TEANECK, N.J. — The motorized chairs, ceiling rails and support bars inside a New Jersey family's home are not for senior residents, but for children -- four of them in all, all suffering from a mysterious, debilitating illness.

You may initially have some trouble believing the story Esther and her husband Arthur are about to share.

"I admire my kids because they are relentless. They are brave. They face the world with tasks (like) squeezing toothpaste out of a tube, zipping zippers -- these are things that come easily to use," mother Esther Herzfeld said.

It all began 12 years ago when the first of the Herzfelds' four children began having difficulty walking.

"I mean if your child is walking around, and tripping and falling, for the first week, or month or so. He’s clumsy. There are clumsy kids out there," father Arthur Herzfeld said.

But Tziporah’s condition worsened. And then one by one, their other three children started developing the same symptoms.

Fast forward several years, tens of thousands of dollars in medical tests and genetic analysis and there is still no diagnosis.

The Herzfeld’s youngest daughter -- now 15 -- is away at summer camp. Tziporah, the first to come down with the mystery condition, was not available to speak with PIX11 News.

But speaking with Rivka, now 23, and the couple's only son Tzvi told us all we need to know about the tenacity that drives this family through one challenge after another.

“When I turned thirteen, I noticed that I started walking on the side of my foot, so I couldn’t walk straight. I just woke up when I was fourteen, and couldn’t walk anymore. I haven’t walked since,” Tzvi said.

“I want to work as hard as I possibly can, physically, and emotionally can, to make myself stronger, so that if this degenerative condition is going to get me, fine. It will get me a little bit - less,” said Rivka.

The path forward for this faithful yet practical brood is uncertain. And the Herzfelds are well aware of that.

But Arthur and Esther’s decision to go public with their story last month, after more than a decade of trying to quietly to forge ahead, is borne out of willingness to do whatever they can for their children while they can.

“If life gives you lemons, you make lemonade. We’ve gotta make the best of a bad situation, because we don’t’ have a choice. We want our kids to be as dignified possible and we have to be role models for them,” Esther said.

To learn more about the Herzfelds' story or to help them, click here or here.