Swimming with a brand new leg

Dan Lasko, a broad-shouldered former Marine wearing green-trimmed blue swim goggles, emerged from the locker room at Nassau County Aquatic Centre, ready to hit the pool with a brand-new leg.

For the first time in years, he would be able to stride from the pool deck into the water without having to remove his reliable prosthesis, the one with an Asics sneaker attached, then hop one-legged on the slippery deck to get in. And as a long time triathlete, he had mostly relied on his arms during swim competitions. The water-friendly prosthesis on his left leg promised to change that.

While waterproof prosthetic legs have been available for decades, “this is the first fully functional swim leg,” said Matthew Flynn, a certified prosthetist at Eschen Prosthetic and Orthotic Laboratories, the company on Long Island that is part of the team that produced the prototype.

“Other legs can certainly be used in the water,” added Flynn, himself an amputee. “But they can’t propel you through the water.”

An estimated 1.9 million people have lost a limb nationwide, a number that is expected to double by 2050, mostly as a result of Type 2 diabetes, according to the Amputee Coalition of America.

Swimming is particularly good exercise for amputees, because it “doesn’t put shear force on the residual limb,” said Dr David Crandell, medical director of the amputee programme at Spaulding Rehabilitation Hospital in London. “They are not running or jumping.”

During high-impact sports like jogging, the end of an amputated limb can develop blisters or deeper tissue wounds; doing laps in a pool is more “skin friendly,” he said.

“Prosthetic devices that people use don’t typically offer advantages once you’re in the water,” Crandell added. More often, they are “like an anchor.”

Since 2004, when an explosion in Afghanistan shredded the lower part of his left leg, Lasko’s swimming routine had involved some degree of acrobatics to get in the pool. But now that Lasko, 34, of Bethlehem, Pennsylvania, is the father of two water-loving boys, ages 2 and 6, he has been dreaming of climbing in and out with them with ease.

The leg Lasko was testing had a jet-black foot with a nonslip tread on its sole, which he described as “awesome” even before entering the water. His excitement was palpable from the first whiff of chlorine.

Todd Goldstein, the designer of the new prothesis, with a doctorate in molecular biology and tissue engineering, was enlisted for the project because of his experience with 3-D printing as a researcher for Northwell Health, a network of hospitals and local facilities.

On a Friday night before the swim test, he programmed a 3-D printer to make a crucial part of the prosthesis: a downward-pointing triangle of nylon and plastic located at calf height that provides some propulsion but, with cone-shaped holes that lets some water through, is not overly forceful.

The aim of the aquatic test run was to work out the prototype’s kinks to prepare for commercial sales. Lasko, at first not comfortable enough with the new leg to dive in, stepped into the water and took off into a gliding freestyle. He had not swum like this, using both legs, since his injury at 21, more than a decade ago.

“It feels good,” he said after finishing his first lap, hanging on to the pool’s edge. “I can definitely feel the difference, but I just have to get used to the bit of extra weight.” As he did lap after lap, not everything went smoothly. First, the foot filled with water, creating drag. That was an easy fix, Goldstein said: Holes could be added to release the water. Then the all-important triangle disappeared.

Lasko said, “I was kicking so hard it popped right off.” Goldstein turned some screws to secure it, but a few laps later, it briefly went missing, until it was discovered snagged in the lane lines. Goldstein, by now a poolside MacGyver, found nylon cable ties to temporarily secure the triangle back onto the prosthesis.

As Lasko continued to propel himself through the water with both legs, he was elated. “I haven’t done that in years,” he said. “I felt good and free.”

Final tweaks have been made, and now the triangle is firmly secured. Lasko is putting it to the test playing with his sons, Ben and Luke, both of whom love the water. For Lasko, getting a new prosthetic leg for swimming is comparable to getting new shoes or gear for specific sports. “You don’t wear CrossFit gym sneakers to run a marathon,” he said.

High-impact exercise
He has one leg for walking, one for high-impact exercise, one for cycling, and even one for sprinting, all kept in a special closet. The new swim leg is Lasko’s seventh.

The device, which will be called “The Fin,” is expected to become commercially available in about six months, said Eric Feinstein, a manager at Northwell Ventures, the venture capital arm of Northwell Health, which funded the project.

Eschen’s high-end ready-made parts were used, and Composite Prototyping Centre, also based on Long Island, provided equipment and machinery.

The cost will range from $2,000 to $5,000, depending on customisation and which off-the-shelf parts are used, Feinstein said (Lasko got his prosthesis free for participating in the project.)

Most likely, amputees will have to pay out of pocket. Most insurance companies do not provide coverage for recreational prostheses, Crandell said, “even though ultimately getting back to sports is best physically and for psychological recovery.”

After swimming on and off for a couple hours, Lasko’s energy was flagging. But he could not resist trying one of the diving boards at the expansive facility. By then, feeling sure of his footing, he backed all the way up the board, taking a couple of stomps and diving off again and again.

Then he did a flip. Then a flip and a half — with, ouch, an awkward landing. “Not too bad,” he said while climbing the pool’s ladder. He was beaming.