Many autistic children have what are known as sensory processing disorder. To get an idea of what that is, you can take a look at this video –>
Occupational therapy uses sensory integration tools* to help deal with this disorder (at our end, we use bioenergy therapy to achieve the same results). One tool which can be used for the child which is taught by occupational therapists is what is known as the Wilbarger Brushing Protocol. It is a relatively simple technique and you can view a demonstration of it in the next video.
Some other helpful techniques including swinging on the swings (you notice some autistic children naturally likes it and like to swing constantly because it calms them down) or for you to simulate the same process by rocking the child.
*It is not our intention to replace a qualified occupational therapist. You may still want to consult a professional OT for his opinion on whether this therapy will be helpful for your child. Contact us if you need to find an OT.