Obviously you do need to look after your hands and arms too
circular needles allow a heavy weight, as is my gansey jumper, to lie in my lap with no weight on hands or arms
I find steel needles, although chiagoo are excellent, do put strain on my fingers. Silky bamboo are gentle and surprisingly I have not had any finger-joint pains using those by seeknit
I do sit comfortably and have a swivel, serious -readers lamp by me. Dark yarns are difficult when patterning
I do get up every so often and walk about the house doing things or I will go on a hilly town walk for 30 minutes. Blood needs to keep circulating
If I am making something small and simple then I will go upstairs and knit while sitting in my bed before sleep, that rhythm sends me to sleep quicker than anything
At one time I had 4 UFOs ( unfinished objects) on the go, it took a lot of mental effort to finish the Mouche animals, I did it and now have two bears and a pig for the AC. They used very small needles and a tight tension. All the implements are in a craft bag, just in case I might want to make another Mouche animal in the future
I like nice things for my knitting craft, last thing I bought was a project 39 leather bag by redesigned, expensive yes but so what, a fraction of the price of a bought hand made gansey