What do you know about myopathy?

Do you know anyone who has it, or do you have it yourself? Have any treatments worked for you, and or anyone you know? Just curious: I’d never heard of it, but apparently a dear friend of mine’s father just got diagnosed a couple of weeks ago, after falling down a lot. This man went from completely active (well, as active as a 69 year-old can get, which is about triple where I’m at.. lol) to needing a cane and not being able to walk up steps without a bannister. So, any feedback would be greatly appreciated…