scholarly journals Effects of Maturation on Lower Limb Neuromuscular Asymmetries in Elite Youth Tennis Players

Sports ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 106 ◽  
Author(s):  
Marc Madruga-Parera ◽  
Daniel Romero-Rodríguez ◽  
Chris Bishop ◽  
Maria Reyes Beltran-Valls ◽  
Alex T. Latinjak ◽  
...  
Keyword(s):  
Peak Height ◽  
Composite Score ◽  
Height Velocity ◽  
Peak Height Velocity ◽  
Biological Index ◽  
Balance Test ◽  
Tennis Players ◽  
Youth Athletes ◽  
Training Interventions ◽  
Jumping Test

Neuromuscular asymmetries have been previously associated with reduced performance. Similarly, maturation has shown that youth athletes may experience a loss of motor control, which could also lead to compromised physical performance. The present study aimed to evaluate and quantify the level of asymmetry among chronological and maturational groups. Forty-one youth tennis players performed the single leg countermovement jump (SLCMJ), star excursion balance test (SEBT) and a change of direction speed (CODS) test. Differences were found between the strongest and weakest limbs across all tests (p < 0.001), and also for SEBT in the posteromedial direction (p = 0.02), SEBT composite score (p < 0.01) in maturation groups, and for SEBT posterolateral direction (p = 0.03) and SEBT composite score (p = 0.01) in chronological groups. The SLCMJ showed the largest inter-limb asymmetries for the circa peak height velocity (PHV) group (19.31 ± 12.19%) and under-14 (U14) group (17.55 ± 9.90%). Chronological and maturation groups followed similar trends for inter-limb asymmetries, but the biological index showed larger asymmetry scores in the jumping test at PHV compared to that found in the chronological group (U14). These results show that inter-limb differences may be heightened during PHV. Practitioners can use this information to inform the decision-making process when prescribing training interventions in youth tennis players.

Associations Between Balance and Muscle Strength, Power Performance in Male Youth Athletes of Different Maturity Status

2016 ◽  
Vol 28 (4) ◽  
pp. 521-534 ◽  
Author(s):  
Raouf Hammami ◽  
Anis Chaouachi ◽  
Issam Makhlouf ◽  
Urs Granacher ◽  
David G. Behm
Keyword(s):  
Muscle Strength ◽  
Dynamic Balance ◽  
Correlation Coefficients ◽  
Young Male ◽  
Peak Height ◽  
Height Velocity ◽  
Power Performance ◽  
Peak Height Velocity ◽  
Youth Athletes ◽  
Back Extensor

Balance, strength and power relationships may contain important information at various maturational stages to determine training priorities. Purpose:The objective was to examine maturity-specific relationships of static/dynamic balance with strength and power measures in young male athletes.Methods:Soccer players (N = 130) aged 10–16 were assessed with the Stork and Y balance (YBT) tests. Strength/power measures included back extensor muscle strength, standing long jump (SLJ), countermovement jump (CMJ), and 3-hop jump tests. Associations between balance with strength/power variables were calculated according to peak-height-velocity (PHV).Results:There were significant medium-large sized correlations between all balance measures with back extensor strength (r = .486–.791) and large associations with power (r = .511–.827). These correlation coefficients were significantly different between pre-PHV and circa PHV as well as pre-PHV and post-PHV with larger associations in the more mature groups. Irrespective of maturity-status, SLJ was the best strength/power predictor with the highest proportion of variance (12–47%) for balance (i.e., Stork eyes opened) and the YBT was the best balance predictor with the highest proportion of variance (43–78%) for all strength/power variables.Conclusion:The associations between balance and muscle strength/power measures in youth athletes that increase with maturity may imply transfer effects from balance to strength/power training and vice versa in youth athletes.

scholarly journals Improving the Prediction of Maturity From Anthropometric Variables Using a Maturity Ratio

