Robot-Assisted Gait and Bicycle Training for Stroke Patients With Pre-Sarcopenia

Not Applicable

Recruiting

• Conditions: Stroke; Sarcopenia in Elderly; Muscle Weakness; Muscle Quality

• Registration Number: NCT06910254
• Lead Sponsor: Sahmyook University

Brief Summary

This study aims to evaluate the effects of overground robot-assisted gait training (o-RAGT) using a wearable robotic exoskeleton (Angel Legs M20) combined with recumbent cycling on muscle mass, physical function, and fall-related self-efficacy in patients with subacute stroke and pre-sarcopenia. Participants will be randomly assigned to either an experimental group receiving both o-RAGT and recumbent cycling, or a control group receiving recumbent cycling alone. Interventions will be performed 5 times per week for 4 weeks. Primary outcomes include changes in skeletal muscle mass (SMI), muscle quality, and fall efficacy. Secondary outcomes include balance (SPPB), gait endurance (6MWT), neurological recovery (FMA-LE), mobility (TUG), and functional ambulation (FAC). This study will help determine whether combining robotic gait training with cycling improves muscle function and rehabilitation outcomes more effectively than cycling alone. Participants will be subacute stroke patients (\< 6 months post-onset) with pre-sarcopenia diagnosed using the SARC-F questionnaire and AWGS 2019 criteria.

Detailed Description

Stroke is a leading cause of long-term disability worldwide, with many survivors experiencing difficulties in walking and functional mobility. In the early phase of recovery (subacute stage), patients are especially vulnerable to loss of muscle mass and strength, a condition known as sarcopenia. Pre-sarcopenia, defined by reduced skeletal muscle mass without significant loss of strength or function, is considered an early warning sign. Timely intervention is essential to prevent further decline and progression to sarcopenia.

This study investigates the effectiveness of a combined rehabilitation program using overground robot-assisted gait training (o-RAGT) and recumbent cycling in subacute stroke patients diagnosed with pre-sarcopenia. The goal is to evaluate whether adding robotic gait training to conventional cycling exercises leads to greater improvements in muscle mass, physical function, and fall-related confidence.

A total of 53 participants will be recruited from a rehabilitation hospital in Seoul, Korea. All participants must meet the following criteria: stroke onset within the past 6 months, height between 140-190 cm, body weight under 80 kg, minimal ambulatory ability (FAC ≥ 1), and adequate cognitive function (MMSE ≥ 24). Pre-sarcopenia will be diagnosed based on the SARC-F questionnaire (≥ 4 points) and low muscle mass according to the Asian Working Group for Sarcopenia (AWGS 2019) criteria.

Participants will be randomly assigned to one of two groups:

* Experimental Group: o-RAGT using a wearable robotic exoskeleton (Angel Legs M20) combined with recumbent cycling.

* Control Group: Recumbent cycling only.

Both groups will receive training 5 times per week for 4 weeks. Each session will last approximately 30 minutes. o-RAGT sessions will be tailored to the participant's functional level, beginning with full robotic assistance and gradually reducing support as recovery progresses.

Primary outcomes will include changes in:

Muscle mass (measured by bioelectrical impedance analysis), Muscle quality (assessed with a near-infrared spectroscopy-based device), Fall-related self-efficacy (using the Korean version of the Falls Efficacy Scale-International, KFES-I).

Secondary outcomes will include:

Balance and lower extremity function (Short Physical Performance Battery, SPPB), Gait endurance (6-Minute Walk Test), Neurological motor recovery (Fugl-Meyer Assessment for Lower Extremities), Functional mobility (Timed Up and Go test), Ambulation independence (Functional Ambulation Category, FAC), Upper-limb strength (Grip strength, measured using a digital hand dynamometer with bilateral testing and average value recording).

All assessments will be conducted at baseline and after the 4-week intervention period.

This study aims to determine whether integrating robotic gait training into early stroke rehabilitation can more effectively improve muscle mass, muscle quality, and fall-related outcomes. The findings may contribute to evidence-based, targeted strategies for preventing sarcopenia progression in stroke survivors.

Study Timeline

• Study First Submitted: 2025-03-17
• Study First Submitted QC: 2025-04-01
• Study First Posted: 2025-04-04
• Study Start: 2025-06-09
• Status Verified: 2025-07
• Last Update Submitted: 2025-07-07
• Last Update Posted: 2025-07-10
• Primary Completion: 2025-08-31
• Study Completion: 2025-08-31

