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L'article revisa els temes principals en la preservació i reutilització de les dades de recerca (beneficis, cicle de vida, projectes, normatives, etc.) i identifica la falta d'un registre mundial de bancs, repositoris i biblioteques de dades. Exposa la creació d'una eina web que reculli aquest tipus de dipòsits i els classifiqui per àrees disciplinàries: ODiSEA, International Registry on Research Data, que ofereix resultats sobre nombre i tipologia temàtica d'aquest tipus de dipòsits a escala mundial. Aquesta aportació facilita el descobriment de nous conjunts de dades, la recombinació de les quals, des d'una perspectiva multidisciplinària, ha de fomentar la innovació i la rendibilitat de la inversió en ciència.This paper reviews the main issues in the preservation and reuse of research data (including benefits, life cycle, projects and regulations) and identifies the lack of a world register of data banks, repositories and libraries. It describes the creation of a web tool that lists these kinds of data stores and classifies them by field. This tool is called the International Registry on Research Data (ODiSEA) and it describes the number of data stores worldwide and the topics they cover. The registry makes it easier to discover new data sets, which can be recombined from a multidisciplinary perspective to promote innovation and increase returns on science investments.

This study aimed to capture the multidimensionality of adolescents' motivation in the physical education (PE) setting, within self-determination theory, by employing self-organizing maps (SOM) analysis. Particularly, it examined the topological relationships among students' basic psychological needs satisfaction, their perception of more or less self-determined motivation and the affective and behavioural consequences in PE lessons across several sociodemographic variables. A nationally representative sample of 3029 Spanish students (51% girls), aged 12 to 18 years, was surveyed. SOM mapped well-defined students' profiles that embraced interrelatedly a considerable number of students' motivational characteristics. Four target profiles, out of 10, were explored. The first two profiles, highly motivated to be active girls and boys, mainly experienced senses of self-determination, but also controlled reasons for participating in PE lessons, high perceived competence, relatedness and autonomy fulfilment, perceived exerted effort and satisfaction. However, the reluctance to be physically active presented two gendered motivational profiles. Barely motivated to be active girls showed the lowest levels of self-determined motivation, including introjected regulation, low perceptions of competence, autonomy, relatedness, and dissatisfaction in PE. Vaguely motivated to be active boys revealed that despite their perceptions of competence the neglect of the other two psychological needs was more likely to determine a controlled motivation and, consequently, maladaptive outcomes. SOM proved to be a more robust and accurate clustering technique than the k-means algorithm and helped to portray and visualize the complexity behind the decision to become an active person considering the motivational processes in PE. Implications are provided for practitioners.

Objective: To determine which type of feedback (visual, verbal, or both combined) facilitates to a greater extent the learning of a specific skill (passing in volleyball). Methods: Three groups of students between 14 and 15 years of age belonging to the third year of Compulsory Secondary Education in a Spanish public high school (n = 58) were randomly assigned a type of feedback implemented in the part of the syllabus dedicated to volleyball. The students' knowledge, motor performance, accuracy, and self-perception about the action were evaluated before and after the intervention and enjoyment afterwards. Results: All the groups obtained improvements in all the variables studied (p < 0.05); the verbal and visual feedback group was the one that obtained greater improvements, showing also a greater enjoyment than the visual feedback group. Conclusions: It has been found that the use of the combination of verbal and visual feedback is most recommended for learning a specific skill, such as passing in volleyball.

This study analyzed the development of postural control and the cost of the cognitive task on postural control in the bipedal standing position during childhood. Sixty-six normally developed children divided into four groups by age participated in this study. Single (ST) and dual-tasks (DT) were conducted in the bipedal standing position with eyes open. DT included carrying out a cognitive task consisting of a modified Stroop Test. A Wii Balance Board was used to measure postural sway data. The results showed effects of age and condition on postural control (p < 0.01). The interaction of age x condition showed that in DT, 4-year-old children presented higher ellipse area than 5, 6, 7-year-olds (p < 0.01). Moreover, an effect of age on cognitive performance was found (p < 0.001). In conclusion, four-year old children present lower postural control than 5, 6, 7-year-olds. The youngest children gave fewer correct answers than the 6 and 7-year-olds.

