Journal of Sports and Motor Development and Learning

Abstract Introduction: Studies that have examined the upper limb function of children with cerebral palsy and hemiplegia have mostly used single-handed tasks, including the constraint of the healthy hand technique; however, this method led to emotional problems in the child. This study aimed to investigate hand function after bimanual handball training in children with hemiplegic cerebral palsy.
Methods: Five children referred to Fakhr e Sadegh Clinic with a mean age of 10.2±2.28 years were selected via convenience sampling. Parents of the children completed the consent form. Each participant was tested once before and once after the training using the Purdue pegboard test, and one-handed, simultaneous bimanual, and sequential bimanual performance were assessed. The participants performed two 30-minute bimanual exercise sessions per week for a total of six weeks.
Results: The results were analyzed using SPSS 27 software. Paired t-test showed that performance of the less affected hand (p=0.03) and sequential bimanual coordination (p=0.00) increased significantly, while simultaneous bimanual coordination (p=0.08) did not improve significantly. Also, the Wilcoxon test did not show a significant improvement in the more affected hand (p=0.06).
Conclusion: It seems that the use of bimanual handball catching exercises can be effective in improving sequential bimanual coordination and the function of the less affected hand in children with hemiplegic cerebral palsy and can be used as an intervention method in motor rehabilitation of these children.

Abstract Background: 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.
Methods: 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.
Results: 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.
Conclusion: 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.

Abstract 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.

Abstract Nowadays, universities are known as the main context of thinkingNowadays, 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 research performance are of great importance .The aim of the present study was to investigate the effect of PETTLEPimagery on bilateral transfer of handball skill.The Sample included B.Sc students in physical education at the University of Tehran,24 of which participated in this research 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 for12 sessions.A posttest similar to the pretest was done after the last session.This was followed by aretention test after 24 hours 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 a significant level of α=.05 were used.The results showed that intervention of PETTLEP imagery had a 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.

Abstract This study aimed to investigate the effects of peripheral and central fatigues on depth perception error in students. The statistical population consisted of students in Khodabande city. 42 subjects (mean age of 16.88 ± 0.49 years) were selected by convenience sampling method. All subjects took depth perception pretest. Then, they were divided into the intervention and control groups. To produce peripheral fatigue (physical), the first group received physical fitness activity and the second group received mental activity to produce central (mental) fatigue. The third group did not perform any activity during the intervention period. The depth perception posttest was performed after the fatigue intervention. The results of one-way analysis of variance showed no significant differences in the pretest among the groups, but there was a significant difference in the posttest among the groups. LSD post hoc test results showed that central fatigue increased depth perception error in comparison with peripheral fatigue and no intervention (control group). But no significant differences were observed in depth perception error between peripheral fatigue and control groups. Paired t test results showed an increase in depth perception errors resulted from both types of fatigue and the lack of change in the control group. Overall, it can be concluded that central fatigue had an effective role in increasing students' depth perception error when compared to peripheral error. Therefore, coaches are advised to adopt appropriate conditions that reduce central fatigue.

Abstract Cognitive constrain of individual constrains which can be created with imagery and is a factor in many tasks affecting the performance has been investigated. Thus, the aim of the present study was to investigate the effect of PETTLEP imagery on the accuracy and speed basketball pass skill. 44 female students of Faculty of Physical Education, University of Tehran (mean age of 22.45±2.3 years) were selected by convenience sampling method and participated in this study. In pretest, participants performed 2 blocks of 10 trials of accuracy and speed basketball pass. Then, they were assigned to one of the four groups homogeneously: accuracy pass PETTLEP imagery, speed pass PETTLEP imagery, accuracy control, and speed control. Two groups of imagery listened to the imagery audio during 3 days for 8 minutes per day. Then, subjects participated in posttest, retention and transfer tests. For data analysis, mixed ANOVA was used. In case of significance, independent t test was used for intergroup comparisons and analysis of variance with repeated measures was used for within-group comparisons with significance level of α=0.05. The results of analysis of variance indicated no significant differences between imagery and control groups in pretest. However, there were significant differences in posttest, retention and transfer tests between imagery and control groups (P≤0.05). Also, PETTLEP imagery of accuracy and speed pass improved accuracy and speed pass performance from pretest to retention test; however, there was no such process in transfer test (P≥0.05).

Abstract Theoretically, skill presentation will change behavior through processes such as imitation and motor repetition. If we want learning to happen, we need a process called training. Training can be delivered by the instructor through verbal and non–verbal instructions to the learner. One type of non–verbal instruction is pattern representation in which learner can learn through observation. The purpose of this model is to use the pattern representation as a means of transmitting information. Thus, the aim of this study was to evaluate the effect of three training methods: immediate, interspersed and combined imitation on Juno kata form performance. Therefore, 45 girls (9-12 years old) in Tehran city voluntarily participated in this study and were divided into three groups (each group 15 subjects) based on the type of intervention. Groups of immediate, interspersed and combined imitation had special imitation training programs with specific repetitions. In order to quantify data, 10-point Kata scale was used. As the data distribution and variance homogeneity were obtained, the result of analysis of variance with repeated measures showed that all three observational methods helped to improve the performance and this progress remained stable in the retention and transfer tests (P≤0.05). Also, the results of multivariate analysis of variance showed the priority of immediate imitation group on interspersed (P=0.0005) and combined (P=0.0005) imitation groups. The combined imitation group gained better scores than interspersed group (P=0.0005) and this differences was stable in retention and transfer tests.

