Essentially one can label shoes as minimalist/"barefoot" or "traditional", by the type of injuries runners tend to incure while running in them.
"Traditional" running shoes comfortably allow runners to land with excess impact, especially heel-striking (as well as other forces, including skidding, scuffing, etc.). Therefore, we tend to see more chronic knee and back pain caused by repeated excess impact over many miles.
Minimalist (or "Barefoot") shoes make heel-striking less comfortable, and if anyone has read Dr. Lieberman's website, or McDougall's book "Born to Run" people running in these "shoes" tend to use more of a fore-foot landing/strike.
The problem is they often adapt only a fore-foot landing, and change little else (relaxing, bending the knees, letting the heels touch down), then they put excess stress on the calves, achilles, and the foot itself (which now has none of the support it may have become used to - lazy - over the past years/decades of running in highly supportive shoes), leading to stress fractures in the feet (usually proceeded by sore calves and Achilles).