The end-state comfort effect in young children

The end-state comfort effect has been observed in recent studies of grip selection in adults. The present study investigated whether young children also exhibit sensitivity to end-state comfort. The task was to pick up an overturned cup from a table, turn the cup right side up, and pour water into it. Two age groups (N = 20 per group) were studied: preschool children (2-3 years old), and kindergarten students (5-6 years old). Each child performed three videotaped trials of the task. Only 11 of the 40 children exhibited the end-state comfort effect, and there were no differences between age groups. Results revealed the emergence of five different performance patterns, none of which were consistent with sensitivity to end-state comfort. The findings have implications for the advance planning of manual control in young children.     

The end-state comfort effect in bimanual grip selection

During a unimanual grip selection task in which people pick up a lightweight dowel and place one end against targets at variable heights, the choice of hand grip (overhand vs. underhand) typically depends on the perception of how comfortable the arm will be at the end of the movement: an end-state comfort effect. The two experiments reported here extend this work to bimanual tasks. In each experiment, 26 right-handed participants used their left and right hands to simultaneously pick up two wooden dowels and place either the right or left end against a series of 14 targets ranging from 14 to 210 cm above the floor. These tasks were performed in systematic ascending and descending orders in Experiment 1 and in random order in Expiment 2. Results were generally consistent with predictions of end-state comfort in that, for the extreme highest and lowest targets, participants tended to select opposite grips with each hand. Taken together, our findings are consistent with the concept of constraint hierarchies within a posture-based motion-planning model.     

儿童动作发展测试(TGMD-2)信度和效度的研究

以511名3～10岁儿童为测试对象,探讨了大肌肉动作发展测试（TGMD-2）的信度和效度,结果表明测试者信度系数为0.436～0.876;内部一致性信度系数为0.607～0.925;重测信度系数为0.608～0.876;内容效度、结构效度、效标效度也都令人满意。TGMD-2可作为3～10岁儿童大肌肉动作发展状况的测评工具。     

大肌肉动作发展位移分测试性别差异之研究

1前言动作是人类适应环境的重要手段,也是个体发育、成长必不可少的活动能力。儿童早期的动作发展,不仅会影响个体成长后动作技能的学习和发展,还会影响个体的认知发展、心理发展和社会交往等多方面能力的发展。而大肌肉动作的发展是个体动作发展的重要组成,是各类感知觉动作的     

Tracking of gross motor coordination in Portuguese children

The purpose of this study was to investigate the tracking of gross motor coordination (GMC) and to profile children at 6 years of age who consistently showed higher stability patterns in different levels of GMC. The participants were 245 children (123 boys and 122 girls) who were assessed longitudinally from 6 to 9 years of age. GMC was assessed using the Korperkoordinationtest fur Kinder (KTK) test battery. Anthropometry, physical activity, and health- and performance-related physical fitness were also measured. Cohen’s kappa (κ) was used to estimate tracking. Tracking was poor for all GMC tests (0.17 ≤ κ ≤ 0.38) and moderate for the GMC motor quotient (MQ) in both boys and girls (0.44 ≤ κ ≤ 0.45). Instability at the extremes was low in GMC tests and negligible for MQ. Children who consistently showed high GMC levels during the 4 years of follow-up were lighter, had lower body mass index and subcutaneous fat, and showed higher scores in physical fitness tests at 6 years of age than those who consistently had low GMC levels. In conclusion, GMC showed low-to-moderate tracking over time in childhood. However, children who consistently demonstrated high GMC levels over time had healthier profiles at 6 years of age.     

Test of gross motor development-2 for Filipino children with intellectual disability: validity and reliability

This study aimed to examine aspects of validity and reliability of the Test of Gross Motor Development-2 (TGMD-2) in Filipino children with intellectual disability. Content and construct validity were verified, as well as inter-rater and intra-rater reliability. Two paediatric physiotherapists tested 81 children with intellectual disability (mean age = 9.29 ± 2.71 years) on locomotor and object control skills. Analysis of covariance, confirmatory factor analysis and analysis of variance were used to test validity, while Cronbach’s alpha, intra-class correlation coefficients (ICC) and Bland–Altman plots were used to examine reliability. Age was a significant predictor of locomotor and object control scores (P = 0.004). The data fit the hypothesised two-factor model with fit indices as follows: χ² = 33.525, DF = 34, P = 0.491, χ²/DF = 0.986. As hypothesised, gender was a significant predictor for object control skills (P = 0.038). Participants’ mean scores were significantly below mastery (locomotor, P < 0.001; object control, P < 0.001). Cronbach’s alpha was 0.830 for locomotor and 0.792 for object control components. ICC for locomotor and object control scores ranged from 0.995 to 0.998, suggesting excellent intra-rater and inter-rater reliability, confirmed by Bland–Altman analysis. This study provides evidence of sufficient content and construct validity, internal consistency and rater reliability of TGMD-2 for Filipino children with intellectual disability.     

