To test your wrists, the best indicator of disfunction is pain. If you feel pain while you're typing, lifting, or having any sort of movement through your wrists, it's and indicator that you might need more mobility in your wrists and forearms.
TEST 1: To test external rotator cuffs
A) Extend the right arm overhead, and put your hand behind you as you bend your elbow. You should be able to scratch your head without collapsing your chest, it's a good indicator that your external rotators of your rotator cuffs have disfunction. Test both sides.
TEST 2: To test internal rotator cuffs
A) Rotate your thumb towards the ground and bend the elbow. your hand should be able to reach behind your back. You'll be able to feel how high your hand gets up your back. Your shoulder shouldn't be rotating forward, and your back should be nuetral. If your shoulder is rotating forward or you back isn't neutral, it's an indicator that your internal rotator cuffs are tight.
TEST 3: To test shoulder and pec mobility
A) Lay on your back. Your shoulders should be flat, and your elbows should be about shoulder height. Your hands should be able to drop overhead and about touch the ground without your back lifting off the mat. If you feel a lot of the stretch in your pecs, its an indicator that your shoulders and pecs are too tight.