shahzad tahmasebi

In previous studies, the effect of arousal on performance has been investigated. However, whether arousal during learning stages affects bimanual coordination has not been investigated. Therefore, the present research aimed to investigate the effect of arousal levels during different learning stages on the performance of the hand-eye coordination task.

For this purpose, 36 male physical education students aged 20-35 were conveniently selected and based on normal IQ, normal trait anxiety, and right-handedness, were matched into three Low Arousal, Normal Arousal, and High Arousal groups. The study involved pre-test, post-test, retention, and transfer stages. In the pre-test stage, the participants performed 10 trials of the eye-hand coordination task. The training period consisted of 10 sessions and 50 trials per session, in which at the end of each session 10 trials were recorded as performance. The retention and transfer tests were performed 24 hours after the last training session. The data were analyzed using repeated measure analysis of variance, one-way analysis of variance, and Tukey's post hoc tests.

The results of the present study showed that high, normal, and low arousal levels have a significant effect on the duration of the eye-hand coordination task during the cognitive, association, and automatic stages, and also the time of the eye-hand coordination task was improved.

According to the results of the study, it is suggested that educators use these arousal stimulation effects to improve the performance and learning of athletes in pursuit tasks.

Behavioral studies in team sports are typically constrained by dynamic factors, such as positioning of defenders for interception. Handball player have to coordinate their steps when running to throw a ball on goal from a different positions. In this study were analyzed the movement patterns during locomotors pointing, throwing velocity and accuracy of 12 succesful elite handball players under defensive constraints (defender- absent, defender-far, defender-near, or defender pairing). It was captured data from the locomotors patterns of the attacking participant by speed camera with 120Hz, throwing speed by sports radar gun and throwing accuracy by camera. ANOVA with repeated measures and Bonferroni post hoc test and Friedman test was used to analyze effects of these constraints on gait and throwing parameters. In addition to Pearson and Spearman correlation coefficient test was used to analyze speed-accuracy trade off (P<0.05). The results revealed significant differences in overall mean movement velocity, first and second step mean velocity, first and second step mean length. For the mean foot/gate area distance variability was shown pattern of ascending/descending variability in all defense conditions. Since regulation of offensive players was continuous and based on perception of current and required behaviors, results supported from perception-action coupling and prospective control models of locomotors pointing. Also it is suggested that the technical aspects of the running and throwing in handball can affect by nested tasks constraints.

Children with Attention Deficit Hyperactivity Disorder, in addition to attention deficit hyperactivity disorder and alertness problems, show the the lowest level of social activity and they have more trouble finding and keeping friends.

The aim of this study was to investigate the effect of motor and computer games on the attention and social communications of male students with attention deficit hyperactivity disorder aged 10-12 years.

The statistical population of the present study was all elementary male students aged 10-12 years with Attention Deficit / Hyperactivity Disorder in District 4 of Tehran in 2021 and 36 of them were purposefully and accessibly selected. Motor and computer games were performed in 8 weeks and in each session in 3 sessions of 60 minutes. The Connors questionnaire of the parents' version and the Zebov questionnaire were filled out by the parents in the pre-test and post-test. Repeated measure analysis and paired t-test were used to analyze the data using SPSS software version 23.

Motor and computer games had a significant positive effect on attention and social communication; also, motor and computer games have a significant positive effect on the perceptual-motor skills of male inactive students (P≤0.05), but there was no significant difference between the effects of these two interventions on any of the research variables (P≥0.05).

Motor and computer games improve attention and social communications in children with attention deficit / hyperactivity disorder; therefore, it is recommended that these games be used to help children with attention deficit / hyperactivity disorder.

Nowadays,universities are known as the main context of thinking and contemplation and students have an essential role in the development of the society.Therefore,factors affecting educational and researchperformance are of great importance.The aim of the present study was to investigate the effect of PETTLEP imagery on bilateral transfer of handball skill.The Sample included B.Sc students in physical education at the University ofTehran,24of which participated in thisresearch voluntarily.After taking part in the pretest, the participants were randomly divided into2groups of imagery with dominant hand and non-dominant hand.Then PETTLEP imagery was applied on both groups for12sessions.A posttest similar to the pretest was done after the last session.This was followed by aretention test after24hours and then a transfer test in the form of handball tripleshootafter30minutes.After ensuring the consistency of variances by Leven test and normality of the data by Shapiro-Wilk test,a multivariate analysis of variance(MANOVA)and an analysis of variance with repeated measures with asignificant level of α=.05 were used.The results showed that intervention of PETTLEP imagery hada significant effect on skill transfer through the entire process(P≥.05).Thus,PETTLEP imagery causes the occurrence of bilateral transfer.Therefore,PEETLEP mental imagery is recommended to be used for the improvement of people's skill when employing bilateral transfer.Therefore,PEETLEP mental imagery is recommended to be used for the improvement of people's skill when employing bilateral transfer.Therefore,PEETLEP mental imagery is recommended to be used for the improvement of people's skill when employing bilateral transfer.

