Stabilometer Performance of Educable Mentally Retarded and Normal Children

Abstract

Five trials on the stabilometer were administered to 274 EMR children ages 6 to 13 years and 151 normal children ages 6 to 9 years. Older EMR boys and girls had slightly more board movement than younger EMR children whereas there was a tendency for board movement to decrease with age for the normal children. There were no appreciable sex differences between the EMR and the normal age groupings with the exception that board movement of the young EMR boys was significantly less than that of the young and old EMR girls. Normal children had significantly less board movements than EMR children at all age levels. There was some decrease in relative intra-individual variability with increasing age for both EMR and normal children but normal children were more efficient in early learning than EMR children.     

The Determination of the Weight and Size of a Standard Discus for College Women

Abstract

The purpose of this study was (1) to determine the relationship between roentgenographic measures of muscle size of the leg and ankle extensor strength of 51 seven-year-old children, and (2) to examine sex differences in strength and leg muscle size at this age level. The correlations between ankle extensor strength and the measures of leg muscle size ranged between .58 and .63 for the boys and between .22 and .52 for the girls. The boys were substantially stronger than the girls in ankle extensor strength (P = .02) and possessed on the average the greater muscle size. When boys and girls were paired on the basis of measures of muscle size, the superiority of the boys in strength was significant at only the 30-per-cent level of confidence.     

Gender Differences in Children's Throwing Performance: Biology and Environment

Abstract

This study evaluated the influence of biological and environmental variables on the differences between the throwing performance of 5-year-old girls and boys. A total of 100 children (48 girls, 52 boys) were tested on throwing for distance and rated on two components of throwing form—trunk rotation, and foot action. Children were evaluated on eight biological characteristics—height, weight, body mass index, ponderal index, sum of four skinfolds, body diameters, arm and leg girths, and somatotypes—and four environmental characteristics—older brother, older sister, presence of adult male, and playing with older children. Results indicated that boys threw farther than girls and exhibited more mature form. Boys had greater joint diameters than girls, a smaller sum of four skinfolds, and more estimated arm muscle. Boys were more likely to play regularly with older children. Girls' throwing performance was only 57% that of boys, but when throwing was adjusted for a linear composite of biological variables, girls' throwing performance increased to 69% of boys'. Thus, while the differences in most motor performance tasks between boys and girls prior to puberty have been attributed to environmental factors, some of the differences in throwing performance appears to reflect biological characteristics, even as early as 5 years of age.     

Children's Frequency of Participation in Moderate to Vigorous Physical Activities

Abstract

Third and fourth grade boys (n = 422) and girls (n = 390) in four Texas elementary schools reported their participation in moderate to vigorous physical activities (MVPAs) over a 3-day period. Students were surveyed during class on successive days. On a subsample (n = 44), the agreement between reported and observed physical activities during physical education or recess was 86.3%. Running, walking fast, games and sports, and bicycling accounted for 70% of Total MVPAs. Of Total MVPAs reported, 47.0% for boys and 44.6% for girls were 10 min or longer in duration (LMVPA). The average number of LMVPAs per day was 1.7 for both boys and girls. Students reported significantly more occurrences of LMVPAs out of school than during school. Significant interaction between grade and gender indicated that third grade boys reported more Total MVPAs and LMVPAs than third grade girls, but fourth grade boys reported fewer Total MVPAs and LMVPAs than fourth grade girls. During the 3-day reporting period, 12.3% of boys and 13.3% of girls reported no LMVPAs, and 35.6% of boys and girls reported fewer than one LMVPAs per day. While the majority of children reported obtaining at least some activity daily, a substantial proportion of children in this sample reported fewer than one LMVPA daily, indicating that many children may not be obtaining adequate amounts of physical activity.     

Physical Characteristic,Perceptual-Motor,and Intelligence Differences between Third- and Sixth-Grade Children

Abstract

The following measures were recorded for third- and sixth-grade children: height; weight; grip strength of the dominant and nondominant hands; elbow flexion and elbow extension strength; hip flexion and hip extension strength; dynamic balance; ball-throwing accuracy; speed of hand-arm movement; eye-hand coordination; stimulus discrimination and hand speed; perceptual ability; academic achievement; and intelligence. It was concluded that sixth-grade boys had, in general, the most favorable recorded measures, followed by sixth-grade girls, third-grade boys, and third-grade girls, these differences usually being significant.     

