Motor abilities in dance structure performance in female students

The aim of the study was to analyze the relation between motor abilities and performance in folk dances originating from the island of Hvar and modern social dances. Two groups of variables were used in a sample of 78 female students of the Teacher Training College from Split: 7 motor variables as a battery of predictors, and performance evaluation of 4 dances (2 folk dances, i.e. ciciliona and pasavijen, and 2 social dances, i.e. cha-cha-cha and rock-'n'-roll) as criterion variables. Canonical correlation analysis between the groups of variables yielded two canonical correlations of 0.94 and 0.73, with a level of significance of p<0.001. The first canonical correlation was based on marked determination of coordination and ciciliona dance, and the second one on explosive strength of the running type with below-average coordination and the cha-cha-cha, rock-'n'-roll and pasavijen dances. Regression analysis indicated the battery of motor variables used to be a good predictor of performance in all study dances, with multiple correlation of 0.93 in ciciliona, 0.84 in pasavijen, 0.75 in rock-'n'-roll and 0.73 in cha-cha-cha. In ciciliona and pasavijen, the latent dance structure is predominantly explained by coordination, in rock-'n'-roll by explosive strength, and in cha-cha-cha by explosive strength and speed. Discriminative analysis revealed the general dance performance to mostly depend on coordination, then on explosive strength, and to a lesser extent on speed (movement frequency). Dance is an irreplaceable educational tool in kinesiologic education of female students, among others for its considerable contribution to the development and maintenance of basic motor abilities.     

Development of biomotor characteristics and sprint and throw athletic abilities in six- to eight-year-old girls

The aim of the study was to assess the effect of programmed physical education on biomotor changes in girls, and the impact of these changes on relations between the set of morphological and motor variables, and athletic variables evaluating the sprint and throw abilities. Study sample included 310 six- to eight-year-old girls, elementary school first-graders from the Split area, divided into control group (n = 138) attending regular physical education classes and experimental group (n = 172) attending programmed physical education classes based on the elements of athletics, apparatus gymnastics, games and general preparatory exercises. Relations between the predictor set of variables consisting of 4 morphological measures and 6 motor tests, and the sprint and ball throw criteria were determined by regression correlation analysis at the beginning and at the end of the academic year. Both groups achieved favorable quantitative result improvement between the two measurement points, however, the improvement was considerably more pronounced in experimental group, especially in the motor abilities of coordination, flexibility, movement frequency, and explosive, repetitive and static strength. On final measurement, the number of significant predictors for the criterion variables of sprint and ball throw increased from the initial measurement in both experimental and control group of subjects. In control group, trunk strength, explosive strength and movement frequency as motor abilities and body height as a morphological characteristic were found to be the best result predictors in sprint. In experimental group, coordination, flexibility, static arm strength and trunk strength as motor abilities were the best result predictors in sprint. In the study sample as a whole, explosive strength and trunk strength were identified as the best predictors of ball throw as a criterion variable. In experimental group, it was accompanied by muscle mass development and adipose tissue reduction. Based on comparison of these results and those obtained in previous studies, a new model of work in the athletics events of sprint and throw in elementary school physical education is proposed.     

Impact of motor abilities on belly dance performance in female high school students

The aim of the study was to determine the relation of motor abilities and belly dance performance in female high school students, 1st to 4th graders aged 15-18 years. A battery of 19 motor tests were used and nine belly dance elements evaluated in the study sample that included 148 students aged 15-16 (1st and 2nd graders) and 123 students aged 17-18 (3rd and 4th graders). Factor analysis of the motor space isolated six factors in either study group: in 1st and 2nd graders, the first factor integrated coordination, trunk strength, aerobic and muscle endurance, and speed of lower extremity movements; second factor defined explosive strength; third factor defined flexibility; fourth factor defined rhythm coordination; fifth factor defined equilibrium; and sixth factor defined back musculature strength; in 3rd and 4th graders, the first factor integrated coordination and lower extremity explosive strength; second factor defined flexibility; third factor integrated trunk strength and aerobic-muscular endurance; fourth factor defined equilibrium; fifth factor defined rhythm coordination; and sixth factor defined lower extremity strength. Factor analysis of the scores allocated to particular belly dance elements isolated only one factor as a factor of the general specific ability for belly dance performance. Regression analysis in the latent space indicated the factor of flexibility, which is responsible for muscle tone regulation, to be the best predictor of belly dance performance in 1st and 2nd graders. In 3rd and 4th graders, the factor of rhythm coordination was found to be superior in predicting belly dance performance, followed by the factor of trunk strength and aerobic-muscular endurance, the factor integrating coordination and lower extremity strength, and factor of equilibrium.     

