نشریه رفتار حرکتی
پیاپی 36 (تابستان 1398)

The purpose of this research was to determine the effect of the model’s skill level and frequency of feedback on learning a simple serial aiming task. For this purpose, 48 female students aged 19 to 25 years old were selected as the sample. Based on pre-test movement times, they were divided into four groups of 12 subjects (expert model and 100% feedback, expert model and 50% feedback, novice model and 100% feedback, and novice model and 50% feedback). In the acquisition phase, the groups performed the serial aiming task 80 times according to specific instructions. The immediate retention test was conducted 15 minutes after completion of the acquisition phase, and the delayed retention test was conducted 24 hours later. The results of mixed analysis of variance with repeated measures on training blocks in the acquisition phase showed that the main effect of the model in both variables of movement time and spatial error were significant, and expert model observer groups had longer movement times and fewer spatial errors than other groups. The results of two-way analysis of variance in the immediate and delayed retention tests indicated that in both variables of movement time and spatial error, the main effect of the model is significant, but the main effect of the frequency of feedback is not meaningful. Comparing the means showed that the expert model observer groups had longer movement times and fewer spatial errors than other groups that observed novice models.

Pre-conditioning with physical activities reduces brain injuries caused by stroke. However, the effect of aerobic continuous and interval training on memory has not been measured after stroke. Therefore, the aim of this study was to investigate the effect of six weeks continuous and High intensity interval training before stroke on spatial memory and hippocampus BDNF levels in wistar rat brain. For this purpose, seventy-five 12-weeks-old wistar rats were randomly divided into three groups including Control (N=25), Moderate continuous training (N=25) and High intensity interval training (N=25) to do the moderate continuous (5 sessions per week) and the high-intensity interval (3 sessions per week) for six weeks. The acquisition of spatial memory was done for 3 days after 48 hours after the last training session and the surgery of cerebral ischemia was conducted after 24 hours. Then spatial memory test was taken after seven days later. Immediately after test, animals were anesthetized for measuring hippocampus BDNF levels. ANOVA results revealed MCT decrees destruction in memory and learning (P = 0.0002). In addition, Kruskal-Wallis statistical test indicated, that MCT increased the BDNF levels in the hippocampus rather than HIIT (P = 0.02). Moderate intensity continuous training plays a significant effect on preventing memory loss, learning, and the BDNF amount of hippocampus after brain stroke. Indeed, MCT can reduce brain tissue injuries that are cause of the brain stroke.

The purpose of this study was to investigate the effect of rhythmic aerobic exercise on motor proficiency and emotional intelligence in children with developmental coordination disorder and to compare the relationship between emotional intelligence and motor proficiency in these children before and after exercise. The research sample size included 30 children with developmental coordination disorder. Participants were selected by purposeful cluster sampling. They went through an aerobic exercises program for eight weeks. The study results revealed that emotional intelligence and motor skills in post-test were significantly improved by aerobic exercise. Also, the correlation between motor skill and emotional intelligence increased after training compared to pre-exercise. In the aerobic exercise program, children experience a better team participation, which makes them happy and excited. Also, it was better in improving the coordination level rather than other exercises. Therefore, this study suggests that aerobic exercise could be used to increase the motor skills and effective motor triggers such as emotional intelligence in children with developmental coordination impairment.

The purpose of this study was to examine the effect of manipulating attentional focus on performance of top-spine strike of skilled and novice table tennis players under high psychological pressure. Thirty (15 skilled and 15 novices) persons participated in this study. Participants performed top-spine strike under high/low psychological pressure and different attentional focus conditions (single task, dual task with internal focus, dual task with irrelevant external attention, dual task with relevant external attention). Results revealed that novice group experienced lower decrease during high psychological pressure when their attentional focus was directed internally. No decrease was observed in the performance of skilled group when their attention was directed externally (relevant or irrelevant) during high pressure. These results were explained according to the dual effect of psychological pressure and the notion of controlling degrees of freedom.

