Actually there are. I too suffer the pains of aging bones, shoulders in my case. Initially I bought the Spector Spectorcore 5 which is partly hollow and about 8lb then I got the Gibson EB5 (2013j which is a remarkably light 7.7lb. I gather the 2017/18 version is also similarly lightweight. Of course in a bit more expensive category Maruszczyk does a light version with internal chambers which would also fil the bill, Elwood L.
In the end health and welfare is paramount if we are to continue to play and not too would be the end of life as we know it!