Randomized, Crossover Clinical Trial on the Safety, Feasibility, and Usability of the ABLE Exoskeleton: A Comparative Study with Knee-Ankle-Foot Orthoses

Wearable exoskeletons are emerging as a new tool for gait training. However, comparisons between exoskeletons and conventional orthoses in terms of safety and feasibility are scarce. This study assessed the safety, feasibility, usability, and learning process of using the ABLE Exoskeleton in people with spinal cord injury (SCI) while comparing it with knee-ankle-foot orthoses (KAFOs). In this randomized, crossover clinical trial, 10 patients with chronic complete SCI (T4-T12) conducted a 10-session training and assessment protocol with each device: KAFOs and the ABLE Exoskeleton. Outcomes on safety (adverse events), and feasibility and usability (level of assistance, donning/doffing, therapy activities) were recorded for both devices. Evaluation sessions included standard clinical tests (Timed Up and Go, 10-Meter Walk Test, and 6-Minute Walk Test) to assess gait performance. The therapy metrics (number of steps, distance, gait speed, and standing and walking time) were recorded at each session for the robotic device. Participants quickly learned how to use the ABLE Exoskeleton, showing improvements in all therapy metrics (p < 0.05) and the 6-Minute Walk Test (p < 0.05). The robotic device reported less adverse events than KAFOs (17 and 31, respectively). Total donning and doffing time was 43 seconds faster with the robotic device using comparable levels of assistance. The time to complete the therapy activities was very similar between devices. Overall, participants needed 1 to 4 training sessions to perform essential therapy activities (sit/stand transitions, walking 10 meters, turning around) with both devices using minimum assistance or less. The results of this study show that it is feasible and safe for people with motor complete paraplegia due to SCI (T4-T12) to use the ABLE Exoskeleton for gait training in a rehabilitation hospital setting. The ABLE Exoskeleton proved to be safer than KAFOs in terms of adverse events, and as practical and easy to use as the conventional orthoses. ### Competing Interest Statement I have read the journal's policy and the authors of this manuscript have the following competing interests: JL-P is an employee and receives salary from ABLE Human Motion S.L. (Barcelona, Spain), which was the sponsor of the present clinical investigation and manufacturer of the ABLE Exoskeleton. JMF-L is co-founder and owns stock in the company ABLE Human Motion S.L. (Barcelona, Spain), which was the sponsor of the present clinical investigation and manufacturer of the ABLE Exoskeleton. ### Clinical Trial Trial ID: [NCT04855916][1] Due to organizational issues, the investigation team failed to register the study before the first participant enrollment. As a result, five participants had been enrolled before registration. Nonetheless, S1 File shows the Clinical Research Ethics Committee's resolution of the trial protocol, which was accepted prior to the study's start date and has not been modified since then demonstrating the clinical trial's prospective nature. ### Funding Statement AR-F would like to acknowledge the funding that was provided by the PhD grant No. 2020 FI_B1 00195 funded by the Agency for Management of University and Research Grants (AGAUR) along with the grant CDTI NEOTEC 2019 (SNEO-20191281) of the Centre for the Development of Industrial Technology (CDTI) - Spanish Ministry of Science and Innovation JL-P would like to acknowledge grant PTQ2018-010227 funded by the Spanish Ministry of Science and Innovation (MCI) - Agencia Estatal de Investigación (AEI) This clinical investigation was sponsored by ABLE Human Motion, S.L. (), which was partly involved in the study design and reviewed the final manuscript. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethics committee Grupo Hospitalario Quironsalud-Catalunya (study code: 2020/157-REH-ASEPEYO) and Spanish Agency of Medicines and Medical Devices (EUDAMED: CIV-ES-21-01-035724) gave ethical approval for this work. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The data underlying the results presented in the study are available from ABLE Human Motion, Barcelona, 08028, Spain (). Email: hello{at}ablehumanmotion.com [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT04855916&atom=%2Fmedrxiv%2Fearly%2F2023%2F04%2F17%2F2023.04.11.23288209.atom