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The effects of the use of reduced feedback frequencies on motor learning remain controversial in the scientific literature. At present, there is still controversy about the guidance hypothesis, with some works supporting it and others contradicting it. To shed light on this topic, an experiment was conducted with four groups, each with different feedback frequencies (0%, 33%, 67%, and 100%), which were evaluated three times (pre-test, post-test, and retention) during a postural control task. In addition, we tested whether there was a transfer in performance to another similar task involving postural control. As a result, only the 67% feedback group showed an improvement in their task performance in the post-test and retention evaluations. Nevertheless, neither group showed differences in motor transfer performance compared to another postural control task. In conclusion, the findings of this paper corroborate the hypothesis of guidance and suggest that the use of a reduced frequency of 67% is a better option for improving motor learning than options that offer feedback at a lower frequency, at all trials or not at all. [ABSTRACT FROM AUTHOR]

Purpose: To profile the participants using a system of self-organizing maps (SOM) based on their motor and cognitive performance during a dual-task version of the Canadian Agility and Movement Skill Assessment (Cognitive CAMSA). Methods: A total of 169 secondary school students (39.3% girls) volunteered to participate. The original CAMSA, cognitive CAMSA, the Corsi and Digit Span tests were used to assess (a) motor competence, (b) motor competence with cognitive load, and (c) cognitive performance, respectively. SOMs and the k-means clustering algorithm were used to establish the adolescents’ dual-task performance profiles. Results: Including decision making based on verbal and visual cues in the original CAMSA significantly increased the participants’ total scores but also the time required to complete the test, while the skill score remained unchanged. However, not all the participants showed changes in their performance in the same direction during the cognitive CAMSA. Person-centered analyses by SOMs and k-means clustering identified six performance profiles with variations in the cognitive, motor skill, and time scores (H5 = 146.15, H5 = 102.68, and H5 = 108.07, respectively; all p < 0.01). Conclusion: The cognitive CAMSA was shown to be a feasible field-motor test for assessing motor competence with a cognitive load in an ecological setting. Some of the profiles identified in the SOM approach represented adolescents with similar motor and cognitive performance in dual-task or single-task contexts, although other participants obtained high motor competence in single and dual-tasking while their cognitive performance declined or rose more in dual-task than in single task situations. The cognitive CAMSA emerges as a tool of great potential, applicable in educational and sports environments, to know subjects’ characteristics and try to individualize the interventions accordingly with their dual-task profile. [ABSTRACT FROM AUTHOR]

Copyright of Educación XX1 is the property of Editorial UNED and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The popularity of 29-inch mountain bike wheels for cross-country races has been increasing since 2010, but scientific studies supporting their benefits are very scarce. The aim of this study was to analyse the effect of the different bicycle version (i.e. 26 vs 29-inch) in terrain with varying inclinations. Our results indicated that for full laps, the 29" version was slightly faster than 26" version (15.92 vs. 15.74 km/h; p <.001). No differences in the power outputs for these two conditions were reported (p >.05), but a higher mean heart rate (p =.009) was obtained for the riders using the bike with the 29" wheels (167.84 vs. 167.19 bpm; p <.015). Similar results were obtained for the uphill and flat sections, however, there were no differences (p >.05) between the bikes during the downhill sections for any of the studied variables. In conclusion, the 29" version performed better on the flat or uphill terrain but their use also resulted in increased rider heart rates compared to those using the 26"-inch version; no differences were reported for the downhill terrain. This information is relevant to MTB cyclists and could help them to improve their performance. [ABSTRACT FROM AUTHOR]

Physical literacy is crucial for children's appropriate development and physical, social and mental health. In a school setting, class-based physical activity (PA) interventions are considered to be appropriate programs to foster PA participation and cognitive development. The purpose of this project, named the Active Learning in PHYsical Literacy (ALPHYL) study, was to describe a multicomponent classroom-based physically-active learning randomised control trial (RCT) in primary school children. The main purpose was to promote children's physical literacy, academic achievement and cognitive function. The ALPHYL study is mainly based on physical literacy, active school models and the Supportive, Active, Autonomous, Fair and Enjoyable principles. The ALPHYL is an 8–10-week RCT to be conducted in six primary schools (12 classes) in Valencia (Spain) and its metropolitan area. Schools will be randomly assigned to the intervention or waiting-list control group. After a 30 h in-person training course for teachers and weekly meetings in the three months of resource preparation, the ALPHYL intervention will be conducted in physical education (PE) and non-PE lessons by teachers. The intervention consists of at least three daily sessions of physically active learning in addition to model-based PE teaching. Its feasibility will be evaluated weekly according to the Reach, Effectiveness, Adoption, Implementation and Maintenance framework. To assess its effectiveness, a pre-test, post-test and retention (8–10 weeks post-intervention) with primary outcomes (i.e., PA level, motor competence, perceived motor competence and PL, motivation, perceived social support, academic achievement and cognitive function), secondary outcomes and covariates will be collected. [ABSTRACT FROM AUTHOR]

