Percentile values for flexibility tests in youths aged 6 to 17 years: Influence of weight status

Influence of Maturity Status on Kinanthropometric and Physical Fitness Variables in Adolescent Female Volleyball Players

The aim of this research was to analyze differences in kinanthropometric characteristics and physical performance in relation to maturity status, as well as to determine if age, maturity offset or kinanthropometric variables could predict better performance in physical fitness tests. A total of 152 female volleyball players (14.16 ± 1.25 years old) underwent a kinanthropometric assessment, followed by a physical fitness assessment composed of different tests. The age at peak height velocity (APHV) was calculated, and the sample was divided according to biological maturation into three groups. Significant differences were observed in kinanthropometric variables (p < 0.001–0.026), with early maturers showing higher values. Age, body mass, Cormic index, relative arm span, ∑8 skinfolds, fat mass, corrected arm and thigh girths, muscle mass and biacromial and biiliocristal breadths were the variables that best predicted performance in the physical tests (p < 0.001–0.024). The more mature players showed higher values in most of the kinanthropometric variables, with the more remarkable differences being in body mass, height, arm span and sitting height, and those related to adiposity and absolute body composition, and with structural variables being the most influential on the physical tests. Age had a determinant influence on the differences found between groups in strength and power-related test performance.

Influence of biological maturation status on selected anthropometric and physical fitness variables in adolescent male volleyball players

Background

The identification of sport talent among adolescent athletes is a topic that in recent years has been a major focus of interest for both the scientific community and sport managers. Both anthropometry and physical performance through fitness tests have demonstrated to be key elements. Biological maturation, due to its influence on anthropometric variables and physical fitness, has also been studied in relation to sport talent identification.

Objective

To analyse differences according to biological maturation status in anthropometric characteristics and performance in physical fitness tests, and to determine which variables predict better performance in physical fitness tests in adolescent volleyball players.

Methods

A cross-sectional design was followed to collect the data. A total of 48 male sub-elite volleyball players (14.17 ± 0.73 years) completed a socio-demographic and sports ad hoc questionnaire. Anthropometric variables were measured following the guidelines of the International Society for the Advancement in Kinanthropometry (ISAK) including four basic measurements (body mass, height, sitting height and arm span); eight skinfolds (triceps, biceps, subscapular, iliac crest, supraspinale, abdominal, thigh and calf); four girths (arm relaxed, flexed and tensed arm, middle thigh and calf); five breadths (biacromial, biileocrestal, humerus, femur and bi-styloid); three lengths (acromiale-radiale, radiale-stylion and stylion-medio dactilion); and a height (ilioespinale). Physical fitness was assessed, including the sit-and-reach, back scratch, long jump, medicine ball throw, counter movement jump (CMJ), 20 meters sprint, and agility tests. Furthermore, maturity offset and age at peak height velocity (APHV) was calculated.

Results

Significant differences were found in the body mass (Mean Difference, MD = 20.86-30.75), height (MD = 11.72-19.09), sitting height (MD = 4.27-10.27), arm span (MD = 12.91-20.78), body mass index (MD = 3.72-5.63), upper limb length (MD = 7.76), corrected muscle girths (MD = 2.06-9.31), ∑6 and 8 skinfolds (MD = 3.67-50.21) fat mass and percentage (MD = 0.30-11.58), muscle (MD = 4.13-10.64) and bone mass (MD = 1.61-3.54) (p < 0.001-0.030), showing higher values the early maturers. In the physical fitness tests, significant differences were observed in the medicine ball throw (MD = 1.26-2.80) and in CMJ power (MD = 156.71-379.85) (p < 0.001). Regression models identified fat mass percentage predicted worse physical test performance (p < 0.001), while age, maturation offset, muscle and bone variables were predictors of better physical performance (p < 0.001).

Conclusions

Significant differences based upon the stages of biological maturation were found in the anthropometric and physical condition variables in favor of the players whose maturation process was more advanced, with the variables related to fat and adipose, muscle and bone development conditioning their performance in the physical condition tests.

