Sven Zarling demonstrates running

On Tuesday, the U.S. Army showed off a redesigned lower-limb prosthesis that's meant to improve mobility for its wearers. The updated C-Leg, still in prototype, aids amputees in turning around while walking and in moving backward, while also adapting automatically between walking speeds and gaits, according to staff from the Walter Reed Army Medical Center in Washington, D.C., where the demonstration took place. Expected to be available to military service members in 2009, the revamped C-Leg will feature more sensors, more memory and a faster hard drive.

In this photo, Sven Zarling of Germany-based C-Leg maker Otto Bock International, shows how the prosthetic limb handles a running tempo. The current version of the prosthesis has two operating modes--one for walking, and one for bicycling or other activities. Switching between modes requires the amputee to jerk the leg forward, a movement that may not be feasible for users with limited movement. Redesign requirements call for development of a small remote control that would handle as many as 10 modes.

In May, Otto Bock introduced a new version of its 10-year-old 3R80 rotary hydraulic knee joint designed to enhance the swing phase of the prosthesis. It also handles patients weighing up to 275 pounds, up from the original version's 220 pounds.

Caption text by Jonathan Skillings

July 18, 2007 12:37 PM PDT

Photo by: Fred W. Baker III