Copyright of Retos: Nuevas Perspectivas de Educación Física, Deporte y Recreación is the property of Federacion Espanola de Asociaciones de Docentes de Educacion Fisica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Active travel in adolescence contributes to improved health outcomes. Self-Determination Theory suggests that motivation and basic psychological needs influence travel behavior. Person-centered approaches can examine interrelationships of these constructs underlying travel behavior. The aim of this study was to investigate (i) which clusters can be identified in adolescents, (ii) whether clusters explain overall active travel behavior, (iii) whether clusters were associated with travel mode to various destinations or distance, and (iv) whether differences across clusters appear regarding sex/gender, age, and weight status. The sample included 517 (263 male, 254 female) adolescents from Germany, aged 11–15. Self-organizing maps analysis identified six clusters from nine input variables: intrinsic motivation, integrated regulation, identified regulation, introjected regulation, external regulation, amotivation, autonomy satisfaction, competence satisfaction, and relatedness satisfaction. The most beneficial cluster regarding active travel demonstrated highest basic psychological needs satisfaction and autonomous motivation with low controlled motivation and amotivation. The most vulnerable cluster was characterized by generally low levels of motivation except for external regulation and amotivation. Clusters were not associated with distance to school, friends/relatives, shopping facilities, or leisure facilities. The findings support the importance of high quality and high quantity of motivation for active travel in adolescents. [ABSTRACT FROM AUTHOR]

Background: Golf swing performance in medium- to high-handicap players must be reliably measured to use this variable in both research studies and in applied settings. Nevertheless, there are no studies published on this topic and test–retest evidence is only available for low-handicap players. The aim of this study was to determine the number of attempts necessary to obtain a reliable measurement protocol for swing performance variables in medium- to high-handicap players. Methods: Ten amateur players (55.67 (13.64) years, 78.4 (11.4) kg, 1.75 (7.95) m) took part in a test–retest study in two experimental sessions one week apart. In each one, fifteen swings with a six iron and a driver were evaluated with a 3D Doppler tracking golf radar. Results: The results showed that variables related to side carry could not be reliably measured in medium- to high-handicap players in only fifteen trials (ICC < 0.26, SEM > 12.05 m and MDC > 33.41 m). The rest of the performance variables related to the club and ball trajectories could be reliably measured with a 3D Doppler radar with between seven and ten swings. Conclusions: At least seven swings are recommended for the driver and ten for the six iron to measure golf swing performance. [ABSTRACT FROM AUTHOR]

Copyright of Retos: Nuevas Perspectivas de Educación Física, Deporte y Recreación is the property of Federacion Espanola de Asociaciones de Docentes de Educacion Fisica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper describes a study on postural stability and cognitive function according to the difficulty increment of a working memory task (WMT) and age group in adolescents. One hundred and twenty-three participants (13-16 years) performed single and dual tasks in a bipedal standing position while barefoot. Four trials were conducted, consisting of single and dual tasks in three progressively difficult WMT conditions (i.e., 3-, 5-, and 7-digit sequences). Friedman's analysis of variance and Kruskal-Wallis tests were conducted to test the effect of the WMT and age group, respectively. Both the WMT and age were found to affect performance (p < .01). As the cognitive requirements increased, the adolescents were not able to maintain their performance in both balance and cognition, while postural control and cognition were found to evolve with age. [ABSTRACT FROM AUTHOR]

