نشریه رفتار حرکتی
پیاپی 51 (بهار 1402)

The main purpose of this study was to investigate the effect of representative tasks on anticipation and decision - making skills in the laboratory environment. 58 participants with mean age 22. 30 ± 3.08 selected based on inclusion criteria and purposefully allocated in five groups (cognitive, cognitive-motor, motor, athlete (skilled) and control). A video-based temporal occlusion test was used to first assess the anticipatory and decision-making skills based on the situations (monitoring, evaluating events, predicting future events, and planning future actions). Cognitive and cognitive-motor groups experienced 8 session training in lab atmosphere, then all groups completed a post-test. Accuracy and quality of anticipation and decision-making was recorded during verbal reports. The frequencies of correct tactical responses were calculated and evaluated for each statement type. Data were analyzed using analysis of covariance in SPSS 21. The results showed that the effect of group on design and planning for decision making was significant (F (53,4)) = 3.68, P = 0.011, eta coefficient 0.23) and the athlete )skilled ( group had high values compared to the cognitive group in this variable (p

Optimal performance of complex Forehand stroke needs coordination between postural adjustment and focal movement. the purpose of this study was to investigate the relationship between onset time and magnitude of Anticipatory Postural Adjustment (APA) and constant and variable error of Table Tennis Forehand stroke among skilled and novice players. For this, skilled (n=10) and novice (n=10) participants, perform Forehand stroke under Coincident Anticipation Timing (CAT) paradigm and EMG of selected postural muscles were simultaneously recorded. The results of investigating the EMG data showed that in all postural muscles, APA was occurred before focal movement initiation. In addition, the results of two way MANOVA test showed that in comparison with novices, skilled players had higher accuracy and lower variable error in their performance (P<0.05). Also, the result of Pearson moment correlation test revealed that among skilled players, both early onset time and greater magnitude of APA correlated with higher accuracy (P<0.05); however, only the APA’s onset time correlated significantly with both accuracy and variability of novices’ performance (P<0.05). Lower variable error in skilled players’ performance in comparison to novice counterparts and yet lack of correlation with onset time and magnitude of APA, probably indicates the consolidation of internal models as a result of practice and long term experience of skilled players in that sports skills.

Although the effect of ankle muscles on postural control and muscle synergies has well been investigated, it is needed to study more about the contribution of central and peripheral fatigue of submaximal contractions on postural control and muscle synergies. The aim of this study was to investigate the effect of submaximal fatiguing exercise that induce preferentially central fatigue on muscle synergy and postural control. For this purpose, 12 volunteer subjects participated in this study. The tibia nerve was electrically stimulated to assess the M-wave, central fatigue (voluntary activation) and peripheral fatigue (rest imposed twitch) during voluntary maximal contractions on dynamometer. Moreover, electromyography activity of ten muscles and COP were recorded to assess muscle synergy and postural stability respectively during anterior-posterior voluntary sway on force plate. In order to induce fatiguing exercise the subjects performed submaximal fatiguing contractions on dynamometer and all of the mentioned variables again were measured. The effect of the fatiguing protocol tested with paired-samples T Test and Z Fisher Test. Submaximal contractions induced greater increases of COP sway area. Muscles activation, muscle synergies variance decreased and the number of co-contractions increased significantly after submaximal contractions (P = 0.01). Contribution of central fatigue (16.64%) significantly greater than peripheral fatigue (2.32%) after submaximal contractions (P = 0.02). The results of this study showed that more central fatigue after submaximal contraction leads to more COP changes. Therefore, investigating central and peripheral mechanisms following ankle fatiguing contractions may be useful for scheduling rehabilitation and balance training programs.

