Effect of Reduced Feedback Frequencies on Motor Learning in a Postural Control Task in Young Adults.

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.

A Classroom-Based Intervention to Promote Physical Literacy in Children: ALPHYL Study Protocol.

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.

Motivation and Basic Psychological Needs Satisfaction in Active Travel to Different Destinations: A Cluster Analysis with Adolescents Living in Germany.

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.

Detection of intermuscular coordination based on the causality of empirical mode decomposition.

Considering the stochastic nature of electromyographic (EMG) signals, nonlinear methods may be a more accurate approach to study intermuscular coordination than the linear approach. The aims of this study were to assess the coordination between two ankle plantar flexors using EMG by applying the causal decomposition approach and assessing whether the intermuscular coordination is affected by the slope of the treadmill. The medial gastrocnemius (MG) and soleus muscles (SOL) were analyzed during the treadmill walking at inclinations of 0°, 5°, and 10°. The coordination was evaluated using ensemble empirical mode decomposition, and the causal interaction was encoded by the instantaneous phase dependence of time series bi-directional causality. To estimate the mutual predictability between MG and SOL, the cross-approximate entropy (XApEn) was assessed. The maximal causal interaction was observed between 40 and 75 Hz independent of inclination. XApEn showed a significant decrease between 0° and 5° (p = 0.028), between 5° and 10° (p = 0.038), and between 0° and 10° (p = 0.014), indicating an increase in coordination. Thus, causal decomposition is an appropriate methodology to study intermuscular coordination. These results indicate that the variation of loading through the change in treadmill inclination increases the interaction of the shared input between MG and SOL, suggesting increased intermuscular coordination.

Cognitive CAMSA: an ecological proposal to integrate cognitive performance into motor competence assessment.

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.

Test-Retest Reliability of Task Performance for Golf Swings of Medium- to High-Handicap Players.

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.

Encouraging People with Spinal Cord Injury to Take Part in Physical Activity in the COVID-19 Epidemic through the mHealth ParaSportAPP.

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.

Do Active Commuters Feel More Competent and Vital? A Self-Organizing Maps Analysis in University Students.

University students represent a population that faces high risks regarding physical inactivity. Research suggests that a regular engagement in physical activity (PA) may be more likely established when it leads to the experience of subjective vitality. Subjective vitality, in turn, is more likely achieved through physical activities that individuals feel competent in, and that take place in natural outdoor environments. An activity that may fulfill these conditions is active commuting to and from university (ACU). To examine whether and in which form ACU can combine this promising pattern of aspects, a person-oriented analysis was conducted. The sample contained 484 university students (59.3% females). Leisure-time PA, ACU by walking, ACU by cycling, subjective vitality, PA-related competence and body mass index were included as input variables in a self-organizing maps analysis. For both female and male university students, the identified clusters indicated that students who intensively engaged in ACU did not exhibit subjective vitality levels above average. Consistently, they did not show elevated levels of PA-related competence, which suggests that ACU does not support the perception of their physical abilities. Considerations regarding urban university environments lacking sufficient natural elements finally add to the conclusion that engaging in ACU does not suffice to establish a vitality-supportive and thus sustainable PA behavior. Additionally, the identified clusters illustrate a large heterogeneity regarding the interaction between leisure-time PA, body mass index and subjective vitality.

Diseño y usabilidad de ParaSportAPP: una mHealth destinada a promocionar la actividad física en personas con lesión medular / Design e usabilidade do ParaSportAPP: uma mHealth para promover a actividade física em pessoas comlesões da medula espinal / Design and usability of ParaSportAPP: an mHealth aimed at promoting physical activity in people with spinalcord injury

