Here is an extract from a study published on the web site sportscience regarding barefoot running.
Running barefoot is associated with a substantially lower prevalence of acute injuries of the ankle and chronic injuries of the lower leg in developing countries, but well-designed studies of the effects of barefoot and shod running on injury are lacking. Laboratory studies show that the energy cost of running is reduced by about 4% when the feet are not shod. In spite of these apparent benefits, barefoot running is rare in competition, and there are no published controlled trials of the effects of running barefoot on simulated or real competitive performance.
The full article can be read here
Interesting article! Seems barefoot running has many benefits. I may have to try out the Vibram 5 Fingers. However, while I do not think the following points sway the argument decisively one way or another, these two parts of the full article seem relevant for trail runners who run on technical or rocky trails, and they suggest that truly ‘bare-foot’ running has its limits, even after the skin on the foot is fully adapted/thickened. …And perhaps this is where Vibram 5 fingers comes in… Thoughts?
Second paragraph under ‘Acute Injuries’:
“The skin on the plantar surface (sole) of the foot is more resistant to the inflammatory effects of abrasion than skin on other parts of the body (Robbins et al., 1993), but stones, glass, nails or needles can still cause bruising or puncture wounds even when the plantar skin is thickened by adaptation to barefoot running. Extremes in temperature can also cause discomfort, blistering or chill blains. Running shoes therefore will play an important role in protection on some courses and in some weather conditions.”
Conclusions (note the last two)
• Running in shoes appears to increase the risk of ankle sprains, either by decreasing awareness of foot position or by increasing the twisting torque on the ankle during a stumble.
• Running in shoes appears to increase the risk of plantar fasciitis and other chronic injuries of the lower limb by modifying the transfer of shock to muscles and supporting structures.
• Running in bare feet reduces oxygen consumption by a few percent. Competitive running performance should therefore improve by a similar amount, but there has been no published research comparing the effect of barefoot and shod running on simulated or real competitive running performance.
• Research is needed to establish why runners choose not to run barefoot. Concern about puncture wounds, bruising, thermal injury, and overuse injury during the adaptation period are possibilities.
• Running shoes play an important protective role on some courses, in extreme weather conditions, and with certain pathologies of the lower limb.