Today the 2012 Paralympic Games opened in London and from now until September 9, some of the best athletes with disabilities in the world will compete in 21 different events ranging from wheelchair rugby to swimming. Some of the sports will require wheelchairs designed with cutting edge engineering. What is really interesting about these chairs is how they vary so much from sport to sport. Just like you wouldn't use a basketball shoe to run track, the wheelchairs paralympians use differ greatly to suit the event. Check out this video by the National Science Foundation and NBC Learn to see how these high-end pieces of sporting equipment are designed.