Brain Powered Prosthetic Ankle


RALEIGH, N.C. (Ivanhoe Newswire) – More than two million Americans are living with limb loss. Prosthetics are a solution – helping with mobility and some function – but in most cases, the artificial limbs may be fixed. That means the wearer’s movements aren’t natural and may be uncomfortable. Now, scientists are testing a powered prosthetic ankle that may be game-changing for amputees.

Fifty-five-year-old Greg Phillips was on his way home on Labor Day 2013, when a car pulled out in front of his motorcycle.

“It was called a compression fracture in which the foot was crushed between an 850-pound motorcycle and the rear axle of a car,” Phillips recalls.

After two years fighting infection and instability, Phillips and his doctors agreed to amputate.

But traditional prosthetics also require the wearer to compensate with their hips or back.

Biomedical engineer at North Carolina State University & University of North Carolina Chapel Hill, Helen Huang, PhD, says, “It doesn’t provide power, doesn’t provide enough range of motion.”

In a lab at North Carolina State University, biomedical engineers are studying how these prosthetic ankles can restore more natural movement.

“The difference of our prosthesis is that we’re actually giving control to people by using the muscle signals that are still there, even after amputation,” biomedical engineer at NC State University & UNC Chapel Hill, Aaron Fleming, explains.

Fleming attaches sensors to track Phillips’ calf muscles. With the device on, Phillips can stand up from a chair without using his arms. He can walk with a fluid motion, and bend to pick up objects.

While the powered ankle isn’t commercially available yet, Greg Phillips says he’d like to have one someday.

The researchers say before the technology could be made more widely available, it would be important to test the prosthetics in real-world settings as they go through their daily routines. That would help the scientists assess the reliability of the devices.

Contributors to this news report include: Cyndy McGrath, Producer; Kirk Manson, Videographer; Roque Correa, Editor.

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REPORT:       MB #5110

BACKGROUND: Prosthetic ankles are for people who have had unilateral below-knee amputation to help them move and continue living their regular everyday life. Prosthetic ankles are built for three different speeds, standing, walking, and running. The speeds imply some of the physiological factors that weigh more heavily while also determining the stiffness of the prosthetic and that preference can be associated with clinically relevant improvement.


DIAGNOSING: Ankle prosthetics can be painful for many people and having that loss of motion can impact quality of life. Sometimes amputees can experience what is called residual limb pain which is a type of pain that is felt in the limb after an amputation and it can be caused by problems in the bone or the soft tissue, an infection, poor blood supply to the limb and even a tumor. Diagnosing something like this is done iin a physical exam in which the doctor will inspect the residual limb and feel it for skin breakdowns, pressure sores and problems with the bone. Image testing such as MRIs, CT scans, X-rays or ultrasounds can be helpful in identifying the source of residual limb pain.


NEW TECHNOLOGY: Finding the best prosthetics for an amputee’s lifestyle can be very challenging, especially for an ankle. One new piece of technology is a product called Empower which is a prosthetic with an active ankle joint. This device is battery powered and it propels the foot forward; it imitates life-like movement of lost muscles and tendons which is said to normalize gait and reduce stress on the joints and helps people wear prosthetics for longer distances and on uneven ground.



Laura Barker

(910) 528-2285

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