I 2nd the yellow mustard ( as crazy & economical as it sounds)
After sudden OA onset and resulting left hip replacement, trauma accelerated spinal stenosis followed by a ladder -involved spine fracture- nothing else helped my nightly and sometimes daily leg cramps-hamstring, calf, & foot. And my MD recommended it- although he didn't know why it works. (acetic acid possibly) I also tried dijon & another brown mustard first and they did nothing. Yellow mustard worked the 1st and every night I've taken about a teaspoon of it. I still get 'tremors' or spasms in the morning but nothing painful. Best nights sleep in years for 2 bucks a month.