The purpose of the present study was to investigate the effect of PETTLEP imagery on accuracy and speed basketball pass. For these purpose 44 physical education students of University of Tehran with mean age of 22/45±2/3 participated in this study. In pre-test participant performed 2 blocks of 10 trials of accuracy and speed basketball pass. Then, they distributed in one of four groups homogeneously: accuracy pass PETTLEP imagery, speed pass PETTLEP imagery, accuracy control, and speed control. Two groups of imagery listened to audio during three days for 8 minutes. Then, subject did post-test, retention and transfer. Mixed ANOVA, independent t-test and repeated measures analysis of variance used with significant level P≤0.05. Statistical analysis results indicated that there was no significantly difference between imagery group and control group in pre-test. However, in post-test there was significantly difference (P≤0.05). Also PETTLEP imagery of accuracy and speed pass improved accuracy and speed pass performance from pre-test to retention significantly, however in transfer test there was no meaningfully difference (P≥0.05).

balance and suprapostural task is the important ability in usual life and sport activities of children that always, the importance of focus of attention in balance discussed. In this regard, the aim of the present study was to investigate effectiveness the focus of attention of suprapostural task on balance in girl’s from four to 6 and 9 to 11 years old.

In this study, 90 female have participated, that randomly, divided into three groups, external attention, internal attention and control group. The participants asked to maintain their balance by attention on suprapostural task. Instructions included focus of attention on the bar (external focus), hands (internal focus) and no instructions (control).

The results showed that in both age groups, external attention of suprapostural task leads to meaningful learning of balance.

The findings support of applying the external attention instruction as an effective strategy to improve children learning.

Peripheral visual perception is a concept of cognitive-perceptual processes, which, although it is referred to in the ballfields, has not yet been studied in the non-ballfields and the examination of gender differences is also a challenge to be addressed. So, the purpose of this study was to examine the peripheral visual perception of ballplayers and non-ballplayers. The samples of this study were randomly selected from the young girls and boys (average and standard deviation 26±4.5 age) in ball fields (14) and non-ball fields (16) of the Faculty of Physical Education of the University of Tehran. All subjects had complete visual acuity and the consent form of the research. The instrument of Vienna was used to measure peripheral visual. The statistical results of MANOVA test showed that there is no significant difference in the peripheral visual perception between ballplayers and non-ballplayers in girls and boys (P≤0.05). In general, this research showed that the type of exercise (ball and non-ball) and gender cannot be a factor in the superiority of peripheral perception, and although the importance of peripheral perceptual skill in ball exercises has been shown in research, this skill is also very important in non-ball exercises.

  Various theoretical approaches have different views regarding the role and importance of vision information in the production and control of movements, but how vision control mechanisms act under anxious conditions?

The present research  aimed to evaluate vision control mechanisms under anxious conditions in novice golf players.

In this  quasi-experimental study, 20 novice golf players were selected through convenience sampling in the city of Isfahan. The task of the current study was the performance of golf-putting skill under different anxious conditions (baseline vs. anxiety). In this study, participants in the baseline and anxious conditions performed 6 trials of counterbalance in each condition without blocking (control), the first phase blocking, and the last phase blocking of movement in each task. Simultaneously with  golf-putting  performance, the quiet eye data were recorded by an eye tracker system. Data were analyzed via two-way ANOVA and Tukey’s post hoc statistical methods.

The results indicated that participants’ quiet eye significantly decreased under anxiety conditions (p=0/0001). Also, the results showed that the initial blockage of movement caused further weakening of the accuracy and quiet eye compared to the final blockage of movement (p=0/0001).

Overall, the results of the current study emphasize the pre-programming system in the performance of golf-putting skill in novice golf players.

The purpose of this study was to investigate the effect of sport stacking on self-confidence and bimanual coordination of female students. 55 female students from 10 to 12 years old were randomly selected from schools in Qaemshahr. The tool used in this study was the Eysenck self-confidence questionnaire and the bimanual coordination system of the 32532 model developed by Lafayette company. Participants were divided into control and examination groups after pre-test. The examination group spent 36 sessions on the sport stacking exercises. At the end of the fourth, eighth and twelfth weeks, their self-confidence and bimanual coordination were evaluated as the pre-test. The results showed a significant improvement in self-confidence and bimanual coordination of the intervention group compared with pre-test and control group. Therefore, sport stacking is not a one-dimensional sport, which will only reinforce important physical skills such as coordination between the eyes and hands, but also self-confidence.

One of psychological interventions that can be effective on improving performance and learning behaviors is at the focus of attention. Thus, the aim of the present study was to determine efficacy of instructions on the focus of attention of suprapostural task on learning of postural control in boys with 9 to 12 years old. In this study, 45 boy students of one of the Malayer city schools were participated, and divided into three groups (15 people), including: external attention, internal attention and control group randomly. The participants were asked to keep their postural control by using instructions on suprapostural task. Instructions included attention on the bar horizontally held in their hands (external attention), their own hands (internal attention), and no instruction (control). The result showed that learning process in both internal focus group (P=0.022), and external focus group (P=0.04), is significant compared to the control group. However, no significant differences were found in learning between external focus group and internal focus group (P=0.794).  The findings support of applying the attention instructions as an effective strategy to improve learning. Also the fact that children can take advantage from the attention instructions, has important applications for physical education.

