Behind the Scenes: Checking Foot Angular Range Accuracy

Hi, I’m Naoto from the R&D Department at LEOMO. Today I’ll be introducing how we checked the accuracy of the TYPE-R’s Foot Angular Range algorithm.

Although the accuracy for all our algorithms has been meticulously validated using the OptiTrack motion capture system, we had one athlete that sometimes had a whopping 20-degree average difference between his left and right Foot Angular Range. We couldn’t believe it, so we had to double check the TYPE-R’s numbers, just in case.

We had the athlete come to LEOMO for testing and had him ride on an indoor trainer at roughly 80 to 100 rpm.


If you look at lap 5, you can see that his left and right Foot AR has the largest discrepancy during the test. Here’s a close-up of lap 5:

LEOMO TYPE-R Accuracy 2

LEOMO TYPE-R Accuracy 3

We compared the measurements recorded on the TYPE-R to the measurements we took from the video:

Left foot: 
- TYPE-R: 62.9 deg
- Video: 62.877 deg
- 62.877/62.9*100=0.99 = 99.9% accuracy

Right foot:
- TYPE-R: 50.8 deg
- Video: 48.577 deg
- 48.577/50.8*100=0.956 = 95.6% accuracy


The athlete did indeed have a very large gap between his left and right Foot Angular Range. We were also able to confirm the high accuracy of the Foot Angular Range algorithm — which can be off by no more than 5%(max).

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