Differences in fatigability between the sexes during a sustained submaximal contraction protocol in prepubertal children

The aim of this study was to determine whether there are differences in the fatigability of plantar flexor muscles during sustained submaximal contractions in prepubertal boys and girls. Fifteen boys (age 10.0 +/- 1.0 years) and 15 girls (age 9.8 +/- 0.9 years) participated in the study. The fatigue protocol consisted of a 10 min isometric plantar flexion at 20% of the maximal voluntary contraction. Immediately after this, five maximal isometric contractions were performed with a 3 min interval between contractions. During the experiment, electromyograms of the agonist muscles soleus and medial gastrocnemius and antagonist tibialis anterior were recorded. We observed no differences between the sexes (P < 0.05) in the decrease in torque or in the recovery rate after the fatigue protocol. Nor were there any differences between the sexes (P < 0.05) in agonist or antagonist muscle activation during the fatigue protocol and recovery period. The results indicate that there are no differences in fatigability between prepubertal boys and girls during submaximal sustained contractions, probably because the agonist and antagonist muscles were activated similarly in both sexes.     

The Relationships Among Isokinetic Endurance,Initial Strength Level,and Fiber Type

Abstract

Knee extension isokinetic peak torque was assessed at angular velocities of 0, 30, 180, and 240[ddot]/sec, and isokinetic endurance was assessed by 50 consecutive contractions at 180[ddot]/sec in eight college age men. Also, muscle fiber type of the vastus lateralis was determined and related to isokinetic strength and fatigability. To determine the influence of initial strength on isokinetic endurance the 50 serial isokinetic contractions were assessed after subjects performed two bicycle exercise regimens designed to affect initial strength levels. Neither isokinetic peak torques (made relative to MVC or per Kg of body weight) nor the amount of strength loss over the 50 contractions correlated with fiber type. The peak torques at 180[ddot]/sec at the start of the 50 contractions differed over the three conditions (unfatigued and after the two bicycle exercise regimens), however, the amount of of strength loss over the 50 trials was similar for the three conditions. Also, the patterns of the three isokinetic fatigue curves were remarkably similar. Thus, the initial strength level across the treatments did not affect the rate of fatigue. However, when the treatment conditions were examined separately, the amount of strength loss over the 50 trials correlated significantly with initial strength. Thus, factors other than, or in addition to, fiber type and initial strength level must influence the rate of isokinetic fatigue.     

Foot strike pattern in preschool children during running: sex and shod–unshod differences

Purpose: This study aims to determine the foot strike patterns (FSPs) and neutral support (no inversion [INV]/eversion [EVE] and no foot rotation) in preschool children, as well as to determine the influence of shod/unshod conditions and sex. Methods: A total of 1356 children aged 3–6 years (673 boys and 683 girls) participated in this study. A sagittal and frontal-plane video (240?Hz) was recorded using a high-speed camcorder to record the following variables: rearfoot strike (RFS), midfoot strike (MFS), forefoot strike (FFS), inversion/ eversion (INV/EVE) and foot rotation on initial contact. Results: There were no between-sex significant differences in both shod and unshod conditions in RFS. In the unshod condition, there was a significant reduction (p?Conclusion: In preschool children, no between-sex differences were found in relation to prevalence of RFS and neutral support (no INV/EVE). Shod running alters FSP of running barefoot, producing a significant increase of RFS prevalence.     

A cross-sectional study on the deprivation and sex differences in health-related fitness measures in school children

ABSTRACT

This study aimed to investigate deprivation and sex differences in selected health-relatedfitness measures in 9-12-year-old children. Data were captured on 3,407 children (49.3% boys; aged 10.5 ± 0.6 years). Cardiorespiratory fitness(20 m multistage shuttle run test; 20 m MSRT), muscular strength (handgrip strength) and body mass index (BMI) were measured. Welsh Index of Multiple Deprivation (WIMD) scores were used to make quintile groups. A two-way Analysis of Variance examined differences in BMI z-score by sex and WIMD quintiles. Two-wayAnalysis of Covariances investigated the effect of sex and WIMD quintiles on grip strength and shuttles achieved in 20 m MSRT, adjusting for BMI z-score and maturation, repectively. Independent of sex, children in the middle quintile had a significantly higher mean BMI z-score (p = 0.029) than their least deprived counterparts. There was a significant increase in grip strength (p = 0.005) and20 m MSRT (boys p < 0.001; girls p = 0.028) between most and least deprived quintiles. Significant differences in 20 m MSRT score were more apparent with decreases in deprivation in boys.Overall, inequalities exist in health-related fitness by sex and deprivation. These results can be used to inform focused services to improve current and future health.     

