A fresh zombie's body if intact would be the exact same as a human body other than a bite mark so fresh zombies probably could run. Over time as the zombie begins its decomposing process the zombie would weaken and no longer be able to run and thats when it would begin to shamble. I dont really think that when a zombie eats human flesh it actually digests it, so if there ever was a zombie outbreak you would just have to wait it out until they all decomposed.
 "Warzone tower defense"){kind=icon}
 "Pandemic 2"){kind=icon}
 "Thing-Thing Arena 3"){kind=icon}
 "The Last Stand 2"){kind=icon}