I am not diagnosed with MG..but do have some myasthenic symptoms- however i do have muscle tenderness - when my kids climb on me my muscles are sore and if i over exert myself I am VERY sore the next day (lactic acid build up - like I worked out quite a bit the day before). even my eye muscles are sore and tired by the end of the day- if i move my eyes in any direction at night they hurt!