I HAVE BEEN EXPERIENCING MUSCLE SPASMS IN MY RIGHT BUTTOCK

I HAVE BEEN EXPERIENCING MUSCLE SPASMS IN MY RIGHT BUTTOCK AREA, THERE IS NO PAIN WHEN I AM SITTING OR LYING IN BED,ITS JUST WHEN I GET UP AND START MOVING AROUND, I CAN BE STANDING AT MY KITCHEN CABINET AND I WILL JUST HAVE A MUSCLE SPASM OUT OF NO WHERE...THERE IS NO RHYME OR REASON TO WHEN THESE SPASMS HIT, IT IS NOT IN MY BACK OR AROUND MY SPINE, IF YOU COULD LIFT MY RIGHT BUTT CHEEK UP, THATS WHERE YOU WOULD FIND IT...DURING THE SPASM IT FEELS LIKE A BASEBALL UNDER MY BUTT CHEEK. I CAN PALPATE IT DURING THE SPASM.