurements will be used for each muscle. Muscle Thickness of Rectus Femoris and Medial Gastrocnemius.

Time frame: Baseline, Week 6, Week 12

Six-Minute Walk Distance

Walking endurance will be assessed using the 6-Minute Walk Test. Participants will be instructed to walk as far as possible along a level indoor walkway within 6 minutes. The total distance covered will be recorded in meters. Higher values indicate better walking endurance.