Modelling the dynamics of children’s gross motor coordination

ABSTRACT

This study modelled children’s gross motor coordination, investigated sex-differences and identified the effects of fixed and dynamic correlates on motor coordination development. A total of 344 Portuguese children (170 girls), from 6 age cohorts (5 to 9 years of age), were followed consecutively for three years (age range 5 to 11 years) using a mixed-longitudinal cohort design. Birth weight, hand dominance and socioeconomic status (SES) were identified. Gross motor coordination, body mass index, physical fitness (PF) and physical activity (PA) were assessed annually. A sequence of multilevel hierarchical linear models were developed. Model 1 found that age, age², sex, sex-by-age and sex-by-age² were significant predictors (p < 0.05) of gross motor coordination. Boys outperformed girls from 6 years of age onwards. Model 2 found a cohort effect (p < 0.05). Model 3 found that right handers were more coordinated (p < 0.05). When the confounders of body mass index, PF and PA were added to the model (Model 4) it was found that boys and girls had parallel trajectories in their gross motor coordination development. In conclusion children with increasing body mass index were less coordinated, while those who were stronger and more agile had steeper trajectories of gross motor coordination with age.     

The Effect of CHAMP on Physical Activity and Lesson Context in Preschoolers: A Feasibility Study

Purpose: This feasibility study compared the effects of 2 movement programs, traditional and mastery climate (i.e., the Children’s Health Activity Motor Program [CHAMP]), on lesson context and children’s physical activity (PA) levels. A secondary aim was to examine sex differences in PA levels in both programs. Method: Seventy-two preschoolers served as participants and were assigned to a movement program. Physical activity levels and lesson context were assessed with the System for Observing Fitness Instruction Time. Results: Preschoolers in CHAMP spent more time walking (p < .05, d = 3.3), more time in moderate-to-vigorous PA (MVPA; p < .05, d = 3.6), and less time standing (p < .05, d = 3.8) compared with those in a traditional movement program. Boys in both programs spent less time standing (p < .05, d = 4.8) and more time in vigorous activity (p < .05, d = 5.8) and MVPA (p < .05, d = 4.4) compared with girls. During CHAMP, children spent less time engaged in management and knowledge (p < .05, d = 1.4, and p < .001, d = 0.9, respectively) and more time in skill practice (p < .05, d = 1.5). Conclusion: The findings support that participation in CHAMP elicits more MVPA in preschool-age children compared with a traditional movement program. The Children’s Health Activity Motor Program provided children with more class time devoted to skill practice. The program appears to be an innovative approach that is beneficial for PA engagement and could contribute positively to children’s health.     

Higher anterior knee laxity influences the landing biomechanics displayed by pubescent girls

Despite an increase in anterior knee laxity (AKL) during the adolescent growth spurt in girls, it is unknown whether landing biomechanics are affected by this change. This study investigated whether pubescent girls with higher AKL displayed differences in their lower limb strength or landing biomechanics when performing a horizontal leap movement compared to girls with lower AKL. Forty-six pubescent girls (10–13 years) were tested at the time of their peak height velocity (PHV). Passive AKL was quantified and used to classify participants into higher (HAKL; peak displacement > 4 mm) and lower (LAKL; peak displacement < 3 mm) AKL groups (n = 15/group). Three-dimensional kinematics, ground reaction forces (GRF) and muscle activation patterns were assessed during a horizontal leap landing. HAKL participants displayed significantly (P < 0.05) reduced hip abduction, increased hip abduction moments, as well as earlier hamstring muscle and later tibialis anterior activation compared to LAKL participants. Girls with HAKL displayed compensatory landing biomechanics, which are suggested to assist the functional stability of their knees during this dynamic task. Further research is warranted, however, to confirm or refute this notion.     

