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

This study aims to investigate the effects of overground robot-assisted gait training (o-RAGT) and recumbent bicycle training on muscle mass, physical function, and fall efficacy in subacute stroke patients with pre-sarcopenia. Stroke survivors often experience significant muscle loss and functional decline, especially during the subacute phase. o-RAGT, using a wearable robotic exoskeleton, provides intensive, repetitive gait training on real ground, enhancing sensory feedback and muscle activation. Recumbent bicycle training offers stable lower extremity exercise, promoting muscle strengthening and cardiovascular health. Participants will be randomly assigned to either the combined o-RAGT and recumbent bicycle training group or the recumbent bicycle-only group. Interventions will be provided 5 times a week for 4 weeks. Primary outcomes include changes in muscle mass, muscle quality, and fall efficacy. Secondary outcomes include physical performance (SPPB), functional ambulation (FAC), balance (TUG), and neurological recovery (FMA). This randomized controlled trial aims to establish evidence-based rehabilitation strategies for improving physical function and reducing fall risk in stroke patients with pre-sarcopenia.

Background and Rationale Stroke-induced physical decline includes muscle wasting and reduced functional mobility, particularly in the subacute phase. Pre-sarcopenia-characterized by decreased appendicular skeletal muscle mass without significant loss in strength or performance-can worsen into full sarcopenia without timely intervention. Early physical rehabilitation targeting both muscle mass preservation and gait improvement is critical in this period.

Recent advancements such as overground robot-assisted gait training (o-RAGT) using wearable exoskeletons enable repetitive, real-environment gait practice with adaptive feedback, enhancing motor learning and proprioception. Recumbent bicycle training, in contrast, provides safe, low-impact exercise improving lower limb strength and aerobic capacity. The combination of these modalities may have synergistic effects on muscle mass maintenance and physical performance.

Study Objective This randomized controlled trial aims to evaluate the effects of combining o-RAGT and recumbent bicycle training on muscle mass, physical function, and fall efficacy in subacute stroke patients with pre-sarcopenia.

Study Design and Intervention Overview

This is a single-center, assessor-blinded RCT including two parallel groups. Participants diagnosed with pre-sarcopenia (per AWGS criteria) within 6 months post-stroke will be randomized into:

Experimental group: 30 minutes of o-RAGT using a robotic exoskeleton (adjusting gait assistance in real time), followed by 30 minutes of recumbent bicycle training per session.

Control group: 30 minutes of recumbent bicycle training alone.

Both groups will train 5 days/week for 4 weeks (20 sessions total).

The primary aim is to examine changes in appendicular muscle mass (via BIA) and fall efficacy (Falls Efficacy Scale). Secondary outcomes include SPPB, FAC, TUG, and FMA-Lower Extremity scores.

Eligibility Criteria:
Inclusion Criteria:

* Age 19 years or older
* Diagnosis of subacute stroke (within 6 months after stroke onset)
* Diagnosis of pre-sarcopenia based on the Asian Working Group for Sarcopenia (AWGS) criteria
* Able to follow simple instructions and participate in rehabilitation exercises
* Functional Ambulation Category (FAC) level 2 or higher (indicating ability to walk with assistance or supervision)
* Medically stable and cleared for participation in rehabilitation programs by a physician

Exclusion Criteria:

* Severe cognitive impairment (Mini-Mental State Examination (MMSE) score \< 24)
* Uncontrolled cardiovascular, respiratory, or metabolic diseases that may interfere with exercise participation
* Severe musculoskeletal disorders or joint deformities limiting participation in gait or cycling training
* History of other neurological disorders affecting gait (e.g., Parkinson's disease, multiple sclerosis)
* Participation in other clinical trials involving rehabilitation interventions within the past 3 months
* Contraindications to robot-assisted gait training or recumbent bicycle training
* Significant visual or vestibular impairment affecting balance training
* Any medical condition deemed inappropriate for study participation by the attending physician