2018 ◽  
Vol 30 (2) ◽  
pp. 296-307 ◽  
Author(s):  
Job Fransen ◽  
Stephen Bush ◽  
Stephen Woodcock ◽  
Andrew Novak ◽  
Dieter Deprez ◽  
...  
Keyword(s):  
Akaike Information Criterion ◽  
Nonlinear Models ◽  
Information Criterion ◽  
Peak Height ◽  
Prediction Equation ◽  
Original Model ◽  
Height Velocity ◽  
Peak Height Velocity ◽  
New Model ◽  
Youth Athletes

Purpose:This study aimed to improve the prediction accuracy of age at peak height velocity (APHV) from anthropometric assessment using nonlinear models and a maturity ratio rather than a maturity offset.Methods:The dataset used to develop the original prediction equations was used to test a new prediction model, utilizing the maturity ratio and a polynomial prediction equation. This model was then applied to a sample of male youth academy soccer players (n = 1330) to validate the new model in youth athletes.Results:A new equation was developed to estimate APHV more accurately than the original model (new model: Akaike information criterion: −6062.1,R2 = 90.82%; original model: Akaike information criterion = 3048.7,R2 = 88.88%) within a general population of boys, particularly with relatively high/low APHVs. This study has also highlighted the successful application of the new model to estimate APHV using anthropometric variables in youth athletes, thereby supporting the use of this model in sports talent identification and development.Conclusion:This study argues that this newly developed equation should become standard practice for the estimation of maturity from anthropometric variables in boys from both a general and an athletic population.

Asymmetry in Volume between Dominant and Nondominant Upper Limbs in Young Tennis Players

2008 ◽  
Vol 20 (3) ◽  
pp. 263-272 ◽  
Author(s):  
Isabelle Rogowski ◽  
Gaële Ducher ◽  
Olivier Brosseau ◽  
Christophe Hautier
Keyword(s):  
Upper Limb ◽  
Peak Height ◽  
Height Velocity ◽  
Upper Limbs ◽  
Peak Height Velocity ◽  
Control Groups ◽  
Tennis Players ◽  
Control Subjects ◽  
Truncated Cone ◽  
Side Asymmetry

This study aimed at demonstrating the asymmetry in volume between the dominant and nondominant upper limbs in tennis players, controlled for maturity status. Upper limb volumes on both sides were calculated in 72 tennis players and 84 control subjects, using the truncated cone method. The participants’ maturity status was determined using the predicted age at peak height velocity (PHV). The results showed significant larger side-to-side asymmetry in volume in tennis groups than in control groups. These findings suggested that, even before PHV, specific-sport adaptations occurred in the dominant upper limb in tennis players.

scholarly journals Sports injuries aligned to predicted mature height in highly trained Middle-Eastern youth athletes: a cohort study

BMJ Open ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. e023284 ◽  
Author(s):  
Abdallah Rejeb ◽  
Amanda Johnson ◽  
Abdulaziz Farooq ◽  
Ruth Verrelst ◽  
Samuel Pullinger ◽  
...  
Keyword(s):  
Cohort Study ◽  
Injury Risk ◽  
Middle Eastern ◽  
Peak Height ◽  
Height Velocity ◽  
Injury Incidence ◽  
Peak Height Velocity ◽  
Early Maturity ◽  
Youth Athletes ◽  
Individual Sports

ObjectivesTo investigate the association of maturity status with injury incidence in Middle-Eastern youth athletes.DesignProspective cohort study.SettingFour consecutive seasons (2010–2014), Aspire Academy, Qatar.ParticipantsMale athletes (age range: 11–18 years) representing four disciplines enrolled and grouped into two categories: individual sports and racquet sports.Outcome measuresInjury data collected over four seasons. Athletes’ anthropometric characteristics assessed to calculate age at peak height velocity. Predicted mature heights (PMHs) collected and categorised into four quartiles. Athletes had wrist and hand radiographs for assessment of skeletal age (SA). Early and late maturers with an SA of >1 year older or younger than their chronological age (CA).ResultsFor the sample (n=67) across all groups, 43 (64%) athletes had one or more injuries: total of 212 injuries, 4.9 injuries per athlete across study. Survival analysis of maturity status using SA found early maturing athletes had two-fold greater injury risk compared with late maturers (HR 2.04, 95% CI 1.15 to 3.61, p=0.015). PMH associated with injury risk (HR 1.05, 95% CI 1.01 to 1.08, p=0.006).Athletes in fourth quartile (≥184 cm) had up to two-fold injury risk (HR 2.41, 95% CI 1.42 to 4.08, p=0.001). Racquet and individual sports involved similar injury risk (HR 1.14, 95% CI 0.86 to 1.52, p=0.37).ConclusionSA early maturity and PMH gradient were significant predictors of injury in youths.