The impact of dance-aerobics training on the morpho-motor status in female high-schoolers

The aim of the study was to analyze the impact of special programmed physical education including dance, aerobics and rhythmic gymnastics on the development of motor and functional abilities and morphological characteristics of female fourth-grade high-schoolers in Zagreb. A total sample of 220 high-schoolers aged 16-18 years were divided into two groups: experimental group of 115 students attending the program composed of dance structures and aerobics, and control group of 105 students attending classic program of physical education. A set of 3 morphological variables, 6 motor variables and one functional variable were applied in both groups on three occasions during an academic year (initial, transient and final measurements). Two-factor analysis of variance (MANOVA repeated measure design) showed the experimental program to significantly influence the development of coordination/agility and specific rhythm coordination, functional aerobic ability, repetitive and explosive strength and flexibility, along with significant reduction of overweight and adipose tissue. Study results clearly indicate that the existing programs of physical education should be revised and replaced by more appropriate ones.     

Predictors of Views about Punishing Animal Abuse

The current study used scenarios of animal cruelty based on actual events to explore what factors predict perceptions of punishments for animal cruelty. Five hundred thirty-eight university undergraduates participated in the study. Participants read scenarios based on an actual event of animal cruelty and with information on statutes addressing animal cruelty in their state. Participants were then asked to give ratings for punishment of the animal cruelty perpetrator. A canonical correlation analysis was used to test the multivariate shared relationship between the set of eight predictor variables and the criterion variable set of 15 punishment ratings. The response distributions were highly skewed for seven of the 15 criterion variables, highlighting the strong sentiments participants expressed against animal cruelty. The canonical correlation analysis identified significant criterion variables that were predicted by two of the empirically manipulated predictor variables (Perpetrator Age and Location of Crime) along with one subject variable (Participant Femininity). This set of predictor variables correlated with the criterion variable set that included Allowed with Children and Amount of Fine for Suffering. There was a main effect for Perpetrator Age, such that the degree to which participants thought a perpetrator of animal cruelty should be allowed alone with children depends on the age of the perpetrator. Mean responses were stronger for scenarios with perpetrators aged 28 than with perpetrators aged 12. The average response to Amount of Fine for Suffering was larger when the animal cruelty happened at a pet kennel than if the crime occurred at an animal shelter. Implications for these significant predictor and criterion variables are discussed in the context of interdisciplinary theory and practical implications for public policy.     

Prediction Models in Configural Frequency Analysis

Configural frequency analysis models are presented for predicting a discrete criterion variable from combining 2 or more discrete predictor variables nonparametrically. Predictions are made via so-called prediction types which allow to predict a criterion class from combined predictor classes. Prediction types are implicitely defined as cells of a 2-dimensional contingeney table with rows as predictor combinations and columns as criterion classes. The CFA is extended for two criteria, and for stratified sampling.     

Development of biomotor characteristics and athletic abilities of sprint and throw in boys aged six to eight years

