Repetitive Movements Are Not Seen Only in Children with Autism

Repetitive movements of arms, hands, and other parts of the body (complex motor stereotypies) are often seen in children with autism spectrum disorders, mental retardation, or sensory deprivation. These movements can take the form of hand flapping, arm or body shaking, hand clenching, and body stiffening. When found in healthy infants and children, they may cause concern. To describe the clinical course of this condition, researchers analyzed data on 40 typically developing children (age range, 9 months to 17 years; 63% male) with persistent repetitive movements -- defined as involuntary, patterned, coordinated, and repetitive rhythmic movements associated with a trigger and usually performed for a few seconds to minutes many times each day…