Background: Although mHealth tools have great potential for health interventions, few experimental studies report on their use by people with spinal cord injuries in physical activity. Objective: The main objective of this study was to analyze the effect of the ParaSportAPP on different physical and psychological variables in people with paraplegia. Methods: Fourteen of these subjects made up the final sample. All the participants performed two pre-tests (control period) and a post-test with 8 months between the evaluations (COVID-19 broke out between pre-test 2 and the post-test). The ParaSportAPP was installed on their smartphones when they performed pre-test 2. The same tests were performed in the same order in all the evaluations: (i) the questionnaires PASIPD, HADS, RS-25; SCIM III and AQoL-8D, (ii) respiratory muscle strength, (iii) spirometry and (iv) cardiopulmonary exercise test. Results: The results showed no differences in any of the variables studied between the measurement times. Conclusions: Although none of the variables experienced improvements, the ParaSportAPP mobile application was able to lessen the impact of the pandemic on the variables studied. [ABSTRACT FROM AUTHOR]

Copyright of Retos: Nuevas Perspectivas de Educación Física, Deporte y Recreación is the property of Federacion Espanola de Asociaciones de Docentes de Educacion Fisica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Previous research shows contradictory findings on potential competing effects between sedentary screen media usage (SMU) and physical activity (PA). This study examined these effects on adolescent girls via self-organizing maps analysis focusing on 3 target profiles. Methods: A sample of 1,516 girls aged 12 to 18 years self-reported daily time engagement in PA (moderate and vigorous intensity) and in screen media activities (TV/video/DVD, computer, and videogames), separately and combined. Results: Topological interrelationships from the 13 emerging maps indicated a moderate competing effect between physically active and sedentary SMU patterns. Higher SES and overweight status were linked to either active or inactive behaviors. Three target clusters were explored in more detail. Cluster 1, named temperatemedia actives, showed capabilities of being active while engaging in a moderate level of SMU (TV/video/DVD mainly). In Cluster 2, named prudent-media inactives, and Cluster 3, compulsive-media inactives, a competing effect between SMU and PA emerged, being sedentary SMU behaviors responsible for a low involvement in active pursuits. Conclusion: SMU and PA emerge as both related and independent behaviors in girls, resulting in a moderate competing effect. Findings support the case for recommending the timing of PA and SMU for recreational purposes considering different profiles, sociodemographic factors and types of SMU. [ABSTRACT FROM AUTHOR]

Perceived motor competence (PMC) is important to health as it mediates the association between actual motor competence (AMC) and physical activity. Many instruments assess the broader construct of physical self‐perception but no scale has been developed to assess PMC in stability. The aim of this study was to develop and analyze the reliability and validity of a new pictorial PMC in stability skill assessment when completed by early adolescents. A Delphi method showed ≥70% of experts' consensus in the seven proposed items. A sample of 904 students (11‐14 years old) self‐reported PMC in locomotion, object control, and stability using two pictorial scales: Perceived Movement Skill Competence (PMSC) and the newly developed Stability (PMSC_Stability). The Körperkoordinations test for Kinder (KTK) was also administered as a measure of AMC in skills that utilize stability. Two different subsamples were randomly assigned to criterion validity and reliability assessments. Spearman's correlation, confirmatory factor analysis, and a general linear model for sex and age were conducted. The internal consistency (α) and test‐retest (intraclass correlation coefficient) reliability values were good (>0.70). A single‐factor latent model represented stability and did not differ by sex. Stability perception was associated with AMC (rho = 0.51). Stability is important to the performance of many movement skills (eg, single‐leg balance or moving on a narrow surface). Understanding which adolescents have poor stability perception could highlight stability as an area that needs targeting in order to increase physical activity and sport participation. [ABSTRACT FROM AUTHOR]

Longitudinal designs enhance our understanding of children's development and its influence on movement behaviors and health. This three‐year follow‐up study aimed to develop profiles according to perceived and actual motor competence (MC) (locomotion, object control, and overall) and physical fitness in boys and girls longitudinally including children's temporal migrations among clusters in terms of profiling trends. A secondary aim was to compare physical activity participation and weight status at each time point according to these profiles. One hundred and four typically developing Spanish children (45.8% girls) between 4 and 9 years old at baseline participated in this study. Data were collected at three time points one year apart, between January 2016 and May 2018. A self‐organizing map and K‐means cluster analysis were used to classify and visualize the values and temporal trajectories longitudinally. The study of the profiles in three consecutive years revealed five profiles, three for boys [ie, profile 1 (aligned—high), profile 2 (aligned‐partially—low perception‐medium actual MC and fitness), and profile 3 (non‐aligned—medium perception‐low actual MC and fitness)]; and two for girls [ie, profile 4 (aligned—high) and profile 5 (aligned—low)]. For highly perceived and capable children, boys (profile 1) and girls (profile 4), there was a tendency for higher physical activity participation and lower body mass index and waist circumference over time compared to their counterparts who had medium and/or low levels in perception and actual MC and fitness (P <.05). As children age, those with low values in perceived and actual MC and fitness in object control skills will present a higher probability of maintaining unhealthy lifestyles. So, prior intervention, children's profiles identification should be analyzed according to the type of MC. [ABSTRACT FROM AUTHOR]

