Why are there missing contact forces in the provided b3d files?

[yunhanwang1105]

Thank you for open-sourcing this brilliant work.

From my visual inspection of the provided preview data. There are quite some frames with contact forces being 0 while the foot was in contact with the ground. I have uploaded the gif of this phenomenon.

May I kindly ask why this happens? And how could we solve this? Thank you for your help.

[yunhanwang1105]

I see that those missing forces are just not detected by the force plates.