'Maximal' running shoes have extra cushioning, particularly in the forefoot region of the midsole. But is this actually beneficial?
A previous study by Oregon State University-Cascades' Functional Orthopedic Research Center of Excellence (FORCE) Lab found that maximal shoes may increase impact force and loading rates, indicating a greater risk of injury such as plantar fasciitis or tibial stress fractures.
Now, the same research team has looked at whether a six-week transition period helps wearers adjust to this style of sports footwear.
The study involved 20 male and female runners aged between 18 and 45, who ran at least 15 miles a week. The runners took part in two biomechanical testing sessions in the lab, each session about six weeks apart. They completed a series of running trials wearing maximal shoes and also wearing traditional running shoes.
After the first testing session, the runners continued their regular running mileage but gradually increased the proportion of running in the maximal shoes over the six-week period, with the last two weeks only in the maximal shoes.
Findings published in the American Journal of Sports Medicine show that there were no changes in running mechanics over time in either type of shoes. Supporting the earlier findings, there were increased impact forces and loading rates in the maximal shoe, even after the transition.
"These shoes may work for certain people, but right now we just don't know who they are good for," said FORCE Lab director Christine Pollard, an associate professor of kinesiology at OSU-Cascades and a co-author of the study. "The findings suggest that people aren't really changing the way they run in the shoes, even after a six-week transition, potentially leaving them at increased risk of injury."
Pollard concluded: "If someone is going to try them out, I would suggest they try them out on a treadmill at a running store to see how they feel. How they feel then is how they'll feel in six weeks."