Becker muscular dystrophy has 2 different meanings across 1 category:
a form of muscular dystrophy that sets in in adolescence or adulthood and progresses slowly but will affect all voluntary muscles; characterized by generalized weakness and muscle wasting that affects limb and trunk muscles first; similar to Duchenne's muscular dystrophy but less severe; inheritance is X-linked recessive (carried by females but affecting only males)
benign pseudohypertrophic muscular dystrophy: an X-linked recessive inherited dystrophinopathy characterized by slowly progressive muscle weakness of the legs and pelvis