Welcome @melissa24, I never experienced leg cramps with my PMR when I was on prednisone but @terryartist, @lsjaustin, @dadcue, @hopeinal and others have mentioned having leg cramps while on prednisone and may have some suggestions to share with you.

My wife gets leg cramps frequently when she doesn't drink enough water during the day in case you haven't already tried that. Have you discussed the cramps with your doctor or rheumatologist?