On April 25, 2009 -- he remembers that date, too -- he tested his new knee for the first time. The result? A beefy, CNC-machined prosthetic leg, which looks like it could've been pulled off the front suspension of his Ski-Doo.

"An everyday walking knee is a shock with no spring on it," he says. "It will slow a movement down, but it won't hold the weight. Mine does both. It has a shock and a spring that holds my weight up when I stand and also has a shock in it that slows the rate of the knee collapsing. Works like your quadriceps do when you jump and land."

The leg uses a Fox mountain bike air shock "that's super light and super adjustable," he says. He adds that he can get a full season of riding on it before it needs rebuilding. He adjusts the spring rate, depending on which sport he's doing, and has to make considerations for cold weather because it gets much stiffer. He also has different "feet" for different applications.

The leg has become the talk of the Minnesota prosthetic community, and Schultz now has his eyes on marketing the leg to a wider, action-sports loving audience. The apparatus is called Moto Knee, and he's incorporated as Biodapt Inc. "There's a really good career here," he says.

The knee has been through three generations -- each version functioning on the same principle, but becoming lighter and more compact in the process. He's used various generations at Winter X, where he won SnoCross Adaptive gold in 2010, as well as during his gold-winning performance in Super X Adaptive in July at X Games 16. It's fine-tuned enough that Schultz hopes to get it to market this winter. The timeline isn't firm, but he thinks it's ready.

It's not just the Moto Knee that's kept Schultz busy: he's become something of an evangelist for adaptive sports.

In addition to his own success (his Winter X and X Games medals, he also has Super X Adaptive silver from 2009; medals in the 2010 Extremity Games events in Kayaking, gold, and Wakeboarding, silver; and the Roger McCarville Male Athlete of the Year award from the Athletes with Disabilities Network), he wants to increase his competition. He, with the support of the Athletes With Disabilities Network, is hosting an adaptive snocross racing clinic on Dec. 29 in Minnesota, with a race on Dec. 30.

"A snowmobile is a really good machine for a disabled rider to get on," he says. "You don't have to worry about modifying the controls. You have a throttle and brake and that's about all you need to control it." He says he expects some cross-over from the adaptive motocross scene to show up as well as disabled snowmobilers who want to learn snocross skills.

Those new skills could come in handy for potential snocrossers, because Schultz is also behind a new adaptive racing circuit on the National snocross (ISOC) circuit for the 2010-11 season. The three-race adaptive series will start after WX '11. In the meantime, Schultz is sating his racing jones by competing in the able-bodied Veterans National class (for racers 30 years of age and older; Schultz got an exemption to race).

For Schultz, the thrill of victory is back -- though his competitive drive never left. His WX gold is a lifetime athletic highlight. "It was cool to be back," he says of Winter X 2010. "Just being able to come back a year later and get a gold was the highlight of all my Winter X races."