Nathan did encourage Doris in forming her business, as well as indirectly suggesting what direction she pursue.
For years, Nathan talked about the number of patients he saw suffering from lower back pain. The insoles are designed with arch supports and a disk on the heel of the insole to help those who work on concrete floors by taking pressure off the lower back. They can fit in many different styles of footwear, such as work boots or athletic shoes.
Collier markets the soles to companies as a cost-saving measure to prevent lower back, knee and foot injuries.
"They're more cost-effective than floor mats, which have a trip hazard," Collier said. "Studies show worker productivity increases because the worker isn't as fatigued by the end of the work day."
To market the shoe, Collier and her husband have traveled to safety and health conferences and offer custom fittings at factories for employees.
"We go in to make sure everyone has a proper fit," she said.
And then, the two are off to their next destination. Business has also given the Colliers an outlet for mission work in Honduras, Jamaica, Mexico and Costa Rica, Doris said. The two distribute free medicine in temporary clinics for one-week stretches and share their faith.
"I tell people, it's not about the sole, it's about the soul," Doris said.