What Kind Of Virus Causes Severe Muscle Pain And Weakness

What kind of virus causes severe muscle pain and weakness with no other symptoms? My son had this afflict him a week ago and hurt so bad he couldn't get out of bed for a couple of days. He had no other symptoms except for a mild fever one of the days. The severe muscle pain and weakness gradually subsided after about four days. Now I am feeling that muscle pain in my outer extremities, from elbow to wrist and a little in my lower back. My son said this is how it started with him and got worse. I suspect virus because he had the same thing first.