Stephen Welch has been competing in wheelchair tennis for 20 years. In that time, he's amassed over 100 major titles, including two number one world titles, three U.S. Opens, and a gold medal at the 2011 Parapan American Games and another at the 1996 Paralympic Games. At the age of 39 Welch is looking forward to London this year as part of the National Wheelchair Tennis Team. See his story, in this profile from medal Quest.