Relative Age Effect,Biological Maturation,and Coaches’ Efficacy Expectations in Young Male Soccer Players

Purpose: The talent identification and selection process in young male soccer players is mainly focused on anthropometrics and physical performance, but social factors are also considered in this process. The purpose of this study was to test the existence of the relative age effect and its possible influence on anthropometrics and physical performance and to analyze coaches’ efficacy expectations. Method: Data for 564 young male soccer players (M_age = 13.7 ± 1.5 years; M_weight = 53.7 ± 11.6 kg; M_height = 160.2 ± 11.6 cm) included their birth quartile, maturity status, anthropometrics, a physical test battery, and coaches’ efficacy expectations. Results: Early-born players were overrepresented (p < .05). Early-born players were not statistically taller, heavier, or better at physical performance (p > .05) when maturation and chronological age were controlled as confounding factors. However, coaches expected more from early-born players (p < .05), and the inferential analysis showed likely to very likely worthwhile differences between the coaches’ expectations for players born in the first quartile of the year and those born in the fourth quartile of the year. Conclusions: Anthropometrical and physical performance variables were not affected by birth quartile, and coaches’ efficacy expectations were related to the relative age effect.     

Effects of a feint on reactive agility performance

Abstract

This study compared reactive agility between higher-standard (n = 14) and lower-standard (n = 14) Australian footballers using a reactive agility test incorporating a life-size video image of another player changing direction, including and excluding a feint. Mean agility time in the feint trials was 34% (509 ± 243 ms; p < 0.001; effect size 3.06) longer than non-feint trials. In higher-standard players, agility time was shorter than for lower-standard players in both feint (114 ± 140 ms; p = 0.18; effect size 0.52; likely beneficial) and non-feint (32 ± 44 ms; p = 0.22; effect size 0.47; possibly beneficial) trials. Additionally, the inclusion of a feint resulted in movement time increasing over three times more in the lower-standard group (197 ± 91 ms; p = 0.001; effect size 1.07; almost certainly detrimental) than the higher-standard group (62 ± 86 ms; p = 0.23; effect size 0.66; likely detrimental). There were weak correlations between the feint and non-feint trials (r = ?0.13–0.14; p > 0.05), suggesting that reactive agility involving a feint is a unique skill. Also, higher-standard players are more agile than their lower-standard peers, whose movement speed deteriorates more as task complexity increases with the inclusion of a feint. These results support the need for specific training in multi-turn reactive agility tasks.     

Factors affecting sports involvement in a school-based youth cohort: Implications for long-term athletic development

ABSTRACT

The aim of the present study was to determine the factors affecting sports involvement in a school-based adolescent population. The cross-sectional cohort study assessed anthropometry, physical capacities and motor competence in 501 boys (aged 10–16 y), from junior (10–12 y) and senior (13–16 y) cohorts. Sports participation data was collected from junior participants. Multivariate analysis of covariance revealed moderate maturity, anthropometry, physical capacity and motor competence differences between sports in the senior cohort (F = 2.616, p < 0.001, η² = .08), but not in the junior cohort. Furthermore, differences in physical fitness were revealed between playing levels (F = 2.616, p < 0.001, η² = .08), with a discriminant analysis correctly classifying 73% of participants using aerobic fitness and vertical jump measures. Representative level participants engaged in more structured training and commenced organised competition at a later age (F = 4.332, p < 0.001, η² = .21). This study’s findings are twofold: 1) physical and motor competence profiles differ more between sports with increasing age, and 2) participants at a higher level of competition report delayed engagement in their main sport. As a result, schools may be the ideal environment in which to provide children and adolescents with the opportunity to sample different sports.     

The Influence of Feedback on Competence,Motivation, Vitality,and Performance in a Throwing Task

Purpose: The purpose of this work is focused on the study of the effect that feedback has on competence valuation, perceived competence, autonomous motivation, vitality, and performance in a throwing task. Method: Thirty-five college students (26 men and 9 women), without previous experience in the task, participated in this study. The students were randomly assigned to three experimental conditions (positive, negative, and lack of feedback). Results: The results of this study point out that only those who received positive feedback before the handball throwing task, in contrast to those who received negative feedback or did not receive any feedback, showed increased levels of competence valuation (p < .05, Cliff’s delta effect size = ?.30), perceived competence (p < .001, Cliff’s delta effect size = ?.77), and autonomous motivation (p < .05, Cliff’s delta effect size = ?.48). This group also presented higher levels of perceived competence (p < .001, Cliff’s delta effect size = ?.84) and subjective vitality (p < .001, Cliff’s delta effect size = ?.80) than the group who received negative feedback after the throwing task. Those who received positive feedback also showed a higher throwing speed at the end of task than those who received negative feedback (p < 0.001, Cliff’s delta effect size = ?.71) or than those who did not receive any feedback (p < .05, Cliff’s delta effect size = ?.56). Conclusions: Competence valuation, perceived competence, autonomous motivation, subjective vitality, and throwing speed were favorably influenced by positive feedback. These results have important implications for the training style applied by coaches.     

