I reckon åkerfelt is rather skinny if you compare to earlier mikael åkerfelt(sorry boss)
Also now that I think about it, all my favorite musicians are SKINNY, at least not muscular at all, I mean, I had broader arms than mikael since I was 17 (I'm 18 now). The only "muscular" artists I can think about are Jon Nödveidt from Dissection and Trent Reznor from Nine inch nails (contemporary reznor, that is).
EDIT: I realize skinny isnt all about the arms but hell...!
I reckon åkerfelt is rather skinny if you compare to earlier mikael åkerfelt(sorry boss)