Crystal - There was Nonparalytic Polio - that kids had where they ran a fever and were very sick- alot of them ended up in hospital back in the 40's & 50's.
They have proven that non-paralytic Polio Survivors also can get PPS- so I am no doctor but I bet alot of the symptoms your dad has, stems from the Polio when he was a kid... We all just pushed our bodies to the limit, not knowing the damage Polio already had done.. It is a shame but that is what makes us Polio Survivors- and now with alot of us that have PPS we can still keep going- just have to listen to what our body is telling us and rest more and pace.
If it causes pain, weakness or fatique "Don't do it or do much less" - Our bodies have aged faster than the normal persons... So hopefully this will help your dad... My advice is read all you can on Polio and the after affects- Knowledge is Golden and it could help the progression of PPS.
Hugs to you Janet