Gait breakthrough

Karen Quast misses her high-heeled shoes. They were a wardrobe staple for the 5-foot, 2-inch Hingham resident before surgery to remove brain tumors weakened and partially paralyzed her left leg. She has to wear flats now, but she's not complaining. She can walk.

After the surgery a year and a half ago, Quast wasn't sure she would be so mobile. But thanks to a technologically advanced leg brace, her gait is close to normal, she said.

The Swing Phase Lock orthotic knee brace, which has an automatic lock-and-release mechanism, was developed in the Netherlands five years ago by Basko Healthcare, an affiliate of Tennessee-based Fillauer Inc. Although it has been used in Europe for three years, it has only been available in the United States for two years, said Jack Richmond, a Fillauer sales manager. HealthSouth Braintree Rehabilitation Hospital was the first medical facility in Massachusetts to have the brace, and Quast was the first person in the state to try it out, he said.

Conventional braces keep the knee in a locked position, which causes users to swing their leg away from their bodies in order to step forward, said John Griffin, a HealthSouth certified prosthetist and orthotist who worked with Quast. The Swing Phase allows a more natural movement because the knee can bend and then return to a straight position for the next step.

Quast, 39, is the general manager of F1 Boston, an indoor go-cart racing and entertainment complex in Braintree. She used a cane during a recent brisk walk through the 106,000-square-foot building. It primarily serves as insurance against losing her balance, she said.

"Falling on your face in front of your employees is not good," Quast said. "They never look at you the same."

Quast has been wearing the brace since January. The plastic-and-aluminum device, which runs from her thigh to her foot, is undetectable under her trim black slacks.

The device's "brain" is a circular mechanism at knee level that can be left in the automatic lock-and-release setting to allow Quast to walk freely, or locked with the flip of a button to help her climb stairs, or unlocked so she can sit with her knee bent.

With other, less advanced braces, a user would have to grab clips on the side of the device and manually lift them to unlock it. "That's difficult to wear under pants," said Quast.

Her problems began in December 2002. She was having a breast biopsy and started having seizures. The biopsy was negative, but an MRI done after the procedure found multiple tumors on the right side of her brain. The tumors are benign, but they tend to grow with time, she said.

"I actually grow tumors better than I grow tomatoes," said Quast, displaying the sense of humor that she said has gotten her through the ordeal.

In February 2003, doctors removed a large tumor and three smaller ones. She still has seven others on her brain that need to be removed, but she said she is "avoiding the knife." After her brain surgery, she spent seven months as an inpatient at HealthSouth working to regain strength and mobility on her left side. Still, she was unable to walk and had to use a wheelchair for about eight months, and was in the chair when she returned to work at F1 Boston.

"What was important to me was getting back to work and getting back to normal," Quast said. "Your self-esteem takes a huge shot when you're in a wheelchair."

Quast saw a reflection of herself in the chair for the first time at work when she passed the glass panels of the billiard room. "I cried. It wasn't me. I'm looking at that reflection and saying, 'That isn't me,' " she said.

When Quast was told about the leg brace she was eager to try it, even though doctors doubted she had sufficient muscle control in her hip, and insurance companies are not yet paying for the device, which costs $3,000-$5,000.

But Quast paid for it herself and doctors worked with her for months through trial-and-error to adjust the brace to compensate for her lack of strength. "It wasn't an easy process," she said. "It took a lot of effort on both our parts to stick with it."

Jonathan Huber, a certified prosthetist who worked on the brace team, said it was Quast who made it work. "We give people a tool, but the real work lies in their hands. She has the drive to keep herself going," he said.

During the months she spent in the wheelchair, Quast said, she faked confidence. Recently, as she walked across the lobby of F1 Boston in her flat black shoes, she exuded the real thing.

"It's not only the benefits of mobility, but my self-confidence that is coming back to me," she said. "Being able to stand up and hold my shoulders back and look someone in the eye is a huge boost."

Sandy Coleman can be reached at sbcoleman@globe.com