abnormal movement is known as
Dystonia is a movement disorder characterized by involuntary muscle contraction leading to abnormal postures and twisting movements. The frequency of this disorder is similar to multiple sclerosis. Several types are known and they are classified according to age of onset, distribution of dystonia, and cause.ovement Disorders Program-Introduction. Movement disorders are neurological diseases characterized by an abnormality of motor control because of diminished voluntary movements or increased involuntary movements.