Alvaro Gallegos took up running after his wife passed away. He was nearly 60 and looking for a way to stay healthy. But it didn’t take long before pain in his knees and back made running difficult. He kept running anyway. Then he started cutting open his shoes.
He had this idea that maybe—just maybe—a spring in the heel could cushion the impact. He grabbed a sneaker, cut into the sole, and glued in a conical steel spring. The ride felt softer. The pain didn’t shoot up his leg like before. It worked well enough that he kept tinkering. Friends started asking for a pair.
Al called the idea Z-CoiL and began filing patents. His son Andrés came onboard to help turn it into a business. At the time, Andrés was working in the pharmaceutical industry in New Jersey. He handled sales and operations and understood regulatory hurdles. He knew this wasn’t going to be a regular sneaker company. They weren’t aiming for fashion or fitness. They were building a shoe for people who hurt.
Alvaro and Andrés spent years testing prototypes, securing manufacturing, and sorting out materials. They partnered with engineers in South Korea who could fabricate the design. The challenge wasn’t just making a spring-loaded heel—it was making sure it supported the foot properly. Al added a rigid orthotic platform above the spring and a curved, rocker-style sole to guide motion.
The final design used a visible steel coil in the heel that compressed with each step. The rest of the foot sat on a firm contoured base that didn’t flex. The shoes weren’t soft or spongy. They were engineered more like medical equipment than athletic gear.
Word spread quietly. People who had stopped walking long distances started wearing Z-CoiLs again. The shoes were especially popular among nurses, warehouse workers, runners with injuries, and older adults. Many customers found the shoes through their podiatrist, chiropractor, or physical therapist.
Each Z-CoiL shoe contains a visible conical spring embedded in the heel. The spring compresses under pressure to absorb shock and reduce the force transmitted to the foot, knee, and back.
Above the coil is a rigid orthotic base that supports the arch and controls foot motion. The base is not removable and doesn’t flex. The design reduces stress on the plantar fascia and other soft tissues.
The outsole has a rocker-bottom curve that encourages a forward rolling stride. The idea is to create a stable, pain-reducing platform rather than a cushioned or minimalist experience.
Many models let users rotate the heel coil to adjust for overpronation or supination.
Some models use leather uppers. Others are made with breathable mesh or work-boot materials. All are built around the same core: coil, orthotic, and rocker sole.
Z-CoiL launched in the mid-1990s and gradually built a following through word-of-mouth and independent distributors. At one point in the early 2000s they had over 150 retail outlets across the U.S. They later shifted to direct sales through their website, though a small number of third-party stores still carry the line.
The company operates from Albuquerque, New Mexico. Andrés Gallegos serves as CEO. Alvaro, now in his 90s, still helps with fittings and occasionally answers the phone. Z-CoiL has sold over one million pairs of shoes. Most sales come from people with foot, leg, or back pain. The company does not advertise heavily and rarely launches new models. Instead, they continue to refine the core technology Alvaro started building in his kitchen with a pair of scissors and a spring.