Abstract The aim of this study was to investigate the emergence of special skill in basketball free throw at different skill levels based on Newell's model of learning stages. Participants were assigned to three skill groups (n=10): coordination group, coordination control group, and optimization group. They threw 350 fixed shots from 7 parametric points (2.74, 3.35, 3.96, 4.57, 5.18, 5.79, 6.4), carrying out 50 shots in each point. Regression analysis showed that the accuracy of those who were in the third stage of Newell's model in 4.57 m point, which is the same line of penalty, was significantly higher than the anticipated regression equation and supported the emergence of special skill (P>0.05), but the rest of the points did not follow the principles of force variability and performance accuracy decreased by increasing distance parameter. Moreover, multiple regression analysis showed that the rest of the points had no contribution to the emergence of special skill and this conclusion may be the reason for rejecting generalized theory in the creation of special skill.

Abstract Coordination is an important part of successful movements in daily life and sports. The aim of this study was to investigate the effect of different levels of cognitive activities on intrapersonal and interpersonal motor coordination in taekwondo athletes (Poomsae). The population consisted of Poomsae male athletes in Tehran city. 30 individual Poomsae athletes and 30 team Poomsae athletes (age range: 17 - 30 years old) were selected by convenience sampling method. The sample was divided into 3 groups: control, easy cognitive activities and difficult cognitive activities. The control group only performed the motor coordination task whereas the cognitive groups performed the dual task. The results of one-way ANOVA test showed a significant difference for two handed (P=0.003) and two legged (P=0.04) coordination in total time factor (speed). Also, there was a significant difference in the error percentage factor for interpersonal motor coordination (P=0.02). In a two by two group analysis, the easy (P=0.003) and difficult (P=0.001) cognitive activities groups in two handed motor coordination and the difficult cognitive activities group in two legged (P=0.02) and interpersonal (P=0.01) motor coordination performed better than the control group. It is suggested that difficult activities should be used in addition to regular physical activities.

Abstract The aim of this study was to investigate the effect of music types on depth perception during fatigue. Statistical population consisted of female students of Faculty of Physical Education at University of Tehran. 45 subjects (mean age 23.3 ± 2.16 years) voluntarily participated in this study. Participants were divided into three groups: slow music, fast music and control. Initially, all subjects participated in the pretest of depth perception using depth perception apparatus. Then, they received a similar exercise until reaching the threshold of exhaustion. After reaching fatigue, their error of depth perception was reassessed. Then, participants were asked to listen to the music specific to each group for 3 minutes in order to assess the effect of music on their depth perception during fatigue. Their depth perception was immediately measured as the posttest. Analysis of variance with repeated measures and one-way analysis of variance were used to analyze the data. The results showed that fast music did not significantly change depth perception error (P=0.602), but slow music significantly reduced this error (P=0.006).

Abstract  
Postural control is one of the important abilities in daily life and sport activities of human beings and the importance of focus of attention is always discussed in this issue. In this regard, the aim of the present study was to investigate the effect of the instructions of focus of attention of supra-postural task on performance and learning of postural control in girls aged between 9 and 12. 45 female students in an elementary school in Malayer city participated in this study and were randomly divided into 3 groups: external attention, internal attention and control by drawing of lots. The participants were asked to maintain their postural control by instructions on supra-postural task. Instructions included focus of attention on the bar they held horizontally (external focus), on their hands (internal focus) and no instructions (control). The results of analysis of variance with repeated measures showed that learning process in external focus group was significant compared with the internal focus (P=0.049) and control (P=0.005) groups. However, no significant differences were found in learning between internal focus and control groups (P=0.345). It can be concluded that external attention instruction on supra-postural task led to better postural control than internal attention instruction.

Abstract   Challenge point framework is a theoretical framework to understand the effects of exercise variables in motor learning. According to this framework, contextual interference and knowledge of results (KR) feedback have a close relationship with the skill level and task difficulty. So, the aim of this study was to investigate the effect of exercises based on challenge point framework on postural control in patients with multiple sclerosis. The postural control of 22 MS patients (age range 20 - 65 years) from patients of Ahvaz MS Association who were randomly selected and assigned to experimental and control groups was measured by the force platform. Subjects in the experimental group performed exercise for 12 sessions, 3 sessions per week and 45 minutes each session. The control group did not receive any interventions. The data were analyzed by mixed analysis of variance and analysis of variance with repeated measures (P≥0.05). The findings showed that the postural control of experimental group significantly improved compared with the control group as a result of four weeks of exercise protocol. Also, postural control of the experimental group significantly developed in the posttest compared with the pretest. So this study supported challenge point framework and instructors and practitioners can use this protocol for effective clinical interventions to improve balance and postural sways in MS patients.

