Interested in ?Add as an interest to stay up to date on the latest news, video, and analysis from ABC News.
In fact, Hough, 28, told ABC News that Purdy, a double amputee champion snowboarder, is one of the reasons he decided to come back for season 18.
"They told me about her and I said, 'I have to dance with her, I have to do this. I'm too inspired,'" he said. "We are just going to continue to defy the odds."
After scoring 24s through the first two weeks, Hough and Purdy have a secret weapon they are busting out tonight.
"This week, we are trying new feet that have never been used to dance before, so we are getting mechanical with it as well," Hough said. "They are actually made for swimming."
The "DWTS" legend -- who spoke to ABC on behalf of his new movie "Make Your Move," out nationally April 18 -- said the new feet are pointed and locked into that position for a reason.
"It allows for her to be on her toes for that entire time," he said. "It creates a prettier line aesthetically for dancing, it's pretty remarkable."
Purdy, who lost both of her legs at 19 to meningitis and went on to become a world champion in adaptive snowboarding and competed at the recent Paralympics for the USA, is the reason Hough loves dancing on this big of a stage.
"For me, it's all about progress, progress and people's happiness, and growing and contributing," he said. "I told her the other day, every step you take is already a success. Take that pressure off and just enjoy it."
Follow #MakeYourMove on Twitter at @MYMTheMovie.