Board Thread:Theories and Speculation/@comment-43776375-20190921063938/@comment-32685487-20191017195350

You're not getting it. His nerves and muscles in his legs have not been stimulated nor used in so long they have atrophied and even though he gained his health back his legs were still super weak, yes if he had time he could easily rehabilitate them by walking, then jogging, and then eventually running. In the 4th War when his body was restored his legs were still not rehabilitated and thats because he did not have the time to rehabilitate them. If he had been restored when he was first Edo Summoned, given that Naruto is a manga so real world stuff can either be ignored or skewed I would say by the time Nagato fought B and Itachi he would have been rehabilitated good enough that he wouldn't need any help moving at all and his legs would not have costed him when he got controlled by Kabuto fully.