[Comparison of ADHD [Attention Deficit Hyperactivity Disorder] prevalence between female and male students of primary schools in Arak City in academic year of 2009-2010]

The aim of this study was to compare the prevalence of ADHD [Attention Deficit Hyperactivity Disorder] between female and male students of primary schools in Arak City. This study was a descriptive-analytical, cross-sectional study which included 2000 female and male students of primary schools in Arak City between 2009 and 2010. The method of sampling was stratification. We used Intelligence-Matrix of Raven Scale intelligence, Canners questionnaire [parents and teachers] to study ADHD, the demographic checklist for recording students' demographic data, and K-SADS-E questionnaire to document diagnosis of ADHD. Data were introduced into SPSS software and analyzed by chi-square test to determine the relationship between qualitative variables and also logistic regression model to determine odds ratio. In this study among 2000 students, 168 were suffering from one type of ADHD. Also this study showed that the prevalence of attention deficit was 2.3 percent [%1.6 in boys and%2.9 in girls], prevalence of the combined type of disorder was 2.7 percent [%3 in boys and%1.3 in girls]. There were a significant relationship between prevalence of ADHD and each of the following variables including: gender [p<0/001], educational level [p<0/027], and monthly family income of the students who were suffering from ADHD [p<0.019], but there was no significant relationship between the parents' educational level, the parents' occupation, living in areas polluted with heavy metals, living style and ADHD. According to the results of this study we recommend that the educational departments in every city provide training programs for the teachers and parents about the identification of signs and symptoms of ADHD to prevent deterioration of ADHD and educational problems in the children

Effect of movement direction variation in relation to gravity on generalized motor program recruitment in fast single joint elbow movements by use of surface electromyography

The precise control of arm kinematics and kinetics as well as interaction of the arm with the external word, is an essential condition to perform skillful motor actions. Gravity has significant effect on spatial orientation, proprioception, displacement, start and stop of hand movements. The purpose of this research was to study the effect of movement direction variation in relation to gravity on generalized motor program recruitment in fast single joint elbow movement by use of surface electromyography. Fifteen volunteer students [mean age 24.8 +/- 3.8 years] without sensory motor impairments participate in this study. Ninety percent of full range of motion at the elbow joint was used as goal degree. Subjects asked to do aimed elbow flexion as fast as possible in seven different direction in relation to gravity. While they were performing movements, surface electromyography was recorded from biceps and lateral head of triceps muscles. Relative timing, relative activity and sequence of contraction were derived from RMS. Data were analyzed by using repeated measure variance analysis. Muscle activation patterns were different in three positions from rest. There were significant difference between relative activity [p<0.001] and relative timing [p<0.003] in some positions. In fourth position, sequence of muscle contraction was different in seven subjects. It seems that change in movement direction in relation to gravity is one of effective parameters in movement planning and execution and it can recruit different generalized motor program