Fine Motor Deficits. Movement skills are typically divided into two categories: gross motor skills and fine motor skills. Gross motor skills involve large-scale coordinated activities such as walking, while fine motor skills involve detail-oriented activities such as drawing, sewing or playing a musical instrument.
Children with autism frequently show developmental delays in developing fine motor skills. While some children enjoy fine motor activities like lacing their shoes or coloring, others become very agitated when directed to complete fine motor activities. Writing is especially troublesome for some children. Many choose to use a keyboard rather than writing things out by hand.
Part of the issue children with autism have with fine motor activities is that they tend to interfere with their need to engage in stereotyped repetitive movements and self-stimulatory behaviors. Children with autism with hyposensitivities to sensory stimulation constantly feel under-stimulated, and engage in a variety of self-stimulation behaviors such as hand flapping or rocking just to help themselves feel more 'normal'. Likewise, hypersensitive children may engage in self-stimulation as a means of blocking out otherwise overwhelming environmental stimulation. In either case, children with autism find it aversive to be prevented from self-stimulating by the need to concentrate on tasks and are likely to resist efforts to motivate them to complete such tasks.
Self-stimulation behaviors are often varied in nature. In addition to hand flapping and rocking, children with autism may engage in visual self-stimulatory behaviors. They may squint their eyes, or otherwise defocus their eyes to create odd visual sensations. Alternatively, they may engage in "sighting"; repetitiously focusing closely on an object, then pulling away, and then repeating the process over and over.