The aim of this research was to examine the influences of specially programmed physical education lessons on biomotor development in boys, as well as the influence of those changes on relations between the set of morphological and motor variables and athletic variables for the assessment of sprint and throw abilities. For this purpose, an overall sample of 325 primary school first grade pupils from the city of Split area, aged 6-8 years, was divided into control group of subjects (N=140) attending regular physical education lessons and experimental group attending specially programmed lessons based on athletics, sports gymnastics and games elements as well as on general preparatory exercises. The relations between the predictor set of variables composed of 4 morphological measurements and 6 motor tests with the criteria of sprint and ball throwing were established by the regression correlation analysis at the beginning and at the end of the academic year Both groups of subjects achieved positive quantitative resultant shift between the two points of measurements, whereas this shift was more significant in the experimental group in relation to the control group, especially in motor abilities coordination of flexibility, movement frequency and of explosive, repetitive and static strength. The number of significant predictors for criteria variables of sprint and ball throwing increased in the final measurement in relation to the first one in both groups of subjects. While in the control group the best results predictor in sprint were the motor abilities of explosive strength and trunk strength, the best results predictor in sprint in the experimental group were coordination, trunk strength, flexibility and explosive strength. As far as the morphological characteristics are concerned muscle mass has a positive and body mass a negative effect on the sprint result. The best results predictor in ball throwing are explosive strength and trunk strength which, in the experimental group of pupils are additionally followed by coordination development as well as the overall body mass development. By comparison of these and the earlier obtained results, a new work model for the disciplines of sprint and throws within the athletic sport school, has been proposed.     

Integration of aerobic power into the morphological-motor system in children aged 7-11 years

The aim of the study was to analyze integration of aerobic power into other dimensions evaluated. For this purpose, predictor relations of the morphological-motor variables were analyzed with a 3-minute run as a criterion (according to school grade and sex). Four morphological and 6 motor variables covering the morphological-motor system were used in a sample of 4,440 children of both sexes aged 7-11 years, elementary school first- to four-graders from the Primorje-Gorski Kotar County, Republic of Croatia, divided into 8 groups. Data were processed by use of regression analysis. Study results clearly showed the values of the criterion variable to rise and criterion prediction using the set of predictor variables to improve with age. Also, the number of predictors included in power run prediction was observed to significantly increase with age. Strength factors with a predominance of explosive strength and repetitive strength in boys and girls, respectively, were the best criterion predictors. It is emphasized that development of the morphological-motor system and thus functioning of the body as a whole are influenced by aerobic power upgrading. Appropriate systematic kinesiologic activities accelerate the process of aerobic power integration in the morphological-motor system. As indicated by study results, this integration occurred at a faster rate and was more intensive in girls than in boys.     

The impact of cognitive processors and conative regulators on specific motor abilities in boxers

The aim of the study was to analyze the relations of cognitive processors and conative regulators with specific motor abilities of elite boxers. Three sets of variables including 3 cognitive and 6 conative variables as predictors, and 6 specific motor (boxing) variables as criteria were used in a sample of 92 boxers. A series of regression analyses between the set of cognitive variables and particular criterion variables revealed a predominant impact of serial processor on specific motor abilities based primarily on specific speed (frequency of boxing technique performance). The series of regression analyses also showed a predominant negative impact of dysregulation of the organ function regulators from the set of conative variables on the manifestation of specific motor abilities in boxers. The data obtained in the study were used to develop an alternative model of the motor - cognitive - conative processes in boxing.     

Motor abilities at belly dance in elementary female schoolers

The aim of the study was to determine the relation between motor abilities and belly dance performance in elementary school fifth- and sixth-grade female students. A battery of 19 motor tests was used in a sample of 96 students twice, i.e. at the beginning (initial measurement) and at the end (final measurement) of the academic year. On initial measurement, five factors were isolated by the motor space factor analysis: first factor of muscular-aerobic endurance; second factor integrating the strength of legs, coordination of foot and hand movement, and agility; third factor integrating explosive strength of the arms with speed and body coordination; fourth factor defined by flexibility (muscle tone regulation); and fifth factor integrating explosive strength of legs with equilibrium. On final measurement, five factors were isolated as well: first factor as a general one integrating coordination abilities, explosive strength of legs and flexibility; second factor defined by repetitive strength of the trunk and legs; third factor defined by rhythm coordination accompanied by flexibility; fourth factor predominantly defined by equilibrium (accompanied by explosive strength of throwing type and speed); and fifth factor predominantly defined by static strength of arms and legs (accompanied by arm movement frequency). On initial measurement, fourth factor responsible for muscle tone regulation and second factor integrating the strength of legs, coordination of movement frequency of arms and legs, and agility were found to be the best predictors of belly dance performance. In this setting, the tests of forward bow (flexibility) and sit-ups (repetitive strength of abdominal musculature) proved superior in differentiating high performance students and those less successful in belly dance. On final measurement, third factor named rhythm coordination (accompanied by muscle tone regulation) and second factor defined by repetitive strength of the trunk and legs were the best predictors of belly dance performance. In this setting, the tests of rhythm coordination, flexibility tests, tests of repetitive strength of the trunk and legs, and test of aerobic endurance proved superior in differentiating high performance and less successful students in belly dance.     

