Although much has been learned regarding the pathophysiology and imaging characteristics of orthopaedic muscle injuries, more is unknown and areas of controversy still exist. Consequently, there are two main goals of this article. The first is to address what is known regarding magnetic resonance imaging (MRI) of orthopedic muscle disorders, focusing on selected entities rather than an exhaustive review of the subject. The second is to address areas of current controversy. Our hope is that the discussion that follows will stimulate further interest and investigation.