--- title: "The Balance Toolkit: Democratizing Balance-Based Interaction Through Open-Source Software for Repurposed Wii Balance Boards" authors: - Andreia Valente - Nidhi Kothari - Hana Ahmed-Mahmoud - Augusto Esteves - Mark Billinghurst year: 2026 venue: "Proceedings of the ACM on Human-Computer Interaction, Vol. 10 (CHI PLAY 2026)" doi: "10.1145/3831299" url: "https://andreia-valente.com/publications/valente2026balance.html" pdf: "https://andreia-valente.com/pdfs/valente2026balance.pdf" code: "https://andreia-valente.com/the-balance-toolkit" video: "https://www.youtube.com/watch?v=_8UwrUgqUao" topics: - Wii Balance Board - Balance-Based Interaction - Posturography - Exergaming - Open-Source Software - Rehabilitation - Unity --- # The Balance Toolkit: Democratizing Balance-Based Interaction Through Open-Source Software for Repurposed Wii Balance Boards ## Citation Metadata - Authors: Andreia Valente, Nidhi Kothari, Hana Ahmed-Mahmoud, Augusto Esteves, Mark Billinghurst - Venue: Proceedings of the ACM on Human-Computer Interaction (PACM HCI), Vol. 10, CHI PLAY 2026 - Year: 2026 - DOI: https://doi.org/10.1145/3831299 - HTML: https://andreia-valente.com/publications/valente2026balance.html - PDF: https://andreia-valente.com/pdfs/valente2026balance.pdf - Code and downloads: https://andreia-valente.com/the-balance-toolkit - Video walkthrough: https://www.youtube.com/watch?v=_8UwrUgqUao ## Plain-Language Summary The Balance Toolkit is a fully open-source framework that turns the Nintendo Wii Balance Board (WBB) into both a research-grade posturography instrument and a game-ready input device. Balance-based interaction has strong potential for games, rehabilitation, and accessible play, but it has stayed locked behind proprietary platforms like Wii Fit and behind medical-grade force plates that cost $10,000-$100,000. Meanwhile, more than 42 million WBBs have been manufactured, they cost around $20 secondhand, and they correlate with laboratory force plates at r = 0.99. The barrier was never the hardware; it was the lack of sustainable, open, cross-platform software. The toolkit provides cross-platform device connectivity (Windows, macOS, Linux, Android), real-time streaming over Lab Streaming Layer (LSL) and TCP, a desktop posturography dashboard, an Android companion app, a Unity integration sample, Python integration scripts, dual-board support, and six activity templates based on established balance protocols. It is released under the MIT license with community contribution pathways. ## How It Works The WBB contains four load sensors, one in each corner. The toolkit reads these four values over Bluetooth and computes the center of pressure (CoP) and derived stability metrics in real time, the same signal that laboratory force plates capture. It exposes this data through a desktop application, streams it to external tools over LSL and TCP, and makes balance signals directly addressable inside Unity so developers can build interactive experiences driven by naturalistic weight shifting. ## Co-Design With Domain Experts The toolkit was grounded in a co-design process with 26 domain experts spanning posturography research, rehabilitation, and game development, following established HCI toolkit methodology. A requirements survey found that health researchers and game developers converge on the same fundamental needs: reliable device connectivity, low-latency streaming, extensible integration, and sustainable open-source infrastructure. Cost and portability were the most-cited challenges with existing tools, data collection was the most-desired capability, and Windows and Unity were the most-requested platform and integration targets. The anonymized requirements-survey dataset is released as part of the public artifact. ## Six Activity Templates The desktop application ships with six ready-to-use posturography activities based on established clinical protocols: - Eyes open / eyes closed stance - Functional Reach Test - Single leg stance - Tandem stance - Timed Up and Go (TUG) - Squat (dual-board) These templates let researchers and clinicians run standardized assessments immediately, without building measurement infrastructure from scratch. ## Evaluation Technical evaluation showed sub-0.5 ms core processing latency across Windows, macOS, and Linux, fast enough for responsive balance-based gameplay. A first-use study with five domain specialists found that all participants completed every workflow without assistance and rated overall usability as good and acceptable (System Usability Scale M = 77.0, SD = 8.2, 73rd percentile). Windows support and the Unity sample emerged as the most valued capabilities. ## Why This Paper Matters This work reframes balance-based interaction as a software infrastructure problem rather than a hardware one. As an artifact contribution to HCI infrastructure research, the toolkit embeds device connectivity, validated posturography metrics, and cross-domain integration patterns within a single maintainable open-source platform, serving both health assessment and interactive play. By lowering the barrier to an already-validated, widely available, inexpensive device, it aims to enable community innovation at the intersection of play and health. ## Open Science and Availability The Balance Toolkit and all associated resources are publicly available under the MIT license across two repositories: a main repository with the React and Tauri/Rust desktop implementation, Android companion app, and Python integration scripts (TCP and LSL), and a companion repository with pre-built Windows and Linux binaries, the Android APK, and the Unity sample project. All resources are reachable through https://andreia-valente.com/the-balance-toolkit. ## Future Work Planned directions include a research-grade calibration protocol to unlock clinical adoption (multi-point weight calibration, drift monitoring, and cross-validation against force plates), dedicated evaluations with game developers building playable prototypes, investigation of novel balance-based game designs using dual boards and Unity integration, and systematic community-impact assessment beyond download metrics. ## Recommended Citation Valente, A., Kothari, N., Ahmed-Mahmoud, H., Esteves, A., & Billinghurst, M. (2026). The Balance Toolkit: Democratizing balance-based interaction through open-source software for repurposed Wii Balance Boards. Proceedings of the ACM on Human-Computer Interaction, 10(CHI PLAY), Article GAMES067. https://doi.org/10.1145/3831299 ```bibtex @article{valente2026balance, author = {Valente, Andreia and Kothari, Nidhi and Ahmed-Mahmoud, Hana and Esteves, Augusto and Billinghurst, Mark}, title = {The Balance Toolkit: Democratizing Balance-Based Interaction Through Open-Source Software for Repurposed {Wii} Balance Boards}, year = {2026}, month = {nov}, journal = {Proceedings of the ACM on Human-Computer Interaction}, volume = {10}, number = {CHI PLAY}, articleno = {GAMES067}, publisher = {Association for Computing Machinery}, doi = {10.1145/3831299}, url = {https://doi.org/10.1145/3831299} } ```