The difficult element has helped propel the Canadians up the pairs figure skating rankings.
Duhamel and Radford go into the Grand Prix Final this week ranked No. 2, trailing Olympic silver medallists Ksenia Stolbova and Fedor Klimov of Russia.
The two-time world bronze medallists spent much of the off-season perfecting the quad throw Salchow, which has Radford throwing Duhamel four revolutions through the air.
"Anything that pushes us and pushes the sport we feel is important," Duhamel said. "Adding the throw quad to our skating has kept us really motivated, it's encouraged us. . . and not just for us, we're looking to push the sport of skating. We've been seeing the throw triple Salchow for 30 or 40 years now, so I think it's time that people push it and try harder things."
Canada has three entries at the Final in Barcelona — Duhamel and Radford, and ice dancers Kaitlyn Weaver and Andrew Poje, and Piper Gilles and Paul Poirier.
Duhamel, from Lively, Ont., and Radford, from Balmertown, Ont., had considered doing the throw quad years ago, but their coaches believed it wasn't worth the risk. They decided to add it this past off-season, and drew an audience when they were working on it during practices in Montreal.
"Every day it got closer and closer, eventually I would land on my feet and put my hand down, or I would step out, and it was so exciting for us and our coaches and teammates, they would all stand back and watch, and would be like 'Ooh, is this the one she's going to nail?'" Duhamel said.
"Then the one day we hit it clean with a lot of flow out of it, we were like, 'Oh that's it, that's what it feels like.' And we've been able to repeat that feeling quite consistently."
Duhamel landed the quad throw at Skate Canada International, but then fell on it at the NHK Trophy two weeks ago in Japan.
The Canadians have a season's best score of 210.74 points, just behind the Russians, whose best is 211.97. Yuko Kavaguti and Alexander Smirnov, the only other pairs team in the world currently doing the quad throw, are also in the field.
Partly because of the quad throw, Duhamel and Radford went into this season reinvigorated after a gruelling Olympic campaign that saw them finish seventh in Sochi.
"We don't have any fear when we're skating anymore. Last year, I was always scared, I was scared we would lose, I was scared we'd be bad, I was scared the other Canadian teams would score higher than me," Duhamel said. "I'm so happy. . . that I didn't decide to quit last year because I would never know what it feels like to skate with this freedom and relaxation that we've found."
"There was a lot of pressure last season, and at the end we realized we put too much pressure on ourselves," Radford added. "We were always comparing ourselves with everybody else, rather than just concentrating on ourselves, and I think that we've just sort of learned to let all of that go, all of that extra worrying and energy that we put everywhere else."
Weaver and Poje, from Waterloo, Ont., will also be in the gold-medal hunt in Barcelona. The Canadians have the season's second-best ice dance score behind Americans Madison Chock and Evan Bates.
The post-Olympic landscape for ice dancing has changed with the absence of Canadians Tessa Virtue and Scott Moir and Americans Meryl Davis and Charlie White, and Weaver and Poje could be favourites three years from now at the Games in South Korea.
"It's been very exciting, it's a new year, a new quadrennial and we're happy to be at the forefront of it, and hoping to continue Canada's tradition of great domination in ice dance," Weaver said.
Asked if they'd sought out any advice on how to handle the new pressures that came with heightened expectations, Weaver mentioned Canadian bobsledder Kaillie Humphries.
"The biggest thing she has is confidence in herself, and she knows how she's prepared and she knows that that's the best she can do, and I think that's what really exudes from her," Weaver said.
"It's tough in a different sport with something like bobsled where you're racing against the clock and you don't have to convince people you're the best. But that type of persona is fun to learn from, and I consider us pretty different individuals, but that strength of power and confidence is something I would love to bring as a part of our game as well."
In men's singles, Olympic champion Yuzuru Hanyu hopes to defend his title and recover his winning form after a scary on-ice accident.
Hanyu won last year's final at home in Japan. He then started the year by claiming gold at the Sochi Games in February, and a month later he won the world title to become the first man to complete the Olympic-world double in the same year since Alexei Yagudin in 2002.
But Hanyu, who turned 20 on Sunday, barely qualified for the Final after he was injured in a collision with another skater during warm-ups at the Cup of China in early November, receiving bruises on his head and hurting his left thigh.
Three weeks later, he could only manage a fourth-place finish at the last of six qualifying events in Tokyo. That result, however, was just good enough for him to join the other five finalists and keep alive his bid to repeat.
"I'll be going to the final as a challenger," Hanyu said. "It doesn't matter if you are Olympic champion, people know they can beat the Olympic champion. I'll be starting from scratch and aiming to get to the top by any means."
Hanyu will be up against Japanese teammates Tatsuki Machida and Takahito Mura, Russian rivals Maxim Kovtun and Sergei Voronov, and Spanish skater Javier Fernandez.
Fernandez, the European champion, trains in Canada with former Olympic silver medallist Brian Orser. Orser also coaches Hanyu.
Four Russian teenagers will look for a possible medal sweep in the women's final against Ashley Wagner of the United States and Rika Hongo of Japan. Hongo qualified after American skater Gracie Gold withdrew because of a broken foot.
The Russian contingent includes two-time junior world champion Elena Radionova (15), European champion and world silver medallist Julia Lipnitskaia (16), Anna Pogorilaya (16) and Elizaveta Tuktamysheva (17).
— With files from The Associated Press.Suggest a correction