**2.2 The importance of sensory integration systems and techniques in children with autism spectrum disorder**

As Ayres [27] mentioned about the sensory integration system, it can be observed as a dynamic system and process which can be effective in motor behavior vestibular system can coordinate the head-body position in space, muscular, tonisity and also, eye movement control. Also, this system has relationship with limbic system and reticular formation system that lead to emotional and feeling control and response to the environmental change [27, 28].

The proprioceptive system in which it's receptors are found in the joints, bones, muscles and tendons, are very important parts in the sensory integration process. Its main role is regulation of information for control and bilateral coordination of central nervous system that lead to the integrated outputs. The proprioceptive system can lead to body schema and body image that are necessary for adaptation ad learning in their life's environment [17, 23, 27, 28].

The tactile system has two subsystems as following: protective subsystem and discriminatory subsystem. The first subsystem has responsibility for receiving information from the pain temperature and touch receptors and finally this subsystem can protect person in activities of daily living. The second subsystem duties are the identification of the touch points, two points discrimination, steregnosis and graphesthesis. This kind of subsystem can be as a suitable base for fine motor skills in the hands [2, 17, 28].

In children with autism spectrum disorder these three systems cannot work as well as other normal children. Then, we can observe the main autism spectrum disorders symptoms such as stereotypical behaviors, social skills impairment, or odd verbal skills and also, due to dysfunction in sensory integration process we can observe another issues such as hypo-sensitivity, hypersensitivity, problems in sleeping, eating, bathing and the other activities of daily living, emotional problems, play, and etc. [1, 17].

According to rehabilitation studies, regular and logical instructions in the field of sensory integration process and focus on tactile, proprioceptive and vestibular techniques can help to reduction of these symptoms and they can communicate in environment and learn better than previous. Regular massage therapy during the classroom activities with similar plays with color balls, board, tilt-board, balancebeam and sport movements in which proprioceptive and vestibular receptors can activated will be suggest strangely, if the children with autism spectrum disorder received a sensory integration techniques regularly they will show normal behaviors and can communicate well [1, 17, 23, 28].