Bidirectional relationships of physical activity and gross motor skills before and after summer break: Application of a cross-lagged panel model

Background:Gross motor skills are postulated to have a bidirectional relationship with physical activity(PA);however,no study has tested this relationship before and after a summer break.The purpose of this study was to examine the bidirectional relationships between school PA and gross motor skills in children before and after a summer break.Methods:Participants were a sample of 440 children recruited from 3 low-income schools(age=8.9±1.2 years,mean±SD).PA was assessed as average school-day step counts using Yamax DigiWalker pedometers(Yamasa Tokei Keiki,Tokyo,Japan)worn for 5 consecutive school days.Gross motor skills were assessed using the Test for Gross Motor Development,3 rd edition.Data were collected at 2 timepoints:at the end of spring semester(T1)and at the beginning of the subsequent fall semester(T2).An age-and body mass index-adjusted cross-lagged model was employed to relate T1 school step counts with T2 gross motor skills and T1 gross motor skills with T2 school step counts.Results:T1 gross motor skills significantly predicted T2 school step counts(β=0.24,95%confidence interval(95%CI):0.08-0.40,p=0.003);however,Tl school step counts did not predict T2 gross motor skills(β=0.04,95%CI:-0.06 to 0.14,p=0.445).The model explained 35.4%and 15.9%of the variances of T2 gross motor skills and T2 school step counts,respectively.Additional analyses indicated that these relationships were driven primarily by ball skills.Conclusion:The relationship between gross motor skills and school PA was not bidirectional;however,higher gross motor skills,specifically ball skills,predicted higher school PA after a 3-month summer break.     

Part and whole practice: chunking and online control in the acquisition of a serial motor task

A four-component aiming movement was used to examine the relative effectiveness of part and whole practice. Following a pretest, participants were assigned to one of three practice groups. Participants in a "Whole" group practiced the four components together as a unit. A "No Overlap" group practiced the first two and last two components of the task, alternating every fifth trial. An "Overlap" group practiced the transition between the second and third components on every trial by alternating practice of the first three and last three components every five trials. Participants in all groups improved significantly from pretest to immediate posttest and maintained their performance over a 24-hr delay. Contrary to the "chunking hypothesis," participants in the No Overlap group improved as much as those in the other two groups. Kinematic data indicated that participants in all three groups learned to use response-produced feedback earlier in the individual movement trajectories. Moreover, participants appeared to acquire a general ability to make transitions between movement components rather than specific transitions. The results suggest that segmented or segmented "overlap" practice regimes may benefit learning movement sequences of short duration.     

Association between gross motor competence and health-related quality of life in (pre)schoolchildren: the mediating role of cardiorespiratory fitness

ABSTRACT

Background: Motor competence, defined as a person’s ability to execute different motor skills, is directly associated with children’s physical, mental, and social development and may be essential in encouraging an active lifestyle in childhood. Although health-related quality of life (HRQoL) in children has been described as an individual’s subjective perception of the impact of health status on physical, psychological and social functioning, in very young children, a HRQoL parent-proxy report is needed since (pre)schoolchildren have problems expressing their feelings and understanding items on HRQoL instruments. In addition, the influence of motor competence on fitness levels has strong empirical support, so it seems reasonable to hypothesize that cardiorespiratory fitness might play a crucial role in the association between motor competence and HRQoL in children.

Objectives: This study examined the association between gross motor competence (G-MC) and HRQoL in typically developing children, and whether this association between G-MC and HRQoL was mediated by cardiorespiratory fitness.

Methods: An observational cross-sectional study with 1088 (pre)schoolchildren (51.84% boys, 48.16% girls) aged between 4 and 7 years (5.32?±?0.60) belonging to 21 schools in the Spanish provinces of Cuenca and Ciudad Real were included. G-MC was evaluated using the MABC-2 battery, HRQoL was assessed using the KINDL-R questionnaire and cardiorespiratory fitness using the 20m-shuttle-run-test. Partial correlations, covariance models and mediation analyses were conducted.

