I too have a bad back. That gas guzzling ride on
lawn mower is hell on my back. The scything motion looks very relaxing and I
think if done gently, it could actually benefit my back problems as it's very close to the motions the doctors recommend.
Ian's book has a whole chapter on how to care for our body while scything. He describes scything as a dance that can be gentle and joyful for the body.
One of the tools for keeping our backs healthy, Ian talks about in his book is the Alexander Technique as a way of retraining our body.
I really like the idea that scything is an opportunity to teach our bodies how to move in a gentle way.