Objetivo: Diseñar y evaluar la usabilidad de una mHealth destinada a aumentar los niveles de actividad física en personas con paraplejia usuarias de sillade ruedas manual. Método: En primer lugar, se diseñó la mHealth ParaSportAPP mediante un comité de expertos en ejercicio físico y lesión medular. Posteriormente, una vezcreada la mHealth, se instaló ParaSportAPP en los teléfonos inteligentes de 15 personas con lesión medular dorsal usuarias de silla de ruedas. 8 mesesdespués de la instalación de la mHealth, se citó de nuevo a los participantes del estudio y cumplimentaron la Escala de Usabilidad del Sistema. Resultados: Se creó una mHealth con 79 ejercicios físicos diferentes y con dos modos distintos de transmitirlos al usuario. Además, la aplicación es capazde registrar los ejercicios físicos realizados al margen de los proporcionados por la misma y ofrece un informe a modo de feedback sobre el ejercicio físicorealizado durante el día. Asimismo, los resultados hallados mostraron una puntuación media de 77.5 (18.85) en la Escala de Usabilidad del Sistema.Conclusiones: Se ha conseguido diseñar y crear una mHealth funcional y con buenos niveles de usabilidad centrada en promocionar la actividad física enpersonas con lesión medular dorsal.(AU)

Aim: To design and evaluate the usability of an mHealth aimed at increasing physical activity levels in people with paraplegia who use manualwheelchairs. Method: Firstly, the ParaSportAPP mHealth was designed by a committee of experts in physical exercise and spinal cord injury. Subsequently, once themHealth was created, ParaSportAPP was installed on the smartphones of 15 wheelchair users with dorsal spinal cord injury. 8 months after theinstallation of the mHealth, the participants were summoned again and completed the System Usability Scale. Results: An mHealth was created with 79 different physical exercises and with two different ways of transmitting them to the user. In addition, theapplication is able to record the physical exercises performed in addition to those provided by the application itself and offers a feedback report on thephysical exercise performed during the day. The results also showed an average score of 77.5 (18.85) on the System Usability Scale. Conclusions: It has been possible to design and create a functional mHealth with good levels of usability focused on promoting physical activity in peoplewith dorsal spinal cord injury.(AU)

Objectivo: Conceber e avaliar a usabilidade de uma mHealth destinada a aumentar os níveis de actividade física em pessoas com paraplegia que utilizamcadeiras de rodas manuais. Método: Primeiro, o ParaSportAPP mHealth foi concebido por um comité de peritos em exercício físico e lesões da medula espinal. Subsequentemente,uma vez criada a mHealth, o ParaSportAPP foi instalado nos smartphones de 15 utilizadores de cadeiras de rodas com lesão da espinal medula dorsal. 8meses após a instalação do mHealth, os participantes do estudo foram novamente convocados e completaram a Escala de Usabilidade do Sistema. Resultados: Foi criada uma mHealth com 79 exercícios físicos diferentes e com duas formas diferentes de os transmitir ao utilizador. Além disso, o pedidoé capaz de registar os exercícios físicos realizados para além dos fornecidos pelo próprio pedido e oferece um relatório como feedback sobre o exercíciofísico realizado durante o dia. Além disso, os resultados encontrados mostraram uma pontuação média de 77.5 (18.85) na Escala de Usabilidade doSistema. Conclusões: Tem sido possível conceber e criar uma mHealth funcional com bons níveis de usabilidade centrada na promoção da actividade física empessoas com lesões da espinal-medula dorsal.(AU)

Impact of COVID-19 on the self-reported physical activity of people with complete thoracic spinal cord injury full-time manual wheelchair users.

CONTEXT: The emergence of COVID-19 caused a new public health crisis, leading to major changes in daily life routines, often including physical activity (PA) levels. The main goal of this study was to analyze the differences in self-reported physical activity of people with complete spinal cord injuries between the time prior to the COVID-19 lockdown and the lockdown period itself. METHODS: A sample of 20 participants with complete thoracic spinal cord injuries completed the Physical Activity Scale for Individuals with Physical Disabilities before and during the COVID-19 lockdown. RESULTS: The results showed differences between the pre-lockdown and lockdown measurements in total self-reported PA (z=-3.92; P<0.001; d=1.28), recreational PA (z=-3.92; P<0.001; d=1.18) and occupational PA (z=-2.03; P=0.042; d=0.55). Nevertheless, no differences were found in housework PA between the two time periods. Furthermore, the results showed differences in total minutes (z=-3.92; P<0.001; d=1.75), minutes spent on recreational activities (z=-3.82; P<0.001; d=1.56) and minutes spent on occupational activities (z=-2.032; P=0.042; d=0.55) of moderate/vigorous intensity. CONCLUSIONS: Individuals with thoracic spinal cord injuries who were full-time manual wheelchair users displayed lower levels of PA during the pandemic than in the pre-pandemic period. The results suggest that the prohibition and restrictions on carrying out recreational and/or occupational activities are the main reasons for this inactivity. Physical activity promotion strategies should be implemented within this population to lessen the effects of this physical inactivity stemming from the COVID-19 pandemic.

