How Voluntary Closing Prostheses Outshine Their Counterparts

In the world of prosthetic technology, the choice between voluntary opening (VO) and voluntary closing (VC) body-powered devices can significantly impact the quality of life for users. Groundbreaking research from the University of Tokyo Hospital reveals compelling evidence that VC devices offer superior performance in key areas, making them the preferred choice for individuals seeking enhanced functionality and ease of use.

A recent study led by experts at the University of Tokyo compared the functionality and user-friendliness of VC and VO prosthetic devices using the Southampton Hand Assessment Procedure (SHAP). The study involved 52 non-amputee adults and aimed to simulate the experience of using these devices in everyday activities.

The findings were unequivocal: VC prostheses consistently outperformed VO devices in several critical aspects. When it comes to tasks requiring strong grip strength and rapid response, such as holding or manipulating heavy objects, VC devices enabled users to perform with greater efficiency and ease. In contrast, VO devices, which rely on a different mechanism for operation, lagged in performance, particularly in tasks where quick, forceful interaction was necessary.

The study's statistical analysis reveals that participants using VC devices completed tasks not only with higher overall SHAP scores but also in significantly shorter times for specific tasks. For instance, tasks labeled as 'Heavy Power,' 'Heavy Extension,' and 'Cutting' were completed more swiftly by the VC group, with the 'Cutting' task showing a particularly striking difference in completion time—almost halving the time taken by the VO group.

The superior performance of VC devices can be attributed to their design, which allows for a more intuitive and natural grip. Unlike VO devices that require an initial opening movement which can delay task execution, VC devices are primed for immediate action, enabling quicker and stronger grip. This design not only makes VC devices more effective for daily tasks but also enhances their suitability for recreational and occupational activities that demand robust hand functionality.

The research from the University of Tokyo underscores the necessity of choosing the right prosthetic device based on the user's daily needs and lifestyle. For those who require a prosthetic that can keep up with dynamic and strength-oriented tasks, the VC device emerges as the clear frontrunner. It's time for users and clinicians to lean towards VC technology, a decision that promises to elevate the standard of living and operational efficiency for prosthetic users around the world.

If you or someone you know is considering a body-powered prosthesis, it's crucial to explore the benefits of VC devices. For more information and to understand if a VC device is right for you, consult with your prosthetic specialist and consider how this technology can transform daily activities and enhance independence.

University of Tokyo research article