Kid was terrified of the father that he's was willing to jump and fall off the treadmill multiple times as he knows the father would do worse.
I don't see how that can
necessarily be inferred from the video.
Sons often try to act tough around their dads, to put on a brave face. If a boy falls off a treadmill, a good dad would pick him up, dust him off, and tell him to get back on.
What's happening in that video might be abuse, but it could also just be tough love and paternal involvement. (Which the state is desperately trying to erode and discredit by all means possible.)