Running frequency

[Edilson Borba]

Hello,

We collected samples during runs at 8km/h (we know there is a recommendation to use 100 to 200Hz) and I would like to know if you have any material comparing the results for running at different OpenCap collection frequencies.

Tks

[Antoine Falisse]

No, we don't have such material. Feel free to share your findings. Antoine

[Edilson Borba]

Hi Antonie

We recorded with both setups combined, we recorded at 60 and 120 for runs of 8, 10, 12... up to 30km/h. I only analyzed at 8km/h due to time, and the analyzes returned almost identical data for the temporal variables, work, coordination analyzed in a Python routine, and identical when we cut 10 passes and analyzed them in a routine written in Excel. It seems that at 8km/h it doesn't make a difference. We need to expand this analysis to be sure of the data, but I also need to process and analyze other speeds.

Below, a small section of the analysis, the ones above analyzing all the steps and below a central section



Thank you for your support

[Edilson Borba]

Another question

I have, I looked for it and really couldn't find it. About speed and acceleration, what are the Pelvis_X and Pelvis_Ox data, for example. The spreadsheet below is about velocity, and I would like the angular velocity, but I'm having trouble finding that answer.

[Antoine Falisse]

Is it the spreadhsheet you get from OpenCap? If so, it is positions not velocities.
You can use our API to get velocities: https://github.com/stanfordnmbl/opencap ... ple.py#L50

Best,
Antoine

[Edilson Borba]

No, this output is from OpenSim, I'll ask on its forum

[Antoine Falisse]

The text at the top is "standard". Typically you only get positions, and you can get velocities by taking the first time derivative.
Best, Antoine