Developmental changes and predictability of static strength in individuals of different maturity: A 30-year longitudinal study

Abstract

This longitudinal study analyses the development and predictability of static strength and their interactions with maturation in youth. Of 515 children followed annually from age 6 to 18 years, 59 males and 60 females were measured again at age 35. Early, average, and late maturity groups were established. Body height and mass were assessed. Static strength was measured using handgrip dynamometry. Pearson correlations were used as tracking coefficients. From 6 to 12 years of age, no static strength differences were found to exist between the maturity groups of both sexes. Static strength is significantly higher in early than in average and late maturing boys (age 13–16). In girls, a dose–response effect exists (age 11–14). Adult static strength predictability is low in early maturing boys and late maturing girls. It is moderate to high (50–76%) in the other maturity groups up to age 14. Predictors for adult static strength are childhood and adolescent handgrip dynamometry (in females only), medicine ball throw, sit-up, hockey ball throw, and 25-m sprint. Handgrip is a fair predictor of adult static strength at most ages in early and average maturing females; in average maturing males, it is a predictor at age 11. Other indicators of strength (e.g. hockey ball throw) are predictors in males.     

Age and Sex Differences in Motor Performance of 3 through 6 Year Old Children

Abstract

This study examined the relationship of age and sex to the performance of 3, 4, 5, and 6 year olds on seven motor performance test items. Although significant age and sex differences were found on most of the motor tests, it appears that age generally was related more to performance than was gender. Overall, change with age was fairly linear except perhaps for balancing and a general tapering in improvement in the 5 to 6 year old category. On the tests of throwing and balancing, gender was as important as age, or more so, in its relationship to performance. Boys were superior to girls at all ages on the throwing tests; girls were superior to boys at age 6 on the Balance test. Gender differences of a lesser magnitude were found on the Speed Run and Standing Long Jump tests with the performance of boys generally being superior to the performance of girls. Thus, it appears that gender differences in motor performance occur as early as the preschool years. Interestingly, except for the Balance test, on all the tests the 3 and 4 year old boys performed similarly and the 5 and 6 year old boys performed similarly. For the girls there were more significant differences from year to year in performance, with the data generally indicating at least three distinct skill groups for girls from age 3 to 6.     

Development of the Overarm Throw: Movement and Ball Velocity Changes by Seventh Grade

Abstract

Children studied longitudinally from kindergarten through second grade were refilmed in seventh grade as they performed 10 trials of the forceful overarm throw. The horizontal ball velocities of the 22 boys and the 17 girls were compared with predictions made when the children were in second grade. The original estimate of an annual rate of change (a “developmental year”) of 5–8 feet/sec/year (1.52–2.44m) remained accurate for the boys; the original estimate for the girls had to be increased to 2–4.5 feet/sec/year (.61–1.37m). While the gap between the sexes increased throughout elementary school, it increased at a slower rate from second to seventh grade than it had during the primary years. By seventh grade, however, the girls were 5 developmental years behind the boys. The data also suggested a difference in the degree to which the sexes maintained their relative positions within their groups: girls appeared more stable than boys across the elementary years. Change was also assessed in the developmental levels exhibited by the children as they threw. The girls' rate of development was 5–6 years behind the boys' rate. Few boys, however, had reached an advanced level in all movement components by seventh grade. Self-reports suggested that the boys had participated in more overarm throwing than had the girls.     