Previous studies have shown that postural stability can be enhanced by directing performers’ attention to the effects of their movements (external focus), rather than to the body movements producing the effect (internal focus). We examined whether the balance training and the attentional focus adopted on postural and supra-postural tasks have to influence postural control. Twenty elderly men (59.27 ± 5.77 years) selected randomly and participated in a single group pretest-posttest protocol. Balance training protocol consisted of 16 sessions of manipulated Romberg test for 30 min. Pretest and posttest components of the center of pressure, central-peripheral, and anterior-posterior displacement of participants’ balance were assessed by the Biodex Stability System (BSS) in postural and supra-postural tasks and also in 2 conditions of internal and external focus. The postural task included standing on the BSS in normal condition and the supra-postural task was standing on the BSS by holding a glass full of water. The attention manipulated by a focus on a point outside the body, and focus on decreasing the sway of the body during performing the tasks. Repeated measures of ANOVA with post-hoc Bonferroni test used at a p-value less than 0.05 and using by SPSS software (v. 22®). The present results showed the positive effects of balance training on all the components of postural control. Also, the findings indicated that external focus of attention in comparison with internal focus leads to a decrease in postural sway in all three components of postural control. This study suggests that the application of automatic control processes can be facilitated by simply directing performers’ attention away from their own body movements.

In this investigation, the throwing patterns variations of children were examined as the resultants of changing in task constraints. A total of 24 children (12 males and 12 females), aged 5 and 6 years old voluntarily participated in the study. The manipulation of task constrains was done via changes in target orientations (horizontal vs. vertical hoops) and ball sizes (6 cm vs. 12 cm diameters) and were considered as the main constraints. The observable throwing patterns of children were evaluated, and the kinematic changes of the components of their preferred throwing pattern were analyzed. Though, transitions from two- to one-hand throws and switching from underhand to overhand one-hand throws were observed in the first few trials (mostly in throwing the bigger balls), yet, the preferred pattern was found to be one-hand overhand throwing. The kinematic analysis revealed the existence of sensitivity of the backswing, forearm, and upper arm components of overhand one-hand throwing pattern toward the imposed task constrains. It was also found that most changes took place in the kinematic properties related to the forearm component. The findings represent some empirical evidences for dynamical systems theory to explain changes of movement patterns in motor development. We discussed the potential advantages using constraints for appropriate skill acquisition processes in physical education settings.

The purpose of this study was to investigate psychometric aspects (reliability and validity) of this test set in 7-9-year-old Tehrani children. The research method was descriptive and cross-sectional research design. A total of 234 children aged 7-9 from Tehran, Iran were selected randomly from three regions of western, central and southeast of Tehran. The tool for this study was the TGMD-3 test suite. For data analysis, the statistical methods of confirmatory factor analysis were used using structural equation modeling (SEM), Cronbach's alpha, intra-class correlation coefficient, Pearson correlation coefficient and paired t-test. The internal consistency of the subtest of ball test, displacement and total test for girls was 0.74, 0.78 and 0.77 for boys respectively 0.69, 0.85 and 0.78, respectively, and the reliability of the test-retest was 0.84, 0.73 and 0.79 respectively. The reliability coefficients within the evaluator of the hub, displacement and total test were 0.89, 0.92 and 0.91 respectively and the reliability of the evaluators was 0.85, 0.89 and 0.87, respectively. Structural validity, Ulrich's two-factor model was confirmed through confirmatory factor analysis. Correlation coefficients between age and scores of sub-tests were significant and moderate. Structural reliability coefficients for ball and displacement subscales were 0.74 and 0.71 respectively, so the test and its subscales have good structural reliability. Considering the confirmation of both the reliability and validity of the TGMD-3 test, it can be safely used to test and assess the development of large motor skills in 7-9-year-old children in Tehran.

The present study aims to investigate the Modeling dynamic factors affecting gross motor development milestone of 9- 12-month-old infants. The study was a descriptive- survey, that considering the type and aims of the research was considered as an applied research. To this end 283 infants were screened in regard with age and stage questionnaire. The applied measures were preparation of the home environment for the infant motor development, the parental postpartum attachment scale, Beak habitual physical activity questionnaire and General health questionnaire. Factors affecting motor activities were grouped into three sections including Individual, Environmental and Mother Factors. The related data were analyzed by independent T, MANOA, step by step regression and structural equation. The results of structural equation indicated that individual factors (0.85) has the most important effect on anticipation gross motor development, after that environmental factor (-0.42) and finally mother factor (0.15) has effects on anticipation gross milestone in 9-12 month old infants, Results of the regression showed that considering individual factors, motivation is significant and in regard with environmental factors, affordance is significant in anticipation of gross motor development milestone in 9-12 month old infants. Results of the present study were concentrated on Branfen bernner model. This model claims that development of the infants was first affected by individual and biological factors and then by the environmental factors of the infants.