Can We Redesign a Shoulder Exosuit to Enhance Comfort and Usability Without Losing Assistance?

2026-02-04

AI Summary

This work proposes Soft Shoulder v2, a soft wearable shoulder exoskeleton designed to overcome the limitations of existing systems that often compromise user comfort and thus hinder long-term daily use. By adopting a user-centered design approach, the assistive plane is reoriented from the coronal to the sagittal plane to better support natural hand positioning. The system integrates soft structural components with electromyographic and kinematic evaluations alongside user feedback to optimize human–device interaction. Experimental results demonstrate that Soft Shoulder v2 maintains reductions in muscle loading and improvements in endurance while increasing forward reach range of motion by 30 degrees and significantly lowering perceived pressure. Users rated the v2 version markedly higher than its predecessor in comfort, usability, and perceived effectiveness, achieving a synergistic enhancement of both assistive performance and user experience.

Technology Category

• Humans and AI: Interaction Techniques and Devices
• Intelligent Robots: Manipulation
• Cognitive Modeling & Cognitive Systems: Social Cognition And Interaction

Application Category

• User Modeling, Personalization and Recommendation: Practical large-scale studies of user experience
• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization

Abstract

Reduced shoulder mobility limits upper-limb function and the performance of activities of daily living across a wide range of conditions. Wearable exosuits have shown promise in assisting arm elevation, reducing muscle effort, and supporting functional movements; however, comfort is rarely prioritized as an explicit design objective, despite it strongly affects real-life, long-term usage. This study presents a redesigned soft shoulder exosuit (Soft Shoulder v2) developed to address comfort-related limitations identified in our previous version, while preserving assistive performance. In parallel, assistance was also improved, shifting from the coronal plane to the sagittal plane to better support functionally relevant hand positioning. A controlled comparison between the previous (v1) and redesigned (v2) modules was conducted in eight healthy participants, who performed static holding, dynamic lifting, and a functional pick and place task. Muscle activity, kinematics, and user-reported outcomes were assessed. Both versions increased endurance time, reduced deltoid activation, and preserved transparency during unpowered shoulder elevation. However, the difference between them emerged most clearly during functional tasks and comfort evaluation. The redesigned module facilitated forward arm positioning and increased transverse plane mobility by up to 30 deg, without increasing muscular demand. User-reported outcomes further indicated a substantial improvement in wearability, with markedly lower perceived pressure and higher ratings in effectiveness, ease of use, and comfort compared to the previous design. Taken together, these findings show that targeted, user-centered design refinements can improve comfort and functional interaction without compromising assistive performance, advancing the development of soft exosuits suitable for prolonged and daily use.

Problem

• shoulder exosuit
• comfort
• usability
• functional movement
• wearable robotics

Innovation

• soft exosuit
• shoulder assistance
• user-centered design
• wearability
• functional mobility