Abstract   Perceptual-motor skills play a vital role in many tasks of daily life and sports skills. The measurement of coincidence anticipation timing ability is a method to evaluate perceptual and perceptual-motor skills. Thus, the main aim of the present study was to investigate the role of different organism, task and environment constraints in coincidence anticipation timing accuracy. For this purpose, 30 female adolescents (17-15 years old), young (20-40 years old) and elderly (60-80 years old) participated in 4 tests of coincidence anticipation timing. The tests included a coincidence anticipation timing task with green (1), blue (2), red (3) color background and an additional environment constraint (4) and participants had to coincide with the arrival of the stimulus in the target point and press the corresponding key. For data analysis, mixed ANOVA (3*4), 4 one-way ANOVA and 3 ANOVA with repeated measures were used for each group with adjusted Bonferroni. Statistical analysis showed a significant difference in test 1, 3 and 4 (P≤0.0125). Also, all groups showed a significant reduction in performance when the background color changed from green to red and the addition of the secondary task (P≤0.017). In addition, results indicated that the elderly group had the weakest performance compared with the adolescent and young groups and the reason might be a weakness in perceptual-motor systems related to age increase. Finally, different coincidence anticipation training programs were recommended for athletes, elderly and patients with perceptual-motor system weakness.

Abstract 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

Abstract 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).          

Abstract Increased level of stress has negative effects on cognitive functions. Thus, it is necessary to identify appropriate strategies to prevent cognitive and motor performance decline. The aim of this research was to study the effect of immobilization stress on learning and memory and the protective role of physical activity in them. From male Albino-Wistar rats of Pastor Institute, 32 rats were randomly divided into four groups. According to the type of the groups, rats were exposed to stress interventions including immobilization (two hours per day for 21 days), moderate running (30 minutes per day for 21 days), combination of stress interventions and running and also without any interventions. In order to determine the effectiveness of stress, animal weights were measured in two phases: before the protocol and after the tests. Morris Water Maze in several steps (four days for the acquisition phase, the fifth day for Probe test, three days for resting and the ninth day for recall test) was used for learning and testing of rats. ANOVA test with repeated measures and paired sample t test in acquisition phase and Tukey post hoc test were used to analyze data. The results revealed that stress damaged learning and memory (P=0.03). However, physical activity neutralized performance damage caused by stress (P=0.000). Physical activity group showed a significant positive effect on the time to reach the platform in the acquisition phase (P=0.005) and on cognitive function in recall phase (P=0.006) which was a sign of positive effect of physical activity on learning and memory. Therefore according to the present results which show that stress impairs learning and memory, it is expected that physical activity will be used as an effective factor to moderate stress.

Abstract The concept of imagery is to make an image of successful movement skill or a relaxing image in mind with no body training and external experience. The aim of the present study was to compare the effect of traditional and PETTLEP mental imagery methods on static and dynamic balance. The statistical population consisted of all female University of Tehran students who had general physical education course (1) in the first educational semester in 1389-1390. 54 participants (Mean age 21.94±1.89 yrs) attended voluntary in this study. First, they completed the Revised Movement Imagery Questionnaire (MIQ-R: Hall & Martin, 1997). Afterwards, pretest of static balance (Stork Balance Test) and dynamic balance (Modified Bass Test of Dynamic Balance) were performed. Participants were randomly assigned to three (n=18) groups (Physical training, Traditional imagery and PETTLEP imagery) and trained for 12 weeks (20 min/week). Finally, posttests of static and dynamic balance were performed under the same condition as the pretest. Retention test was performed 24 hours later and transfer test 30 minutes after the retention test. One-way ANOVA test showed no significant difference in static balance, dynamic balance and imagery ability scores in pretest among groups (p>0.05). Although ANOVA with repeated measures illustrated that although all three groups improved significantly in static and dynamic balance (P<0.05), there were no significant differences in posttest among them (P>0.05). Overall, results showed PETTLEP imagery was an effective method but not sufficiently efficient in dynamic balance.

Abstract The purpose of this study was to evaluate the effect of dietary zinc levels during gestation on physical development of offspring. The statistical population consisted of adult male and female rats (Albino-Wistar) which were obtained from Pasteur Institute, Iran. After mating, 9 pregnant female rats were divided into 3 groups: 1) Zinc deficient group (0.050.05). There was a significant decrease in crown-rump length in zinc supplement as compared to control group (P<0.05), but there was no significant difference in brain growth (P>0.05). These findings suggest that zinc deficiency during the last three months of pregnancy impairs brain and physical growth of offspring and to impose enhanced zinc supplement during the last three months of pregnancy has negative effects on physical development.