Try running barefoot heel to toe and it won’t take you long to notice how much it hurts, and change your ways. Running with a forefoot strike cuts out that huge, instantaneous “impact transient” force. Essentially, running this way means a nice, gradual increase in force with no hammer slamming through your bones. It seems likely, although it has not yet been proven by definitive research, that running with a "forefoot strike" will decrease chance of injury.