Public Release: 

Ossur's POWER KNEE widely available in September

Amputees get world's first prosthesis to restore their lost muscle function



IMAGE: Retired Special Forces SGM Brad Halling leaps effortlessly now that he's on the POWER KNEE by Ossur, the first motor-powered and artificially intelligent prosthesis. Halling lost his leg in Mogadishu, Somalia in... view more

Credit: Ossur

Ossur North America, a trusted and global developer of more scientifically advanced prosthetic innovations than any other company in the field, is pleased to introduce its POWER KNEE ™. Although not officially launching until September, the first six POWER KNEE's have already been sold in the U.S., including to Walter Reed Army Medical Center, Brooke Army Medical Center and the Veterans Administration to benefit soldier amputees returning from the Iraq and Afghanistan conflicts as well as veterans of past conflicts.

The POWER KNEE is the world's first and only motor-powered, artificially intelligent prosthesis for above-knee amputees that restores lost muscle function and enables amputees to perform normal daily functions never before possible. Because the prosthesis can actually sense the movement of the sound leg, it is able to mimick its movements. What this means to amputees is that the knee can power them through activities not doable with current prosthetic technology, including:

  • climbing stairs foot over foot, actively lifting them up the next step
  • naturally walking up and down uneven inclines
  • moving through soft surfaces such as sand and dirt without hesitation

The POWER KNEE also boasts other significant advancements. It energizes and smoothes the progress of level ground walking. Users report that the knee walks for them and reduces the effort required to cover longer distances: They can walk faster without increased fatigue. For those involved in the trials, this was the knee's biggest advantage: they used terms like "natural" and "carefree." It also facilitates the deceptively complex actions of effortlessly sitting down and standing up from a chair.

The POWER KNEE, which comes under Bionic Technology by Ossur, the company's brand for pioneering category of prosthetic devices, combines the act of sensing, then thinking, then acting to enable amputees to perform these activites in a normal and functional pattern.

After the nationwide debut of the POWER KNEE on September 27, 2006 at the American Orthotic and Prosthetic Association's (AOPA) annual National Assembly in Hollywood, Florida, the world of prosthetics will have entered a new era: the age of advanced bionic technology.

Among the first to use the POWER KNEE in the United States is retired Special Forces SGM Brad Halling. Halling lost his leg in Somalia in 1993, when his helicopter was hit by a rocket propelled grenade. A certified prosthetist since 2002, he has taken more than a personal interest in new prosthetic technologies and has this to say about his experience: "In the past I actively avoided walking on sand or uneven terrain. Due to the inherent stability and energy savings I gain from the Power Knee, these obstacles no longer need to be avoided. In fact, I can walk through sand or on loose gravel with ease, and the step taken on the prosthetic side often feels easier than the step taken on my sound side." He adds, "When walking on a 3 - 5 degree slope I used to feel a significant amount of energy expenditure, and was often anxious to reach the top of the slope. Now I can walk these grades with ease and the energy expenditure feels no different than that of level ground walking!"

Powering Prosthetic Technology into the Future
Working as an integrated extension of its user - synchronizing motion with that of the sound leg - "the POWER KNEE offers unprecedented functionality lost after amputation," says Hilmar Janusson, Ph.D., vice president of R&D for Ossur. "For transfemoral amputees, it provides new opportunities, many of which are simply not possible with existing prosthetic solutions." While other knee systems provide resistance to knee buckling (acting much like the brakes on a car), the POWER KNEE also replaces true muscle activity, powerfully bending and straightening the knee.

Amputees take a step with their sound leg, which has sensor equipment positioned on the foot to accurately measure motion, load and position of the limb at a rate of 1350 times per second. This information is transmitted to the POWER KNEE, which utilizes advanced artificial intelligence (AI) to anticipate and "feel" the given functions. Having detected the type of activity the user is engaged in, the AI is able to calculate the precise amount of power needed and "act" to generate the appropriate prosthetic function. The software can be fine-tuned based on the personal physical condition and rehabilitation level of individual users.

The POWER KNEE not only won high praise from users in trials, but was also honored by Popular Science magazine with a 2005 Best of What's New Award in the Personal Health category.


This release has been updated since it was originally posted.

Ossur is introducing the POWER KNEE as co-developer of the prosthesis with Victhom Human Bionics, Inc. The partnership has the goal of jointly pioneering products that will greatly enhance the quality of life for people with physical disabilities. Victhom develops technological platforms, and Ossur researches and ensures that those platforms not only meet the medical needs of amputees but also enable them to achieve unparalleled functionality, by implementing its clinical expertise and market know-how.

To purchase a POWER KNEE, prosthetists and amputees will receive training from Ossur's clinical Bionic Technology specialists to guarantee a successful outcome for each user. For more information about the POWER KNEE, or any products under the Bionic Technology by Ossur umbrella, please visit or call one of Ossur's knowledgeable Customer Service Representatives at (800) 233-6263.

Ossur (Icelandic Stock Exchange: OSSR) is as much about helping people to live a life without limitations as it is about its orthopaedic products. A trusted and global leader in the development, manufacturing, sales and marketing of bracing and support products and prosthetics, Ossur pioneers award-winning designs - including its Bionic Technology family of products - and partners with the health practitioners who use them to deliver successful clinical and business outcomes. Headquartered in Reykjavik, Iceland, the company has operations and a distribution network throughout the world. The company allocates an industry record of 6-8 percent of its revenue on research and development to conceive and harness the most advanced technologies for incorporation in its product designs, and provides extensive education programs through the Ossur Academy. Ossur is a 2006 World Economic Forum Technology Pioneer. Website:

Ossur North America
Tabi King
(949) 360-3756

Ossur Public Relations:
Beverly Millson
Missing Sock Public Relations
Office: (310) 399-7599 Cell: (310) 804-3469

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.