robot-assisted gait and bicycle training for stroke patients with pre-sarcopenia

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

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.

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.

Eligibility criteria:
inclusion criteria participants must meet all of the following criteria: 1. subacute stroke patients within 6 months of onset. 2. height between 140 and 190 cm, and body weight ≤ 80 kg. 3. functional ambulation category (fac) score ≥ 1, indicating minimal assistance required for walking. 4. mini-mental state examination (mmse) score ≥ 24, indicating no more than mild cognitive impairment. 5. diagnosed with pre-sarcopenia based on the korean version of the sarc-f questionnaire (score ≥ 4) and low skeletal muscle mass according to the asian working group for sarcopenia (awgs 2019) criteria. exclusion criteria participants will be excluded if they meet any of the following conditions: 1. serious cardiovascular conditions (e.g., heart failure, myocardial infarction) or acute medical issues preventing intervention. 2. musculoskeletal impairments that prevent the use of robotic equipment or recumbent bicycle training (e.g., fractures, joint replacements, severe lower limb deformities). 3. severe language impairment, poor cooperation, or psychological/psychiatric conditions making evaluation difficult. 4. previous exposure to robot-assisted gait training or similar interventions within the last 6 months.

Keywords: stroke-induced sarcopenia muscle strength robotic exoskeletons resistance training muscle composition muscle quality