The effect of 26 versus 29-inch wheel diameter in the transmission of vibrations in cross-country mountain biking.

Vibrations experienced by cyclists can affect their performance and health. We analysed the vibrations transmitted by mountain bike (26 or 29-inch wheels), in a 2,110 m circuit with a sample of 55 cyclists. The results indicate that the 29"-wheel increases speed (p < 0.001) and thus performance but it also increases exposure to vibrations as the root mean square (RMS) indicate (p = 0.001). The wheel diameter significantly affected the accelerometer-related dependent variables (p < 0.01), specifically seen in the RMS variable (p < 0.01). Regarding vibration transmission variables, it was found that the LW/FH, RW/FH, LA/RH, and RA/RH ratios were higher in the 29" bicycle than in 26" one. Average heart rate (p = 0.01) and maximum heart rate (p < 0.01) values were higher for the 29" bike with no significant differences in the average power values recorded. In conclusion, bicycles with 29" wheels transmit higher levels of vibration to riders.

The tightening parameters of the vibratory devices modify their disturbing postural effects.

The purpose was to specify the impact of two different forces exerted by vibratory devices on the Achilles tendon on postural balance. The postural balance of 13 participants was evaluated on a force platform in two 40 s bipedal stance conditions with closed eyes. Tendon vibrations (80 Hz) were triggered 10 s after the beginning of the postural evaluation and applied during 20 s. Two levels of the force exerted by the vibrators were calibrated using load cells to control the tightening parameters of the vibrators: a strong tightening (ST) condition at 45 N and a light tightening (LT) condition at 5 N. The soleus electromyographic (EMG) activity and the spatio-temporal parameters of displacement of the centre of foot pressure (COP) were analysed. To analyse the effects of the introduction, the adaptation and the end of the stimulation, non-parametric tests were used. The results indicated that the soleus EMG activity increased only in the ST condition. However, during the vibration the anteroposterior COP position was significantly more in a backward position in the LT condition. At the end of the vibration, COP parameters increased more in the LT condition than the ST condition. This study demonstrated that the effects of the vibration depended on the force exerted by the devices on the tendons. The ST increased the vibration effects on EMG activity through greater stimulating effects compared to the LT. However, the ST could also increase the ankle joint stiffness and/or somaesthetic sensory information, which attenuated the COP backward shift.

Profiling children longitudinally: A three-year follow-up study of perceived and actual motor competence and physical fitness.

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.

The Impact of COVID-19 on Sport in Twitter: A Quantitative and Qualitative Content Analysis.

The spread of the SARS-CoV-2 virus has transformed many aspects of people's daily life, including sports. Social networks have been flooded on these issues. The present study aims to analyze the tweets produced relating to sports and COVID-19. From the end of January to the beginning of May 2020, over 4,000,000 tweets on this subject were downloaded through the Twitter search API. Once the duplicates, replicas, and retweets were removed, 119,253 original tweets were analyzed. A quantitative-qualitative content analysis was used to study the selected tweets. Posts dynamics regarding sport and exercise evolved according to the COVID-19 pandemic and subsequent lockdown, shifting from considering sport as a healthy bastion to an activity exposed to disease like any other. Most media professional sporting events received great attention on Twitter, while grassroots and women's sport were relegated to a residual role. The analysis of the 30 topics identified focused on the social, sporting, economic and health impact of the pandemic on the sport. Sporting cancellations, leisure time and socialization disruptions, club bankruptcies, sports training and athletes' uncertain career development were the main concerns. Although general health measures appeared in the tweets analyzed, those addressed to sports practice were relatively scarce. Finally, this study shows the importance of Twitter as a means of conveying social attitudes towards sports and COVID-19 and its potential to generate alternative responses in future stages of the pandemic.

