This single-center randomized controlled trial evaluates the effects of combining overground robot-assisted gait training (o-RAGT) with recumbent cycling (RC) compared with RC alone in patients with subacute stroke at risk of sarcopenia. The study examines changes in muscle characteristics (muscle mass and quality), falls efficacy, and physical function following a 4-week intervention. Participants are randomly assigned to receive either combined o-RAGT and RC or RC alone. The findings aim to inform the potential role of overground robot-assisted gait training as an adjunctive intervention in stroke rehabilitation.
This study is a single-center, randomized controlled trial designed to evaluate the effects of combining overground robot-assisted gait training (o-RAGT) with recumbent cycling (RC) in patients with subacute stroke at risk of sarcopenia. A total of 53 participants were randomly assigned to either an experimental group receiving combined o-RAGT and RC or a control group receiving RC alone. The intervention was conducted five times per week for 60 minutes per session over a 4-week period. Overground robot-assisted gait training was performed using the Angel Legs M20 exoskeleton, while recumbent cycling was provided as conventional exercise training. The primary outcomes were changes in skeletal muscle mass index, muscle quality, and falls efficacy. Secondary outcomes included measures of physical performance and functional mobility, such as the Short Physical Performance Battery, 6-Minute Walk Test, Timed Up and Go test, and lower extremity motor function. This study aims to provide clinical information regarding the feasibility and potential effects of combining overground robot-assisted gait training with conventional exercise in stroke rehabilitation.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
53
This intervention consists of overground robot-assisted gait training (o-RAGT) performed using the Angel Legs M20 wearable exoskeleton (Angel Robotics, Seoul, Republic of Korea). Participants perform structured overground walking practice with robotic assistance during scheduled training sessions. The device is used to support repetitive, task-specific overground gait practice under supervised clinical conditions.
Participants perform recumbent bicycle training using a stationary recumbent cycle ergometer (DRAX TBR9000, Republic of Korea). Training is conducted in a seated position with lower-extremity pedaling at a prescribed intensity. Each session is performed according to the study protocol under supervised clinical conditions.
Sahmyook University
Seoul, South Korea
Change in Muscle Quality
Muscle quality will be assessed using the FITTO MQ device (Olive Healthcare, Seoul, Republic of Korea), which is based on discrete multi-wavelength near-infrared spectroscopy (DMW-NIRS). The device emits near-infrared light (650-1,100 nm) and analyzes reflected signals to estimate intramuscular composition, generating a muscle quality index (MQI). Measurements will be performed bilaterally at five muscle sites according to the standardized scan guide: erector spinae, rectus femoris, vastus lateralis, semitendinosus, and gastrocnemius. Each site will be measured twice on both the paretic and non-paretic sides, and the mean MQI value will be used for analysis. Higher MQI values indicate better muscle quality. Assessments will be conducted at baseline and after the 4-week intervention period.
Time frame: Baseline and 4 weeks
Change in Fall Efficacy (K-FES-I)
Falls efficacy will be evaluated using the Korean version of the Falls Efficacy Scale-International (K-FES-I). The K-FES-I is a validated self-reported questionnaire consisting of 16 items rated on a 4-point Likert scale, assessing concern about falling during daily activities. Although higher scores on the original scale indicate greater concern about falling, total scores will be reverse-coded for analysis in this study so that higher scores represent greater falls efficacy (i.e., less concern about falling and greater confidence during daily activities). The total score ranges from 16 to 64. Assessments will be conducted at baseline (Week 0) and after completion of the 4-week intervention (Week 4).
Time frame: Baseline and 4 weeks
Change in Skeletal Muscle Mass Index (SMI)
Skeletal muscle mass index (SMI) will be assessed using multi-frequency bioelectrical impedance analysis (BIA) with the ACCUNIQ BC720 system (T-SCAN PLUS III; SELVAS Healthcare, Seoul, Republic of Korea). This device applies electrical currents across a frequency range of 1-1,000 kHz to estimate whole-body and appendicular body composition, including skeletal muscle mass. Appendicular skeletal muscle mass (ASM) will be calculated as the sum of lean mass from both upper and lower extremities. SMI will be derived using the following formula: SMI (kg/m²) = ASM (kg) / height² (m²). Measurements will be conducted under standardized conditions with participants standing independently. Each participant will be measured twice, and the mean value will be used for analysis. Assessments will be performed at baseline and after the 4-week intervention period. Higher SMI values indicate greater skeletal muscle mass.
