Benefits:

 When you stretch back the hand away from the wrist, it opens up the wrist area which will help carpal issues, and also benefit those who play a lot of hand held games
 When you stretch back the hand away from the wrist you benefit the elbow and whole arm because the stretch lengthens muscles from the wrist, right up to the shoulder.  This will help those who garden a lot, shovel snow for extended periods, golf, play hand held games and type a lot on computers.

Cautions:

If there is pain when you conduct the exercise please see your medical practitioner and have it checked out

Instructions:

Extend your arm out slowly so that it is straight but not locked in the elbow
Slowly draw your wrist backwards away from the inside of the elbow. You want to hold this position for 10-15 seconds.  Breathe deeply while you stretch
You are going to feel this stretch from the wrist all the way up to the elbow
Change sides and repeat. 
Do this exercise every half hour to hour if you think about it. This will help with reducing golfers elbow.

Info to consider

Golfers elbow is typically pain on the inside of the elbow.