When I lived in the triathlete town of San Diego and tagged along for fun with a group who trained, a kind young man always gave me an encouraging word or high-five as he zoomed past me while running or cove swimming. He has a prosthetic leg, and although the device that helps him move around was clearly functional, and even sounded springy on the pavement, I wondered if a small shift in alignment could cause a great deal of discomfort.
This thought came back today as I came across news about an “intelligent” liner for better-fitting prostheses. A prototype of the device, which is being developed by researchers at the University of Southampton, uses sensors to detect pressure and forces at the point of contact between a patient’s stump and the prosthesis. Information on limb loading could lead to a better fitting and perhaps self-adjusting prosthesis, according to a release, which also notes:
There are 50,000 lower-limb amputees in the UK, most of whom use artificial limbs that are attached to the residual limb through a socket. No two stumps are exactly the same shape and size and even an individual’s stump can change shape over the course of a single day.
Pain, discomfort and ulceration are frequently experienced at the socket interface due to poor fit. This stems from the excessive build-up of pressure within the limb socket (causing high ‘loads’ on the stump).
Synthetic liners, worn like a sock over the stump, provide some cushioning against the hard socket, but at present there is no convenient way to accurately measure the critical loads at this interface in the clinic. Without this information, prosthetists face difficulty in fitting replacement limbs and the outcomes for patients are variable.
According to the non-profit Amuptee Coalition, nearly two million people in the United States live with limb loss.
Previously: Stanford graduates partner with clinics in developing countries to test low-cost prosthetic, Biotech start-up builds artful artificial limbs and Two Stanford students’ $20 device to treat clubfoot in developing countries
Photo by U.S. Army