Time frame: Baseline and 4 weeks
Change in Short Physical Performance Battery (SPPB) Score
Physical function will be assessed using the electronic Short Physical Performance Battery (eSPPB; SPPB-100, Cybermedic Co., Seoul, Republic of Korea). The SPPB consists of three components: balance test (side-by-side, semi-tandem, and tandem stance), 4-meter gait speed test, and 5-times chair stand test. Each component is scored from 0 to 4 based on performance, yielding a total score ranging from 0 to 12, with higher scores indicating better physical performance. All assessments will be conducted by trained physical therapists with at least 3 years of clinical experience, who are blinded to group allocation. The eSPPB system incorporates infrared distance sensors, pressure sensors, and a balance platform to automatically detect task initiation and completion, thereby minimizing examiner-related timing errors and improving measurement reliability. Assessments will be performed at baseline and after the 4-week intervention period.
Time frame: Baseline and 4 weeks
Change in Timed Up and Go Test (TUG)
Functional mobility and dynamic balance will be assessed using the Timed Up and Go test (TUG). Participants will be instructed to rise from a chair with armrests, walk 3 meters at a comfortable pace, turn around, return to the chair, and sit down. The time required to complete the task will be recorded in seconds (to the nearest 0.1 s). Each participant will perform two trials using standardized verbal instructions, and the mean value will be used for analysis. Assessments will be conducted by trained physical therapists with at least 3 years of clinical experience. Testing will be discontinued if adverse events such as dizziness, pain, or unstable gait are observed. Lower TUG times indicate better functional mobility. Assessments will be performed at baseline and after the 4-week intervention period.
Time frame: Baseline and 4 weeks
Change in Fugl-Meyer Assessment (FMA) Lower Extremity Score
Lower extremity motor function will be assessed using the Fugl-Meyer Assessment for the Lower Extremity (FMA-LE), a standardized and widely used measure based on the neurological recovery framework for post-stroke motor impairment. The FMA-LE consists of 17 items scored on a 3-point ordinal scale (0 = cannot perform, 1 = performs partially, 2 = performs fully), yielding a total score ranging from 0 to 34, with higher scores indicating better voluntary motor control and coordination of the lower extremity. The assessment includes three subdomains: reflex activity, voluntary movement, and coordination/speed, covering selective movements of the hip, knee, and ankle. All assessments will be conducted by trained physical therapists with at least 3 years of clinical experience using standardized procedures. Assessments will be performed at baseline and after the 4-week intervention period.
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Time frame: Baseline and 4 weeks
Change in 6-Minute Walk Test (6MWT)
Functional ambulation capacity and exercise tolerance will be assessed using the 6-Minute Walk Test (6MWT), conducted in accordance with the American Thoracic Society (ATS) guidelines. Participants will be instructed to walk as far as possible for 6 minutes at a self-selected pace, with the option to slow down or rest if needed. The total distance walked will be recorded in meters, with greater distances indicating better walking endurance and functional mobility. The test will be performed in a controlled indoor environment using a 40-meter rectangular loop track with a flat, non-elastic surface. Standardized verbal instructions and encouragement will be provided at 1-minute intervals. Participants may use their usual walking aids if required. The test will be discontinued immediately if adverse symptoms such as dizziness, chest pain, or severe fatigue occur. Assessments will be conducted at baseline and after the 4-week intervention period.
Time frame: Baseline and 4 weeks
Change in Handgrip Strength
Upper extremity muscle strength will be assessed using a digital handgrip dynamometer (TAKEI T.K.K.5401; Takei Scientific Instruments Co., Niigata, Japan). Measurements will be performed with participants seated, feet flat on the floor, shoulder in a neutral position, elbow flexed at 90°, and wrist in a neutral position. Handle span will be adjusted to fit each participant's hand size. Participants will be instructed to perform a maximal isometric contraction for 3-5 seconds. Two trials will be conducted for each hand, with a rest period of 30-60 seconds between trials to minimize fatigue. The maximum and mean values (kg) will be recorded for analysis. Lower grip strength values indicate reduced upper extremity muscle strength. Assessments will be conducted at baseline and after the 4-week intervention period.
Time frame: Baseline and 4 weeks