 

The purpose of this study was to investigate the effect of attentional focus and frequency of feedback on performance and kinematics in basketball free throwing.

In this semi-experimental research, fifty students were randomly selected using convenience sampling method, and were randomly divided in one control and 4 experimental groups (internal focus and 33% feedback, internal focus and 100% feedback, external focus and 33% feedback, and external focus and 100% feedback). Experimental groups conducted six blocks of ten attempts (every day two blocks of ten attempts) in one week, and in three sessions of training, and received internal or external focus feedback with the corresponding frequency (33% or 100%). After 72 hours, retention and transfer tests were performed with ten-attempt blocks. Performance (throwing accuracy) and kinematic data (joint angle and range of motion) were collected. Data were analyzed using ANOVA with repeated measures and one way ANOVA.

Feedback with external focus (100% and 33%) was more effective in improving throwing performance in retention and transfer tests (P < 0.050). Kinematic data analysis showed that external focus feedback groups had the least maximum flexion in the knee joint in retention test compare to acquisition stage (P < 0.050). Moreover, external focus groups had the least maximum flexion at the knee in retention test compared to internal focus groups (P < 0.050). In range of motion of the knee, external focus groups had more range of motion in retention and transfer tests compared to internal focus groups (P < 0.050).

Performance improvement in external focus groups may be limited to certain changes in kinematic data, and in line with constrained-action hypothesis.

Knee osteoarthritis is one of the most common musculoskeletal problems in older women which affects their daily life. It causes balance impairment, and increases the rate of falling in these patients. Therefore, the aim of this study was to compare the effects between tai chi exercise and glucosamine supplementation on the balance of older women with knee osteoarthritis. This was a clinical trial study, in which 75 women with knee osteoarthritis (according to the Kellgren and Lawrence scale) were chosen, and randomly assigned into 3 groups of tai chi exercise (performed 3 times a week for 3 month), glucosamine supplementation (3 times a week), and control (no intervention). Before and after interventions, static balance (measured by stabilometer in both open and closed eye) and dynamic balance [measured by timed up and go (TUG) test] were examined. Paired sample t and ANOVA tests were implemented for data analyzing at a significant level of less than 0.050. Tai chi exercise had a significant effect on static [open (t = 9.57, P = 0.001) and closed (t = 5.30, P = 0.001) eye] and dynamic balance (t = 8.54, P = 0.001); supplementation variable had a significant effect only on dynamic balance (t = 2.21, P = 0.040); in control group, there was not any significant difference between before and after intervention. Comparing three groups, the ANOVA test showed a significant difference between the exercise and control group in static [open (P = 0.001) and closed (P = 0.001) eye] and dynamic balance (P = 0.040). It seems that tai chi exercises enhance the balance in older women with knee osteoarthritis. It also could be concluded from the results that only the exercise variable has the significant effect on subject’s balance compared to glucosamine supplementation.

the purpose of this research was the effect of visual concurrent feedback on balance ability in 7-13 years old girls. Hence, for this purpose, thirty-four girls student (ranging 7-12 years old) were participated in this study. The students were divided to three group randomly, control, closed eyes and mirror visual concurrent feedback groups, after stork balance test pre-test. Then, groups under interventions completed related trainings. In the present study used paired t-test for comparison of intra-group and one- way ANOVA for inter group (p≤0.05). The result of ANOVA showed that there was no significant difference between pre-test (p≥0/05). But, there was significant improvement in mirror group compared to control group (p=0.001) and closed eyes group (p=0.001). In addition to, the result of paired t-test indicated that only the mirror group has significant progress (p=0.007) in balance and the other groups have significant decrements. Therefore, concurrent feedback in children by use of a mirror to show them self can be improve their balance ability

The self-talk is one of psychological interventions that can be effective on improving and success in the motor performance and sport performance. So, the aim of the present study was to investigation effectiveness the motivational self-talkon secondary task performance (discrimination reaction time). 30 subjects have participated of the 160 students studying at the undergraduate from faculty of physical education and sport science in University of Tehran. They were divided randomly into two control and experimental groups. The intervention was conducted in two sessions per day and each session lasted one minute. The first primary task for the intervention group was walking on the treadmill with a slow speed whereas secondary task (discrimination reaction time), was performed in 10 attempts. The process was performed for the second order in the same manner with the difference that the experimental group performed motivational self-talk 15 seconds before the secondary task performance.Control group was performed test without intervention.The result of paired samples t-test showed that motivational self-talk in experimental group leads to a significant decrement in discrimination reaction time (P=0.001). Also, the result of Mann-Whitney U showed that reaction time in the experimental group decrease than control group significantly (P=0.002).