Results: The mean scores of HRQoL (physical well-being, self-esteem, friends, school and global score index) were significantly higher (p?<?0.05) in children with higher G-MC. When cardiorespiratory fitness was added as a covariate, all the results remained unchanged (p?<?0.05), except for physical well-being for the total sample as well as emotional well-being and the global score index for girls. Simple mediation analyses showed that cardiorespiratory fitness acted as a mediator between G-MC and physical well-being (Indirect Effect?=?0.04 [95% CI?=?0.01; 0.07]) for the total sample. For boys, it acted as a mediator between G-MC and physical well-being (Indirect Effect?=?0.04 [95% CI?=?0.00; 0.08]) and school (Indirect Effect?=?0.05 [95% CI?=?0.01; 0.09]), and, for girls, between G-MC and emotional well-being (Indirect Effect?=?0.04 [95% CI?=?0.01; 0.08]) and the global score index (Indirect Effect?=?0.02 [95% CI?=?0.00; 0.05]).

Conclusions: The results of this study suggest that good G-MC levels are associated with better HRQoL, mainly in global score index of HRQoL and self-esteem, friends, and school dimensions in typically developing children. Further, cardiorespiratory fitness mediates the association between G-MC and the physical dimension of HRQoL in (pre)schoolchildren. Additionally, physical and academic dimensions are mediated by cardiorespiratory fitness for boys and the emotional and global score indices of HRQoL are mediated by cardiorespiratory fitness for girls. These findings provide scientific evidence that improving motor competence and cardiorespiratory fitness might be a practical strategy to increase HRQoL in children. Thus, families and the educational community should promote effective interventions and incorporate opportunities inside and outside school that aim to jointly improve motor competence and cardiorespiratory fitness.     

Developmental modeling effects on the quantitative and qualitative aspects of motor performance

The purpose of the present experiment was to replicate and extend previous developmental modeling research by examining the qualitative as well as quantitative aspects of motor performance. Eighty females of two age groups (5-0 to 6-6 and 7-6 to 9-0 years) were randomly assigned to conditions within a 2 x 2 x 2 (Age x Model Type x Rehearsal) factorial design. Children received either verbal instructions only (no model) or a visual demonstration with experimenter-given verbal cues (verbal model) of a five-part dance skill sequence. Children were either prompted to verbally rehearse before skill execution or merely asked to reproduce the sequence without prompting. Both quantitative (order) and qualitative (form) performances were assessed. Results revealed a significant age main effect for both order and form performance, with older children performing better than younger children. A model type main effect was also found for both order and form performance. The verbal model condition produced better qualitative performance, whereas the no model condition resulted in better quantitative scores. These results are discussed in terms of differential coding strategies that may influence task components in modeling.     

Lumbopelvic motor control and low back pain in elite soccer players: a cross-sectional study

This study aimed to investigate the relationship between the history of low back pain and quality of lumbopelvic motor control in soccer players. Forty-three male elite soccer players (mean age, 18.2 ± 1.4 years) filled in questionnaires related to low back pain and attended a session to assess lumbopelvic motor control by means of five tests (the bent knee fall out test, the knee lift abdominal test, the sitting knee extension test, the waiter’s bow and the transversus abdominis test). A physiotherapist, blinded to the medical history of the participants, scored (0 = failed, 1 = correct) the performance of the players for each of the tests resulting in a lumbopelvic motor control score ranging from 0 to 5. Forty-seven per cent of the soccer players reported a disabling low back pain episode lasting at least two consecutive days in the previous year. These players scored worse lumbopelvic motor control than players without a history of low back pain (lumbopelvic motor control score of 1.8 vs. 3.3, P < 0.01). The between-groups difference was particularly marked for the bent knee fall out test, the knee lift abdominal test and the transversus abdominis test (P < 0.01). In conclusion, most soccer players with a history of low back pain had an altered lumbopelvic motor control. Further research should examine whether lumbopelvic motor control is etiologically involved in low back pain episodes in soccer players.     

