The Nike Free is not a barefoot shoe because the heel is too thickly cushioned and stiff which was found to impair forefoot strike adaption as compared with barefoot running.
Minimalist running shoes prevent injury by encouraging mechanical engagements, such as increased arch mobility and compression, which makes the foot better at holding your stride mechanics more stable and prevents increases in impacts from spreading out onto the rest of the leg!
One of the many functional assets of minimalist running shoes is a wide toe-box because it enables the toes to spread, flex, bend, extend and relax which is incredibly effective in improving both static and dynamic balance, but also helps disperse the little shock that’s produced in forefoot running as compared with narrow running shoes.
Minimalist running shoes and running barefoot delivers a natural stimulus for enhanced neuromuscular and reflexive responses in the knee-joint that result in a faster acquisition of more functional mechanics that are not only safer on the knees, but reduces energy costs!
Barefoot running switches on a range of nerve, reflexive and mechanical responses that prevent underfoot pressure from rising to damaging levels which reduces the risk of severe foot injuries vs thickly cushioned running shoes.