Every time I apply pressure to my radius, I feel it and my ulna shift at the wrist joint, what is wrong?

DRUJ? TFCC. It's time to get evaluated. Pain and shifting at the wrist could be a variant of normal or even being a sign of an injury to your DRUJ or TFCC. Both are critical structures, see your orthopedic surgeon today who will examine you and get initial imaging as well. Many times an MRI is needed. .