06/18/2012 02:35 pm ET

Landon Light, Paralyzed Teen, Becomes A Competitive Swimmer (WATCH)

Making the swim team is an accomplishment any 13-year-old would be proud of. But for Landon Light, earning a spot on the team was a medical miracle. In 2008, he was diagnosed with transverse myelitis, a rare disease that left him paralyzed from the chest down overnight.

Dr. Ben Greenberg, Landon's doctor and the director of the Transverse Myelitis Program at UT Southwestern and Children's Medical Center of Dallas, explained to CBS, "It's a condition where the immune system, which is supposed to keep you healthy, gets confused and thinks that your spinal cord is a foreign invader."

Landon, who lives in Heath, Texas, was told he was not likely to walk again. Although he needs assistance to climb onto the starter's block and has limited use of his legs, he's had no trouble competing against more experienced athletes.

Nikki Ripp, his coach, told CBS Local, "At the first meet, I cried. I think everybody in the stands was absolutely blown away."

An equally miraculous feat was recently accomplished by 18-year-old Patrick Ivson, a paralyzed student who walked across the stage to receive his diploma at graduation. Although Ivson is paralyzed from the waist down and uses a wheelchair, he pledged to receive his diploma by physically walking at graduation. He has spent as many as six hours a day for the past three years in intensive physical therapy, and this month, his efforts paid off.

And last month, 14-year-old Coleman Shannon -- a baseball player who suffers from a medical condition that causes his right arm to end at the elbow -- pitched an elusive no-hitter using his one good arm.

"It really is amazing the number of people out there that can do things with ease and choose not to,” said his mother, Jessica Shannon. "With Coleman, it's a determination and something that he strives to do."

What's the most difficult obstacle you've overcome? Tell us in the comments below or tweet @HuffPostTeen!