You may have heard bits and pieces of the story by now. The new Predict RA road running shoe is built with an entirely new design that’s never been used before. It has individual platforms of support aligned where the runner needs them, when the runner needs them. But how was it done and why? We sat down with one of the people who did the research that led to the shoe’s development to find out.
“We wanted to reduce knee strain. Because of that, the initial research we did that led to the Predict RA was centered around developing a women’s road running product,” says Marlene Giandolini, a biomechanist and footwear product manager who works on Salomon’s road running range and operates the biomechanics lab at the company’s French headquarters. “The reason for that is because women are more exposed to knee injuries partly due to the fact that they have a wider pelvis and muscle weakness/imbalance.”
However, when Giandolini and the research team at Salomon began examining data and observing runners, they realized that the product they were building would greatly benefit all runners. It’s not a well-kept secret that the single biggest cause of people stopping sports participation is injuries. With that on their mind, Salomon’s road running product team—comprised of a number of individuals with years of experienced at road running brands around the globe—examined a number of biomechanical studies inside and outside the walls of Salomon. That was all done in an effort to be sure that reducing knee strain made sense and to find out which motions are related to knee strain.
“We do our own studies, of course, but we also look at what is done outside of our lab so that we are not just telling ourselves stories,” Giandolini says. “What we found in all this research is that knee strain is related to a certain kind of motion—when the knee goes inward. And we saw from previous studies that excessive foot pronation is related to knee strain. We hypothesized that if we reduce these parameters, we could reduce knee strain, and if we do this we might also reduce knee injuries.”
What’s different about the Predict RA from other running shoes that aim to reduce strain on the knee is in how Salomon attacked the problem. While most running shoe manufacturers build shoes designed to control the foot’s motion and prevent pronation, Salomon biomechanics experts believe that pronation is just fine, as long as it is not very excessive.
The idea was hatched to match each foot joint with a groove in the bottom of shoe; what the team refers to as the mirrored decoupling on the sole. While most shoes have a bottom unit in which the heel and forefoot are decoupled to deliver flexibility for the foot from front to back, the Predict RA has grooves along the top and bottom of the midsole to align with the bone and joint patterns of the foot. By providing a platform under the correct joint of the foot throughout the foot, the shoe works with your foot, rather than against it to limit its movement. In short, the individual platforms of the sole allow the foot to move more freely with the shoe.
“What is different from motion control shoes that have been made in the past is that they aim to ‘correct’/ ‘limit’ ankle pronation movement because they say pronation is bad,” Giandolini says. “Pronation is normal and runner-specific. We all have pronation but we have different degrees of pronation depending on our anthropometrics, ligament laxity, tendon stiffness and injury history. As a matter of fact, no one is able to say what a ‘normal’ pronation is! And it’s likely that a certain degree of pronation can be normal for an individual but pathologic for another. Besides, there is no evidence demonstrating that pronation is related to injuries.”
The idea, essentially, is that if the foot movement is not restricted there will be better synergy between the foot and shoe, thus allowing the foot to move naturally in order to have better synergy with the upper joints of the body.
“Let’s imagine you run for 10 minutes in ski boots,” Giandolini explains. “You will have no motion in your foot or ankle. I would hypothesize that after 10 minutes you will have knee and hip pain. Foot strain won’t disappear but they would probably ‘move’ to upper levels. We want to allow the foot to move naturally instead of restricting any frontal motion in order to have natural motion of the foot, ankle, knee and hip, with no forces applied against these motions. This reduces strain and frontal motion by allowing foot movement.”
The first round of runner testing with the Predict RA was done only with women. Since the results were fantastic, the team did the same tests with male runners and again the results were great. They continued to test from there, administering a number of experiments, with 12-20 testers each time.
“What happens is the runner runs across our lab, which has a motion capture system,” Giandolini explains. “There are three force platforms with eight high-speed video cameras. We used recreational runners who have more of a rear foot strike, all running at 12km/hour (a 5-minute km pace or about an 8-minute mile pace). From there, we calculated the parameters of interest (3D range of motion and torques) and did statistics testing.”
They also tested the prototype of the Predict against competitors, most notably a traditional road running shoe that has become very popular over the last few years.
“We looked at how the parameters changed from those shoes to the prototype of the Predict,” Giandolini explains. “On average, we saw a 12 percent decrease in knee frontal torque, which is huge. And we found that was the case in 71 percent of runners. That decrease in these parameters indicated a reduction in knee strain. So for seven out of 10 runners, we saw a reduction in knee strain. We also decreased pronation in 74 percent of runners with the concept.”
Giandolini is quick to point out that the Predict RA is not designed to be a competitive shoe. After Salomon Wear Test Analyst Jeremie Mellet performed field testing with recreational runners and competitive runners in runners, it was noticed recreational runners loved it. Competitive runners loved it for recreational runs. They found it ideal for logging long runs to build base miles and for recovery runs after fats days and races.
“It’s a comfortable shoe, but it’s not designed for all-out speed,” she says. “It’s built for comfort over time and to help reduce strain on the joints.”
To complete the design, the Predict has an innovative 360-degree upper fit that hugs the foot. The material in the heel was made in a bra factory to aid support without restricting motion. The molded heel and articulation in the upper complement the grooves in the midsole, hugging the foot and supporting it without restriction.
The Predict RA shoe is most suited for:
• Competitive runners looking for a shoe for recovery runs and a shoe to use for logging base miles
• The recreational runner whose priority is comfort over time
• A runner with a history of knee or other joint pain
If you want to see the Salomon Predict RA road running shoe in action, watch Every Single Street, the latest episode from Salomon TV, in which Rickey Gates uses the Predict RA to run every single street in San Francisco. Rickey logged 1,303 miles (2097 kilometers) over 46 days.
“I knew that having the right shoe was going to be paramount to undertaking such a massive project entirely run on concrete and asphalt,” Gates told us. “With an innovative support system and ample but precise support, the Predict carried me across 1,300 miles. This is a five day-a-week shoe. You can do a lot of miles in them and feel great the next day. I know I did.”