One of several rare forms of muscular dystrophy in which the forearm, hand, calf, and foot muscles are primarily affected as opposed to the muscles of the shoulders or pelvic girdle. Its onset usually occurs between the ages of 40 and 60. DD is also known as distal myopathy.
A variant of muscular dystrophy, which typically manifests during middle age or later, is characterized by muscular weakness primarily affecting the muscles in the feet and hands.