ZEPU-2000 Limb Rehabilitation Trainer Study (ZEPU2000RCT)

This is a pilot randomized controlled trial evaluating the feasibility, safety, and preliminary efficacy of three robotic upper and lower limb rehabilitation trainer systems - ZEPU-2000A (upper limb trainer), ZEPU-2000D (lower limb gait and mobility trainer), and ZEPU-2000E (multifunctional upper and lower limb trainer) - when added to conventional rehabilitation, compared with conventional rehabilitation alone, in adults with upper and/or lower limb motor dysfunction.

Rationale: Upper- and lower-limb motor dysfunction following stroke, incomplete spinal cord injury, traumatic brain injury, and orthopedic conditions is a major cause of long-term disability. Motor recovery is closely linked to repetitive, task-specific, goal-oriented movement practice, but conventional therapist-led rehabilitation is often limited by therapist availability, fatigue, and variability in delivery. Electromechanical and robotic trainer systems can deliver standardized, repetitive, programmable movement training with objective performance monitoring across passive, active-assisted, and active-resisted modes. While robotic rehabilitation has shown benefit in high-income settings, evidence on feasibility, safety, and effectiveness in low- and middle-income countries remains limited. This study will generate local evidence to support the integration of the ZEPU-2000 series into rehabilitation services at Bangladesh Medical University (BMU) and to inform the design of a future adequately powered trial.

Setting: Robotic Rehabilitation Centre, Department of Physical Medicine and Rehabilitation, Bangladesh Medical University, Dhaka, Bangladesh. Devices are provided and supported by the manufacturer (Shandong ZEPU Medical Technology Co. Ltd) through an approved distributor. Sessions are conducted under the supervision of physiatrists and physiotherapists.

Design: Thirty-six participants will be enrolled for each robotic system and randomized 1:1 into two arms:

Intervention arm (Robotic-Augmented Rehabilitation Group): standard-of-care rehabilitation plus robotic-assisted therapy using the ZEPU-2000A, ZEPU-2000D, or ZEPU-2000E systems.

Control arm (Usual Care Group): standard-of-care rehabilitation alone (individualized rehabilitation and exercise), without robotic training.

All participants undergo baseline assessment at week 0, with outcome assessments repeated at two-week intervals across the 12-week intervention period and during follow-up.

Population: Adults aged 18-60 years with upper-limb motor dysfunction (with or without lower-limb involvement) due to stroke (2-24 months post-onset), incomplete spinal cord injury (ASIA Impairment Scale C or D, neurological level C5 or below), traumatic brain injury with persistent upper-limb limitation, or orthopedic/post-surgical conditions of the shoulder, elbow, wrist, or hand with functional impairment lasting more than 3 months. Participants must be medically stable, able to provide informed consent, and have body size/anthropometry compatible with the devices. Exclusions include complete spinal cord injury, severe cognitive impairment (MMSE < 24), severe upper-limb spasticity (Modified Ashworth Scale > 3), unstable fractures or severe fixed joint contractures, uncontrolled cardiac arrhythmia or incompatible implanted electronic devices, and pregnancy.

Intervention: Robotic training sessions occur 3 times weekly for 12 weeks (approximately 36 sessions total), each lasting about 45 minutes inclusive of donning/doffing and warm-up/cool-down. A typical session includes a 5-minute warm-up, 10 minutes of device set-up, 25 minutes of structured training (e.g., sit-to-stand, standing, in-place and over-ground walking, turning, or upper-limb task-oriented movement depending on device), and a 5-minute cool-down. Training parameters (e.g., support level, range, speed) are progressively adjusted weekly by the supervising physiotherapist based on participant performance and safety. Standard physical therapy continues per institutional protocol in both arms. Pre-session checks include vital signs, skin integrity, and pain/discomfort screening; safety harnesses are used during early sessions until safe performance is demonstrated; a therapist is present throughout; and post-session checks include skin inspection, fatigue/pain rating (VAS), and review of device-logged training data.

Outcome Measures:

Primary (safety/feasibility): incidence of device-related adverse events (AEs) and serious adverse events (SAEs) - including falls, skin breakdown, joint pain/injury, cardiovascular events, fracture, or device malfunction - over the 12-week intervention and follow-up; device tolerability (sessions completed vs. planned, dropouts and reasons).