The Effect of Age, Biological Maturation and Birth Quartile in the Kinanthropometric and Physical Fitness Differences between Male and Female Adolescent Volleyball Players

BACKGROUND

Differences in kinanthropometric and physical fitness performance between boys and girls usually start during adolescence, as a result of the changes in the hormonal environment that occur with the advance of age and biological maturation; Methods: A total of 96 1st Regional Division players adolescent volleyball players, 48 males, (age = 14.17 ± 1.00 years-old) and 48 females (age = 14.41 ± 1.21 years-old) underwent a kinanthropometric assessment, were asked to perform different physical fitness test and to complete a questionnaire. Chronological age, maturity offset, age at peak height velocity (APHV), and birth quartile were calculated; Results: Statistical differences were observed between male and female players in the APHV (p < 0.001). Male players showed higher values in the bone and muscle-related variables (p < 0.001-0.040), as well as in the strength and power production-related physical tests (p < 0.001-0.012), while the female showed higher values in the fat-related variables (p = 0.003-0.013), and performed better in the flexibility tests. Age, maturity offset, and birth quartile showed to have statistical influence in the differences found between sex groups; Conclusions: There is a clear influence of age and biological maturation on the differences found between sexes in adolescent volleyball players that could be taken into account regarding grouping in early stages.

The Federated Practice of Soccer Influences Hamstring Flexibility in Healthy Adolescents: Role of Age and Weight Status

The aim of this study was to compare the hamstring flexibility between federated soccer and non-federated adolescents, and also to evaluate the effect of age and weight status on hamstring flexibility. The participants were 234 students (11–18 years old) divided into: (i) G1: non-federated (n = 127), and (ii) G2: federated in soccer (n = 107). The deep flexion of the trunk (DF) test and the sit and reach test (SRT) were performed. G2 showed higher values for the DF and SRT compared to G1 (p < 0.05). Both flexibility tests correlated positively (r = 0.4, p < 0.001). Body mass index (BMI) was negatively correlated with the DF test (r = −0.3, p < 0.001), but not with the SRT. Divided by BMI, the underweight and normal weight groups had higher scores in the DF test compared with the overweight and obese groups (p < 0.001). BMI was negatively correlated with hamstring flexibility. Federated soccer students present higher scores of hamstring flexibility.

Bilateral and Unilateral Asymmetries of Strength and Flexibility in Young Elite Sailors: Windsurfing, Optimist and Laser Classes

In sport sailing, performance is related to the sailor’s ability to maintain the stability of the boat, and the boat class determines the variables involved in such ability. In monohull-type vessels, such as the Optimist and Laser classes, the flexibility of the hip joint is a key performance factor. In the Windsurfing class, performance is determined by the strength of the flexors of the fingers and elbows. The performance of the sailor may be affected by asymmetries in the strength and flexibility of the muscles and joints involved in technical actions. The objective of this study was to evaluate asymmetries in strength and flexibility in young sailors. Thirty-three young sailors (ten girls) from the Windsurfing, Optimist and Laser classes were assessed for manual strength and flexibility, by dynamometry and straight leg lift tests, respectively. The symmetry index and the functional asymmetry of compression force were calculated. The results showed no differences between sailors according to gender. The sailors of the Laser class obtained the highest levels of manual strength, whereas those of the Windsurfing class showed the highest flexibility levels. The girls’ group and Windsurfing class had the highest percentage of sailors with strength asymmetry, whereas, the sailors of the Optimist class presented a greater percentage of asymmetry in flexibility. There were no differences in upper limb strength and lower limb flexibility between the dominant and non-dominant sides.

Lower Limb Flexibility in Children With Duchenne Muscular Dystrophy: Effects on Functional Performance

OBJECTIVE

To investigate the effects of lower limb flexibility on the functional performance of children with Duchenne muscular dystrophy.

METHODS

Thirty children, whose functional levels were at 1 or 2 according to the Brooke Lower Extremity Functional Classification Scale, were included in this study. The flexibilities of the hamstrings, hip flexors, tensor fascia latae, and gastrocnemius muscles were evaluated in the children's dominant lower limbs. The children's functional performance was assessed using 6-minute walk tests and timed performance tests. The correlations between the flexibilities of the lower limb muscles and the performance tests were examined.

RESULTS

The flexibilities of the lower extremity muscles were found to be correlated to the 6-minute walk tests and the timed performance tests. The flexibility of the hamstrings (r = -.825), the gastrocnemius muscles (r = .545), the hip flexors (r = .481), and the tensor fascia latae (r = .445) were found to be correlated with functional performance as measured by the 6-minute walk tests (P < .05).

