When I was running a railway station I met a lady who could give you some hints about handling heavy suitcases, KJN.
She was an African lady, dressed in a traditional African (beautiful, multi-coloured) dress. She had a trolley-load of luggage and (as it was before the station had lifts installed) I was escorting her as she pushed the trolley across the tracks.
The reason that I wasn't pushing the trolley myself was because I was struggling with an additional (massive) suitcase, which there was no room for on the trolley. (The only time I'd had to handle a suitcase as heavy as that one was when I'd assisted a weightlifter, who had all his weights in his suitcase).
Seeing that I was struggling though, the lady simply said "Oh, don't worry about that". So saying, she grabbed hold of it herself and, with just a flick of her wrist, plonked it on top of her head. She then strode across the tracks, pushing the trolley with one hand and steadying the suitcase on her head with the other, with no apparent effort whatsover.
So the trick to handling heavy suitcases, KJN, is to USE YOUR HEAD ;-)