NewsNational NewsScripps News


New motion-capture app captures complex health data with a cellphone

Stanford engineers have created a motion-capture app that makes it possible to see muscle and skeletal movement with just a cellphone.
New motion-capture app captures complex health data with a cellphone
Posted at 10:57 PM, Nov 10, 2023

At the Stanford Human Performance Lab, biomechanical engineers study how we move, and how to make that information more accessible to others.

For scientists like Scott Uhlrich, movement is crucial to life and his life's work. In this lab hundreds of thousands of dollars of high-tech tools fill the space, including 27 cameras that capture motion, specialized infrared cameras, floor plates that measure force and sensors showing muscle energy. 

These expensive labs have shaped how athletes perform or patients recover — but enter something Stanford scientists have developed called OpenCap. 

"There's the cost of the equipment, right? And that's a barrier. This technology and these sorts of analysis that are valuable really aren't accessible to to folks in their normal medical care," said Uhlrich, the research director at Stanford's Human Performance Lab.

With OpenCap, instead of spending $150,000 to $200,000 on equipment, for about $50 and two cellphones that work together, anyone can move and their musculoskeletal system shows up, along with thousands of data points. 

The tech is not stuck in a lab. The cloud, good wifi, and AI make visualizations from that data quick and easy. They've made it free to researchers worldwide.

"We can just visualize it here on the laptop," said Uhlrich.

"It took me 10 years to study 2,000 patients. Today with OpenCap, there are 2,000 labs that are getting 2,000 patients in one day," said Scott Delp, the director for Wu Tsai Human Performance Alliance.

Delp says the technology not only paves the way to find nuances in different sex, racial or ethnic patient groups — it can also make a difference in physical therapy, in clinics, doctors' offices, even patients' homes. 

"We can measure whether you're getting better or give you feedback without the need to drive to the hospital, check in, pay hundreds of dollars, have expensive insurance. We can really have physical therapy everywhere in your home inexpensively," said Delp. 

Uhlrich says they're now testing cellphone-based open capture and the expensive lab-based motion capture to make sure they stack up against each other side by side.

From there, OpenCap could begin to make its way to patients very soon, as they quickly move towards improving lives. 

SEE MORE: Man receives first whole eye transplant after losing half his face

Trending stories at