The hip control test is a valid and reliable measure of hip neuromuscular control

Abstract

Insufficient hip neuromuscular control may contribute to non-contact sport injuries. However, the current evaluative test of hip neuromuscular control, the single-leg squat, requires hip abductor muscle strength to complete. The purpose of this study was to develop the hip control test (HCT) and determine the test’s reliability and construct validity. Nineteen healthy adults visited the laboratory twice. The HCT is a 10-s test of reciprocal toe-tapping accuracy. Both automated and manual HCT ratings were recorded simultaneously during each visit. Additionally, eccentric hip abductor torque was measured. HCT reliability was assessed with intra-class correlation coefficients (ICC). Agreement between automated and manual ratings was determined with Bland–Altman plots. Construct validity was established if HCT performance significantly decreased with a secondary cognitive task (p < 0.05). Bivariate regression determined the relationship between HCT performance and eccentric hip abductor torque. Automated and manual HCT ratings both had moderate reliability (ICC = 0.72) and yielded similar results (limits of agreement = ?1 to 2 taps). The HCT had construct validity (p = 0.001), and no correlation with hip abductor muscle strength (r = 0.213). Thus, the HCT is a reliable and valid test. The HCT is simple to administer and measures hip neuromuscular control separately from strength.     

The value of a non-sport-specific motor test battery in predicting performance in young female gymnasts

Gymnastics talent identification focuses on the identification of young gymnasts who display characteristics for potential success in the future. The aim of this study was to identify which current performance characteristics are related to performance in competition 2 years later. Twenty-three female gymnasts aged 7-8 years completed a multidimensional test battery measuring anthropometric, physical, and coordinative characteristics and were technically evaluated by expert coaches. Two years later, the all-around competition results of those gymnasts now participating in elite (n = 12) and sub-elite (n = 11) competition were obtained. None of the initial measurements significantly correlated with the results of the sub-elite gymnasts 2 years later. For the elite gymnasts, a non-sport-specific motor test battery correlated strongly with the competition result, with more than 40% of the variation in competition performance being explained by the result on that test 2 years earlier. Neither the coaches' judgement nor the anthropometric and physical characteristics were sensitive enough to predict performance. A motor coordination test might be valuable in the early identification of gymnasts, as its discriminative and predictive qualities might be sufficiently powerful for selection within a relatively homogeneous population of gymnasts exhibiting similar anthropometric and physical profiles.     

Health locus of control predicts free-living, but not supervised, physical activity: a test of exercise-specific control and outcome-expectancy hypotheses

We statistically controlled fitness (1.5-mile run), outcome-expectancy values, and perceived barriers for physical activity and then compared internal health locus of control (IHLOC) with internal exercise locus of control (IEXLOC) for predicting the physical activity of college students (N = 84). Prospective observations of self-reported free-living physical activity (seven-day recall) and supervised running (time x distance) were made at 2-, 5-, and 9-week intervals. IHLOC predicted seven-day recall at Week 2 (beta = .19) and Week 5 (beta = .36) (increase in adjusted R2 ranged from .05 to .12, p less than .05). Consistent with theory, the prediction was not reproducible when generalized outcome-expectancy value rather than outcome-expectancy value for health was assessed. IHLOC was unrelated to supervised running. IEXLOC was unrelated to activity in all analyses, even though exercise-specific measures of outcome-expectancy values (beta s = .20) and perceived barriers (beta s = .27-.32) predicted both seven-day recall and supervised running (p less than .05). IHLOC also discriminated (p less than .05) high active and low active subjects when criterion groups were formed from population norms on seven-day recall (greater than or less than 280 kcal.kg-1.week-1). Results indicate that tests of decision theories that include locus of control measures specific to health or exercise must adjust for fitness, perceived barriers to physical activity, and behaviorally relevant outcome-expectancy values of physical activity when studying college students. The construct validity of exercise locus of control remains uncertain for college students.     