Morphological characteristics, technical and situation efficacy of young female volleyball players

The aim of the study was to identify differences in morphological variables and variables for quality assessment of volleyball techniques in young female volleyball players according to age and situation efficacy, and to estimate the effect of technique quality on situation efficacy. A set of 13 morphological measures and 6 technique elements were used in a sample of 246 female volleyball players divided into four age groups: 32 players aged 12-13, 147 players aged 14-15, 50 players aged 16-17, and 17 players aged 18-19. The quality of performance was assessed as a criterion variable. Analysis of variance showed the female volleyball players of various age groups to differ significantly according to the variables assessing the longitudinal skeleton dimensionality, and body mass and volume, as well as in all tests used on volleyball technique evaluation. Analysis of variance within particular age groups additionally clarified the process of modification in all study variables. Regression correlation analysis indicated the set of variables for the 6 evaluated techniques to be a rather good predictor of situation efficacy in all age groups, with service technique as the best predictor of performance quality in youngest players aged 12-13 and 14-15; spike and block techniques in players aged 16-17; and field defense technique in players aged 18-19.     

Integration of coordination into the morphological-motor system in male children aged 7-11 years

The study objective was to analyze the integration of psychomotor coordination into other dimensions evaluated. Four morphologic variables (stature, body mass, forearm circumference and triceps skinfold) and 7 motor variables (hand tapping, standing jump, sit-ups, forward bow, bent arm hang, 3-min run and polygon backward) were assessed in a sample of 2205 male children (subdivided into 4 groups) aged 7-11 years, elementary school first- to fourth-graders from the Primorje - Gorski Kotar County, Republic of Croatia. Relations between the set of morphologic-motor variables and the coordination variable (of backward polygon) as a criterion were analyzed Data were processed by use of regression analysis. Study results clearly indicated the values of the criterion variable (coordination) to rise and the criterion prediction using the set of variables to improve with age. Explosive strength, movement frequency and static strength were the best positive criterion predictors, whereas body weight at age 7-10, and skeletal longitudinality and subcutaneous adipose tissue at age 10-11 were the best negative criterion predictors. Also, developmental characteristics of coordination were found to be a major determinant on programming the work in kinesiologic education of elementary school children.     

Biomotor systems in elite junior judoists

The aim of the study was to assess the impact of motor abilities and morphological characteristics on junior judoka performance. A set of 14 morphological parameters and a set of 14 motor tests as predictor variables, and 3 variables evaluating judo performance as criteria were applied in a sample of 40 judoists aged 17 years +/-6 months. Three factors were isolated by factor analysis in morphological area: factor of muscle mass and bone volume (muscle and bone mass mesoectomorphy), factor of longitudinal skeleton dimensionality, and factor of subcutaneous adipose tissue (endomorphy). Four factors were isolated by factor analysis in motor area: factor of coordination and strength (regulated force), factor of movement frequency (speed), factor of muscular and cardiovascular endurance (endurance), and factor of tonus regulation and synergy regulation (flexibility/balance). Canonical correlation analysis between latent morphological and motor variables, and variables for assessment of competitive performance of junior judoists yielded two linear combinations, i.e. two pairs of canonical factors. Correlation in the first pair of canonical factors was underlain by the favorable impact of coordination/strength, speed, flexibility and balance, along with above-average muscle mass and bone volume, and above-average skeleton longitudinality on performance in judo. Correlation in the second pair of canonical factors was based on positive determination of above-average endurance along with moderate coordination/strength and speed, and below-average muscle mass and bone volume and skeleton longitudinality upon judo performance as expressed by the fight winning score.     