A cross-sectional and prospective analyse of reallocating sedentary time to physical activity on children’s cardiorespiratory fitness

Cardiorespiratory fitness (CRF) is associated with health benefits in children, improving cardiac morphology, cardiovascular disease risk factors, and biological outcomes. This study aimed to examine the substitution effects of displaying a fixed duration of sedentary time with a fixed duration of physical activity (PA) at different intensities on children’s CRF. A total of 315 children (136 boys) were assessed (age: 10.6 ± 0.6 years old). Outcomes at baseline and follow-up (16-months) were CRF determined using a maximal cycle test and sedentary time and PA measured with accelerometers. Data were analysed by isotemporal substitution analyses estimating the effect of reallocating 30 min/day of sedentary time by light (LPA), moderate (MPA) and vigorous physical activity (VPA) on CRF. VPA was positively and significantly associated with CRF cross-sectional (β = 0.026, p < 0.001) and prospectively (β = 0.010, p < 0.001). Reallocating 30 min/day of sedentary time into VPA was positively cross-sectionally (β = 0.780, p < 0.001) and prospectively (β = 0.303, p < 0.05) associated with CRF. Conversely, relocating 30-minutes of sedentary time into 30 minutes of LPA and MPA was not associated with CRF. These results suggest that reallocating an equal amount of time from sedentary into VPA is cross-sectional and prospectively associated with a favourable CRF.     

Prevalence and correlates of resistance training skill competence in adolescents

The aim of this study is to examine the prevalence and correlates of adolescents’ resistance training (RT) skill competence. Participants were 548 adolescents (14.1 ± 0.5 years) from 16 schools in New South Wales, Australia. RT skills were assessed using the Resistance Training Skills Battery. Demographics, BMI, muscular fitness, perceived strength, RT self-efficacy, and motivation for RT were also assessed. The proportion demonstrating “competence” and “near competence” in each of the six RT skills were calculated and sex differences explored. Associations between the combined RT skill score and potential correlates were examined using multi-level linear mixed models. Overall, the prevalence of competence was low (range = 3.3% to 27.9%). Females outperformed males on the squat, lunge and overhead press, whereas males performed better on the push-up (p < .05). Significant associations were seen for a number of correlates, which largely differed by sex. Muscular fitness was moderately and positively associated with RT skills among both males (β = 0.34, 95%CIs = 0.23 to 0.46) and females (β = 0.36, 95%CIs = 0.23 to 0.48). Our findings support a link between RT skills and muscular fitness. Other associations were statistically significant but small in magnitude, and should therefore be interpreted cautiously.     

Changes in the school and non-school sedentary time in youth: The UP&DOWN longitudinal study

ABSTRACT

The aims of this study were (i) to examine the sedentary time (ST) during different time periods [i.e., weekend, out-of-school weekdays hours, school hours, recess, physical education classes (PEC)] in children and adolescents; (ii) to identify 2-year longitudinal changes in the ST for these periods; and (iii) to examine if ST at baseline is associated with ST 2 years later. This was a 2-year follow-up study with 826 (51.9% boys) children and 678 (50.7% boys) adolescents. Accelerometers were used to assess ST. Students spent more than 60% of their weekend, out-of-school hours and school hours in ST. During these periods, girls and adolescents were more sedentary than boys and children, respectively (p < 0.05). Over 2-year follow-up, ST increased during the weekend, out-of-school hours, school hours and recess in all subgroups studied (p < 0.001). ST during PEC declined 2% per year in children (p < 0.001) but it increased in adolescents (p < 0.05). ST during the periods analysed at baseline was lowly associated with ST during these periods 2 years later (intraclass correlations from <0.001 to 0.364). Interventions in these settings may be adequate if the intention is to avoid ST increase in students.     