scholarly journals The Effectiveness of Progressive and Traditional Coaching Strategies to Improve Sprint and Jump Performance Across Varying Levels of Maturation within a General Youth Population

Sports ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 186
Author(s):  
Regan Standing ◽  
Peter Maulder
Keyword(s):  
Youth Development ◽  
Peak Height ◽  
Height Velocity ◽  
Emotional Needs ◽  
Peak Height Velocity ◽  
Jump Performance ◽  
Male Youth ◽  
Training Interventions ◽  
Coaching Strategies ◽  
Youth Population

Literature pertaining to youth development has identified the importance of understanding the physical, intellectual and emotional needs of adolescents prior to, during, and after their peak height velocity (PHV) period. The purpose of this study was to compare the use of a ‘traditional’ and ‘progressive’ coaching style to train a general male youth population to improve sprint and jump performances whilst assessing enjoyment to comment on long-term application. Maximal sprint times, sprint kinematics, unilateral jump distances and repetitive tuck jump scores were measured alongside anthropometric variables to characterise performance. The results revealed significant (p < 0.05) pre/post differences in anthropometric variables across all maturation groups, and each of the maturational levels displayed a tendency to favor a particular coaching or control condition. Pre-PHV groups responded most effectively to the progressive style of coaching, displaying improvements in horizontal jump performances, and −0.7% to −2.7% improvements in all sprint times, despite also showing the largest increase in tuck jump scores (25.8%). The circa-PHV group produced their greatest improvements in the traditional intervention, as displayed through significant improvements (p < 0.05) in 20-m sprint times and dominant-leg horizontal jump performance, whilst also revealing the greatest deterioration in tuck jump scores (14.2%). Post-PHV displayed the greatest improvements in the control setting, suggesting that the natural benefits gained through adolescent development were greater than the influence of the training interventions. In conclusion, the results suggest that matching coaching strategies and delivery techniques to the period of biological maturation may have implications for both performance and athlete safety.

scholarly journals Adaptive Alterations in Shoulder Range of Motion and Strength in Young Tennis Players

2017 ◽  
Vol 52 (2) ◽  
pp. 137-144 ◽  
Author(s):  
Benoit Gillet ◽  
Mickaël Begon ◽  
Violaine Sevrez ◽  
Christian Berger-Vachon ◽  
Isabelle Rogowski
Keyword(s):  
Range Of Motion ◽  
Glenohumeral Joint ◽  
External Rotation ◽  
Peak Height ◽  
Biological Age ◽  
Height Velocity ◽  
Peak Height Velocity ◽  
Tennis Players ◽  
Functional Changes ◽  
Shoulder Range Of Motion