Back to school after lockdown: The effect of COVID-19 restrictions on children's device-based physical activity metrics

BackgroundThe coronavirus disease-2019 (COVID-19) pandemic and national lockdowns took away opportunities for children to be physically active. This study aimed to determine the effect of the COVID-19 lockdown on accelerometer-assessed physical activity (PA) in children in Wales.MethodsEight hundred participants (8–18 years old), stratified by sex, age, and socio-economic status, wore Axivity AX3 accelerometers for 7 days in February 2021, during the lockdown, and in May 2021, while in school. Raw accelerometer data were processed in R-package GGIR, and cut-point data, average acceleration (AvAcc), intensity gradient, and the acceleration above which the most active X minutes are accumulated (MX) metrics were extracted. Linear mixed models were used to assess the influence of time-point, sex, age, and socioeconomic status (SES) on PA.ResultsDuring lockdown, moderate-to-vigorous PA was 38.4 ± 24.3 min/day; sedentary time was 849.4 ± 196.6 min/day; mean ± SD. PA levels increased significantly upon return to school (all variables p < 0.001). While there were no sex differences during lockdown (p = 0.233), girls engaged in significantly less moderate-to-vigorous PA than boys once back in school (p < 0.001). Furthermore, boys had more favorable intensity profiles than girls (intensity gradient: p < 0.001), regardless of time-point. PA levels decreased with age at both time-points; upper secondary school girls were the least active group, with an average M30 of 195.2 mg (while in school).ConclusionThe lockdown affected boys more than girls, as reflected by the disappearance of the typical sex difference in PA levels during lockdown, although these were re-established on return to school. Upper secondary school (especially girls) might need specific COVID-recovery intervention.     

Body Fatness and Motor Performance During Preadolescence

Abstract

Performance differences between males and females have been attributed to both biological and cultural factors, although the relative significance of each has not been ascertained. Differences in body fatness between males and females has been frequently mentioned as one biological factor responsible for variations in physical performance. In children, it has been shown that boys exhibit slightly higher performance levels than girls until adolescence, when the differences favoring the boys become greater. The purpose of this study was to investigate the relationship between selected physical performance tests and body fatness in preadolescent boys and girls. Measures of age, height, weight, skinfold thicknesses at two sites, and performance scores on the vertical jump, standing broad jump, modified pullup, 40-yard dash, and 400-yard run were obtained on 563 elementary school children. The results of a one-way ANOVA indicated that there was a significant difference between boys and girls on all of the physical performance tests. Although the boys were slightly taller and heavier and scored better than the girls on the performance tests, there was no significant difference between the sexes in the sum of two skinfolds. Separate regression equations for the sum of two skinfolds by performance on each test indicated that, with the exception of the modified pullup test, body fatness was only marginally related to performance. These findings indicated that, although inversely related to the ability to move the total body weight, body fatness was of minimal importance in explaining performance differences between young boys and girls.     

Children's physical activity and physical self-perceptions

The aim of this study was to determine the relationship between physical self-perceptions and physical activity in Canadian school children aged 10-14 years. The sample consisted of 220 boys and 246 girls in grades 5-8. Physical activity was assessed by 7-day recall using the Physical Activity Questionnaire for Older Children. Self-perceptions of physical conditioning, sports competence, strength, body appearance and general physical self-worth were measured by the Physical Self-Perception Profile (PSPP). We found that boys were more physically active than girls and had higher perceptions of sport competence and strength. All PSPP scales were significantly correlated with physical activity in both boys and girls. Structural equation modelling procedures found the hierarchical PSPP model provided a good fit to the observed data, with little evidence of differences between the sexes. Analysis of five alternative structural models of the relationship between the PSPP and physical activity found the most parsimonious model to have significant pathways from both physical conditioning and sport skills to physical activity. Models for the sample as a whole, for boys and for girls were similar, accounting for an R2 of 0.27-0.29 for physical activity. Our results demonstrate that physical self-perceptions, especially physical conditioning and sport skills, are significant correlates of activity in this population.     

Moving Well-Being Well: Investigating the maturation of fundamental movement skill proficiency across sex in Irish children aged five to twelve

ABSTRACT

Fundamental movement skills (FMS) are the basic building blocks of more advanced, complex movements required to participate in physical activity. This study examined FMS proficiency across the full range of Irish primary school children (n = 2098, 47% girls, age range 5–12 years). Participants were assessed using the Test of Gross Motor Development, 3rd edition (TGMD-3), Victorian Fundamental Movement skills manual, and the balance subtest from the Bruininks-Oseretsky Test of Motor Proficiency 2 (BOT-2). Independent sample t-tests and a one way between groups ANOVA with planned comparisons were used analyse sex and age differences. Mastery or near mastery of skills ranged from 16% for overhand throw, to 75.3% for run. Girls scored significantly higher than boys in the locomotor and balance subtests with the boys outperforming the girls in object control skills. Improvements in ability can be seen over time (F(8,1968) = 70.18, p < 0.001), with significant increases in FMS proficiency seen up to the age of 10, after which proficiency begins to decline. The findings demonstrate the low levels of FMS proficiency amongst Irish primary school children, the differences between sex that exist, and highlights the need for more programmes that focus on developing these FMS at an early age.     

