6.6.2 Nike Free Concept The Nike Free shoes were developed with the goal of mimicking the kinematics of barefoot running. The Nike Free shoes have a wide, relatively soft heel and a flexible forefoot sole construction. Running in Nike Free shoes results in a flat-foot landing that is typical of barefoot running. It seems that this result is influenced by the wide heel and that the flat-foot landing could not be achieved using a heel shape similar to the human heel. The flexible forefoot construction increases the contact area of the foot, distributing the pressure over a larger area. Furthermore, it forces the foot to be more active than in a conventional shoe. The result of this increased foot activity with the Nike Free shoe on a sample of 100 test subjects was a significant decrease (7%) in the actual path of motion of the metatarsophalangeal (MTP) joint