5th Finger Pushups?

Hi, When experimenting with my hands I noticed a funny thing. When I lie my hand on my 5th finger, like a karate hit - fingers straight and thumb on the top, I can push my fingers 1-4 upwards with my 5th finger. I can easily do it and put pressure on the hand and still make this pushup. But this is much better with my left hand. With right hand I can isolate 5th from the rest of the hand but this pushup is much more difficult. Now the question: is this kind of exercise good for strenght and 5th finger individuation? I've read that lateral movements can strenghten interossei muscles of the hand. For example, one Finnish piano pedagogue advised to do finger circles, drawing circles to air with individual fingers. Do these ideas make any sense?

Same thing here! Doing it with left hand is significantly easier. I see nothing wrong with the exercise. Puts my hypothenar muscles to work.

I don't know why one hand is better than the other, but to strengthen the right hand I would start with my fifth finger pull-ups from my first book, and once you can do those well, then graduate to the very ingenious exercise you describe here. AFF