The co-incidence of instrument playing and related injuries is something that is well documented and definately affects my choice of instruments in my advancing years. The effects of bad habits, e.g. technique, poor posture, heavy instruments etc are probably cumulative and therefore become more noticeable to older players, but having said that my son did cause damage, fortunately temporary, to his wrist/forearm by playing a guitar with an absurdly slender neck. Solution - rest (very frustrating) and got rid of the guitar and now plays very happily on one with a more substantial neck. But I digress..........
I used to play a large body acoustic bass in pub sessions with my fingers, and sitting down. Got a lot of volume from it but with considerable physical effort and ultimately considerable pain. I'm not tall and the effects of reaching over the body and the finger movements lead to a chronic case of tennis elbow, which is the inflamation of tendons at the the elbow joint. I ignored the telltale signs and suffered with it for a couple of years, during which time I improved my mandolin playing considerably (smaller body, different moves) and found that a relatively slim acoustic guitar which I had bought shortly before suited me (and still does) far better than my Yamaha dreadnought. Bass playing was on hold but as I recall the problem more or less coincided with my acquisition of the Ashbory. A godsend!! I can honestly say that playing it has not caused any relapse - I still play with my fingers (thumb resting on the edge of the fret board) but the main difference to me is not reaching over a big acoustic body. Obviously being an amplified instrument means I don't have to work so hard and it is physically easy to play.
One thing I would say from painful experience - if you do suffer pain as a result of playing don't ignore it. It's your body telling you something isn't right and it's very possible that it will get worse if you don't investigate it and find the cause. I did, so did my son, and we both found solutions.
Long live the Ashbory, thick necks and slim guitars!! :-D
Mike