Reference values of vertical jumping performances in healthy Tunisian adolescent

Reference Values of Physical Performance in Handball Players Aged 13-19 Years: Taking into Account Their Biological Maturity

Biological maturity status significantly influences success in handball, impacting an athlete's performance and overall development. This study aimed to examine the anthropometric and physical performance variables concerning age and maturity status, establishing reference values for physical performance among Tunisian players. A total of 560 handball players (309 males and 251 females aged 13-19 years) were categorized based on maturity status: early (n = 98), average (n = 262), and late (n = 200), determined through Mirwald and colleagues' equations. Anthropometric, physical fitness, and physiological data were collected for reference value creation. Our findings revealed significantly higher anthropometric parameters (p = 0.003) in late-maturing athletes compared to their early-maturing counterparts. Post-pubertal athletes showed significantly superior (p = 0.002) jumping ability, change of direction, and aerobic performance compared to their pre-pubertal peers. Additionally, male athletes outperformed females in both fitness (p = 0.001) and aerobic (p = 0.001) performance. A notable age-by-maturity interaction emerged for most performance outcomes (η2 ranging from 0.011 to 0.084), highlighting increased sex-specific differences as athletes progressed in age. Percentile values are provided for males and females, offering valuable insights for coaches and sports scientists to design personalized training programs. Understanding a player's performance relative to these percentiles allows trainers to tailor workouts, addressing specific strengths and weaknesses for enhanced development and competitiveness.

Influence of muscle volume on jumping performance in healthy male and female youth and young adults

BACKGROUND

Sex differences that appear throughout puberty have a substantial impact on the training process. It remains unclear what effect these sex differences should have on how training programs are planned and performed and what objectives should be established for boys and girls of different ages. This study aimed to investigate the relationship between vertical jump performance and muscle volume based on age and sex.

METHODS

One hundred eighty healthy males (n = 90) and females (n = 90) performed three different types of vertical jumps (VJ): squat jump (SJ), counter movement jump (CMJ), and counter movement jump with arms (CMJ with arms). We used the anthropometric method to measure muscle volume.

RESULTS

Muscle volume differed across age groups. There were significant effects of age, sex, and their interaction on the SJ, CMJ, and CMJ with arms heights. From the age of 14-15, males exhibited better performances than females, and large effect sizes became apparent in the SJ (d = 1.09, P = 0.04), CMJ (d = 2.18; P = 0.001) and CMJ with arms (d = 1.94; P = 0.004). For the 20-22-year-old age group, there was a significant difference in VJ performance between males and females. Extremely large effect sizes became apparent in the SJ (d = 4.44; P = 0.001), CMJ (d = 4.12; P = 0.001) and CMJ with arms (d = 5.16; P = 0.001). When performances were normalized to the lower limb length, these differences persisted. After normalization to muscle volume, males exhibited better performance when compared to females. This difference persisted only for the 20-22-year-old group on the SJ (p = 0.005), CMJ (p = 0.022) and CMJ with arms (p = 0.016). Among male participants, muscle volume was significantly correlated with SJ (r = 0.70; p < 0.01), CMJ (r = 0.70; p < 0.01) and CMJ with arms (r = 0.55; p < 0.01).

CONCLUSIONS

The results indicate that muscle volume may be one of the major determining factors in sex differences in vertical jumping performance.

Muscle Strength Reference Values and Correlation with Appendicular Muscle Mass in Mexican Children and Adolescents

Strength and muscle mass are important determinants of health status, and reference values for pediatric populations from every country or geographic region are needed. The aim of this study was to develop age- and sex-specific reference values of muscle strength and evaluate the correlation between muscle strength and appendicular lean mass in Mexican children and adolescents. A cross-sectional study was conducted in 1111 healthy subjects ages 5 to 19 years of age participating in the "Body Composition Reference Values in Mexican Children and Adolescents" study. Smoothed reference values for the 1, 3, 5, 15, 25, 50, 75, 85, 95, 97, and 99 percentiles of muscle strength for upper and lower limbs were developed based on age and sex using Jamar® and Microfet2® dynamometers. Mean values were derived using the Generalized Additive Models for Location, Scale and Shape (GAMLSS), and lean mass was determined using dual-energy X-ray absorptiometry. Highly positive correlations of muscle strength with lean mass in upper limbs were found r-values 0.87-0.92 for boys and r = 0.80-0.86 for girls. High and moderate positive correlations for lower limbs were also noted for upper limbs: r = 0.74-0.86 for boys and r = 0.67-0.82 for girls. The reference values for appendicular muscle strength established in this study demonstrated a high and positive correlation between appendicular mass and muscle strength. These data will be useful when evaluating conditions and diseases affecting muscle or sports.

