OK I have a lesson wed, but supposed to be working on raindrop prelude, a Chopin piece. The c sharp minor part, lots of that is octaves in the RH, poking some notes periodically in addition to an endlessly repeating octave. The top part of my forearm gets really fatigued, and kiunda cramped, but there really isn't time to relax my hand because the octaves are repeating. An octave is my max stretch (small hands). Ideas? This is a hard piece for me, so I'll have to work it a lot. Thanks for tips! I brought it up before with the teacher, and in that case was not relaxing after hitting the notes. But no opportunity here. For now, I will do 5 minute practices a few times a day on that section, working on other stuff between so I don't hurt my arm. I do have an injured rotator cuff in that arm that hasn't got better for several months with exercises, if maybe that's a contributing factor for all you experts in piano playing physiology!
Dribbling, my hand relaxes. And my hand is not opened so far.