Using Multiple Data Points for Motion Analysis — DSS and Pelvic Stability

By Naoto Saita

Hi, I’m Naoto from the R&D department at LEOMO. Today we did an FTP test with Kohei Yokotsuka and found out some interesting ways for using the TYPE-R’s MPIs (Motion Performance Indicators). Yokotsuka is a member of our company’s racing team, LEOMO Bellmare.

Here’s the FTP activity data recorded by the TYPE-R:

Raw data from the motion sensors. Top line: Amount of change in pelvic tilt, Middle line: Pelvic Anterior-Posterior Rotation (rotation of pelvis with the spine as the axis), Bottom line: Pelvic Lateral Rotation (rotation of pelvis with a perpendicular line from the sacrum as the axis):

LEOMO TYPE-R Raw Data

We noticed the following trends towards the end of the FTP assessment test:

  • DSS decreases.
  • Pelvic movement erraticness increases: Magnitude for the change of Pelvic Tilt and Pelvic Lat. Rot. increases. Pelvic AP Rot. trend line decreases but variance increases.
  • Difference between Foot AR and Foot AR Q1’s left and right data increases.

LEOMO TYPE-R Data

LEOMO TYPE-R Data 2

Conclusion

When we were watching Yokotsuka by eye, we were able to see that his movements were becoming erratic, even though his DSS score (which looks at pedaling smoothness) continued to decrease. We then saw his erratic movements quantified after uploading his activity and observing it on LEOMO’s web app and in-house tools. He had an unbalanced left /right Foot Angular Range, and increasingly erratic pelvic motion. We believe that it’s important to look at multiple MPIs to get an accurate picture of how the whole athlete is moving since each MPI is only a piece of the puzzle.

 


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