A neutral foot strike would match with the ideal model of footstep. Statistically, only between 15 and 20% of runners have this kind of footstep.
You have a neutral footstep if the wearing out of the trainer sole makes an S shape, that is to say, an initial wearing out in the external side of the heel, making an S shape until the big toe. When you have a neutral footstep you can use a wide range of running shoes. In this case, you should choose the most suitable ones according to your weight, required pressure absorption, running pattern, training surface and usual running distance.