ZEPU-AI5 Strength Training Study (ZEPUAI5RCT)

Overview

The goal of this clinical trial is to learn if robot-assisted lower-limb strength and gait training can improve safety, feasibility, and functional recovery in adults aged 18-60 years with lower-limb motor dysfunction due to stroke, incomplete spinal cord injury, or persistent gait impairment following orthopedic surgery. The main questions it aims to answer are: Is robot-assisted training using the ZEPU-AI5 device safe and well-tolerated, with an acceptable rate of device-related adverse events? Does adding ZEPU-AI5-assisted training to standard-of-care rehabilitation improve functional outcomes (such as walking distance, muscle strength, balance, and mobility) compared to standard-of-care rehabilitation alone? Researchers will compare an intervention group receiving standard-of-care rehabilitation combined with ZEPU-AI5-assisted training to a control group receiving standard-of-care rehabilitation alone, to see if the addition of robotic training leads to greater improvements in safety, functional recovery, and quality of life. Participants will: Undergo a baseline assessment before starting the study Receive either robot-assisted training plus standard-of-care rehabilitation, or standard-of-care rehabilitation alone, three times per week for 12 weeks Complete follow-up assessments every two weeks to evaluate safety, functional outcomes, and durability of any benefits

Walking impairment due to neurological and orthopedic conditions significantly limits independence and functional mobility, making lower-limb strength training a key focus of rehabilitation. Robotic-assisted rehabilitation systems have shown promising results in improving strength and functional outcomes in high-income countries; however, their feasibility, safety, and efficacy remain underexplored in low- and middle-income settings. In Bangladesh, the ZEPU-AI5 lower-limb strength training and evaluation robot is a novel technology that has not yet been systematically evaluated in this population. The ZEPU-AI5 is a computer-controlled electromechanical rehabilitation device consisting of a rigid main frame, a motor-driven walking training table, bilateral robotic mechanical legs aligned with the patient's hip and knee joints, adjustable foot pedals, thigh and calf fixation straps, and a body-weight support suspension system. The walking platform supports up to 135 kg, with continuously adjustable body-weight unloading from 0-80 kg, allowing progressive loading according to patient tolerance and recovery stage. Prior to training, individualized calibration is performed by measuring thigh and calf lengths to align the robotic joints with the participant's anatomical hip and knee axes, with bilateral symmetry adjustment available when needed. The system provides programmable control over hip joint angles (30°-50°) and knee joint angles (50°-80°) in 1° increments, with gait offset parameters adjustable by ±10 units to allow individualized correction of abnormal gait patterns. Walking speed is adjustable from 0.1 to 3.5 km/h, allowing graded progression from slow assisted stepping to higher-speed gait training. At study entry, participants will undergo a face-to-face interview to gather clinical and sociodemographic data using a semi-structured, pre-tested questionnaire. Weight and height will be measured to calculate Body Mass Index (BMI). All participants will be allocated a study ID, and assessments will be conducted at the Robotic Rehabilitation Center, Department of Physical Medicine and Rehabilitation, Bangladesh Medical University.