نشریه رشد و یادگیری حرکتی - ورزشی
پیاپی 2 (پاییز 1388)

The purpose of this study was to investigate the effect pf weight-bearing exercise and calcium supplement invention programs on femur bone mineral density in children. For this purpose, 32 subjects were selected voluntarily from Rahe Zafar kindergarten. These children had the intervention program for 5 months. Calcium consumption questionnaire and density evaluation apparatus (DEXA) were used to collect the data. One-way ANOVA and dependent t-test were used to analyze the data. The mean difference between pre and post test was significant in all groups (weight-bearing exercise and calcium consumption t=4.919, sig=0.002; weight-bearing exercise t=6.232, sig=0.00; calcium consumption t=7.86, sig=0.00; and control t=5.499, sig=0.002). Totally, the comparison of BMD scores in groups showed a significant difference in mean scores of all groups (F=3.981, sig=0.019.) Tukey test showed a significant mean difference between 1 and 2 groups with control group. These results emphasized that childhood and adolescence play a crucial role in forming bones. They also emphasized this theory about bones that: “Bones respond to receiving loads by enhancing minerals”.

The purpose of this study was to evaluate the effect of two regimes during rat's gestation and lactation on learning, memory and motor function of their offspring. For this purpose, female rats (Albino-Wistar) were obtained from Pasteur Institute, Iran. After mating, 12 pregnant rats were divided into three groups and they had their special regimes during their last week of pregnancy as well as their lactation. Control group used a standard diet, the zinc deficient (ZnD) group a diet deficient in zinc and the zinc supplement (ZnS) group a standard diet and enhanced zinc (10ppm) in their drinking water. 12 male offspring in each group were selected as the statistical sample and they were tested for learning and memory in MWM on their 56th natal day (ND) and were tested for motor activity in open-field on their 66th natal day. One-way ANOVA, post hoc Tukey test and repeated measures ANOVA were used to analyze the data (P<0.05). These findings showed that zinc deficiency during the last week of pregnancy and during lactation impaired learning and memory of their offspring and had also a negative effect on motor function. In addition, zinc supplement had a significant effect on learning and memory but no effect on motor function of their offspring.

The purpose of this research was to determine the effects of perceptual motor training on improving the motor abilities of children with developmental coordination disorder. A total of 194 male and female elementary school students (aged between 6 and 11) were selected from three regions of Tehran and participated voluntarily in this study. The subjects were randomly assigned to two groups of experimental and control. The subjects performed a pretest prior to participating in the training program. The training program included two months of adjusted perceptual motor activities for 24 sessions. Following the training program, both the experimental and control groups took part in the posttest. The test included manual dexterity, dynamic and static balance, and ball handling skills. The data were analyzed by PC: SPSS-13. The results showed that children with perceptual motor training significantly improved their development coordination disorder or dyspraxia.

The aim of the present study was to investigate the effects of various scheduled practices (self-regulated and non-self-regulated) on the acquisition, retention and transfer of simple and complex tracking tasks. 96 right-handed undergraduate students (age rang: 18-24 years old) volunteered to participate in this study (48 females, 48 males). These students participated in physical education classes (1 & 2) in their first semester of 1387-88. Participants were assigned to one of eight different groups (n=12), which differed in types of tasks performed (simple tracking or complex tracking) and the practice schedule used (blocked, random, self-regulated, or yoked). The method was quasi-experimental. These tasks were designed as software and appeared on a computer monitor. The movement time and movement error (click) were assigned as scores in different groups. After the pretest, the subjects practiced 8 16-trial blocks in 2 sessions. 24 hours later, they participated in the retention and transfer tests. The data were analyzed by mixed factorial ANOVA and Bonferroni post hoc test. The results showed a significant difference between various scheduled practices and type of task in various stages of movement time (P<0.05) (i.e. the effect of contextual interference in the acquisition and retention of movement time of tracking tasks was observed). Meanwhile, there was no significant difference between various scheduled practices and type of tasks in various phases of movement error (click). The differences were not significant in transfer test, but the self-regulated groups showed the most improved performance in various phases of test. These findings suggest the effectiveness of contextual interference and they show that self-regulated practice is an important variable for scheduled practice.

