For the most part do you have pain when you have muscle weakness or just weak muscles. I have weak muscles without any pain and sometimes I do have pain and I do have muscles spasms. I am just trying to see how mg works. A week ago I had a lot of pain and weak muscles for three days. Most everyday I have weak jaw or tongue. Yesterday I was fine just a little tired but nothing major. Today my legs are extremely weak, I can barley pick them up. when I sat down it is hard because my leg muscles are not wanting to holding me up. They just starting hurt a little but I feel like it because I keep trying to walk but the pain is not like I had a week ago.