ain ▁control ▁of ▁parts ▁of ▁his ▁body ▁to ▁the ▁point ▁where ▁he ▁was ▁eventually ▁able ▁to ▁talk ▁and ▁use ▁his ▁arms . ▁Still ▁unable ▁to ▁walk , ▁he ▁decided ▁to ▁train ▁his ▁body ▁further ▁by ▁emb ark ing ▁- ▁alone ▁- ▁on ▁a ▁thousand - mile ▁can oe ▁trip ▁with ▁only ▁a ▁few ▁dollars . ▁After ▁this ▁gru eling ▁trip , ▁he ▁was ▁able ▁to ▁walk ▁with ▁a ▁can e . ▁This ▁experience ▁may ▁have ▁contributed ▁to ▁Er ick son ' s ▁technique ▁of ▁using ▁" orde als " ▁in ▁a ▁th era pe ut ic ▁context ▁( see ▁below ). ▁ ▁Er ick son ▁was ▁an ▁av id ▁medical ▁student , ▁and ▁he ▁was ▁so ▁curious ▁about , ▁and ▁engaged ▁with , ▁psych iat ry ▁that ▁he ▁obtained ▁a ▁psych ology ▁degree ▁while ▁he ▁was ▁still ▁studying ▁medicine . ▁ ▁Much ▁later , ▁in ▁his ▁f ift ies , ▁he ▁developed ▁post - pol io ▁synd rome , ▁character ized ▁by ▁pain ▁and ▁mus cle ▁weak ness ▁caused ▁by ▁the ▁chron ic ▁over - use ▁of ▁partially ▁par al yz ed ▁mus cles . ▁The ▁condition ▁left ▁him ▁even ▁more ▁sever ely ▁par al yz ed , ▁but , ▁having ▁been ▁through ▁the ▁experience ▁once ▁before , ▁he ▁now ▁had ▁a ▁strategy ▁for ▁recover ing ▁some ▁use ▁of ▁his ▁mus cles ▁which ▁he ▁employed ▁again . ▁After ▁this ▁second ▁recovery , ▁he ▁was ▁obliged ▁to ▁use ▁a ▁wheel ch air ▁and ▁suffered ▁chron ic ▁pain . ▁ ▁In ▁the ▁early ▁ 1