I'm going to focus this week on research involving running shoes. Exciting, right? Well, here it is:
Why aren't shoes preventing running injuries?
Good question, explored here.
A change in footwear can affect the amount of impact the body absorbs during running, but it doesn’t change the fundamental stress of the activity.
I would change that slightly. Based on what I've seen and some basic laws of physics, I believe it would be better stated that a change in footwear can affect how the body absorbs impact during running. The amount is at least very close to constant and the fundamental stresses are still very similar. You're just moving those stresses from one joint or muscle group to the other when you change shoes. If you know that, for you individually, you have strengths and weaknesses, you might be able to find a shoe that works with them and reduce your injury risk. As a whole, though, no one shoe is going to reduce our injury risk. Only move the injuries from one part of the body to the other.
Shoes and running economy
What kind of shoe is the most economical? Interesting question. Here's a meta-analysis (review of many studies) that looked at different kinds of shoes and running economy.
Certain models of footwear and footwear characteristics can improve running economy. Future research in footwear performance should include measures of running performance.
I agree with that second sentence. As for the results of this meta-analysis, it's basically the following:
Cushioned shoes appear to improve running economy more than stiff-soled shoes.
Weight matters a lot. Minimal shoes and light shoes are more economical than more standard or heavy shoes.
No surprises here, based on what I've seen in the past. Is anyone surprised that having a heavier weight on the end of the pendulum that is your leg will require more energy to move it? This is why racing shoes are light and the lightest racing shoes heavily advertise their featherweight features. We all know lighter is more economical. Also, past studies have shown that cushioned shoes allow us to relieve our muscles from some of the demands of cushioning our step. Less hard working muscles means less energy expended means more economical.
I've said this before and I'll say it again, though. It's good to see the science confirming what we've already known.