Longitudinal associations between motor competence and different physical activity intensities: LabMed physical activity study

An appropriated level of motor competence is essential for children´s healthy growth and development and a key factor in the promotion of lifelong active lifestyles and health.

The purpose of this study was to examine associations between motor competence and different physical activity intensities (light, moderate, moderate-to-vigorous and vigorous physical activity), as well as total physical activity, over a two-year period, in adolescents. The sample comprised of 103 adolescents (13.49 ± 0.87 years, 53 girls), from the north of Portugal. Motor competence was evaluated with the body coordination test, Körperkoordination-Test-für-Kinder. Physical activity was objectively assessed with GT1M accelerometers (ActiGraph, Pensacola, FL, USA). Physical activity variables were expressed as proportions of accelerometer wear time. Regression analyses showed positive longitudinal associations between motor competence at baseline and moderate physical activity (B = 0.0033, p = 0.018), moderate-to-vigorous physical activity (B = 0.0052, p = 0.024) and total physical activity (B = 0.067, p = 0.040) at follow up, after adjustments for age, sex, the corresponding physical activity intensity at baseline, body mass index, pubertal stage and socioeconomic status. Our ?ndings highlight the importance of motor competence development to promote moderate-to-vigorous physical activity during adolescence.     

Changes in performance and poling kinetics during cross-country sprint skiing competition using the double-poling technique

In this study, changes in skiing performance and poling kinetics during a simulated cross-country sprint skiing competition were investigated. Twelve elite male cross-country skiers performed simulated sprint competition (4 × 1,150 m heat with 20 min recovery between the heats) using the double-poling technique. Vertical and horizontal pole forces and cycle characteristics were measured using a force plate system (20-m long) during the starting spurt, racing speed, and finishing spurt of each heat. Moreover, heat and 20-m phase velocities were determined. Vertical and horizontal pole impulses as well as mean cycle length were calculated. The velocities of heats decreased by 2.7 ± 1.7% (p = 0.003) over the simulated competition. The 20-m spurting velocity decreased by 16 ± 5% (p < 0.002) and poling time increased by 18 ± 9% (p < 0.003) in spurt phases within heats. Vertical and horizontal poling impulses did not change significantly during the simulation; however, the mean forces decreased (p < 0.039) (vertical by 24 ± 11% and horizontal by 20 ± 10%) within heats but not between the heats. Decreased heat velocities over the simulated sprint and spurting velocities within heats indicated fatigue among the skiers. Fatigue was also manifested by decreased pole force production and increased poling time.     

Psychological characteristics of developing excellence in elite youth football players in English professional academies

ABSTRACT

This mixed-longitudinal prospective study examined the development of psychological characteristics of developing excellence in relation to the career progression of elite youth football players. In a 20-month period, 111 academy football players aged 11–16 completed the Psychological Characteristics of Developing Excellence Questionnaire (PCDEQ) on 1–5 occasions. This combination of single and repeated assessments resulted in a mixed-longitudinal sample of 226 completed PCDEQs. Players were then prospectively tracked, and their scholarship status assessed at follow-up, at age U17. Multilevel modelling revealed that coping with performance and developmental pressures scores increased with age, and that Category 1–2 academy scholars (4.35 ± 0.61) scored higher than Category 3–4 academy scholars (3.99 ± 0.67) and non-scholars (4.02 ± 0.78) (p < .05). Evaluating performances and working on weaknesses scores increased with age for Category 1–2 academy scholars (U12-U14 vs. U15-U16 = 5.16 ± 0.48 vs. 5.38 ± 0.45), compared to non-scholars (U12-U14 vs. U15-U16 = 5.11 ± 0.59 vs. 5.03 ± 0.71) (p < .05). Imagery use during practice and competition scores decreased with age (U12-U14 vs. U15-U16 = 4.45 ± 0.66 vs. 4.29 ± 0.70) (p < .05). A blend of PCDEs may facilitate optimal career progression. Football academies should develop players’ PCDEs, with a particular focus on developing their coping skills and their ability to realistically evaluate performances and work on weaknesses.     