SNP interaction detection with random forests in high-dimensional genetic data

ABSTRACT: BACKGROUND: Identifying variants associated with complex human traits in high-dimensional data is a central goal of genome-wide association studies. However, complicated etiologies such as gene-gene interactions are ignored by the univariate analysis usually applied in these studies. Random Forests (RF) are a popular data-mining technique that can accommodate a large number of predictor variables and allow for complex models with interactions. RF analysis produces measures of variable importance that can be used to rank the predictor variables. Thus, single nucleotide polymorphism (SNP) analysis using RFs is gaining popularity as a potential filter approach that considers interactions in high-dimensional data. However, the impact of data dimensionality on the power of RF to identify interactions has not been thoroughly explored. We investigate the ability of rankings from variable importance measures to detect gene-gene interaction effects and their potential effectiveness as filters compared to p-values from univariate logistic regression, particularly as the data becomes increasingly high-dimensional. RESULTS: RF effectively identifies interactions in low dimensional data. As the total number of predictor variables increases, probability of detection declines more rapidly for interacting SNPs than for non-interacting SNPs, indicating that in high-dimensional data the RF variable importance measures are capturing marginal effects rather than capturing the effects of interactions. CONCLUSIONS: While RF remains a promising data-mining technique that extends univariate methods to condition on multiple variables simultaneously, RF variable importance measures fail to detect interaction effects in high-dimensional data in the absence of a strong marginal component, and therefore may not be useful as a filter technique that allows for interaction effects in genome-wide data.     

Motor simulation without motor expertise: enhanced corticospinal excitability in visually experienced dance spectators

The human "mirror-system" is suggested to play a crucial role in action observation and execution, and is characterized by activity in the premotor and parietal cortices during the passive observation of movements. The previous motor experience of the observer has been shown to enhance the activity in this network. Yet visual experience could also have a determinant influence when watching more complex actions, as in dance performances. Here we tested the impact visual experience has on motor simulation when watching dance, by measuring changes in corticospinal excitability. We also tested the effects of empathic abilities. To fully match the participants' long-term visual experience with the present experimental setting, we used three live solo dance performances: ballet, Indian dance, and non-dance. Participants were either frequent dance spectators of ballet or Indian dance, or "novices" who never watched dance. None of the spectators had been physically trained in these dance styles. Transcranial magnetic stimulation was used to measure corticospinal excitability by means of motor-evoked potentials (MEPs) in both the hand and the arm, because the hand is specifically used in Indian dance and the arm is frequently engaged in ballet dance movements. We observed that frequent ballet spectators showed larger MEP amplitudes in the arm muscles when watching ballet compared to when they watched other performances. We also found that the higher Indian dance spectators scored on the fantasy subscale of the Interpersonal Reactivity Index, the larger their MEPs were in the arms when watching Indian dance. Our results show that even without physical training, corticospinal excitability can be enhanced as a function of either visual experience or the tendency to imaginatively transpose oneself into fictional characters. We suggest that spectators covertly simulate the movements for which they have acquired visual experience, and that empathic abilities heighten motor resonance during dance observation.     

Motor structures in female volleyball players aged 14-17 according to technique quality and performance

The aim of the study was to identify motor structures in elite female volleyball players aged 14-17, and to assess the effect of these motor structures on their technical and situation efficiency. For this purpose, a battery of 12 motor tests as predictor variables, and a set of six technical elements and evaluation of performance quality as criterion variables were applied in a sample of 147 female volleyballers aged 14-15 and a sample of 50 female volleyballers aged 16-17. Analysis of variance between subgroups within the groups of volleyballers aged 14-15 and those aged 16-17 showed the results on all motor tests to improve with the increase in situation performance, which was especially pronounced in the tests assessing explosive strength and agility. The same held true for the results on all tests assessing volleyball techniques, spike and block in particular. In both samples, factor analysis of motor tests isolated two factors underlain by the generation and regulation of strength, and the mechanism of speed regulation. Canonical correlation analysis between the motor regulatory mechanisms and technical elements revealed determination of the mechanisms of strength and technical efficiency in both samples. Regression correlation analysis showed the mechanisms of strength regulation and speed to be good predictors of game performance in female volleyballers aged 14-15 and 16-17, whereby the mechanism of strength regulation had greater effect on the game performance than the mechanism of speed regulation. Regression correlation analysis also revealed the set of 6 techniques evaluated to be a good predictor of situation efficiency in both groups of female volleyballers aged 14-15 and 16-17. The block and spike techniques were found to be the best predictors of game performance quality in the former, and the techniques of spike and block in the latter. Based on the results obtained, a possible model of selection for supreme score achievement in female volleyball is described.     

