Did they correct for actual activity?
I can't recall details, but of course the study design is important in interpreting results. My recollection is that they did, and the principal investigator on the study said they were theorizing that a lot of high-end running shoes have so much cushioning that they boost the runner or walker 2-3 inches off the ground, which creates a platform you can fall off of if you place your foot a bit wrong or hit an uneven patch on the ground. This is what kept happening to me, and I had some severely strained ankle ligaments.
I read also that there was a move to return to the light slippers Roger Bannister had used, and some companies were making little soft running shoes with very little padding. They seemed like a costly gamble, so I spent $14 on a pair of pool shoes at Costco and have been running happily injury-free for the past several months.