Factors related to lower limb performance in children and adolescents aged 7 to 17 years: A systematic review with meta-analysis

BACKGROUND

The literature identifies several factors that are associated with lower limb performance (LLP). However, there is little consensus on which factors have the major associations with LLP.

OBJECTIVE

Examine, analyze and summarize the scientific evidence on the factors associated with the performance of LLP in children and adolescents of both sexes aged between 7 and 17 years.

DESIGN

This systematic review was conducted following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement and was registered in PROSPERO.

DATA SOURCES

A systematic literature search of five electronic databases (i.e., SPORTDiscus, PubMed, CINAHL, Google Scholar, and SCOPUS) with date restrictions was conducted (2010 to 2021).

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Eligibility criteria included (i) a study published between 2010 and 2021; (ii) a research study with observational design; (iii) a study analyzing LLP; and (iv) a sample composed of young people between 7 and 17 years old (regardless of sex).

ANALYSES

Literature analysis was carried out in English and Portuguese between 2018 and 2021, "blindly" by two researchers. For data sorting, Rayyan® was used. Data extraction and evidence analysis were performed "blindly", using the Loney scale. The minimum items for observational studies were analyzed by the STROBE checklist. Meta-analyses were conducted based on age group (Childhood [7 to 11 Yrs] and Adolescence [12 to 17 Yrs]) and puberty stages (i.e., Prepupertal and Pubertal). The heterogeneity between the samples of the studies was assessed using the "Cochran's Q" and "I^2" statistics. Meta-regression analyses were performed to check the factors related to heterogeneity of the studies and to check the associations between chronological age and LLP.

RESULTS

The literature search resulted in 1,109,650 observational studies of which 39 were included in this review. Through Meta-analysis and Meta-regressions, it was possible to indicate that advancing chronological age related to increased LLP (p<0.01), and that in relation to puberty stages pubertal subjects had higher LLP than their pre-pubertal peers (p<0.01).

DISCUSSION

The main findings of the present systematic review suggest that as chronological age advances (childhood to adolescence), neuromuscular systems mature and this may be due to advancing puberty, which is also associated with an increase in LLP.

CONCLUSION

The factors associated with lower limbs performance are still inconsistent in the literature. However, advancing chronological age and stage of puberty are both associated with increased lower limbs performance.

TRIAL REGISTRATION

ID-PROSPERO-CRD42020137925.

A Review of Countermovement and Squat Jump Testing Methods in the Context of Public Health Examination in Adolescence: Reliability and Feasibility of Current Testing Procedures

BACKGROUND

In the context of a public health physical fitness (PF) examination in adolescence, a countermovement jump (CMJ) and a squat jump (SJ) are two vertical jump (VJ) tests widely used to evaluate lower limb muscle strength and power, respectively. The main criticism of both the CMJ and SJ test is the lack of test standardization. Therefore, the objectives of this review are: (a) to gather information about both jumps; (b) to investigate whether it is possible to identify common procedures referred to in the CMJ and SJ technical execution, and (c) to design standard operating procedures (SOPs) to promote CMJ and SJ standardization in an adolescent population aged 12-18 years.

METHODS

The review partially adopted the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement (PRISMA). Due to growing attention in monitoring physical health through field tests in recent years, articles were collected using the PubMed, Web of Science, and Scopus databases from January 2009 to July 2019. Original articles in which CMJ or SJ were used to assess the muscular strength in adolescents were eligible for further analysis. Articles written in English was imposed as a limit.

