Pronation excursion and roll angle excursion?


#1

Pronation Excursion is the roll angle excursion ?


#2

Yes, measured in the frontal plane. We report 2 pronation excursion metrics. One from foot strike to the point of maximum pronation (FS -> MP). And the second from max pronation to toe off (MP -> TO).
Hope that helps.


#3

@sennologgger My apologies. We no longer report the second pronation metric I mentioned in the previous post.


#4

thanks john,


What is the definition of footstike and toeoff?
is it like the picture , using the pitch anlgle velocity?


#5

@sennologgger – the algorithm that we use to locate footstrike and toeoff was indeed originally coded based solely on the pitch gyro (as shown in the article you reference), but we found that this simple assumption didnt work for all cases. With our validation data, we were able to develop a much more robust algorithm using accelerometer data in addition to the pitch gyro which works well across the wide range of running styles and paces we see in our community.


#6

thanks Tim, the heel strike pitch angle is about 30 degree, but the number in our metric is about 5-10 degree.


#7

@sennologgger that graphic is just an illustration to show where foot strike and toe off are generally located on the pitch angle curve. But yes you are correct, if the curve represents the image of the foot above, the orange dot representing foot strike should be located higher up the curve.


#8

@sennologgger – the other thing I should note (just in case there was any confusion) is that the number we are reporting for FS Type is a scale from 1 to 16 – 1 being strong heel strike, and 16 being very forefoot. It isn’t an indication of the number of degrees of pitch.


#9

Hello RunScribe team,

thanks for those precisions. Do you have any link publically available to the validation data you mentioned ? I didn’t find it in the science litterature but might have missed it?