Hello @dallas, Welcome to Connect. I've had two occurrences of PMR but have not noticed weakened tendons in my knees. My PMR is currently in remission but when it was active I did have trouble with stability and walking due to the pain which went away while on prednisone.

You will notice that we moved your post into the following existing discussion on the same topic so that you can meet other members like @mary4, @raven1955, @tillysam, @naezzo, @kmeikle1, @tsc and others. If you click the link it will take you to the first post in the discussion where you can read through the experiences of other members.

-- PMR Dosages and Managing Symptoms:
https://connect.mayoclinic.org/discussion/pmr-dosages/
How long ago were you diagnosed with PMR and started on 40mg of prednisone?