Ulnar / radial deviation fist or patent pending URDF! This is both a wrist mobilization and a strengthening exercise I use as part of my wrist sequence. It is using what&;s known as a closed kinetic chain (the hand is fixed against the ground) eccentric movement(you contract your muscles while they lengthen) The more weight you apply with your body the more tension there is on your muscles. Start off with minimal bodyweight and slowly progress through the motion feeling the end ranges of your wrist. This exercise is great used as a warmup before crushing and to bulletproof your wrist. You can also use it after the sharp pain subsides with a series