  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 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 six-week follow-up sessions. Kinetic, kinematic, and patient
experience outcomes were also assessed. Results: Mixed-effect models showed a
significant improvement in Box and Blocks scores in the post-intervention
session for the treatment group (effect size: 2.1, p = .04). No significant
effects were found between the treatment and control groups for ARAT scores and
other clinical metrics. Direct kinetic effects revealed a significant reduction
in muscle activity during free exploration with an effect size of (-7.12%, p<
005). There were no significant 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.