RESULTS

A total of 117 studies met the inclusion criteria. The description of the CMJ and SJ test procedures was different within the literature, with discrepancies in the jump technique, number of jumps, and measurement devices used.

CONCLUSIONS

A lack of method standardization for both the CMJ and the SJ test was identified. Based on the literature, SOPs for both VJs were proposed. These are useful in the context of public health PF examination in adolescents, as they facilitate an unbiased comparison of jump performance data between published studies.

Vertical Jump Performance in Hungarian Male Elite Junior Soccer Players

PURPOSE

Vertical jump is a common test to measure impulsive ability in soccer; however, limited normative data have been published on young soccer players from vertical jump measurements on a force platform. The purpose of this study was to provide normative values for three chronological age groups of male junior soccer players (U16, U17 and, U18 years).

METHOD

Vertical jump performance of 365 soccer players (16.4 ± 0.8 years) was assessed using a force platform measurement system. Net impulse, force, power, jump height (impulse-momentum), jump height (flight time) were reported for each age group for squat jump (SJ) and countermovement jump (CMJ).

RESULTS

Mean values ± SD of jump height were 32.9 ± 4.1, 33.5 ± 4.0, and 33.9 ± 4.2 cm for the three age groups respectively in SJ and 36.3 ± 3.8, 37.5 ± 3.9, and 38.6 ± 4.4 cm in the CMJ. Mean values of all age groups for maximum force and maximum power were 1559 ± 211 N and 3261 ± 492 watt respectively for SJ and 1598 ± 241 N and 3287 ± 502 watt for CMJ. Based on descriptive data, percentiles were reported for all examined variables.

CONCLUSIONS

Jump height and relative values were less sensitive discriminator variables between age groups in the studied age range, while maximum impulse, maximum force, and maximum power were more sensitive to changes in maturational status. Normative values can be used by the coaches in the interpretation and evaluation of their athletes' performance and for training and talent identification purposes.

Muscle fitness and its association with body mass index in children and adolescents aged 7-18 years in China: a cross-sectional study

BACKGROUND

The present study was the first one aimed to investigate the current muscle fitness and its associated factors among children and adolescents in mainland China.

METHODS

From Nov 2013 to Jul 2014, 2283 children and adolescents aged 7-18 were recruited in Hainan and Shaanxi Provinces in China by cross-sectional design. Information on anthropometry and muscle fitness, measured by hand grip strength (GS), vertical jump (VJ) and sit-and-reach (SR), were collected. Analysis of covariance was performed by using general linear regression models to identify the association between BMI and muscle fitness.

RESULTS

The means of GS, VJ and SR in boys were 22.30 ± 11.55 kg, 22.93 ± 6.80 cm and 3.58 ± 7.31 cm, respectively, and in girls were 16.61 ± 6.87 kg, 18.11 ± 4.08 cm and 7.18 ± 5.72 cm, respectively. GS (from 8.26 kg in the 7-8-year-old group to 27.91 kg in the 17-18 group) and SR (from 1.75 cm in the-8-year-old group to 10.12 cm in the 17-18 group) increased with age (both p for trend < 0.001). Boys had higher GS and VJ, but significantly lower SR than girls in each age group (p < 0.001). After adjusting for age, sex, residential areas and study regions, GS increased with elevated BMI (compared with normal weight group, the regression coefficient for thinness and overweight/obesity were - 2.997(95%CI: -3.693 to - 2.301) and 1.220 (95%CI: 0.285 to 2.155), respectively. With the p values less than 0.001 and 0.011, respectively). For VJ, there was no difference found between normal weight group and overweight/obesity group (p = 0.550), but the thinness group had the lowest performance (regression coefficient = - 2.681, 95%CI from - 3.965 to - 1.397, p < 0.001). For SR, compared with normal weight group, the regression coefficients for thinness and overweight/obesity were - 1.313(95%CI: -2.228 to - 0.399) and - 1.623(95%CI: -3.216 to - 0.030) respectively, both p < 0.05.

CONCLUSIONS

Increased body weight may have a positive association with isometric muscle strength measured by grip strength, but a negative one with strength of lifting the body. Sex difference was also found in the performance of flexibility.