As Seenie says this is us trying our best to collectively get an angle on things so don't take anything that I say as knowledge based. I think Jon_sparky and Jules have come up with some good explanations though.
I was thinking you might be able to try out some exercises on your feet because you can see them clearly and can stretch and flex and wriggle them. The muscles and tendons around the ribs seem more hidden, more difficult to experiment on.
I took what Jon said to mean that anything that tenses the muscle will tense up the attached tendons too. And also that anything that relaxes one will be likely to relax the other because they go together. (I think tendons are the things that anchor muscles onto bones).
I bet that muscle relaxers would work as a quick fix for those that stop me kneeling because I think that they probably have just shortened & stiffened due to not bending my legs that much for years.
However, there's enthesitis to consider and that is inflammation at the places where tendons attach to bones. I'd guess that muscle relaxers would not necessarily help in that case unless they tackle inflammation, it doesn't sound to me as if that's what they do. Perhaps they'd help to a certain extent though .... a lot of things help so far and no further.
As soon as you mentioned your ribs I thought that enthesitis might be involved because so many people say they get that in this area. Whereas something about the way you described your feet made me think that you've just got tenser feet these days ..... a bit like my thigh muscles or tendons that don't bother me unless I try to crouch or kneel.
I've kind of gone round in a circle really 'cos I suppose that what we need to know is exactly what is causing what so that we can act accordingly. I think Jules' suggestion about getting a physio's advice might fit the bill. I think I'd look for one that understands PsA though.
Rachael said:
Ok so of I understand it correctly there is nothing but stretching to relax tendons. Muscle spasms are a side effect of the tendons being tight and those are treatable. I have used fexeril in the past which really knocks me out and leaves me almost druelling on the couch, lol. I have used methocarbomal as well but it did not work as well and still left me unable to fully function as well. I am back to flexeril which I can now use a pill cutter to take smaller doses because biting in half leaves your tongue half numb (big muscle stupid on my part) which is only funny to my kids. So new challenge to the medical industry we want tendon relaxers! Thanks the info was really informative!