To determine the effect of dual tasking on trunk muscle endurance in patients after lumbar diskectomy. Cross-sectional study. Rehabilitation hospital setting. Individuals (N=14) undergoing primary lumbar diskectomy. Using a randomized design on 2 separate days, muscle endurance was evaluated during prone bridging and Biering-Sorensen tests. Each test was randomly performed under 2 cognitive conditions: single task without cognitive condition and self-regulated dual task (ie, mathematical task). The primary outcomes were time to failure and pain assessed by the visual analog scale from 0 to 100 mm. The secondary outcomes were kinesiophobia assessed by the Tampa Scale and disability assessed by the Oswestry Disability Index. Associations were tested using a repeated measures analysis of variance with relevant interaction test. A significant interaction between condition, endurance tests, and kinesiophobia (P =.005) was found. The post hoc comparison showed positive effects between cognitive conditions in both endurance tests (prone bridging test: mean difference, 15.7s; 95% confidence interval [CI], 7.5-24s; P =.001; Biering-Sorensen test: mean difference, 7.9s; 95% CI, 1.9-14s; P =.014). The linear regression analysis between the Tampa Scale for Kinesiophobia and the difference of time to failure between cognitive conditions showed a positive correlation only during the Biering-Sorensen test (r =0.80; P =.001). A self-regulated dual task increases trunk muscle endurance in patients after lumbar diskectomy. The results suggest that the difference observed in time to failure between the single task and dual task is associated with fear avoidance, especially during back extension. This strategy seems especially relevant for patients with high levels of fear avoidance and may be used to improve trunk muscle endurance. • The effect of dual tasking on muscle endurance performance after lumbar diskectomy remains uninvestigated. • Compared with single tasking, dual tasking has a positive effect on trunk muscle endurance in patients with lumbar diskectomy. • The positive effect of dual tasking is associated with fear avoidance. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the validity of using built-in smartphone accelerometers to estimate the active energy expenditures of full-time manual wheelchair users with spinal cord injury (SCI). Twenty participants with complete SCI completed 10 5-min daily activities that involved the upper limbs, during which their oxygen consumption and upper limb activity were registered using a portable gas analyzer and a smartphone (placed on the non-dominant arm), respectively. Time series of 1-min averaged oxygen consumption and 55 accelerometer variables (13 variables for each of the four axes and three additional variables for the correlations between axes) were used to estimate three multiple linear models, using a 10-fold cross-validation method. The results showed that models that included either all variables and models or that only included the linear variables showed comparable performance, with a correlation of 0.72. Slightly worse general performance was demonstrated by the model that only included non-linear variables, although it proved to be more accurate at estimating the energy expenditures (EE) during specific tasks. These results suggest that smartphones could be a promising low-cost alternative to laboratory-grade accelerometers to estimate the energy expenditure of wheelchair users with spinal cord injury during daily activities. [ABSTRACT FROM AUTHOR]

The potential of the Technologies of Information and Communication in educational contexts has been questioned in recent years. However, the subject of physical education has now become a permeable space for including technological devices, despite the fact that there is some resistance to their incorporation into the classes. This is mainly due fears of the risk derived either from their misuse or because some schools are unable to make the investment in certain devices. This paper describes an innovative experience with mobile devices as gamifying elements in the field of physical education in higher education, by which we aimed to show the symbiotic effect of the use of technology as a facilitator of the practice of physical activity. The study also indicated that it is not necessary to provide each student with an individual device in order to obtain reliable data, as well as suitable procedures for the participants' assessment procedures. After performing different analyses based on a positivist research paradigm, we found that the experience was positively valued by the students and that the daily recommendations for moderate physical activity were improved. The validity and reliability tests confirmed that one device for every two students would be enough provide useful information regarding the students' physical demands. Incorporating technology in PE lessons has thus been shown to be satisfactory for the students. It not only favoured the fulfilment of the recommendations on physical activity but also obtained valid and reliable information without requiring all the students to have their own individual device. [ABSTRACT FROM AUTHOR]

