that's your scaphoid, or once called navicular in the wrist. It is commonly stressed/injured in palm outstretched landing type of forces. Be wary that it isn't fractured. If it is, it could be more serious. Hopefully the pain is low grade, and just give it rest and let it heal. Ice, compress, rest. Bracing your wrists with a piece of tape just wrapped around them can help to stabilize the area as well. Good luck. If the pain is higher grade, def see a doc for an x-ray