A gamekeeper's thumb, also called a skier's thumb, is an injury to one of the important ligaments at the base of the thumb joint. The injury involves the ulnar collateral ligament (UCL), a band of tough, fibrous tissue that connects the bones at the base of the thumb. This ligament prevents the thumb from pointing too far away from the hand.
If you play video games and your hands start to hurt, you run the risk of suffering a repetitive stress injury that causes pain and even numbness in your hands. These symptoms are caused by swelling and compression along the carpal tunnel, a sheath for a nerve and some tendons that run from the palm to the shoulder.
Impingement of the ulnar nerve causes a radiating pain or numbness in the pinky finger, ring finger, and edge of the hand. This is called ulnar neuropathy, which can be caused by two different conditions known as cubital tunnel syndrome and ulnar tunnel syndrome.