Bionic leg’s pilot performance spotlights its technology and the role of teamwork

One year after the international Cybathlon 2024 competition, an Italian team has published a focus article in Science Robotics on the Omnia bionic leg, which took first place in the leg prosthesis race.

The article highlights the experience of Andrea Modica, a transfemoral amputee and the device’s pilot, who successfully completed nine out of 10 tasks in 2 minutes and 57 seconds. The Omnia prosthesis was developed at the Istituto Italiano di Tecnologia (IIT—Italian Institute of Technology) by the joint Rehab Technologies IIT-INAIL Lab, coordinated by Matteo Laffranchi.

The Cybathlon 2024 marked the debut of Omnia, a novel lower limb prosthetic prototype designed for individuals with transfemoral amputations. This system includes a knee (Unico) and an ankle (Armonico), both motorized. Omnia was the only device to reach the “Leg Prosthesis” final without using commercial components. Its pilot, Andrea Modica, successfully completed nine out of 10 tasks, including navigating a balance beam while carrying buckets, ascending and descending stairs with objects, and traversing an inclined plane.

Andrea Modica is a transfemoral amputee who lost his leg in a motorcycle accident in 2021. Since then, Modica has shown remarkable determination, first returning to sports, then progressing to Paralympic-level skiing, and stepping into the world of competitive prosthetic technology. He is currently a support technician at Rehab Technologies—INAIL-IIT lab.

Modica was not only the pilot for the Omnia system but also an active contributor to its design and optimization. His insights, gained by comparing Omnia with his daily-use prosthesis, helped the research team to shape key improvements in both the software and hardware of the device. From adjusting stiffness to fine-tuning propulsion, each component was tailored to match the varied demands of the Cybathlon’s obstacle-based tasks. During months of training, Modica repeatedly practiced each task to improve precision, efficiency, and safety.

Reflecting on the event, Andrea Modica described it as a deeply meaningful experience, not just for the achievement, but for the community he found among other competitors. His role in shaping Omnia exemplifies IIT’s user-centered philosophy, where real-world feedback drives innovation.

The standout feature of the Omnia system is the communication between the two prosthetic components, Unico and Armonico, which exchange information from integrated sensors and adjust parameters for optimal performance across various tasks. The Unico knee combines hydraulic and electric technologies. The hydraulic system effectively aids in level walking or descending, ensuring quiet, smooth movement and energy efficiency.

In contrast, the electrical technology, supported by a patented system, provides active assistance during tasks such as climbing stairs, ascending steep slopes, or standing from a seated position. In the complete Omnia leg configuration, the transition between hydraulic and electric modes occurs automatically, thanks to the synergy of the two prostheses and advanced implemented algorithms.

The Unico prosthesis is equipped with a battery that lasts a full day under maximum usage and is suitable for both right and left knee prosthetics, supporting up to 125 kilograms. The device is customizable based on the user’s height and can be adjusted at the software level to match daily activity patterns, whether sedentary or active.

The Armonico ankle features an elastic foot coupled with an innovative screw mechanism, assisting the user during the initial foot strike by reducing heel impact for enhanced comfort and preventing tripping by lifting the toe during each step. Unlike passive foot prostheses, Armonico actively amplifies the ankle’s flexion angle, providing enhanced stability on sloped surfaces and ensuring a more natural movement. It is available in both right and left configurations and has a battery life of 24 hours.