Heather Martino

Originally published on December 18, 2014

Mike Kacer practices unlacing his worn-out combat boots.

He doesn't use his fingers. He left those in Afghanistan, along with much of his left arm.

He maneuvers two silver pincers, oversized tweezers that tug his laces loose. It does not go well.

"I could actually tie the shoe faster without the prosthesis," Kacer says.

Despite practicing with this artificial arm -- and with more than a dozen other Army-issued prosthetic limbs at his disposal -- Kacer said that most of the time he doesn't wear the devices. Even though the government has probably spent more than $117,000 to provide him with artificial arms over the past five years. Just one of the more sophisticated devices he owns cost more than $100,000, and it's a device he doesn't often use.

"If I had to put a timeframe on it," he says, "[in] a 13-hour day I probably wear a prosthetic four to five hours out of it."

Kacer is far from alone. Of the roughly 1,600 veterans who have suffered major limb losses from the wars in Iraq and Afghanistan, about 319 have faced amputations of some part of their arms. And although they have little trouble getting artificial arms, many abandon them. Former soldiers criticize the devices as uncomfortable, unreliable and painful to wear regularly, according to a 2012 study by the inspector general's office at the Department of Veterans Affairs. "Consistently, veterans with upper limb amputations only reported lower psychosocial adjustment, physical abilities, and prosthetic satisfaction than those with lower limb amputations," the inspector general's investigators wrote.

Read the full investigation on NBCNews.com.