Energy Expenditure and Intensity of Active Video Games in Children and Adolescents

Purpose: This study aimed to compare the energy expenditure and intensity of active video games to that of treadmill walking in children and adolescents. Method: Seventy-two boys and girls (aged 8–13 years) were recruited from local public schools. Energy expenditure and heart rate were measured during rest, during 3-km/hr, 4-km/hr, and 5-km/hr walks, and during active games (Adventure, Boxing I, Boxing II, and Dance). During walking and active games, we also assessed physical activity using an accelerometer. Results: The energy expenditure of the active games Adventure, Boxing I, Boxing II, and Dance was similar to that of treadmill walking at 5 km/hr in boys and girls. Heart rate was significantly higher for the game Adventure compared with walking at 3 km/hr, 4 km/hr, and 5 km/hr and the game Dance in both genders. The heart rate of girls during the games Adventure and Dance was significantly higher compared with boys. There was a statistically significant difference (p < .05, with an effect size ranging from 0.40 to 3.54) in the counts·min^?1, measured through accelerometry, between activities. Conclusion: XBOX 360 Kinect games provide energy expenditure and physical activity of moderate intensity for both genders. The use of active video games can be an interesting alternative to increase physical activity levels.     

Dietary nitrate supplementation does not improve cycling time-trial performance in the heat

This investigation examined the effect of beetroot juice (BR) supplementation, a source of dietary nitrate (NO₃^?), on cycling time-trial (TT) performance and thermoregulation in the heat. In a double-blind, repeated-measures design, 12 male cyclists (age 26.6 ± 4.4 years, VO_2peak 65.8 ± 5.5 mL.kg^?1.min^?1) completed four cycling TTs (14 kJ.kg^?1) in hot (35°C, 48% relative humidity) and euthermic (21°C, 52%) conditions, following 3 days supplementation with BR (6.5 mmol NO₃^? for 2 days and 13 mmol NO₃^? on the final day), or NO₃^–depleted placebo (PLA). Salivary NO₃^? and nitrite, core (T_c) and mean skin temperature (T_sk) were measured. Salivary NO₃^? and nitrite increased significantly post-BR supplementation (p < 0.001). Average TT completion time (mm:ss) in hot conditions was 56:50 ± 05:08 with BR, compared with 58:30 ± 04:48 with PLA (p = 0.178). In euthermic conditions, average completion time was 53:09 ± 04:35 with BR, compared with 54:01 ± 04:05 with PLA (p = 0.380). The TT performance decreased (p < 0.001), and T_c (p < 0.001) and T_sk (p < 0.001) were higher in hot compared with euthermic conditions. In summary, BR supplementation has no significant effect on cycling TT performance in the heat.     

Evidence for data missing at random in youth physical activity monitoring research

This study examined whether or not activity monitor data collected as part of a typical 7-day physical activity (PA) measurement protocol can be expected to be missing at random. A total of 315 participants (9–18 years) each wore a SenseWear Armband monitor for 7 consecutive days. Participants were classified as “compliant” (86 boys and 124 girls) if they had recorded accelerometer data during 70% or more of the predefined awake time (7 AM–10 PM) on four different days; and “non-compliant” (44 boys and 51 girls) when not meeting these criteria. Linear mixed models were used to examine differences in energy expenditure (EE) levels by compliance across 10 different time periods. The results indicated that non-compliant girls were older (13.4 ± 2.9 vs. 12.2 ± 2.5) and taller (156.8 ± 10.3 vs. 152.8 ± 11.3) than their same gender compliant peers (P < .05). Comparisons of EE rates at segmented portions of the day revealed no differences between compliant and non-compliant groups (P ≥ .05). Differences in EE ranged from ?0.32 kcal · kg^?1 · h^?1 (before school time) to 0.62 kcal · kg^?1 · h^?1 (physical education class) in boys and ?0.39 kcal · kg^?1 · h^?1 (transportation from school) to 0.37 kcal · kg^?1 · hour^?1 (recess) in girls. The results showed that compliant and non-compliant individuals differed in a few demographic characteristics but exhibited similar activity patterns. This suggests that data were considered to be missing at random, but additional work is needed to confirm this observation in a representative sample of children using other types of activity monitors and protocols.     

