Metria Innovation Inc - Optical Mocap for Animation, Biomechanics & Robotics
MPT is Missing Link for Brain and Body Research Researchers at Cincinnati Children’s Hospital Medical Center (CCHMC) have identified that the risk for tearing an anterior cruciate ligament (ACL) isn’t just a movement problem, but also potentially a brain problem.


An ACL rupture is a disabling condition that requires 1-2 years of rehabilitation for full recovery. To prevent such traumatic injuries, CCHMC has been investigating whether an athlete’s brain behaves differently prior to the incident.  


“We recently discovered that athletes who experience an ACL injury exhibit a pattern of brain connectivity unique to their teammates who do not experience an injury,” said Jed Diekfuss, PhD, a Post-Doctoral Research fellow at Cincinnati Children’s Hospital Medical Center. “Our data indicate that athletes who tear an ACL exhibit prospective alterations throughout brain regions important for injury-free movement.”


Diekfuss and his colleagues are one of the few research groups to look at brain components underlying ACL injury and knee pain, more generally. They believe that if they can learn how the brain contributes to knee injury and pain, they can create programs to prevent it from happening in the first place.


Technological Limitations

The CCHMC team’s research consists of two parts: brain scans using fMRI and movement assessments in a biomechanics lab. The Sports Medicine research team further created a custom apparatus for the MRI research to assess the brain’s response to knee movement. A patient is asked to press their legs against resistance while inside an fMRI to assess how the brain responds (i.e., more or less brain activity). In the biomechanics lab, they can precisely measure the quality of movement (i.e., movement ‘error’) with a 3D motion capture camera system. 


“We have been successful collecting data in this way, but the biggest limitation has been to precisely measure movement error (i.e., how a patient moves their leg) during fMRI,” said Dr. Diekfuss. “There have always been technical limitations for measuring the brain and the body simultaneously.” 


Until now, brain activity using fMRI and lower extremity body movement has always been studied separately. 


High Field 3D Motion Capture

The CCHMC team’s research capabilities are changing with the use of Metria Innovation’s Moiré Phase Tracking (MPT) High Field camera system. MPT High Field is an easy-to-use, wireless 3D motion capture camera system that was designed for the fMRI environment. 


Once the  MPT motion tracking markers are placed on a subject’s legs, the camera lighting unit will automatically recognize and track all markers individually, providing position and orientation of the respective leg segment. Marker position is measured with an accuracy better than 0.1 mm and marker orientation is measured with accuracy better than 0.05 degrees. A Bolt II tracking and measurement platform reports statistical information including frame number, frame time, and trigger pulse feedback. 


“The fMRI-safe MPT motion tracking system provides reliable movement data, comparable to that of our 3D motion system used in the biomechanics lab,” said Post-Doctoral Research Fellow Dr. Manish Anand.


The CCHMC team placed the MPT High Field camera on the ceiling in the MRI lab to measure frontal and sagittal (symmetry) knee kinematics while the patient completes ankle, knee, and hip movement tasks. The MPT high-field system can precisely capture subtle changes in how the leg moves that researchers were unable to identify through observation. The data, along with the brain scan, can identify coordination deficits and how they are jointly contributing to ACL injury and related knee pain.


The incorporation of MPT High Field into the CCHMC’s custom apparatus opens multiple doors for the research team.

  • First, it provides the missing link to brain scanning and active lower extremity movement research – they can now be measured simultaneously.
  • Second, researchers can develop novel biofeedback technologies that use the movement data in real time to ‘guide’ an athlete towards safer movement by targeting regions of the brain.
  • And third, it has the potential to augment current prevention strategies conducted outside of MRI to no longer just train the body, but to also train the brain.  

The work will lead to a faster and more successful rehabilitation program that addresses the knee and the brain. And it will hopefully lead to programs that prevent ACL injury and knee pain so athletes can stay on the field of play. 


The Potential for Breakthrough

“We can take the brain data, combined with Metria movement data to make a training paradigm that teaches people how to move safer,” said Dr. Diekfuss. “We can now augment our previously successful movement-based prevention programs to also target the brain for a further reduction in ACL injury risk and knee pain.”


A high percentage of ACL tears occur in young athletes and there are several long-term consequences, including disabling conditions like osteoarthritis, thus identifying ways to improve prevention are key according to Dr. Diekfuss. 


“If we can change the ways in which the brain functions prior to an injury,” said Dr. Diekfuss, “it might stave away the long term issues associated with ACL injury while also enhancing athletic performance.”


“The proposed research represents a significant transformation for understanding mind-body interactions using or multimodal approaches that can quantify movement quality simultaneous with brain activity to uncover the neural drivers of movement,” said the Director of Sports Medicine Research, Dr. Greg Myer. “Working with Metria to create movement-based fMRI paradigms with active biomechanical assessments will push a paradigm shift in understanding the actual neural drivers of motor control and disrupted neuromuscular control.”

 Explore Applications 

3D Animation

Industrial Ergonomics
  Sports Bio Mechanics
  Medical Technology

Download the MPT Series 2
Specification Sheet:

Download the MPT High Field
Specification Sheet:


Download the DragonPHY
Specification Sheet

Sign up for our EPub

Copyright © 2015 Metria Innovation, Inc.