Context: Playing tennis requires unilateral and intensive movement of the upper limb, which may lead to functional adaptations of the shoulder and an increased injury risk. Identifying which athletes will be future elite tennis players starts at 5 to 6 years of age. Therefore, highly skilled players practice intensively in their childhood. However, whether these functional changes occur during the prepubertal years has not been established. Objectives: To assess changes in glenohumeral-joint–rotation range of motion and strength of the shoulder-complex muscles in prepubertal elite tennis players. Design: Cross-sectional study. Setting: Tennis training sports facilities. Patients or Other Participants: Sixty-seven male tennis players (age range = 7–13 years) selected by a regional tennis center of excellence were divided into 3 biological age groups relative to their predicted age at peak height velocity: greater than 4 (n = 26; age = 8.7 ± 0.7 years, height = 132.4 ± 12.9 cm, mass = 27.8 ± 3.8 kg), 3 to 4 (n = 21; age = 10.3 ± 0.6 years, height = 144.9 ± 5.7 cm, mass = 34.7 ± 4.0 kg), and 2 (n = 20; age = 12.8 ± 1.4 years, height = 158.5 ± 8.7 cm, mass = 43.0 ± 8.2 kg) years before their age at peak height velocity. Main Outcome Measures(s): We measured the internal- and external-rotation ranges of motion of the glenohumeral joint using a goniometer and calculated the total arc of motion. Maximal isometric strength of 8 shoulder muscles was measured using a handheld dynamometer. Strength values were normalized to body weight and used to calculate 4 agonist-to-antagonist strength ratios. Results: The total arc of motion of the glenohumeral joint decreased gradually with biological age (P ≤ .01) due to the decrease in internal-rotation range of motion (P &lt; .001). Absolute strength increased gradually with biological age (P &lt; .001), but the relative strengths and ratios remained similar. Conclusions: Functional adaptations of the shoulder seen in adolescent and adult tennis players were observed in healthy prepubertal players. This knowledge could help clinicians and coaches more effectively monitor shoulder adaptations to tennis practice during the prepubertal years.

Growth, Maturation, and Exercise

2015 ◽  
Vol 27 (1) ◽  
pp. 3-7
Author(s):  
Jaak Jürimäe
Keyword(s):  
Peak Height ◽  
Height Velocity ◽  
Chronological Age ◽  
Leg Length ◽  
Peak Height Velocity ◽  
Male Youth ◽  
Youth Athletes ◽  
Sitting Height ◽  
Early Maturing ◽  
Mean Differences

This study attempted to validate an anthropometric equation for predicting age at peak height velocity (APHV) in 193 Polish boys followed longitudinally 8-18 years (1961-1972). Actual APHV was derived with Preece-Baines Model 1. Predicted APHV was estimated at each observation using chronological age (CA), stature, mass, sitting height and estimated leg length. Mean predicted APHV increased from 8 to 18 years. Actual APHV was underestimated at younger ages and overestimated at older ages. Mean differences between predicted and actual APHV were reasonably stable between 13 and 15 years. Predicted APHV underestimated actual APHV 3 years before, was almost identical with actual age 2 years before, and then overestimated actual age through 3 years after PHV. Predicted APHV did not differ among boys of contrasting maturity status 8-11 years, but diverged among groups 12-15 years. In conclusion, predicted APHV is influenced by CA and by early and late timing of actual PHV. Predicted APHV has applicability among average maturing boys 12-16 years in contrast to late and early maturing boys. Dependence upon age and individual differences in actual APHV limits utility of predicted APHV in research with male youth athletes and in talent programs.

scholarly journals Breakfast: A Crucial Meal for Adolescents’ Cognitive Performance According to Their Nutritional Status. The Cogni-Action Project

Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1320
Author(s):  
Humberto Peña-Jorquera ◽  
Valentina Campos-Núñez ◽  
Kabir P. Sadarangani ◽  
Gerson Ferrari ◽  
Carlos Jorquera-Aguilera ◽  
...  
Keyword(s):  
Nutritional Status ◽  
Cognitive Performance ◽  
Cognitive Demand ◽  
Positive Association ◽  
Peak Height ◽  
The Body ◽  
Height Velocity ◽  
Peak Height Velocity ◽  
High Quality ◽  
Action Project

This study aimed to determine whether pupils who have breakfast just before a cognitive demand, do not regularly skip breakfast, and consume a high-quality breakfast present higher cognitive performance than those who do not; furthermore, to establish differences according to their nutritional status. In this study, 1181 Chilean adolescents aged 10–14 years participated. A global cognitive score was computed through eight tasks, and the body mass index z-score (BMIz) was calculated using a growth reference for school-aged adolescents. The characteristics of breakfast were self-reported. Analyses of covariance were performed to determine differences in cognitive performance according to BMIz groups adjusted to sex, peak height velocity, physical fitness global score, and their schools. A positive association was found in adolescents’ cognitive performance when they had breakfast just before cognitive tasks, did not regularly skip breakfast, presented at least two breakfast quality components, and included dairy products. No significant differences were found between breakfast components, including cereal/bread and fruits/fruit juice. Finally, pupils who were overweight/obese who declared that they skipped breakfast regularly presented a lower cognitive performance than their normal-BMIz peers. These findings suggest that adolescents who have breakfast just prior to a cognitive demand and regularly have a high quality breakfast have better cognitive performance than those who do not. Educative nutritional strategies should be prioritized, especially in “breakfast skippers” adolescents living with overweight/obesity.

