Polio is known to affect the legs and cripple a person. could having polio twice cripple both legs and make them equal?

Unlikely ever: This is more a theoretical question. The basic response is the first infection would provide an immunity that would stop the second infection from happening. There is more than one strain, and the majority who had it did not develop paralysis,so chance infection by another strain, in an era of vaccine use (3 strains ), it is unlikely.