The aim of this study was to investigate the effect of neurofeedback (NFB) and motor training (MT) on the learning and consolidation of procedural motor performance in novice adolescents. 44 elementary students (mean age 12.1 ±0.6), who had no access to smart devices, were selected as the sample of the research, and then were randomly assigned into four groups; NFB, MT, NFB+MT and control. The implementation of the study included six stages: first baseline, pre-test, intervention (NFB included a 30 minute single-session of alpha suppression on the C4 region for NFB and NFB+MT groups. MT by using 6 blocks of Pursuit Rotor Task (PRT) for NFB+MT and MT groups), secondary baseline, post-test and consolidation test, respectively. Stages 1-5 were done in one day but last stage (learning consolidation test) was conducted 48 hours after the rest period. Participants were right-handed and performed PRT in inverted mode with their non-dominant hand. One-way repeated measures analysis of variance (ANOVA) was used to analyses the data. The results showed significantly different between the performance of NFB and MT (P=0.010), NFB and NFB+MT (P=0.044), MT and Control (P=0.022) groups, but the difference between MT and NFB+MT (P=1.000), NFB+MT and Control (P=0.90), and NFB and Control (P=1.000) groups was not significant. The present findings showed that the alpha suppression in C4 had no significant effect on learning and consolidation of unfamiliar and non-automatic movements in novice adolescents but motor training can be an effective way for these people in the first stage of their learning.

The aim of this study was to investigate the relationship between neonatal health indicators and socio-economic factors with motor development and visual perception in children. Participants were children aged 7 to 9 years in Tabriz, from which 103 people were randomly selected from three public schools. To collect data, a demographic information questionnaire and information related to childbirth, Socio-economic background questionnaire, Bruininks-oseretsky Test of Motor Proficiency and Benton’s visual retention test were used. Analysis of data obtained from Pearson correlation test and multiple linear regression showed, between the variables of mother education (P = 0.001), father education (P = 0.001), place of residence (P = 0.03) and type Birth (P = 0.01) with motor development, in children at the age of 7 to 9 years, a positive and significant relationship was observed. Also, a positive and significant relationship was observed between the variables of income (P = 0.04) and birth weight (P = 0.001) with visual perception. Also, the two variables of mother's education (33%) and father's education (32%) have the power to predict children's motor development and variable of birth weight (46%) can predict children's visual perception. Therefore, it can be said that neonatal health indicators (except birth weight) do not have the ability to predict children's motor and perceptual development; While socioeconomic factors of parents can predict motor and perceptual development. Therefore, it can be said that emphasizing the role of socio-economic status in motor development and visual perception of children is very important.

The home quarantine period caused by the Covid-19 pandemic can affect children's perceived motor ability. The purpose of the present study was to investigate the effect of physical maturity levels and the type of positive or negative attitudes of parents to play in green space on perceived motor competence during home quarantine. This research was a cross-sectional observational study, three hundred female participants by the mean age of 9 to 11 in the academic year of 2020-2021. The data of the present study are in the form of an online survey including 3 sections on demographic characteristics, competence, motor skills, perception and parents' attitudes toward playing in green space , was collected. To determine the status of physical maturity, the method of estimating the percentage of adulthood obtained at a certain age (Khamis-Roche 1994 method) was used. According to the analysis of variance, the main effect of physical maturity and the main effect of parents' attitude toward outdoor playing on mobility skills, object-control and perceived motor competence is significant (p <0.05). Children with normal and premature maturity levels and those children whose parents' attitudes toward outdoor playing were positive in compared to delay children and those children whose parents had a negative attitude towards outdoor playing, had showed a better movement skills, object control and perceptual motor competence. As a result, outdoor playing and playing in nature are recommended for children with different levels of maturity to develop basic motor skills during and after home quarantine.

The emergence of physical adaptations through the confinement of the environment and homework has been widely used as a training method in the study of sports performance. Task and environment constraints are very important in cognitive, perceptual, decision-making, and tactical behaviors. Therefore, the present study intends to investigate the effect of task restraint manipulation on kinetic indicators and excellence associated with the risk of falling in the elderly. For this purpose, 45 elderly people were randomly divided into three groups according to the inclusion and exclusion criteria of the study: homework restraint manipulation, non-homework restraint manipulation and control group. The experimental groups then performed homework restraint exercises and non-restraint exercises for eight weeks. The control group also continued their normal activities during the investigation. Static balance meter was used to evaluate the kinetic index and leaf test was used to evaluate the dynamic balance. The results of analysis of covariance by removing the effect of pretest showed that the group obtained significantly higher scores than the group without manipulation and control by manipulating the task constraints in the kinetic index and Burke scale with (P = 0.000) high reliability. The results of this study supported the use of various manipulations of homework constraints as a kind of teaching strategy for the elderly. It also confirms the effect of exercises by manipulating the restrictions of the task, which improves balance in the elderly, and by improving this ability, the risk of falling in this segment of society is reduced.