The Asics website describes the IGS as "Linked componentry that enhances the foot’s natural gait from heel strike to toe-off." I understand the concept, but does anyone know which parts of the shoe comprise the IGS? What is its effect on running, if any? I like the 1130 much more than the 2130, and I think that might be partially because I'm a mid/forefoot striker and the IGS might push my foot more towards heel impact. Any thoughts?
It's a little piece of plastic they sometimes put on the back or side of the shoe with the letters "IGS" on it.
But seriously, it's just the combination of all of their technologies working together to guide your foot how they see fit. That's why it's a "system". Mainly it would include the medial post, chopped up heel (kinda like Brooks' podular technology so it's not one big stiff piece of rubber), gel, and arch piece(trussic system).