A Missing Data Approach to Correct for Direct and Indirect Range Restrictions with a Dichotomous Criterion: A Simulation Study

A recurring methodological problem in the evaluation of the predictive validity of selection methods is that the values of the criterion variable are available for selected applicants only. This so-called range restriction problem causes biased population estimates. Correction methods for direct and indirect range restriction scenarios have widely studied for continuous criterion variables but not for dichotomous ones. The few existing approaches are inapplicable because they do not consider the unknown base rate of success. Hence, there is a lack of scientific research on suitable correction methods and the systematic analysis of their accuracies in the cases of a naturally or artificially dichotomous criterion. We aim to overcome this deficiency by viewing the range restriction problem as a missing data mechanism. We used multiple imputation by chained equations to generate complete criterion data before estimating the predictive validity and the base rate of success. Monte Carlo simulations were conducted to investigate the accuracy of the proposed correction in dependence of selection ratio, predictive validity, and base rate of success in an experimental design. In addition, we compared our proposed missing data approach with Thorndike’s well-known correction formulas that have only been used in the case of continuous criterion variables so far. The results show that the missing data approach is more accurate in estimating the predictive validity than Thorndike’s correction formulas. The accuracy of our proposed correction increases as the selection ratio and the correlation between predictor and criterion increase. Furthermore, the missing data approach provides a valid estimate of the unknown base rate of success. On the basis of our findings, we argue for the use of multiple imputation by chained equations in the evaluation of the predictive validity of selection methods when the criterion is dichotomous.     

Force production and spatial arm coordination profile in arm crawl swimming in a fixed position

This study analyzed the relationship between mechanical force production and spatial arm position of the swimming movement for each side of the swimmer. Eight internationally recognized male swimmers performed fix positioned arm only swimming with a dynamometer synchronized with underwater cameras. The upper arm positions (α in side, β in frontal view) and the elbow angles (γ in 3D) were determined at the moment where the force production reached the peak (Fmax) and the maximal values of rate of force development (RFDmax). RFDmax and α values showed significant differences between the sides (P<0.05). To show the motion integration structure of the performance, Multiple Regression Analysis (MRA) was employed separately for both sides. For the criterion variable, the impulse of force (ImpF50%) was calculated. The defined parameters as the mechanical and spatial predictor system were used for the model. The results of the MRA showed that the predictor system yielded the model structure of the variables that explain the criterion variables for ImpF50% by the dominant (P=0.007) and by the nondominant side (P=0.001), respectively. The alternate contribution of the variables to the models can objectively express the performance difference between the two sides of the swimmer.     

Biomechanical mechanism of lateral trunk lean gait for knee osteoarthritis patients

The biomechanical mechanism of lateral trunk lean gait employed to reduce external knee adduction moment (KAM) for knee osteoarthritis (OA) patients is not well known. This mechanism may relate to the center of mass (COM) motion. Moreover, lateral trunk lean gait may affect motor control of the COM displacement. Uncontrolled manifold (UCM) analysis is an evaluation index used to understand motor control and variability of the motor task. Here we aimed to clarify the biomechanical mechanism to reduce KAM during lateral trunk lean gait and how motor variability controls the COM displacement. Twenty knee OA patients walked under two conditions: normal and lateral trunk lean gait conditions. UCM analysis was performed with respect to the COM displacement in the frontal plane. We also determined how the variability is structured with regards to the COM displacement as a performance variable. The peak KAM under lateral trunk lean gait was lower than that under normal gait. The reduced peak KAM observed was accompanied by medially shifted knee joint center, shortened distance of the center of pressure to knee joint center, and shortened distance of the knee–ground reaction force lever arm during the stance phase. Knee OA patients with lateral trunk lean gait could maintain kinematic synergy by utilizing greater segmental configuration variance to the performance variable. However, the COM displacement variability of lateral trunk lean gait was larger than that of normal gait. Our findings may provide clinical insights to effectively evaluate and prescribe gait modification training for knee OA patients.