I had fairly severe myotonia through much of my teenage years, though I could stand without falling. My low center of mass gives me a little more stability than most I think, and I've always been cautious with my movements.

As Jan said, it's probably hormones. Gaining weight might also make the myotonia worse. I would try walking regularly but be prepared for the myotonia to get worse before it gets better.

Type of Myotonia: Becker

Country: USA