The purpose of the present study was to investigate the effect of self-controlled (SC) and instructor-controlled (IC) feedbacks on the acquisition of dart motor skill using videotape feedback. For this purpose, 200 female volunteer students of University of Tehran participated in this research. After the questioners had been filled out, 36 individuals were randomly selected from 152 qualified participants. After a 10-trial pretest, they were divided into three groups: SC, IC, and Yoked group. The SC group received videotape feedback whenever they asked for it; the IC group after 5 trails, and the yoked group at the points that SF group received it. All the groups were videotaped. Practice phase consisted of 100 trials including 10 10-trail blocks. Retention and transfer tests were carried out 48 hours later. Foe data analysis, one-way ANOVA, repeated measures and Tukey test were used and EXCEL software was used to draw the plots. The results showed that the type of feedback had a significant effect on the form and accuracy of dart motor skill in acquisition, retention and transfer (P<0.05). In general, the results showed that self-controlled group had a better performance than yoked and instructor-controlled groups.

The aim of the present study was to introduce the methods to extract and to interpret cinematic data in order to explain movement pattern changes via joint coupling and freezing/freeing phenomena in a healthy right-dominant college male (age:26, height: 172 cm, weight: 80 kg) who practiced balance maintenance on a stabilometer. Data were gathered using a three-dimensional registration system which consisted of three cameras and a computer program (Sharif Motion Analyzer-SMA) in MATLAB software and measured the position of 19 passive markers located on subject's limbs and stabilometer. Before each trial, the system was calibrated by a metal frame of known dimensions to transform the two-dimensional camera detector values to real three-dimensional coordinates. Then, the following variables were calculated for the first, fifth and ninth trail from a 3(session) × 3(trail) course of practice: 1) stabilometer variability as a performance index; 2) absolute and relative variability of joint angles to evaluate possible freezing-freeing process; 3) cross-correlations between the angular time series in order to evaluate the presence of joint coupling. Finally, the interpretation method to extract variables was presented and some limits of such studies regarding the variability in degrees of freedom were provided.

The purpose of the present study was to compare the effect of 5 and 10 weeks of aerobic and yoga exercises on physical self–description components of female students. 57 sedentary female students (age range of 19-25 years old) from Ferdowsi University who did not have any experience of those training modes were selected and randomly and equally assigned to two experimental groups (aerobic and yoga) and one control group. The experimental groups participated in the program for 10 weeks, two sessions per week, each session 60 minutes. During this period, the control group did not engage in any organized exercise program. In order to collect data, physical self–description questionnaire was used at three different points (at the beginning, in the middle and at the end of the test). One–way ANOVA and post hoc Tukey test showed that at the end of the 5th week of exercise, coordination and sport competence components in yoga group were significantly higher than aerobic and control groups (P<0.05). At the end of the 10th week of exercise, in yoga group, coordination and physical activity components were significantly higher than control group and strength component was significantly higher than aerobic and control groups (p<0.05). In addition, coordination component in aerobic group was significantly higher than control group (P<0.05). paired–sample T test showed that in yoga group, sport competence and strength components at the end of the 10th week of exercise were significantly higher than the 5th week of exercise (p<0.05). The results showed a significant increase in coordination, sport competence and physical activity components related to the first 5 weeks and a significant increase in strength to the second 5 weeks of exercise in yoga group. These results show the relative priority of yoga exercises and a need for more sessions to improve some components of physical self–description.

The purpose of this research was to study and to analyze the necessity of physical education instruction and sport sciences orientation at universities. For this purpose, a 30-point questionnaire at Likert scale was designed and distributed among 80 subjects (20 subjects at doctorate and scientific boards, 20 graduates, 20 students and 20 distinguished coaches of sports federations as the statistical sample of research). Obtained results were studied and analyzed. The results showed an agreement on orientation of physical education and sport sciences at all educational levels. 88% of subjects believed that the current status of physical education and sport sciences was inappropriate. 83% agreed on the orientation of this field. 92% agreed on the orientation of physical education and sport sciences at bachelor’s degree level and more than 80% at master’s degree level. About 80% of subjects believed that new orientations such as sport nutrition, science of training and design of training, physical education of the disabled and rehabilitation and reform sport and movement-therapy. They also suggested that aforesaid fields should be included at educational complementary programs of physical education and sport sciences.