Secondary (efficacy): Medical Research Council (MRC) muscle strength grading, Modified Ashworth Scale (MAS) for spasticity, Functional Ambulation Category (FAC), Functional Independence Measure (FIM), Timed Up and Go (TUG), Action Research Arm Test (ARAT), and Barthel Index.

Feasibility/usability: screening and recruitment metrics, session adherence, time required for therapist competency training, device set-up time, assistance required for donning/doffing, and the Post-Study System Usability Questionnaire (PSSUQ) administered at week 16 to assess device comfort, perceived benefit, and willingness to continue.

Data Collection: Clinical and sociodemographic data are collected at enrolment via a semi-structured, pre-tested questionnaire. Height and weight are measured to calculate BMI. Assessments are repeated at baseline and two-week intervals for 12 weeks. Telephone and video calls supplement in-person visits to monitor compliance; robotic sessions are tracked via attendance sheets.

Statistical Analysis: Descriptive statistics will summarize safety outcomes (AE/SAE counts, adherence, dropouts). Continuous efficacy variables will be summarized as mean ± SD (or median/IQR if non-normally distributed) at each time point, with paired and unpaired t-tests or Wilcoxon signed-rank tests used to compare baseline versus follow-up findings, as appropriate. Both intention-to-treat (all 36 randomized participants, 18 per group) and per-protocol analyses (participants completing the intervention as specified) will be conducted. Missing follow-up data will be handled using group-wise mean substitution. Statistical significance will be set at p < 0.05 (two-tailed), using SPSS.

Safety Monitoring: Identified risks include falls, joint stress or injury, skin breakdown from device straps, cardiovascular events, equipment malfunction, fatigue, muscle soreness, and spasticity exacerbation. Mitigation measures include safety harnesses, continuous physiotherapist/physician presence, pre-session vital sign screening, gradual progression of training intensity, skin inspections, an emergency stop mechanism, staff training on emergency procedures, and immediate AE reporting. SAEs will be reported to the BMU Institutional Review Board within 24 hours and to the manufacturer per their protocol. A Data Safety Monitoring Committee (including representatives from Neuromedicine, Physical Medicine and Rehabilitation, and Internal Medicine) will conduct monthly safety reviews, with a pre-specified pause rule if more than 2 device-attributable SAEs occur. Any study-related physical injury will be managed free of cost to the participant.

Ethics: The protocol and informed consent form have been reviewed and approved by the BMU Institutional Review Board (Memo No. BMU/2026/5035, dated 13-05-2026) prior to enrolment. Written informed consent will be obtained in Bengali (with an English version available), covering device use, potential risks and benefits, voluntary participation, and the right to withdraw at any time without affecting standard care. Participant confidentiality will be maintained, and the study will be registered on a public trial registry before first participant enrolment.

Inclusion criteria

• Presence of upper-limb motor dysfunction, with or without concurrent lower-limb impairment, due to one of the following: stroke with onset between 2 and 24 months prior to enrolment; incomplete spinal cord injury (neurological level C5 and below), classified as ASIA Impairment Scale C or D; traumatic brain injury with persistent upper-limb functional limitation; or orthopedic/post-surgical conditions involving the shoulder, elbow, wrist, or hand with persistent functional impairment for more than 3 months
• Age between 18 and 60 years
• Ability to understand study procedures and follow instructions, and to provide written informed consent (or assent with guardian consent where applicable)
• Body weight and limb anthropometry compatible with ZEPU-2000A, ZEPU-2000D, and ZEPU-2000E systems, per manufacturer specifications
• Medically stable and cleared by a physician for robotic rehabilitation, with no active infection, uncontrolled cardiac or respiratory disease, severe osteoporosis, uncontrolled epilepsy, or untreated deep vein thrombosis

Exclusion criteria

• Complete spinal cord injury or profound motor paralysis preventing safe interaction with robotic devices
• Severe cognitive impairment, defined as a Mini-Mental State Examination (MMSE) score less than 24, that would compromise safe participation Severe spasticity of the upper limb, defined as a Modified Ashworth Scale score greater than 3
• Unstable fractures, severe fixed joint contractures of the shoulder, elbow, wrist, or hand (e.g., greater than 30 degrees), or severe pain limiting safe robotic training
• Uncontrolled cardiac arrhythmia, or presence of a pacemaker or other implanted electronic medical device incompatible with robotic sensors
• Pregnancy