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 53

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Change in Muscle Quality	Baseline and 4 weeks	Muscle quality will be assessed using the FITTO device, which uses near-infrared spectroscopy (NIRS) to evaluate muscle composition (fat and water content) at five specific sites: erector spinae, rectus femoris, vastus lateralis, gastrocnemius, and semitendinosus. Each site will be measured twice, and the average score will be used. Higher scores indicate better muscle quality. The Minimal Clinically Important Difference (MCID) is 10%, and the Minimal Detectable Change (MDC) is 5%. Measurements will be taken at baseline and after the 4-week intervention.
Change in Fall Efficacy	Baseline and 4 weeks	Fall-related self-efficacy will be measured using the Korean version of the Falls Efficacy Scale-International (KFES-I), which includes 16 items rated on a 4-point Likert scale, for a total score range of 16 to 64. Higher scores indicate greater fear of falling. The Minimal Clinically Important Difference (MCID) is estimated at 6 points, and the Minimal Detectable Change (MDC95) is also typically 6 points in older adults. Assessments will be performed at baseline and after the 4-week intervention period.
Change in Muscle Mass	Baseline and 4 weeks	Change in muscle mass will be assessed using bioelectrical impedance analysis (BIA) with the ACCUNIQ BC720 device. The skeletal muscle mass index (SMI) will be calculated by dividing appendicular skeletal muscle mass (ASM) by height squared (kg/m²). This measure is based on the Asian Working Group for Sarcopenia (AWGS 2019) diagnostic criteria. A decrease or increase in SMI will be used to quantify changes in muscle mass. The Minimal Clinically Important Difference (MCID) is considered to be 0.7 kg/m², and the Minimal Detectable Change (MDC) is 0.5 kg/m². Assessments will be performed at baseline and after the 4-week intervention.

Secondary Outcome Measures

Name	Time	Method
Change in Short Physical Performance Battery (SPPB) Score	Baseline and 4 weeks	The Short Physical Performance Battery (SPPB) is used to assess lower extremity function, including balance, gait speed, and chair rise ability. It is scored from 0 to 12, with higher scores indicating better physical performance. A change of ≥1.0 point is considered the Minimal Clinically Important Difference (MCID), while the Minimal Detectable Change (MDC) ranges from 0.4 to 1.0 points depending on the population. Assessments will be conducted at baseline and after the 4-week intervention.
Change in Functional Ambulation Category (FAC)	Baseline and 4 weeks	The Functional Ambulation Category (FAC) assesses walking independence on a 6-point scale, ranging from 0 (non-ambulatory) to 5 (independent ambulation on all surfaces). Higher scores indicate greater walking independence. Although the Minimal Clinically Important Difference (MCID) is not precisely defined, a change of ≥1 point is generally considered functionally meaningful in stroke rehabilitation. Assessments will be conducted at baseline and after the 4-week intervention.
Change in Timed Up and Go (TUG) Test Time	Baseline and 4 weeks	Change in Timed Up and Go (TUG) Test Time; Description: The Timed Up and Go (TUG) test is a standardized assessment used to evaluate functional mobility and balance. During the test, the participant is instructed to rise from a standard armchair with armrests, walk a distance of 3 meters, turn around at a designated mark, return to the chair, and sit down. The total time taken to complete the sequence is recorded in seconds to the nearest tenth (e.g., 10.3 sec). A TUG time of ≥14 seconds is considered indicative of a high risk of falls. The test demonstrates excellent test-retest reliability (ICC = 0.96) and inter-rater reliability (ICC = 0.98), and is sensitive to changes in dynamic balance and functional mobility. In this study, the Minimal Detectable Change (MDC) for the TUG is set at 7.0 seconds, based on recent findings in subacute stroke populations. Adequate rest is provided prior to each assessment to reduce fatigue-related variance.
Change in Fugl-Meyer Assessment (FMA) Lower Extremity Score	Baseline and 4 weeks	The Fugl-Meyer Assessment for the lower extremity (FMA-LE) evaluates motor recovery in stroke patients. It includes 17 items scored on a 3-point ordinal scale (0 = cannot perform, 1 = performs partially, 2 = performs fully), with a total score ranging from 0 to 34. Higher scores reflect better motor function. The Minimal Clinically Important Difference (MCID) for the lower extremity domain is approximately 6.0 points in stroke rehabilitation. The Minimal Detectable Change (MDC) ranges between 3.0 and 5.8 points depending on the population and study design. Measurements are taken at baseline and after the 4-week intervention.
Change in 6-Minute Walk Test (6MWT) Distance	Baseline and 4 weeks	The 6-Minute Walk Test (6MWT) measures the maximum distance (in meters) a participant can walk in 6 minutes along a 30-meter indoor track. It is used to assess walking endurance, aerobic capacity, and functional mobility. Higher distances indicate better performance. The Minimal Clinically Important Difference (MCID) is 50 meters, and the Minimal Detectable Change (MDC) is approximately 58.21 meters in stroke populations.
Change in Grip Strength	Baseline and 4 weeks	Grip strength will be measured bilaterally using a digital hand dynamometer (TAKEI T.K.K.5401, Japan) to explore changes in upper-limb muscle function and general muscle status. Measurements will be performed with participants in a seated position, elbow flexed at 90°, and the average of two trials per hand will be recorded. While grip strength is not a primary or secondary outcome of the study, it will be analyzed as an exploratory variable to support interpretation of global muscle function. Higher values indicate greater strength.

Trial Locations

Locations (1)

Sahmyook University; 🇰🇷 Seoul, Korea, Republic of