Background: Attention deficit and hyperactivity disorder is a common disorder that causes serious problems in elementary school and it is also implicated in crime statistics, aggression and other behavioral problems in society. This study estimated the prevalence of hyperactivity in elementary school children in Saghez City, Iran, at the age of 6 – 11 years.
Methods: In this study, 760 students were selected from elementary school boys and girls equally, from Saghez. A type of cross-sectional multi-stage random sampling method was used, and from the elementary school student’s academic year, 12 to 2011 were selected. First, variables such as; age, gender, grade level, school status, Children age, employment, parents’ level of education, family size, child’s birth order, and parental psychiatric history were collected. Second, the teacher and parent questionnaire, "ADHD rating scale-IV," which consisted of two parts, was used. For the data collection, a copy of the letter was given to the teacher to complete and the questionnaires delivered. After completion, collected data was analyzed using the SPSS, 11.5 software.
Results: The results showed that the prevalence of ADHD in the children was 34.4%, and by gender: girls 34.2% and boys 34.6%. Higher numbers of hyperactivity disorders were found in families whose parents had lower levels of education. Hyperactivity was observed to be higher in the third and fourth children who were born into larger families, but there was no significant correlation found between the prevalence of hyperactivity and the number of family members (p = 0.16).
Conclusion: The results of this study indicate that the development of training programs for disease prevention and managing hyperactivity disorder, in families with low socio-economic should be a priority.

Background: Musculoskeletal disorders (MSDs) are among the most prevalent pains which could be ignited via material handling. Backpack wearers are among those who may carry heavy loads. Since MSDs mainly originate in school-aged children, students (as the largest group of backpack wearers) are considered more important. The purpose of this study is to design a backpack based on minimization of shearing force.
Methods: At first the relevant patents were investigated at national and international levels. Then the appropriate ones selected for optimizing. The main selection criterion was based on reduction of pressure on body. As an extra function we used a generator to produce electricity. The criterion for electricity generator selection was: 1) small dimension, 2) low weight, and 3) safe voltage.
Results: A suspending system used to eliminate shearing forces. Since a wearing backpack student is under the shearing force caused by walking, a spring system was used as a reducing device for shearing force. Physical spring calculation revealed that springs with stiffness coefficient equal to 588 was appropriate.
Conclusion: In comparison with existing designs, suggested backpack design can reduce forces on upper limb during handling the backpack.

Background; There is scant evidence regarding the prevalence and main determinants of Obsessive Compulsive Disorder (OCD) in early adulthood, especially at university ages. This study aimed to determine the status of OCD among Iranian college students.
Methods; This cross-sectional study was conducted on 330 medical students at different academic grades studying at Kermanshah University of Medicalsciences. The final diagnosis of subclinical OCD was based on Maudsley Obsessive Compulsive Inventory (MOCI). The data were entered into the SPSS statistical software, version 19.0 and analyzed using independent T-test and chi-square test. P<0.05 was considered to be statistically significant.
Results; The students’ mean + SD score of MOCI was 8.1 ± 6.9. Besides, 103 students (32.4%) obtained scores higher than 9 and, consequently, were diagnosed with subclinical OCD. Among the baseline characteristics, only family history of OCD showed a significant relationship with the frequency of subclinical OCD (P<0.05).
Conclusion; Since family history, as the only determinant of OCD in our study, cannot be modified, students and families have to be trained to control their disorder.

Background: Since students spend a lot of time in classrooms and in steady state, many of them may experience signs of musculoskeletal disorders. The aim of this study was to determine the prevalence of musculoskeletal disorders and its related risk factors among students.
Methods: This descriptive-analytical and cross-sectional study was conducted among 129 students of Qazvin University of Medical Sciences in 2016. In order to determine the prevalence of musculoskeletal disorders, Nordic questionnaire was used. The relationship between musculoskeletal disorders and risk factors was evaluated in SPSS20 software.
Results: The highest incidence of musculoskeletal discomfort (80%) was observed in the waist area. The neck (38.3%) and shoulder (35%) were the most prevalent at the next levels. Marital status, age, weight, educational level, job, exercise and stress were identified as risk factors affecting the musculoskeletal disorders in the students.
Conclusion: It is possible to reduce the prevalence of musculoskeletal disorders by the necessary trainings to declare the risk factors and their modifications to the students, considering appropriate time between the classes and the use of ergonomic equipment and furniture in the classes. With these actions also can prevent from stress and consequently can increase the concentration and learning power in this group.