My father (60yo) has had dodgy shoulders (arthritis, apparently) for some 20 years, and it seems to be becoming progressively worse over time, to the point where now he cannot open many doors, lift a dinner plate, lift a large newspaper or indeed a full coffee mug due to the pain or potential to later cause pain. Nor will he shake hands or hug, for the same reason. In short, it's extremely debilitating and difficult for he and my mother, and he claims that there is nothing that can be done to prevent it's continued development.

Yet he swims 1 mile twice weekly (freestyle), so range of movement seems to be quite good.

Now I realise that my experience with injuries is restricted to sports injuries that I have worked to get over from time to time, and I am 'only' 37 years old, but I would have thought that he ought to be doing limited-range strengthening exercises etc (supervised) to build at least a little strength and protection around the shoulders.

So, my questions are;
Is this really arthritis, if he is able to swim regularly without pain?
Is it normal for shoulder arthrits to result in such severe disability?
Should he be more strongly encouraged to seek an excercise regime from a physical therapist?

PS. He is a little paranoid and something of a hypochondriac.