The first 3-D-printed amphibious, prosthetic leg dubbed “The Fin” is getting amputee swimmers back into the water after the loss of a limb.
Amputees Diving Back Into the Water With “The Fin”

Created by Northwell Health headquartered in New Hyde Park, New York, this swim leg allows amputees to move from land to water with ease. A key part is the 3-D downward-pointing triangle of nylon and plastic which improves propulsion underwater.
In a press release announcing the launch of the new prosthetic, Todd Goldstein, Ph.D., director of Northwell Ventures 3D Printing Laboratory, who designed and fabricated “The Fin” prosthetic said, “The Fin attaches to a standard prosthetic with ease, allowing the amputee to enter and exit the water without changing prosthetics. My hope is that this device creates unforeseen opportunities for amputees everywhere.”
According to the release, 33-year old Marine Corps veteran Dan Lasko, whose leg was amputated below-the-knee after his vehicle hit an explosive device while serving in Afghanistan in 2004, finds the amphibious, prosthetic leg to be a real life changer.
“The Fin is greatly improving my quality of life and allows me to return to my love of swimming. I recently got back in the pool with my two young sons and for the first time was able to dive into the pool with them,” Lasko said in the release. He has completed six marathons and more than 30 triathlons around the country since his injury.
Northwell Health collaborated with Eschen Prosthetic and Orthotic Laboratories in Hicksville and Composite Protoyping Center in Plainview to design and print “The Fin”. Northwell and Eschen hope to continue working together on other customized prosthetic devices to improve the quality of life for amputees.
“The prosthetic market is characterized by one-size-fits-all solutions,” said Thomas Thornton, senior vice president of Northwell Ventures in the release. “For amputees with a passion for swimming, there was no device out there that was truly amphibious and allowed them to really swim.”
To help promote this new prosthetic device, Northwell has launched a multimedia advertising campaign called “The Return” created by advertising agency J. Walter Thompson New York.
“Putting people at the heart of innovation is a big part of looking at healthcare differently and that’s what we set out to do with The Fin,” said Ben James, executive creative director at J. Walter Thompson New York.

Discussion
This is a fascinating development. In my practice we've seen similar outcomes with the revised protocol. The key differentiator seems to be patient selection criteria. Has anyone else noticed the correlation with BMI thresholds?
Great point. I'd push back slightly on the conclusion, the sample size in the cited study is too small to draw population-level inferences. That said, the directional signal is compelling and worth a larger RCT.
We implemented a similar approach last year. Early results are promising but we're still gathering 12-month follow-up data. Happy to share our protocol if anyone is interested.
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