When bombs rocked the Boston Marathon last year, emotional reverberations were felt throughout the country: Communities held memorial races and sported Boston Strong ribbons and shirts, created makeshift memorials out of running shoes and American flags, donated money to families of injured runners. Engineers, meanwhile, got down to the nitty-gritty: Building better prosthetics for the 16 survivors who lost limbs that day.

"I think Boston raised awareness and is kind of inspiring for promoting recovery instead of focusing on the injuries," said Levi Hargrove, Director of the Neural Engineering for Prosthetics and Orthotics Laboratory at the Rehabilitation Institute of Chicago. Even though his lab hasn't worked directly with survivors, everyone in the field has felt the impact, he said.

"The survivors are getting back to their lives, working with scientists and therapists, because they're going to be living with this condition for a long time," Hargrove said.

Top Prosthetic Limbs Bring Hope to Amputees

Last month, one of those survivors took the stage at TED2014 and showed off her first-of-its-kind bionic leg that allows the professional ballroom dancer to rumba again. After Adrianne Haslet-Davis danced, she tearfully thanked Hugh Herr, director of the Biomechatronics Group at The MIT Media Lab and creator of the leg.

"All this emotion poured out," Herr said. "The very first time she [tried the new leg], she was ecstatic. She was so joyful about being on that dance floor and feeling that freedom again."

Herr, whose lab partnered on a fund to support the development of specialized prostheses for runners after the Boston attack, based Haslet-Davis's leg on data he gathered from dancers of a similar build and body type to Haslet-Davis's. He invited the dancers to his lab, which was tricked out with sensors to track exactly how they moved and how their forces impacted the dance floor.

The idea, he said, was to extract those principles of dance and imbed them into chips on the bionic limb.

Top Marathon Bombing Conspiracy Tweets

"It's responsive in a way that's appropriate biomechanically," he said. "It doesn't simply output a traditional trajectory that she would have to keep up with like a wind-up toy. It's more like she is the lead and the limb is the partner."

The leg also has to be able to move like flesh and bone, so the lab uses a "smart" material that can flop and stiffen depending on the voltage being applied from the body.

David Sengeh, a graduate students who also works in Herr's lab, recently won the Lemelson-MIT National Collegiate Student Prize Competition for his work on improving the sockets used in prosthetics. Conventional molding methods often result in prostheses that don't fit precisely, and often cause pain. Sengeh uses MRI and a 3D printer to create a design interface based on individual data.

"The goal is to make a model where you can enter someone's data, press play and get a comfortable socket," said Sengeh, who tested the method on one of the Boston survivors.

The end result? Without the short skirt she wore at her TED performance to show off the leg, it may have been impossible to tell she wasn't born with that leg.

The BiOm Ankle System was the first bionic ankle-foot device commercially available for lower-extremity amputees.iWalk Inc.

"My first dance happening to be so near the anniversary of the marathon bombing stands as a reminder that I'm a survivor, not a victim," Haslet-Davis said in a statement.

Because the bombing occurred at a time when the field of prosthetics was on the verge of new developments, success stories like Haslet-Davis's were able to quickly come to fruition. Previous research and development was primarily funded through the military's Defense Advanced Research Projects Agency and focused on veterans who had lost limbs in combat, but"a lot more individuals have had amputations for a variety of reasons, including young people in motor vehicle accidents, people in farming accidents, etc.," Hargrove said.

"The Boston bombing kind of broadened the horizon," Hargrove said.

How to Give Prosthetic Hands Touch Sense

Since most of the survivors were runners or otherwise very active, most will need multiple prostheses designed for different activities. Herr, a double amputee himself, says his closet is filled with different types of prostheses the way most people's closets are filled with shoes. As for a device that would go from ballroom dancing to grocery shopping to rock climbing to running…"No one's working on it yet," Hargrove said.

Still, mind-controlled prosthetics should soon make daily living much easier. Hargrove's team built a prototype of an above-the-knee prosthetic for daily living that should be "ready to send home with someone" in a couple of years.

"We're trying to allow people to perform functions like walking and then seamlessly going up and down stairs, that help you get around for daily living," he said.

This year, survivors may watch the marathon from the sidelines. But Herr predicts that at least one or two of the survivors will return to Boston one day to run the marathon again; the technology already exists to enable runners to do distances even beyond the marathon.