Which frequency range characterizes normal rhythmic movement disorder?

Normal rhythmic movement disorder (NRMD) is characterized by involuntary movements typically occurring during sleep, particularly in infants and young children. The frequency range that accurately defines NRMD lies between 0.3 Hz to 2.0 Hz. This frequency range aligns with the type of rhythmic movements commonly observed, such as rocking or head rolling, which can be rhythmic and repetitive but are not indicative of any disorder.

Understanding the context of these frequencies is crucial; they help distinguish between NRMD and other movement disorders characterized by different frequency ranges or patterns. Frequencies lower than 0.3 Hz generally do not manifest in typical rhythmic movements associated with this disorder, while frequencies above 2.0 Hz may suggest other types of movements or disorders that do not fit the criteria for NRMD. Thus, the correct choice reflects the specific and recognized frequency range for this condition.