Artificial leg with realistic sensory feedback helps wearers walk confidently

Prosthetic technology has advanced a whole lot in the past several years alone. But artificial limbs still have one big problem: Because of their lack of nerve endings, they don’t allow the wearer to experience the same sensations that they would otherwise. That’s a big problem for a variety of reasons — not least of which is that people wearing them tend to be less confident when relying on their artificial leg because it doesn’t provide the same level of feedback.

This is something that researchers from Switzerland’s Swiss Federal Institute of Technology are working hard to change. They have developed a new type of bionic prosthesis featuring onboard sensors that reveal when it is flexing and landing on the ground. In the process, not only can it encourage faster, more confident walking on the part of wearers, but it also reduces so-called “phantom limb” pain. This refers to the strange sensation amputees can get when they feel pain in their missing limb.

bionic leg sensory feedback confidence bicycle prosthetic limb
Federica Barberi

The leg sensors connect to residual nerves in the thigh of the prosthetic wearer, via electrode implants. These electrodes were developed by scientists from the University of Freiburg, while the prosthesis came from the prosthetic company Össur. Both parties were also involved with the project. The research team then developed algorithms able to turn the tactile and motion sensor information from the leg into impulses of current that the body is able to understand.

In a three-month experiment, two above-knee amputee volunteers put the prostheses through their paces. They found the sensing prosthesis useful as it enabled them to adjust their gait when walking. In one particularly challenging test, the volunteers had to walk over sand, an uneven, soft surface. The realistic neurofeedback of the artificial leg allowed them to walk considerably faster than they were able to without the feedback.

There’s no word on when a commercialized version of this technology might be made available for purchase. However, an artificial arm called Ability Hand, which provides sensory feedback through its fingertips, is gearing up to go on sale in the United States. Hopefully, that suggests such technologies are beginning to find their way to those who really need them.

A paper describing the recent research by the Swiss Federal Institute of Technology was published in the journal Nature Medicine.

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