scholarly journals Growth in achondroplasia, from birth to adulthood, analysed by the JPA-2 model

2020 ◽  
Vol 33 (12) ◽  
pp. 1589-1595
Author(s):  
Mariana del Pino ◽  
Virginia Fano ◽  
Paula Adamo
Keyword(s):  
General Population ◽  
Growth Curve ◽  
Growth Velocity ◽  
Adult Height ◽  
Growth Curves ◽  
Peak Height ◽  
Height Growth ◽  
Individual Growth ◽  
Height Velocity ◽  
Peak Height Velocity

AbstractObjectivesIn general population, there are three phases in the human growth curve: infancy, childhood and puberty, with different main factors involved in their regulation and mathematical models to fit them. Achondroplasia children experience a fast decreasing growth during infancy and an “adolescent growth spurt”; however, there are no longitudinal studies that cover the analysis of the whole post-natal growth. Here we analyse the whole growth curve from infancy to adulthood applying the JPA-2 mathematical model.MethodsTwenty-seven patients, 17 girls and 10 boys with achondroplasia, who reached adult size, were included. Height growth data was collected from birth until adulthood. Individual growth curves were estimated by fitting the JPA-2 model to each individual’s height for age data.ResultsHeight growth velocity curves show that after a period of fast decreasing growth velocity since birth, with a mean of 9.7 cm/year at 1 year old, the growth velocity is stable in late preschool years, with a mean of 4.2 cm/year. In boys, age and peak height velocity in puberty were 13.75 years and 5.08 cm/year and reach a mean adult height of 130.52 cm. In girls, the age and peak height velocity in puberty were 11.1 years and 4.32 cm/year and reach a mean adult height of 119.2 cm.ConclusionsThe study of individual growth curves in achondroplasia children by the JPA-2 model shows the three periods, infancy, childhood and puberty, with a similar shape but lesser in magnitude than general population.

scholarly journals Biological maturity and the anthropometric, physical and technical assessment of talent identified U16 Australian footballers

2017 ◽  
Vol 12 (3) ◽  
pp. 344-350 ◽  
Author(s):  
Ashley J Cripps ◽  
Christopher Joyce ◽  
Carl T Woods ◽  
Luke S Hopper
Keyword(s):  
Characteristic Curve ◽  
Vertical Jump ◽  
Binary Logistic Regression ◽  
Peak Height ◽  
Technical Skill ◽  
Height Velocity ◽  
State Representation ◽  
Peak Height Velocity ◽  
Biological Maturation ◽  
Australian Football

This study compared biological maturation, anthropometric, physical and technical skill measures between talent and non-talent identified junior Australian footballers. Players were recruited from the under 16 Western Australian Football League and classified as talent (state representation; n = 25, 15.7 ± 0.3 y) or non-talent identified (non-state representation; n = 25, 15.6 ± 0.4 y). Players completed a battery of anthropometric, physical and technical skill assessments. Maturity was estimated using years from peak height velocity calculations. Binary logistic regression was used to identify the variables demonstrating the strongest association with the main effect of ‘status’. A receiver operating characteristic curve was used to assess the level of discrimination provided by the strongest model. Talent identified under 16 players were biologically older, had greater stationary and dynamic leaps and superior handball skill when compared to their non-talent identified counterparts. The strongest model of status included standing height, non-dominant dynamic vertical jump and handball outcomes (AUC = 83.4%, CI = 72.1%–95.1%). Biological maturation influences anthropometric and physical capacities that are advantageous for performance in Australian football; talent identification methods should factor biological maturation as a confound in the search for junior players who are most likely to succeed in senior competition.

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