Physical fitness normative values for 6–18-year-old Greek boys and girls,using the empirical distribution and the lambda,mu, and sigma statistical method

The aim of the this study was to establish age- and gender-specific physical fitness normative values and to compare percentiles and Z scores values in a large, nationwide sample of Greek children aged 6–18 years. From March 2014 to May 2014, a total of 424,328 boys and girls aged 6–18 years who attended school in Greece were enrolled. The studied sample was representative, in terms of age–sex distribution and geographical region. Physical fitness tests (i.e. 20?m shuttle run test (SRT), standing long jump, sit and reach, sit-ups, and 10?×?5?m SRT) were performed and used to calculate normative values, using the percentiles of the empirical distributions and the lambda, mu, and sigma statistical method. Normative values were presented as tabulated percentiles for five health-related fitness tests based on a large data set comprising 424,328 test performances. Boys typically scored higher than girls on cardiovascular endurance, muscular strength, muscular endurance, and speed/agility, but lower on flexibility (all p values <0.001). Older boys and girls had better performances than younger ones (p?相似文献   

The Stability of Perceived Motor Competence of Primary School Children from Two Countries over One Year

ABSTRACT

Children’s positive perceived motor competence (PMC) provides motivation for physical activity. Theoretically young children (<8 years) have inflated PMC but as children cognitively develop, perceptions are hypothesized to decrease. This study investigated strength of PMC association over time, whether any change was negative (i.e. PMC decreased) and sex differences. A total of 198 children participated, 88 (44.4%) girls and 110 (55.6%) boys, aged 8.37–11.3 years at time point one (T1). Test–retest reliability using intraclass correlation was moderate for locomotor and moderate-to-good for object control perception. Hierarchical regression analysis showed PMC at T1 positively predicted significant variance one year later (T2) for locomotor (23.1%) and object control skill (5 items: 37.7%; 7 items: 39.9%). Whilst boys and girls differed on perception level there was no interaction between PMC and sex. Incongruent with previous theoretical perspectives this study identified stability in children’s PMC across an important developmental period.     

Gross Motor Competence and Peak Height Velocity in 10- to 14-Year-Old Canadian Youth: A Longitudinal Study

The objective of this study was to evaluate gross motor competence and growth spurt in Canadian youth. Eighty-two children (38 boys, 44 girls) were assessed over a time period of five years. Growth rate was measured quarterly; motor competence was evaluated once per year using the Bruininks-Oseretsky Test of Motor Proficiency. Peak height velocity (PHV) occurred at a significantly younger age in the girls (11.3 ± 0.4 years) than the boys (13.4 ± 0.3 years; p < .001), and growth rate during PHV was significantly greater in the boys than the girls (2.8 ± 1.3 vs. 2.0 ± 0.7 cm/quarter; p = .003). Gross motor competence outcomes were significantly above the North American normative scores (p < .05) over the measured time period. After the occurrence of PHV, strength, strength/agility, and gross motor skill significantly decreased in girls (p < .01), and running speed/agility significantly decreased in boys (p < .05). This finding emphasizes that motor competence in pre-adolescent children may suddenly decrease after their growth spurt.     

Age and sex differences in motor performance of pre‐school Nigerian children

Differences in motor performance according to chronological age and gender of 341 young Nigerian children (ages 3 to 5) were examined. Motor test items designed by Morris et al. (1981) were administered to the subjects. Analysis of variance was used to determine significant differences in the motor performance of the groups. In the whole sample, more age differences than sex differences in performance were noted. Except for the balancing and running performances of the girls, a fairly linear trend of improvement with age was observed in the motor performances of the groups. At each age level the boys consistently performed better than the girls in four of the six motor tests (catching, standing long jump, tennis ball throw and speed run). Generally, the 4‐ and 5‐year‐old children performed homogeneously, with a great disparity in performance noted for the 3‐year‐old children. The results of this study confirm that age and sex differences in motor performance occur at early childhood. Prospective studies should seek to control the extraneous factors which influence motor development and account for the observed differences in motor performance of pre‐school children.