Whenever I am in an intense grappeling session (bjj or wrestling) and there a lot of tieing up or resitance between me and my opponent something happens to my arms/forearms. It's as if they completely fill up with blood, they go kind of numbish, and it is SO hard for me to even open and close my hands. I experianced this while doing heavy lifting too. It's so frustrated and it bothers me so much. Does anyone know why this happens, what to do, or has it happened to anyone else? Thx.