In another thread Brad asked...
Originally Posted by BradD
What's your take on modern padded running shoes vs barefoot shoes such as vibrams? I've been thinking of buying some vibrams and giving barefoot running a shot.
I switched to barefoot/minimalist running 2 years ago, and I'm a big proponent. I was over 220 pounds when I began, and when I had previously run at a similar size it bothered my knees. I had no knee pain while running at over 200 pounds.
Since I normally always wore cushioned shoes, even around the house, I started very slowly following the recommendations of multiple sites, and I started walking around the block truly barefoot (S2G; skin-to-ground). I worked up to laps around the block -- this kept me on gentler sidewalks rather than crossing coarse asphalt, and eventually I was up to 3-4 miles running S2G, and I was including some asphalt as well.
Then came winter weather; snow storms, and salt and gravel all over roads, thrown onto sidewalks, and very coarse frozen slush that seems to stick around forever in shaded areas. I went from barefoot to running in the Merrell Trail Glove, then the Vibram SeeYa and the Merrell Road Glove. I have run almost all of this year in the SeeYa, and I probably have close to 1500 miles on them in the past 15 months. The are very thin, no elevated heel (zero drop), but provide abrasion resistance and a little insulation from cold/hot pavement. When spring came, I never went back to truly barefoot.
Most recommendations are to start truly barefoot and then work into Vibrams if that's your goal. You will learn the proper form faster if you are actually barefoot, because poor form hurts. You can run longer than you should in Vibrams without realizing that your form still needs work. That's not to say that you can't start with them, but you need to follow the advice of starting very gradually, and being particularly mindful of any top of foot pain (TOFP) which generally indicates too much too soon.
Below is a summary from the Skeletal Biology Lab at Harvard's running biomechanics page
Our research asked how and why humans can and did run comfortably without modern running shoes. We tested and confirmed what many people knew already: that most experienced, habitually barefoot runners tend to avoid landing on the heel and instead land with a forefoot or midfoot strike. The bulk of our published research explores the collisional mechanics of different kinds of foot strikes. We show that most forefoot and some midfoot strikes (shod or barefoot) do not generate the sudden, large impact transients that occur when you heel strike (shod or barefoot). Consequently, runners who forefoot or midfoot strike do not need shoes with elevated cushioned heels to cope with these sudden, high transient forces that occur when you land on the ground. Therefore, barefoot and minimally shod people can run easily on the hardest surfaces in the world without discomfort from landing. If impact transient forces contribute to some forms of injury, then this style of running (shod or barefoot) might have some benefits, but that hypothesis remains to be tested.
Here are a few resources in addition to the Harvard page above that has lots of information:
Barefoot Running University's How to Barefoot
Runner's World Barefoot Running forum