Morse found that when racers used the new technique along with a preracing conditioning program, the number of injuries they sustained were reduced drastically.
"The main difference is the point of contact with the wheel," Chow tells WebMD.
"It's not that hard to learn," Chow says. "The problem is whenever you learn a new technique you sacrifice your performance at the very beginning."
"PBT may be more suitable for endurance athletes who use less power in their pushing strokes," Chow says. "That's our recommendation, [but] we didn't have enough data to address whether PBT is better in terms of minimizing injuries."
The two techniques are suitable for different types of athletes, often depending on their physical characteristics, he says. To arrive at their findings, Chow and colleagues compared eight elite athletes who used the CVT stroke with seven who used the PBT.
That's not to say that racers have readily adapted to the new technique, which requires a closed hand.
"A lot of people can't push that way so they turn back to the conventional technique," says Morse.
The PBT stroke is hard to pick up, he says. "It can take anywhere from two days to six years to get right."
What does a wheelchair racer need to get started?
"You need a feel for making contact with the hand ring of the wheel, a comfortable pair of gloves, and to be comfortable in the chair itself," says Morse.
Training can be intense, he says. "If you are getting ready for a marathon, you have to do 120 to 200-plus miles a week," Morse says.
In wheelchair racing, "the Boston Marathon is the biggest race. Once you have won it, it's just an incredible rite of passage," Morse says, likening it to what Daytona is for NASCAR drivers.
Morse trained eight-time Boston Marathon winner Jean Driscoll, who has used both methods in her career.
"I used the thumb technique from 1987 through November 1991, and then in December of 1991, I started to experiment with the PBT," she tells WebMD. "It took me about two weeks going nine miles an hour to figure it out, but once I picked it up, I broke the world record by six minutes."