Introduction: Adolescents' physical activity (PA) behavior can be driven by several psychosocial determinants at the same time. Most analyses use a variable-based approach that examines relations between PA-related determinants and PA behavior on the between-person level. Using this approach, possible coexistences of different psychosocial determinants within one person cannot be examined. Therefore, by applying a person-oriented approach, this study examined (a) which profiles regarding PA-related psychosocial variables typically occur in female sixth-graders, (b) if these profiles deliver a self-consistent picture according to theoretical assumptions, and (c) if the profiles contribute to the explanation of PA. Materials and Methods: The sample comprised 475 female sixth-graders. Seventeen PA-related variables were assessed: support for autonomy, competence and relatedness in PE as well as their satisfaction in PE and leisure-time; behavioral regulation of exercise (five subscales); self-efficacy and social support from friends and family (two subscales). Moderate-to-vigorous PA was measured using accelerometers. Data were analyzed using the self-organizing maps (SOM) analysis, a cluster analysis including an unsupervised algorithm for non-linear models. Results: According to the respective level of psychosocial resources, a positive, a medium and a negative cluster were identified. This superordinate cluster solution represented a self-consistent picture that was in line with theoretical assumptions. The three-cluster solution contributed to the explanation of PA behavior, with the positive cluster accumulating an average of 6 min more moderate-to-vigorous PA per day than the medium cluster and 10 min more than the negative cluster. Additionally, SOM detected a subgroup within the positive cluster that benefited from a specific combination of intrinsic and external regulations with regard to PA. Discussion: The results underline the relevance of the assessed psychosocial determinants of PA behavior in female sixth-graders. The results further indicate that the different psychosocial resources within a given person do not develop independently of one another, which supports the use of a person-oriented approach. In addition, the SOM analysis identified subgroups with specific characteristics, which would have remained undetected using variable-based approaches. Thus, this approach offers the possibility to reduce data complexity without overlooking subgroups with special demands that go beyond the superordinate cluster solution. [ABSTRACT FROM AUTHOR]

Copyright of Movement & Sport Sciences / Science & Motricité is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The purposes of the present study were a) to establish postural control profiles for individuals 6–12 years of age, b) to analyze the participants' characteristics (age, sex, weight, height, and physical activity) in those profiles, and c) to analyze the influence of visual information in the profiles found. Two hundred and eight typically developing children aged 6–12 years performed two trials in bipedal standing position with eyes open and closed. Feature extraction involved time, frequency, and sway-density plot variables using signals from the center of pressure. A Self-Organizing Map was used to classify and visualize the values of the participants in all the postural control variables tested. A k-means cluster analysis was applied to generate a small number of postural control profiles. The results determined six postural control profiles; three with participants denoting high stability and three considered as low stability profiles. Age, sex, and height were related to the postural control profiles. Boys were more frequently allocated in high stability clusters than girls, while the other factors yielded unclear difference between high and low stability profiles. The analysis of children's profiles reflecting postural stability should therefore involve more than one factor including the individuals' age, sex, and height. [ABSTRACT FROM AUTHOR]

External supports that reduce ankle joint mobility such as ski-boots can impair postural control of healthy participants. Although this disruptive effect has been attributed to the rigidity of the external supports, the results remained controversial and no study has been conducted in order to evaluate the influence of ski-boots rigidity. Hence, the question about the influence of ankle support rigidity on postural control remains open. This study was therefore undertaken in order to investigate the effect of ski-boots rigidity on postural control. Ten healthy active participants were recruited. The wearing of soft and rigid ski-boots was compared to barefoot while standing on a seesaw generating mediolateral and anteroposterior instability. Centre of pressure displacements were sampled with a force platform. The surface electromyographic activity of the main muscles from the leg, thigh and trunk was recorded. A motion analysis system was also used to calculate the ankle, knee and hip angles. The results did not reveal any negative influence of ski-boot rigidity on postural control but rather suggest a less active postural control with the rigid ski-boots which offered a higher mechanical contribution. [ABSTRACT FROM AUTHOR]