Fundamental Movement Skill Proficiency and Health Among a Cohort of Irish Primary School Children

Purpose: This study aimed to investigate the relationship between fundamental movement skills (FMS) and markers of health among a cohort of Irish primary school children. Methods: Participants (N = 296, mean age: 7.99 ± 2.02 years) were senior infant (n = 149, mean age: 6.02 ± 0.39 years) and 4th class (n = 147, mean age: 9.97 ± 0.40 years) students from three primary schools in Cork, Ireland. FMS proficiency (TGMD-2) and markers of health (BMI percentile, waist circumference percentile, blood pressure percentiles, resting heart rate, cardiorespiratory fitness, objectively measured physical activity; PA) measurements were recorded. Correlation and hierarchical stepwise multiple linear regression analyses were conducted to investigate the relationship between FMS and markers of health. Results: A small, positive relationship was found between FMS (Gross Motor Quotient; GMQ) and cardiorespiratory fitness with small negative correlations between GMQ and 550 m time SDS among 6-year-olds (r(129) = ?.286, p < .05) and 10-year-olds (r(132) = ?.340, p < .05). A moderate, positive correlation was found between GMQ and light PA (r(71) = .400, p < .05). Small positive correlations were revealed between GMQ and moderate PA (r(71) = .259, p < .05) and between GMQ and total PA (r(71) = .355, p < .05). After adjusting for age, sex, the interaction effect of age and sex, and school attended, FMS explained 15.9% and 24.8% of the variance in 550 m time SDS among 6- and 10-year-olds, respectively, and 6% and 6.5% of the variance in light PA and moderate PA, respectively. After adjusting for age and sex, FMS explained 11.6% of the variance in total PA. Conclusion: A wide range of FMS is important for children’s cardiorespiratory fitness and PA.     

Effect of Manual Guidance on Acquiring a New Bimanual Coordination Pattern

Purpose: This study explored the relationship between the caring climate, empathy, prosocial behaviors, and antisocial behaviors, like bullying, in physical education, plus investigated whether empathy mediated the possible relationships between caring and social behaviors for boys and girls. Method: Middle school physical education students (N = 528) completed measures assessing a caring climate, empathy, social behaviors, and bullying. Results: A partial mediation model was supported, χ²(94) = 206.82, p < .001, comparative fit index = .97, Tucker-Lewis index = .96, root mean square error of approximation = .05, standardized root mean squared residual = .04, which was also invariant across sexes. A perceived caring climate positively predicted prosocial behavior and cognitive empathy and negatively predicted antisocial behavior, like bullying. Cognitive empathy mediated the relationship between caring and prosocial behavior. Conclusions: Collective findings suggest that creating a caring climate is one tool that physical education teachers may use to promote positive behavior.     

Can a teacher-led RCT improve adolescent girls’ physical self-perception and perceived motor competence?

Perceived and actual motor competence (MC) influence physical activity (PA) behaviour. Notably, both are lower in girls than in boys. This study aimed to investigate (i) whether a 12-week, teacher-led intervention that improves actual MC (Lander, N., Morgan, P. J., Salmon, J., & Barnett, L. M. (2017). Improving early-adolescent girls’ motor skill: A cluster randomized controlled trial. Medicine and Science in Sports and Exercise. 49(12), 2498–2505) could also improve adolescent girls’ physical self-perception and perceived MC, and (ii) whether change in actual MC is associated with post-intervention perceptions A randomized controlled trial with 171 girls (mean age 12.48 ± 0.34 years), measured perception (i.e., physical self-perception profile (PSPP) and pictorial scale of perceived movement skill competence (PMSC)) and actual MC (i.e., Victorian FMS Teachers’ Assessment Manual). Mixed models with post-intervention perception as the outcome, adjusting for baseline perception, group, and change in actual MC, as well as clustering, were performed. An interaction term between change in MC and intervention status was included to test the secondary aim. There were significant intervention effects on girls’ physical self-perception as well as their perceived MC. However, there was no association between change in actual MC across the intervention and post intervention perception. While the intervention improved both actual MC and perceived MC, they were not associated.