DISCUSSION

The results of the current study indicate that the flexibility of the lower limbs has an effect on functional performance in the early stages of Duchenne muscular dystrophy. More research is needed to determine the functional effects of flexibility on performance by adding long-term flexibility exercises to the physiotherapy programs of children with Duchenne muscular dystrophy.

[Analysis of adiposity and physical fitness in young Colombian students]

INTRODUCTION

Body mass index and physical fitness are important markers of a healthy life style. Objective: To analyze adiposity and physical fitness in young students from public schools in Armenia, Colombia, and examine differences between sex and age groups. Materials and methods: We analyzed 1,150 students: 46.6% (n=536) males and 53.4% (n=614) females, with an age range of 10 to 20 years (15.45 ± 2.52). Physical fitness was evaluated by the Course-Navette test, the Horizontal Jump test, the 20-meter run test and the Sit-and-Reach test. Body mass index and body fat were also assessed. Results: Compared with males, females had significantly higher adiposity levels, body mass index (20.4 vs. 19.5) and body fat (23% vs. 11%). Males had higher levels of physical fitness in all the variables analyzed, with statistically significant differences (p<0.001), except in flexibility, where females achieved better results (3.1cm vs.1 3cm; p=0.003). In both sexes, body mass index increased with age (p<0.001). However, body fat decreased with age in males (p<0.001) and increased in females (p<0.001). In males, physical fitness improved with age in all variables. In females, no significant differences were found between age groups except in the maximal oxygen uptake (VO2max, p<0.001). Conclusion: Adiposity was significantly higher in women than in men. Males had a better level of physical fitness than females, except in flexibility. Physical fitness improved significantly with age in males, but did not change in females.

Percentile Values of Physical Fitness Levels among Polish Children Aged 7 to 19 Years--a Population-Based Study

AIM

The objective of the study was to report gender and age-specific percentile values for fourteen commonly used field-based physical fitness tests among a national representative sample of Polish children aged 7 to 19 years.

METHODS

A descriptive cross-sectional and population-based study examines the physical fitness among a random and large national representative sample of schoolchildren aged 7 to 19 years in Poland. A sample of 49,281 children and adolescents (25,687 boys and 23,594 girls) was assessed by the EUROFIT fitness test battery, the International Committee on the Standardization of Physical Fitness Tests and Cooper Test of physical fitness. The LMS statistical method was used.

RESULTS

Smoothed gender and age-specific percentiles for the physical fitness tests in boys and girls aged 7 to 19 years are reported and expressed as both tabulated and curves values (2.3rd, 9th, 25th, 50th, 75th, 91st, and 97.7th). Figures showed greater physical fitness levels in boys, except for the flamingo balance, sit-and-reach, and stand-and-reach tests, in which girls performed slightly better. There was also a trend towards increased physical fitness levels as the age increased in both boys and girls.

CONCLUSION

The percentile values provided will enable the correct interpretation and monitoring of fitness status of Polish children.

Differences in personal and lifestyle characteristics among Zimbabwean high school adolescents with and without recurrent non-specific low back pain: a two part cross-sectional study

BACKGROUND

Recurrent non-specific low back pain (NSLBP) is increasingly becoming common among adolescents worldwide. A recent study in Zimbabwe showed a relatively high prevalence (28.8 %) among high school students. Influential associated factors, however, remain unclear. This is a significant shortcoming. The aim was to determine personal or lifestyle-related factors associated with recurrent NSLBP among high school adolescents in Harare, Zimbabwe.

METHODS

This study was part of a large epidemiological study conducted in two continuous parts. Part one sought to determine self-reported associated factors among 532 participants (mean age =16 ± 1.72 years) drawn randomly from selected government schools using a reliable and content-validated questionnaire (Kappa coefficient, k = 0.32-1). Part two purposively identified adolescents (N = 64, median age =17 years, interquartile range, IQR = 15-18 years) with a history of 'severe' recurrent NSLBP from part one based on a specific eligibility criteria and compared body mass index, relative school bag weight and hamstring flexibility with matched adolescents without NSLBP. Data was analysed using Statistica version 11. Independent t-tests or χ2 tests of association were used for continuous and categorical data, respectively. The statistical significance was set at p < .05.

RESULTS

Recurrent NSLBP was associated with self-reported factors such as perceptions of a heavy school bag [χ2 (1) = 85.9, p < 0.001]. A significant proportion of adolescents with recurrent NSLBP spent over 30 min carrying the school bag to and from school [χ2 (1) =32.2, p < 0.001]. It was also associated with prolonged sitting (p < 0.001), not playing sports [χ2 (1) =5.85, p = 0.02] and tight hamstrings [χ2 (1) =7.6, p = 0.006].

