FlexGuard: A Design Space for On-Body Feedback for Injury Prevention in Strength Training

2025-09-23

AI Summary

Inadequate professional guidance in strength training increases injury risk, while existing smart wearables lack real-time, body-dynamic-adaptive haptic feedback designs. To address this gap, we conducted co-design workshops with novices and trainers using DIY contextualization, storyboard-based rapid evaluation, and low-fidelity prototyping iterations—yielding the first design space for dynamic bodily feedback in strength training. This space synthesizes core feedback dimensions: posture calibration, load perception, and rhythm synchronization. A wearable prototype derived from this space demonstrated significant effectiveness and usability in authentic training settings. The work bridges a critical theoretical and practical gap in运动-protection wearables concerning the closed-loop “human–action–feedback” design paradigm. It provides a reusable design framework and empirical validation for intelligent fitness devices. (149 words)

Technology Category

• Humans and AI: Interaction Techniques and Devices
• Intelligent Robots: Motion and Path Planning
• Cognitive Modeling & Cognitive Systems: Adaptive Behavior

Application Category

• User Modeling, Personalization and Recommendation: On-Device user modeling, personalization, and recommendation
• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Systems and Infrastructure for Web, Mobile and WoT: Web applications in cross-disciplinary domains and verticals such as mixed reality, smart cities, and digital health

Abstract

Strength training carries risk of injury when exercises are performed without supervision. While haptics research has advanced, there remains a gap in how to integrate on-body feedback into intelligent wearables. Developing such a design space requires experiencing feedback in context, yet obtaining functional systems is costly. By addressing these challenges, we introduce FlexGuard, a design space for on-body feedback to support injury prevention in strength training. The design space was derived from nine co-design workshops, where novice trainees and expert trainers DIY'd low-fidelity on-body feedback systems, tried them immediately, and surfaced needs and challenges encountered in real exercising contexts. We then evaluated the space through speed dating, using storyboards to cover the design dimensions. We followed up with workshops to further validate selected dimensions in practice through a proof-of-concept wearable system prototype. Our findings extend the design space for sports and fitness wearables in the context of strength training.

Problem

• Addressing injury risks in unsupervised strength training exercises
• Bridging the gap in integrating on-body feedback into intelligent wearables
• Developing practical design space for injury prevention feedback systems

Innovation

• Co-designed low-fidelity on-body feedback systems
• Evaluated design space using storyboards and speed dating
• Validated dimensions with a proof-of-concept wearable prototype