Day 18 was a recovery workout day and it felt fine. So I will leave it at that.
Today was power and resistance, a fair bit og jumping and push-up work in this session. My back is still bother me a little so I'm trying to be careful. The biggest area of concern was the very last movement, which is hop squats/push-ups super sets. 8 squats/8 push-ups and repeat for about 4 sets. It isn't the movements that are concerning here it is that it is the final exercise and trying to push it can lead to forgoing form in the push-ups. I think I did okay with it, but back is a tiny bit more sore than before doing it.
Soccer game tonight, so we'll see how the back holds up to it and to tomorrow's session!