In heel strike running (shown above), there is significantly more impact pressure that travels in a straight line starting at the heel, traveling up the 2nd metatarsal head which ends up bearing much of the center of mass during stance. In this case, the 2nd metatarsal head takes most of the body weight thereby increasing bone load magnitudes as compared with forefoot running, which is associated with safer, more even impact load distribution over the foot. Read more here about why heel strike running is the most injurious way to run!