Dan Strzempka works in a lab cluttered with loose feet, legs, hands, arms — all made of plastic and steel. Most are adult size. Some are sadly smaller — the size of a child's foot or hand.
Dan has worn a prosthetic leg since age 4, when he slid under a lawn mower. He now makes them for Hanger Prosthetics & Orthotics. His lab is in Sarasota.
Two years ago, Dan got a call from Hanger Vice President Kevin Carroll about a baby dolphin that lost her tail. She was now in the custody of Clearwater Marine Aquarium. The baby was doing all right, except she had developed scoliosis from moving her stump in an unnatural motion — side to side, like a fish.
How about going partners with me to design a prosthetic tail, Kevin asked. Think it will work?
The idea wasn't outrageous. Dogs and cats have been fitted with new legs. An elephant named Motala in Thailand stomps around on a prosthetic foot. A stork in Bucharest sports a fake beak. Hanger once designed a leg for an ostrich. But Hanger had never had a client whose world is salt water.
Dan didn't hesitate.
"Of course it will work."
Dan didn't admit it to Kevin, but all he knew about dolphins was that they were cute.
What he saw was a challenge.
Dan spent two weeks at the Mote Marine Laboratory in Sarasota boning up on dolphin biomechanics. He made a list of foreseeable obstacles. The more he thought about them, the longer the list got.
Would a wild animal hold still for fittings? Is any prosthesis durable enough for salt water? Will any prosthesis stay on a dolphin as it thrusts itself 9 feet in the air, or speeds through the water at 30 mph? And how would the dolphin tell him what hurt?
Dan had trouble with his own prosthesis. After 36 holes of golf, it sometimes slipped. How could he keep a prosthesis on a zooming, leaping, twirling dolphin?
The aquarium had already been approached by the Bridgestone tire company, which had made a prosthetic tail for a dolphin named Fuji in Japan. But Fuji still had part of her fluke. The tire-maker concluded it couldn't help Winter because she had nothing left to which they could attach the tail.
Dan's first challenge was to make a liner for Winter's lower trunk, or peduncle. A liner fits like a sock over the stump, cushioning skin and bone. The prosthesis cinches to it. It's often made of soft plastic. Winter would need something like that, but thicker and softer, able to stand up to salt water, and perhaps sticky, so it would stay on.
Dan and Kevin worked with a chemical engineer, who concocted a stew of "silicone elastomer." Out of the goo emerged a gel, soft like a baby-bottle nipple, but thick and strong and sticky.
Dan tried the gel on his own fake leg. It stood up to golf.
The next challenge was Winter's state of dolphin mind. She had survived near-drowning and the loss of her tail by her sheer exuberance and resilience, and her emotional bond with her trainer Abby Stone. Over the first year, she had transformed from a traumatized, listless baby to a funny character who swam straight to strangers at the pool's edge and enjoyed country music at mealtime.
If that changed, if Winter gave up, all the prosthetic technology in the world wouldn't matter.
Abby began letting Winter wear the liner for short spells. Dolphins shed heat through their tails, so Abby had to be sure the liner didn't wreak havoc on Winter's metabolism. Abby found she needed a lubricant just to get the liner on. She got stares and smiles at the drug stores in Clearwater when she began buying KY Jelly by the case.
Winter didn't mind wearing the big sock on her stump. After a couple of months, Dan fashioned a hard shell to fit over the liner, to get Winter used to the idea of wearing plastic. Winter didn't mind that either. After a couple more months, he built her a tiny tail.
The first time they put the tail on her, an audience of trainers and Hanger technicians hovered, nervous as helicopter parents on the first day of kindergarten. Winter kicked off her new tail, let it sink to the bottom of the pool, picked it up in her mouth, and fetched it back to Abby.
Abby put the tail on again.
Winter fetched again.
Abby went through buckets of fish treats to get Winter to stop playing fetch.
By now Winter had become Dan's hobby. Instead of golf, he hung out at the aquarium. He brought his kids. The challenge seemed bigger than ever. Could he replicate one of nature's finest propulsion systems?
He visited the Harbor Branch Oceanographic Institution in Fort Pierce to sit in on the necropsy of a dead 2-year-old dolphin. He used the dolphin's fluke as a template for a new tail for Winter.
Over the next two years, Dan and Kevin built 50 prototypes and put in hundreds of unpaid hours. They burned through about $200,000 of Hanger's money on myriad designs. Winter used up 20 cases of KY. Dan fried the high-tech, $3,000 microprocessor in his own prosthesis by kneeling at the squirting end of Winter's water hose.
The latest design allowed the tail to swing up and down on stainless steel joints adapted from children's leg braces. Dan has been working on a design that replaces steel support rods with either Kevlar or nylon. But the innovations have brought him only incrementally closer to the intricate workings of a real dolphin tail.
Winter's biggest improvement: Her scoliosis has been reversed.
• • •
Her physical therapy was a ballet. It usually took place in the morning, when Winter was hungry. Thirty minutes of therapy required two six-pack-sized coolers of fish — double her normal feeding. By November, Winter weighed 250 pounds, four times the size she was when she fought for life in Mosquito Lagoon. She was more than half way to her adult weight of around 400 pounds.
In two years, Abby and Diane Young, the aquarium's director of animal care, had worked out a complex choreography of small, isolated muscle exercises and body motions to thwart scoliosis and nudge Winter toward swimming like a dolphin.
Abby started with a whistle that brought Winter to her side. Winter positioned her peduncle so Abby could slide on the liner and the tail. Winter got a fish.
Winter gently moved her tail up and down. Abby paddled beside her, watching Winter's pectoral fins. Winter had compensated for her lost tail by using her pectorals to help her swim. It was an unnatural motion. Abby had tried for seven months to break her of the habit. Winter held her pectorals still. Abby blew her whistle, meaning "good job," and tossed her a fish.
Abby turned Winter loose. Winter dove, using her tail. They circled together in a waltz, Winter's tail undulating, up and down. She was clearly using the tail properly, but it was not the breakthrough Abby longed for. In surrounding tanks, other dolphins wowed tourists with their acrobatics. Abby wanted to see Winter some day shoot across the tank, leap in the air and clear the water.
They knew that Winter used the tail only to please them, to score fish.
She hadn't figured out — and maybe never would — what this tail can do. She might not even know she's a dolphin.
• • •
The project started as an interesting challenge, but two years later, what had it all been for? How was one dolphin worth so much time and money? Dan and Kevin didn't worry about that in the beginning. The nights and weekends were theirs to give, and innovation always leads someplace unexpected.
Kevin, who first had the idea to put a tail on a dolphin, hoped someday the project would lead to new therapies for humans.
A year and a half ago, he heard about a kid in Oregon who had lost both legs to meningitis. She was just 10. She used a wheelchair. Wearing a prosthesis was painful and abrasive. The skin on her thighs was too fragile, the consistency of paper.
It occurred to Kevin: Why not try Winter's gel liner on this little girl?
Kevin arranged for her parents to bring her to Sacramento for a trial. Months later, she was walking to class on two prosthetic legs.
She was the first kid. One by one, other kids fell into the picture.
They just started showing up.
John Barry can be reached at firstname.lastname@example.org or (727) 892-2258.