There is currently a lot of debate in the running and fitness world about the minimal, or “barefoot” running shoes. The Vibram FiveFingers model is probably the best known, with its’ signature individual compartments for each toe, but other respected manufacturers such as Merrell have jumped on board, marketing their Barefoot shoes as a way to “strengthen, stimulate, and realign your body, naturally” (direct quote from Merrell website). These have had a surge in popularity recently due to their lightweight design and promise of returning the wearer to a more natural running stride. The questions that I hear from my patients are usually, “Should I be wearing barefoot shoes?”, “Will I hurt my feet if I wear these shoes?” and, “Can you put an orthotic in them?”
My personal opinion is that if you have a pretty average arch and foot type, and do not have a history of injuries or other overuse problems, go ahead and try them. However, I caution even the biomechanically-gifted to do so gradually, perhaps wearing them around the home for the first couple of weeks, then for regular daily walking activities, and then, finally- go for a short run. The reason is that your feet, like most of your body parts, need time to adjust to the change.
Most of the traditional running shoes have a multi-layer, multi-density midsole portion, with many options available to support even the flattest of flat feet. If you have been wearing this standard shoe for years (or decades), running on concrete or pavement, it will be quite a shock to your body to convert to minimalist shoes quickly. The injury mantra of “too fast, too far, too soon” will echo through your head as you limp home in your new barefoot-style shoes, hoping to find an ice pack in your freezer.
You may hear friends mention some of the great barefoot East-African marathon runners who never seem to get injured running miles in nothing but skin, and think, “I can do that too!” Well, maybe, but most of these great ones have been barefoot runners since childhood, and are extremely fit and slim, and have taken years to get to their current level (NOT too far, too fast, too soon).
The other concern is that walkers and runners in modern society spend a lot of time on concrete and asphalt, not exactly the back-to-nature experience that you envision when trying on your slipper-like new shoes. Consider venturing to a nearby park or trails for a softer surface which will may help to ease the transition.
As for the final question about whether to put an orthotic into one, I suppose you could, but to me it seems counter to the whole point of wearing a barefoot shoe. If your foot needs that additional support, it would be better to stick to the traditional running shoe design.