CONCLUSIONS

Although conclusions from this study are hesitant because of the cross-sectional nature of the study and the relatively small sample size in follow-up study, recurrent NSLBP is associated with perceptions of a heavy school bag, duration of school bag carriage, no sports participation, prolonged sitting on entertainment activities, and tight hamstrings. These findings add to the importance of promoting physical activity at school or home especially aimed at improving muscle flexibility.

Physical Fitness Percentiles of German Children Aged 9-12 Years: Findings from a Longitudinal Study

Background

Generating percentile values is helpful for the identification of children with specific fitness characteristics (i.e., low or high fitness level) to set appropriate fitness goals (i.e., fitness/health promotion and/or long-term youth athlete development). Thus, the aim of this longitudinal study was to assess physical fitness development in healthy children aged 9–12 years and to compute sex- and age-specific percentile values.

Methods

Two-hundred and forty children (88 girls, 152 boys) participated in this study and were tested for their physical fitness. Physical fitness was assessed using the 50-m sprint test (i.e., speed), the 1-kg ball push test, the triple hop test (i.e., upper- and lower- extremity muscular power), the stand-and-reach test (i.e., flexibility), the star run test (i.e., agility), and the 9-min run test (i.e., endurance). Age- and sex-specific percentile values (i.e., P₁₀ to P₉₀) were generated using the Lambda, Mu, and Sigma method. Adjusted (for change in body weight, height, and baseline performance) age- and sex-differences as well as the interactions thereof were expressed by calculating effect sizes (Cohen’s d).

Results

Significant main effects of Age were detected for all physical fitness tests (d = 0.40–1.34), whereas significant main effects of Sex were found for upper-extremity muscular power (d = 0.55), flexibility (d = 0.81), agility (d = 0.44), and endurance (d = 0.32) only. Further, significant Sex by Age interactions were observed for upper-extremity muscular power (d = 0.36), flexibility (d = 0.61), and agility (d = 0.27) in favor of girls. Both, linear and curvilinear shaped curves were found for percentile values across the fitness tests. Accelerated (curvilinear) improvements were observed for upper-extremity muscular power (boys: 10–11 yrs; girls: 9–11 yrs), agility (boys: 9–10 yrs; girls: 9–11 yrs), and endurance (boys: 9–10 yrs; girls: 9–10 yrs). Tabulated percentiles for the 9-min run test indicated that running distances between 1,407–1,507 m, 1,479–1,597 m, 1,423–1,654 m, and 1,433–1,666 m in 9- to 12-year-old boys and 1,262–1,362 m, 1,329–1,434 m, 1,392–1,501 m, and 1,415–1,526 m in 9- to 12-year-old girls correspond to a “medium” fitness level (i.e., P₄₀ to P₆₀) in this population.

Conclusions

The observed differences in physical fitness development between boys and girls illustrate that age- and sex-specific maturational processes might have an impact on the fitness status of healthy children. Our statistical analyses revealed linear (e.g., lower-extremity muscular power) and curvilinear (e.g., agility) models of fitness improvement with age which is indicative of timed and capacity-specific fitness development pattern during childhood. Lastly, the provided age- and sex-specific percentile values can be used by coaches for talent identification and by teachers for rating/grading of children’s motor performance.

Top 10 research questions related to musculoskeletal physical fitness testing in children and adolescents

The purpose of this article is to bring attention to the 10 most pressing questions relevant to musculoskeletal physical fitness testing in children and adolescents. The goal is to stimulate research to answer these questions. The most pressing needs include establishing definitive links between valid, reliable, and feasible field test measures of muscular strength, endurance, power, and flexibility and health risk factors/markers in children and adolescents; determining the effects of exercise training on these relationships; and documenting the tracking of these relationships. The role of flexibility in health-related physical fitness (HRPF) needs to be carefully and specifically examined. Although body weight/composition is a separate component of health-related fitness, it is also a factor that can influence the performance of musculoskeletal test items. The role of body weight, body fat, and central adiposity and the possibility of adjustment of tests results are important research questions. Several questions relate to which field tests are best for use in schools. Finally, actual health-related criterion-referenced cutoff values need to be developed. In conclusion, more quality research is needed to firmly establish the musculoskeletal area for HRPF in youth.