Colloquia

Summary

Lower limb amputations represent a significant physical, emotional, and social challenge, affecting millions worldwide. The leading causes include peripheral artery disease, diabetes, and trauma—trauma being especially prevalent in low- and middle-income countries and among younger populations. Despite the global need for prosthetic care, only 5-10% of those who could benefit from prosthetic devices currently have access to them, underscoring the urgent demand for affordable, functional, and versatile prosthetic solutions.

In response to this need, Gyromotics introduced the Nova foot in 2024—a dynamic, high-performance, and cost-effective prosthetic foot designed for active lower-limb amputees (K2–K4), including both children and adults. Nova features a modular architecture that allows for customization, ease of maintenance, and adaptability. However, a significant limitation remains: the absence of an adjustable ankle joint, which restricts the foot to a fixed neutral position. This constraint increases socket pressure, reduces terrain adaptability, and limits compatibility with varied footwear.

To address this, this thesis presents the design of a lightweight, backlash-free, low-cost, and user-friendly TRL3 manually adjustable ankle mechanism, along with a design framework to integrate this solution into the Gyromotics product portfolio while ensuring compatibility with other prosthetic systems and company portfolios. The proposed mechanism enables manual adjustment of the ankle in the sagittal plane, offering a range of motion of 33° in dorsiflexion and 56° in plantarflexion, thus enhancing adaptability to different surfaces and footwear. Usability testing indicates that the new ankle mechanism improves ease of use compared to previous ankle models developed by Gyromotics. However, further mechanical testing is required to validate the ankle’s performance under dynamic conditions.