Muscular dystrophies are a group of hereditary degenerative diseases that affect skeletal muscles. They are characterized by progressive muscle weakness and atrophy without involvement of sensory or reflex functions. The document discusses several types of muscular dystrophies including Duchenne muscular dystrophy, Becker muscular dystrophy, facioscapulohumeral muscular dystrophy, scapuloperoneal muscular dystrophy, limb-girdle muscular dystrophy, Emery-Dreifuss muscular dystrophy, and oculopharyngeal muscular dystrophy. Each type has distinct genetic causes, patterns of inheritance, muscle groups affected, age of onset, progression, and other clinical features.