A Step Forward for Artificial Limbs


Four years ago Zac Vawter was in a motorcycle collision that severely injured his right leg. He underwent an amputation at the knee, thereby becoming one of the more than one million amputees living in the U.S. Over half of the amputations in the U.S. are due to vascular disease – poor circulation caused by diabetes, smoking, and high cholesterol. Just under half are due to trauma.

Modern leg prostheses that replace both the knee and ankle joint use motors that power each joint and multiple sensors that inform the prosthesis about its orientation, movement, and load. The prosthesis software has several modes or programs that it can execute – walking on a level surface, climbing stairs, even running. To switch modes the user typically uses a remote control on a key fob. So a user might arrive at the bottom of a flight of stairs, push a button to get the prosthesis into “climbing stairs” mode, and then at the top push another button to go back to “walking on level ground” mode.

This week’s issue of the New England Journal of Medicine (NEJM) published ” target=”_blank”>videos in the NEJM report and ” target=”_blank”>not to ride motorcycles.

Learn more:

” target=”_blank”>First mind-controlled bionic leg a 'groundbreaking' advance (NBC News)
” target=”_blank”>Robotic Leg Control with EMG Decoding in an Amputee with Nerve Transfers (NEJM Brief Report)

The amputation statistics I cited are from the “>Follow me on Facebook

+