I am not a doctor, not an expert in anatomy, nor in biophysics. So take what I am about to say as my anecdotal opinion and not much more, unless of course you decide to try it and it works for you. I know, it works for me and it seems my son independently has discovered it works for him too.
Two evenings ago, my son stopped down in the man cave for a rare after work visit with me; a rare visit in that after he gets home from work he usually does not want to talk to his annoying old man. Well, as it turned out, he picks up the Marlin 25MN that I have leaning up against some molding around one of the doors, makes sure it is empty, brings it to his shoulder pointing it in a safe direction and says: "This is my new favorite gun". Now one has to wonder, why would a soon to be 21 year old young man, in good shape and health, say that. I mean, he owns his own AK47 and his own AR15, he enjoys shooting my SKS, my 91/30 Mosin Nagant and M44 Mosin Nagant and sometimes has fun shooting the Remington 870 12 gauge shotgun - so I really had to ask myself why he said that. He blurted it out before I could ask him and the riddle was solved as to why this young man liked what he had probably thought was a pansy's gun just a week before. He said something to the effect: 'You can shoot this all day long with no recoil and no pain, its good to shoot it to take a break from larger calibers with lots more kick'.
Hmm, he does learn somethings without having to hear them from me. No let me correct that because he has heard that from me numerous times but never paid it much mind. Well, the last time we went shooting he picked it up and started to fire shot after shot and went through about 150 rounds or so, and 100 of them pretty darned fast with a pretty decent group at that. I think he was really impressed at how little recoil there was and at how much fun it was to shoot it after first having pounded his right shoulder with some 12 gauge slugs, some 7.62x54R, lots of .35 Remington and lots of .223 rounds. I had shot them all too, plus some 8mm Mauser out of my Yugo 24/47. I can tell you without a doubt in my mind, taking some time out between the bigger bore rifles to shoot something in .22 caliber is really a smart thing to do if you like your joints. That is why I almost always bring along a .22 caliber rifle to the range when I bring the bigger ones with me.
With me, I do it because I have had joint problems for years due to old injuries and due to Lyme disease. I have arthritis in my neck and shoulders and probably have a burr in each shoulder. I also had a cyst in my neck that probably caused a lot of the neck, upper back and right shoulder and arm pain I used to experience. I had it removed, found out it had been sitting on a nerve that runs down the neck into the shoulder and onto the arm. Since the surgery the arm is feeling better, not without pain but simply much less painful. With all these aches, pains, crackles and crunches in those areas, I decided a couple of years or more back to tone it down on the larger bore guns at the range. I started making it my routine to bring the 22s. I have a bunch of them - so why not enjoy them. I saw a lessening in pain after range days almost immediately.
Now, as I said above, I am not a doctor but I am willing to bet that some of the pain I have in my neck and right shoulder is due to the fact that I have been shooting a 12 gauge shotgun regularly ever since I started my career over 31 years ago. I have also been shooting medium bore rifles since then (some for my job others for pleasure). All that pounding as evidenced by all the bruises (from the 12 gauge) have had to have taken their toll. I am also willing to bet that had I taken it a bit easier and shot some 22 in there along the way I would have wound up with joints in better shape than they are now.
My son seems to have grasped this already, hopefully long before having developed any sort of muscular or skeletal problems like arthritis or town rotator cuffs or bursitis or whatever. What was it the weight lifters used to say: "No pain, no gain". Not for me anymore! I think Steve Reeves (former competitive weight lifter and I think Mr. Universe, and actor who played Hercules way back when) had it right when he said something to the effect of 'if your in pain, you have no brain' in relation to weight lifting. Same goes for shooting as far as I can tell - more or less. Sure, if you shoot a 12 gauge slug gun tactically in a timed event, chances are you will wind up in some pain. If you shoot a fairly large bore rifle to sight it in for hunting season, the same could be true. Same thing for any fairly large bore rifle or shotgun you shoot. The thing is though, you do not need to torture yourself to have fun while shooting, at least not if you have a brain. If you start to ache, if you hear the joints cracking, if you begin to stiffen up, anything like that, then put down the rifles and shotguns, loosen up a bit and if you really want to or need to continue shooting - then maybe you would be better off shooting something in 22 rimfire. Not only is it just as much fun as shooting the larger calibers and less painful at that, it is less expensive too. Yeah, shooting something like our Marlin 25MN in .22WMR (22 magnum) is fairly expensive with a box of 50 rounds going for around $12 to $14 but not as expensive as shooting any of the other calibers I mentioned above if shooting quality ammo. If that is still too expensive for you as an alternate to the shoulder crunching calibers, then go to a rifle in .22LR. It has even less recoil than .22WMR.
Of course, if you suffer from arthritis or other ailments that make it virtually impossible for you to shoot larger bore firearms, you may want to try to see if you can still shoot something in 22 rimfire caliber. It may be a way to still enjoy a pastime that you thought you had been forced to give up - but if you are that bad it may be a good idea to check with your doctor first. It may also be a good idea to hold off on any additional shooting, until you see a doctor, if you get any really serious acute pain while shooting.
If you treat yourself right, and don't inadvertently punish yourself and your joints, you will probably find shooting to be a much nicer experience and may find that your joints wind up staying in good shape a whole lot longer than did mine. Sure, I pointed out above, I have had past joint injuries and Lyme Disease (twice at that) and those things probably took their toll but there is no reason for me to make it worse. So, I bring along a 22 when I also have the larger rifles, heck sometimes they 22s are all I bring along. That way I can keep shooting on those days when the aches and pains start to bother me or already have been bothering me. I can also shoot the 22s on days when the pain is not there, thus probably helping to assure it will not bother me the following days. As I said, I am no doctor but it makes sense to me.
I think my son has hit on something all on his own regardless of me having told him about it countless times and him apparently not listening. Amazing how that happened - how it became his own independent observation that did not cross pollinate with my advice - but I listened to him, even if in amazement when he told me about why the Marlin 25MN has become his favorite gun. I am happy for him if it spares him some of what I have gone through. I only wish I had learned it earlier myself but then I did not have anyone around, as smart as my son, repeatedly telling me about it until I figured it out myself.
All the best,