Whats the easiest way to carry my disabled dad around?

Hi, my father is totally dependent on me. He can't walk anymore on his own. I live far out in the country and don't have anyone nearby to help. I usually can stand him up with my help and hoist him up either onto my back and carry him piggyback style witch is real easy. I tried to cradle carry him around but it can get rather difficult after a while. I can also carry him in a frontal piggyback carry for a good while while transporting him out of bed and around the house. He only weighs 142 lbs and is rather light. Is their any easier way.? I am a pretty strong girl for my age and this is getting my legs stronger.