Think about the way your ankle moves when you walk up a ramp or take the stairs.
It doesn't stay stiff at 90-degree angle, but that's how many prosthetic limbs work right now.
That means something as simple as walking up a ramp can be a barrier for veterans who've lost limbs in combat.
"When you lose a leg or something, you don't realize how much strength and balance you lose," said Holmen resident, Vietnam veteran and amputee Dan Platteter.
New technologies are being developed to make the day-to-day lives of vets like Platteter easier -- technology the Department of Defense showed off this week at the Tomah VA Hospital.
The first of its kind, the BiOM Ankle System by iWalk provides artificial muscle and tendon power that allows amputees to walk with the same effort and function as non-amputees.
"Prosthetic ankles in the past have just really been a foot attached to a post. Sometimes there are springs involved, but they don't actually reproduce a human ankle because there's no power. And your natural ankle actually has muscles attached to it, so as you're walking, you push off and slow down, you push up when you're going up stairs," said Tomah VA amputee clinic physician Dr. John Barry.
A tablet enables the BiOM to be customized to the user's needs.
"It's a total personal bionic experience, where we tune that ankle to that specific patient. And then we can verify that using software to make sure that that patient is basically functioning as they would if they had a biological limb," said iWalk Regional Director John Braddock.
That means less pain and fatigue, and more balance and range of motion.
"It seemed like a lot less effort to do the same things that you're accustomed to doing. And I think you can do them quicker," said Platteter.
For now, it's a test run. But the VA hopes the BiOM is something they'll eventually be able to offer to help strengthen the steps of wounded veterans.
The VA has given iWalk money to help develop the BiOM. To find out more about the bionic ankle system, go to the manufacturer's website at iWalkpro.com.