A Wearable Anti-Gravity Supplement to Therapy Does Not Improve Arm Function in Chronic Stroke: A Randomized Pilot Trial

Background Gravity confounds arm movement ability in post-stroke hemiparesis. Reducing its influence allows effective practice leading to recovery. Yet, there is a scarcity of wearable devices suitable for personalized use across diverse therapeutic activities in the clinic. Objective In this pilot study, we investigated the safety, feasibility, and efficacy of anti-gravity therapy using the ExoNET device in post-stroke participants. Methods Twenty chronic stroke survivors underwent six, 45-minute occupational therapy sessions while wearing the ExoNET, randomized into either the treatment (ExoNET tuned to gravity-support) or control group (ExoNET tuned to slack condition). Clinical outcomes were evaluated by a blinded-rater at baseline, post, and 6-week follow-up sessions. Kinetic, kinematic, and patient experience outcomes were also assessed. Results No significant effects were found between the treatment and control groups for Action Research Arm Test, Fugl-Meyer Upper Extremity, and Wolf Motor Function Test scores though the treatment group showed an improvement in Box and Blocks scores in the post-intervention session (effect size = 2.1, P = .04). Direct kinetic effects revealed a significant reduction in muscle activity during free exploration with an effect size of (−7.12%, P < .005) but no longitudinal kinetic or kinematic trends. Subject feedback suggested a generally positive perception of the anti-gravity therapy. Conclusions Anti-gravity therapy with the ExoNET is a safe and feasible treatment for post-stroke rehabilitation. The device provided anti-gravity forces, did not encumber range of motion, and clinical metrics of anti-gravity therapy demonstrated improvements in gross manual dexterity. Further research is required to explore potential benefits in broader clinical metrics. Trial Registration: This study was registered at ClinicalTrials.gov (ID# NCT05180812).