Engineering: Steps towards improving assisted walking devices

An exoskeleton ‘boot’ that can adapt to the user to help people walk faster and more efficiently in real-world conditions is described in a study published in Nature. The findings demonstrate a new approach to wearable robot design and highlight the potential of such devices being widely used in everyday life.

Exoskeletons that assist leg movement, by increasing walking speed and reducing the energy required, can be helpful for people with mobility impairments or with physically demanding jobs. Benefits of such devices have been demonstrated mostly in research laboratories on treadmills, rather than in real-world conditions, where walking speed and duration is variable.

To address these challenges, Patrick Slade and colleagues developed an approach combining a data-driven model with low-cost, portable sensors. The model can assess how exoskeleton devices affect walking based on information (such as ankle angle and speed) collected by the sensors to tune the device so that it best suits the walking characteristics of the individual user. They found that the new method was not only equally effective as the traditional laboratory methods in optimizing exoskeletons, but did so four times faster. Based on the results and real-world optimization data, the authors designed a specialized ankle exoskeleton consisting of one exoskeleton worn on each ankle and a battery pack at the waist. The device led to a 9% increase in walking speed, and a 17% reduction in energy cost during natural walking compared to normal shoes, where the energy savings are equivalent to removing a 9.2 kg backpack.

The findings demonstrate that the new approach can improve the performance of exoskeletons by optimizing them to individual needs. Future studies are needed to bring the devices to practical use and explore how the methods can be adapted to other devices and activities.