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Background: Due to high risk of physical inactivity in children with autism spectrum disorders (ASD) and its adverse consequences, evaluating their level of physical activity (PA) using accelerometry and investigating its relation with age and severity of the disorder are integral.

Materials and Methods: Fifty two boys and sixteen girls aged 7-14 years -from autism schools in Tehran- participated in current cross sectional study. Level of daily PA was evaluated for seven consecutive days using accelerometers. Autism severity was also assessed in the areas of communication, sociability, sensory and cognitive awareness, and health and physical behavior using Autism Treatment Evaluation Checklist (ATEC).

Results: On the whole 91 percent of participants encountered low level of PA. Girls were remarkably less active than boys and were more inactive. Level of PA significantly reduced as they aged. Level of PA was adversely and significantly correlated with autism severity in the area of sensory and cognitive awareness. Moreover, level of vigorous PA was adversely and significantly correlated with total autism severity. Finally, age, sex, and sensory and cognitive awareness were partially predictors of PA.

Conclusion: It appears that children with HFA are physically inactive and considerably engage in more sedentary activities as they age. Age and gender can be considered as physical activity determinants among this population.

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Background and Aim: Evaluating variability can help to investigate the process underlying motor coordination problems. The current study aimed to measure motor coordination and its variability in children with Developmental Coordination Disorder (DCD). Moreover, the symmetry of motor coordination variability in these children and the relation between motor skills and variability were explored.
Materials and Methods: After evaluating motor skills in children, aged 7-10 years using Movement Assessment Battery for Children-2 (MABC-2), 15 children with DCD and 20 non-DCD children performed a bilateral coordination task. Using motion capture system, motor coordination and variability were recorded and calculated by computing continuous relative phase and its standard deviation, respectively.
Ethical Considerations: The study with an ethical code of IR.UT.SPORT.REC.1396030 was approved by Ethics Committee of Faculty of Physical Education and Sport Sciences of University of Tehran.
Findings: Children with DCD showed significantly higher variability, while there was no significant difference between the groups in performing the coordination task. Moreover, the variability of motor coordination was found asymmetrical in children with DCD. Finally, more variability was shown to be accompanied with lower score in motor skills of the participants.
Conclusion: The current study shows the necessity of employing assessments related to underlying process of movement coordination such as variability, which can help to provide more comprehensive understanding of motor patterns of children with DCD and the strategies that they adopt to execute and produce movement.