Validation of Using Smartphone Built-In Accelerometers to Estimate the Active Energy Expenditures of Full-Time Manual Wheelchair Users with Spinal Cord Injury.

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.

Perceived movement skill competence in stability: Validity and reliability of a pictorial scale in early adolescents.

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.

The Relevance of Dual Tasking for Improving Trunk Muscle Endurance After Back Surgery.

OBJECTIVE: To determine the effect of dual tasking on trunk muscle endurance in patients after lumbar diskectomy. DESIGN: Cross-sectional study. SETTING: Rehabilitation hospital setting. PARTICIPANTS: Individuals (N=14) undergoing primary lumbar diskectomy. INTERVENTION: 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). MAIN OUTCOME MEASURES: 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. RESULTS: 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). CONCLUSIONS: 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.

Physical Activity-Related Profiles of Female Sixth-Graders Regarding Motivational Psychosocial Variables: A Cluster Analysis Within the CReActivity Project.

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.

Children's Single-Leg Landing Movement Capability Analysis According to the Type of Sport Practiced.

(1) Background: Understanding children's motor patterns in landing is important not only for sport performance but also to prevent lower limb injury. The purpose of this study was to analyze children's lower limb joint angles and impact force during single-leg landings (SLL) in different types of jumping sports using statistical parametric mapping (SPM). (2) Methods: Thirty children (53.33% girls, M = 10.16 years-old, standard deviation (SD) = 1.52) divided into three groups (gymnastics, volleyball and control) participated in the study. The participants were asked to do SLLs with the dominant lower limb (barefoot) on a force plate from a height of 25 cm. The vertical ground reaction force (GRF) and lower limb joint angles were assessed. SPM{F} one-way analysis of variance (ANOVA) and SPM{t} unpaired t-tests were performed during the landing and stability phases. (3) Results: A significant main effect was found in the landing phase of jumping sport practice in GRF and joint angles. During the stability phase, this effect was exhibited in ankle and knee joint angles. (4) Conclusions: Evidence was obtained of the influence of practicing a specific sport in childhood. Child volleyball players performed SLL with lower impact force and higher knee flexion than child gymnasts. Training in specific jumping sports (i.e., volleyball and gymnastics) could affect the individual capacity to adapt SLL execution.

Different neighborhood walkability indexes for active commuting to school are necessary for urban and rural children and adolescents.

BACKGROUND: Literature focusing on youth has reported limited evidence and non-conclusive associations between neighborhood walkability measures and active commuting to and from school (ACS). Moreover, there is a lack of studies evaluating both macro- and micro-scale environmental factors of the neighborhood when ACS is analyzed. Likewise, most studies on built environment attributes and ACS focus on urban areas, whereas there is a lack of studies analyzing rural residential locations. Moreover, the relationship between built environment attributes and ACS may differ in children and adolescents. Hence, this study aimed to develop walkability indexes in relation to ACS for urban and rural children and adolescents, including both macro- and micro-scale school-neighborhood factors. METHODS: A cross-sectional study of 4593 participants from Spain with a mean age of 12.2 (SD 3.6) years was carried out. Macro-scale environmental factors were evaluated using geographic information system data, and micro-scale factors were measured using observational procedures. Socio-demographic characteristics and ACS were assessed with a questionnaire. Several linear regression models were conducted, including all the possible combinations of six or less built environment factors in order to find the best walkability index. RESULTS: Analyses showed that intersection density, number of four-way intersections, and residential density were positively related to ACS in urban participants, but negatively in rural participants. In rural children, positive streetscape characteristics, number of regulated crossings, traffic calming features, traffic lanes, and parking street buffers were also negatively related to ACS. In urban participants, other different factors were positively related to ACS: number of regulated crossings, positive streetscape characteristics, or crossing quality. Land use mix acted as a positive predictor only in urban adolescents. Distance to the school was a negative predictor on all the walkability indexes. However, aesthetic and social characteristics were not included in any of the indexes. CONCLUSIONS: Interventions focusing on improving built environments to increase ACS behavior need to have a better understanding of the walkability components that are specifically relevant to urban or rural samples.