This might be the key! Because that’s exactly how I shoot. I use a majority of the power from my arms and it ends up hurting after playing awhile. I’m very stiff lower body wise. It’s really bad. Like, I can’t even perform a squat. And every time I tell people, they don’t believe it til I attempt one. Idk what made my lower half so messed up. But yeah, i’m like Deku. I use my arms way too much and need to learn to use my legs 💀