== History == 

 "The effects of polio have been known since prehistory; Egyptian paintings and carvings depict otherwise healthy people with withered limbs, and children walking with canes at a young age." 
 Please separate these sentences. To put the first part with the second part gives the impression that Egyptian paintings and carvings aren't a historical record of any sort. Please understand the word prehistory means "before written records". Egyptian paintings and carvings need to be older than the first pictographs to necessitate association with "prehistory". Additionally, this whole sentence is conjecture at best. Also, I can't seem to find a readily viewable source for this information. I have found this same sentence in other works as well. http://www.billdoll.com/ref/ideas/health/dis/az/p/pol/pol.html 
    Nikomaru 11:03 EST 01DEC2011 (-5 GMT)