Sam Miller Has Turned His Father’s Dream Into Sports Tech Reality


There was something strange lurking in the basement of Sam Miller’s childhood home in the 1990s. It wasn’t exactly a monster, but a weird mechanical contraption. As a visiting scientist at MIT, Sam’s father, Larry, had been trying to understand and replicate human movement. The apparatus was the fruit of that unfulfilled quest.

“He had this idea while he was at MIT, and then he went off on his own and tried to develop it,” Miller, 32, said, “and was doing it in the basement of my house growing up. Me and everyone that I knew—family, friends—always knew about what we called ‘The Machine.’”

“And it effectively did nothing.”

Larry built the machine with the help of friends who had a machine shop in New Hampshire. When Larry left Boston in 2008, he took The Machine with him to Tybee Island, Ga. He kept tinkering with it, sketching out theoretical calculations and experimenting with the mechanical design.

Larry Miller and The Machine.
An original concept of The Machine from 1995. (Courtesy of Sam Miller)

Sam had left home for Vanderbilt by then. There he studied economics and history, plus a minor in art history, graduating in 2008. After school he worked for architecture and construction firms back in Boston, rising to become the director of business development, science & technology, healthcare at Suffolk Construction. But the machine crept back into his thoughts.

Miller began travelling down to Georgia as many as two dozen times per year, to visit his dad and to learn more about the apparatus he’d built. Miller was fascinated by it, and felt it had untapped potential in the sports tech world and the quantified-self movement. In 2015, he rented a U-Haul truck and drove the machine home to New York City. Two months later, he quit his job.

The machine has now become Proteus, a patented strength training system that combines the range of motion Miller’s father built into the original mechanism with magnetic resistance and data analysis. A partnership with the Hospital for Special Surgery, an NYC-based hospital that specializes in orthopedics and rheumatology, helped validate the technology, demonstrating two to three times the muscle engagement compared with using free weights or gym machines. Boston Biomotion, the company Miller founded, has raised almost $2 million so far, and is now in the middle of a $1.5 million funding round.

Miller describes Proteus as being like aquatic therapy, only on dry land. “You can do sport specific movements. Any sort of rehab protocol, any general exercise. And do it with a lower strain, lower stress,” he explained.

Proteus looks a little like a human-sized, metallic trebuchet. A balance arm pivots on top of a rotating base. The arm itself can extend and contract as a handle slides in or out. Holding the handle, a baseball pitcher can run through his exact three-dimensional pitching motion, with the machine able to adjust the resistance force vector throughout. A user simply needs to go through the motions to teach Proteus new movements.

“You move how you move and Proteus adapts to your movement. You’re prompted to perform an exercise, and it’s just totally fluid,” Miller said. “As soon as you stop and pause for a second, Proteus understands and recognizes that was your movement, your unique movement, whatever that movement was, and then allows you to continue doing that and provides a load based on whatever you set beforehand.”

Proteus tracks and converts motion into data. The information it collects that way is far more complex than the typical numbers of reps and sizes of weights that might be recorded in typical strength training. “This is the first capability to measure strength and muscle performance in three-dimensional space and time,” Miller said. “This data never existed. What does it mean?”

Miller’s business model is focused not on the hardware platform itself—machines will be leased, not sold—but on the analysis of the data Proteus records. As that data becomes bigger, Miller believes it will become more powerful and more impactful.

“There’s 10 million things that we can do and are going to do, and the first step is introducing people and partners to what this is and why it matters, and what’s the value here.”

There are now a total of five Proteus machines in existence, not counting the original concept Larry built. One is installed at the University of Pacific, another is at the Riekes Center in Menlo Park, a multiuse facility that caters to youth baseball players, the elderly, pro athletes, and Paralympians. The University of Wisconsin will get its hands on a third machine within the next couple of weeks, and a fourth is due to be shipped to an MLB team this fall—Miller could not name the team due to contractual reasons. The fifth is used in-house by Boston Biomotion. Three more units will be built by the end of November.

In February, Miller took one of the machines to the MIT Sloane Sports Analytics Conference, where it caught the eye of incoming MBA student Chris Capuano. The former All-Star left-handed relief pitcher is now an investor and an active partner in the company, helping Proteus break into the elite level of pro sports.

“Towards the end of May,” Miller said, “we went out and stayed with him in his house in Scottsdale, and set up Proteus in a centralized location where we could track teams from Spring Training facilities.”

The planned market for Proteus, though, is bigger than just pro ball. Miller sees his target audience being the millions of amateur and recreational athletes who might be looking to get stronger, or who might be returning from injury. “The ambition here is that we are fundamentally changing the process of recovery from an injury, and exercising for sports,” he said.

Miller’s dream is that Proteus could offer an automated solution for both training and physical therapy. The monster in the basement, his father’s unfinished masterpiece, finally harnessed for the real world goals of boosting fitness and improving injury outcomes.