Visually and acoustically augmented performance feedback as an aid in motor control learning: a study of selected components of the rowing action

The present work compares the efficiency of two training techniques as aids to learning selected aspects of a sequentially ordered action such as that of rowing. Subjects in one group were trained with a conventional learning technique (CLT) while those in a second group were trained by an augmented feedback technique referred to as external feedback (EFB). Progress was recorded on learning curves. Rowing athletes with limited experience and psychophysiology students were used for the study. The tasks consisted of learning movement timing (rhythmicity of action and coordination of body parts) and movement intensity (force and electromyogram development), in four separate experiments. The learning curves for EFB subjects were found to have significantly and consistently higher slopes than those for CLT subjects. Optimal criteria were reached by EBF subjects, after a continuous increase in performance levels and a concomitant decrease in standard deviations evaluated from periodicity, movement accuracy and force. Subjects, who after 8 to 10 sessions of CLT learning had not reached optimal level, were exposed to EFB. Their performances then showed a marked improvement and attained the required criterion in 2 to 4 sessions. This further demonstrates the efficacy of EFB as compared with CLT, as an aid to learning a complex sensorimotor action. The efficacy of EFB as a learning technique is discussed in relation to the internal model of the task to be executed and to sensory motor control and motor programmes.     

Road bike comfort: on the measurement of vibrations induced to cyclist

With ride quality being one of the most sought-after characteristics of a road bicycle by customers as well as by bicycle manufacturers, the vibrational behaviour of the bicycle/cyclist system has grown into an active field in sport engineering research in recent years. When assessing bicycle transmissibility and ride comfort, it is important to control test conditions to obtain repeatable load and acceleration measurements at the cyclist’s contact points with the bicycle. Surprisingly, however, this consideration has not yet been specifically addressed in the literature. The aim of this paper is a first effort to investigate the effect of a selected set of test conditions on the measurement of vibration induced to the cyclist by a road bicycle. Our results showed that all the test conditions selected had a significant effect on the level of vibration induced to the cyclist.     

Metamotivational state and dominance: Links with EMG gradients during isokinetic leg extension and a test of the misfit effect

Although electromyographic (EMG) gradients have been observed in passive musculature during perceptual motor tasks, it is unclear whether this is related to metamotivational state or dominance. In addition, a misfit effect has been suggested whereby individuals report negative psychological responses when metamotivational state and dominance do not match. Research examining these phenomena within an exercise context is limited; therefore, this study used a reversal theory (Apter, 2001) framework to examine two hypotheses. The first hypothesis was that an EMG gradient would be observed when individuals performed isokinetic leg extensions in a telic metamotivational state, regardless of telic or paratelic metamotivational dominance. Second, it was hypothesizsed that telic-dominant individuals and paratelic-dominant individuals would perform better on this task when in the telic and paratelic state, respectively. Altogether, 14 telic-dominant and 12 paratelic-dominant individuals performed 100 self-paced isokinetic leg extensions at a rate of 90°?·?s(-1) in both telic and paratelic state manipulated conditions. Regardless of state, an EMG gradient was observed in telic-dominant individuals but not in paratelic-dominant individuals. Paratelic-dominant individuals performed better in the paratelic than the telic state condition, whereas in the telic state condition, telic-dominant individuals performed better than paratelic-dominant individuals. Findings add to the debate concerning the role of telic metamotivational state and dominance in the production of EMG gradients. Performance data support the misfit effect that outcomes are more positive when metamotivational state and dominance are congruent. Suggestions for research developments in this area are offered, as are tentative implications for applied practice.     

The effect of torsional shoe sole stiffness on knee moment and gross efficiency in cycling

Altering torsional stiffness of cycling shoe soles may be a novel approach to reducing knee joint moments and overuse injuries during cycling. We set out to determine if the magnitude of three-dimensional knee moments were different between cycling shoe soles with different torsional stiffnesses. Eight trained male cyclists cycled at 90% lactate threshold power output in one of two cycling shoe conditions in a randomized crossover design. The shoe sole was considered torsionally flexible (FLEX) compared to a relatively stiffer (STIFF) sole. Gross efficiency (GE) and knee joint moments were quantified. No significant effect of shoe condition was seen in GE (21.4 ± 1.1% and 20.9 ± 1.6% for FLEX and STIFF, respectively, P = 0.12), nor in three-dimensional knee moments. 4 of the 8 subjects had reduced knee moments in at least 2 of the 3 moment directions. These “responders” were significantly shorter (1.73 ± 0.02 m vs 1.81 ± 0.04 m, P = 0.017) and had a higher relative maximal aerobic power (MAP) (4.6 ± 0.3 W?kg-1 vs 3.9 ± 0.3 W?kg-1, P = 0.024) compared to non-responders. These results suggest that certain shoe characteristics may influence certain individuals differently because these participants belong to different “functional groups”; certain individuals may respond positively to FLEX, while others may not. Further studies should test this proposed hypothesis.