_:vb50940194 . _:vb50940194 . _:vb50940194 . _:vb50940194 "A musculoskeletal system disease that affects the muscles."^^ . _:vb50940194 . _:vb50940194 "url:http://www.nlm.nih.gov/medlineplus/muscledisorders.html"^^ . _:vb50940194 .