Comparisons Of Countermovement Jump Force Profiles In Youth Athletes

Author(s):  
Zachary M. Gillen ◽  
Malachy P. McHugh ◽  
Marni E. Shoemaker ◽  
Joel T. Cramer
2021 ◽  
Vol 6 (3) ◽  
pp. 57
Author(s):  
Satoshi Mizuguchi ◽  
Aaron J. Cunanan ◽  
Dylan G. Suarez ◽  
William E. Cedar ◽  
Mark A. South ◽  
...  

This study was designed to provide an overview of weightlifting performance as a function of age group and sex and evaluate the potential of countermovement jump height (CMJH) as a tool to gauge performance potential. Data from 130 youth athletes (female, n = 65 & male, n = 65) were used to examine progression of performance (Total and Sinclair total) and the relationship between CMJH and Sinclair total while considering interactions between CMJH and age and/or sex. ANOVAs with post hoc analyses revealed that both totals had a statistical first-order polynomial interaction effect between age group and sex and the difference between age groups of 12–13 and 14–15 years old was statistically greater for male than female. A linear model, developed to examine the relationship, revealed that CMJH and CMJH x sex x age rejected the null hypothesis. Our primary findings are that male youth weightlifters have a higher rate of performance progression, possibly owing to puberty, and CMJH may be a better gauging tool for older male youth weightlifters.


2016 ◽  
Vol 28 (4) ◽  
pp. 542-552 ◽  
Author(s):  
Gillian K. Myburgh ◽  
Sean P. Cumming ◽  
Manuel Coelho E. Silva ◽  
Karl Cooke ◽  
Robert M. Malina

Purpose:To evaluate relationships among skeletal maturity, body size, and functional capacities of elite junior tennis players.Methods:Participants were 88 elite British Junior tennis players (44 male; 44 female), 8–16 years of age (12.4 } 1.9 years). Skeletal age estimated maturty. Anthropometry, grip strength, countermovement jump, squat jump, forehand agility, backhand agility, Yo-Yo, 5-m, 10-m and 20-m sprints were measured. Comparative analysis for each sex was performed, relating advanced maturers (Male: 15; Female: 29) to a combination of on-time and late maturers (Male: 29; Female: 31). ANCOVAs were used to determine absolute differences between male and female players and between the 2 maturity subgroups, with chronological age as the covariate.Results:Advanced maturity afforded male players advantages in absolute measures of grip strength, speed, upper and lower body power but not in acceleration, agility or aerobic endurance. Male players were significantly taller than females in the U13-U16 age group. Advanced maturity in female players afforded advantages in absolute measures of grip strength, agility and overhead power, but not in backhand agility, aerobic endurance or squat jump power.Conclusion:It is important that talent identification protocols consider the maturity of youth athletes to more satisfactorily address athletic potential rather than transient physical capabilities.


2020 ◽  
Vol 29 (3) ◽  
pp. 1389-1403
Author(s):  
Jessica Brown ◽  
Kelly Knollman-Porter

Purpose Although guidelines have changed regarding federally mandated concussion practices since their inception, little is known regarding the implementation of such guidelines and the resultant continuum of care for youth athletes participating in recreational or organized sports who incur concussions. Furthermore, data regarding the role of speech-language pathologists in the historic postconcussion care are lacking. Therefore, the purpose of this retrospective study was to investigate the experiences of young adults with history of sports-related concussion as it related to injury reporting and received follow-up care. Method Participants included 13 young adults with history of at least one sports-related concussion across their life span. We implemented a mixed-methods design to collect both quantitative and qualitative information through structured interviews. Participants reported experiencing 42 concussions across the life span—26 subsequent to sports injuries. Results Twenty-three concussions were reported to a parent or medical professional, 14 resulted in a formal diagnosis, and participants received initial medical care for only 10 of the incidents and treatment or services on only two occasions. Participants reported concussions to an athletic trainer least frequently and to parents most frequently. Participants commented that previous experience with concussion reduced the need for seeking treatment or that they were unaware treatments or supports existed postconcussion. Only one concussion incident resulted in the care from a speech-language pathologist. Conclusion The results of the study reported herein shed light on the fidelity of sports-related concussion care management across time. Subsequently, we suggest guidelines related to continuum of care from injury to individualized therapy.


Author(s):  
Adebiyi Oyekunle Olusegun ◽  
Bulus Tikon ◽  
Stephen Sanaah Hamafelto
Keyword(s):  

Author(s):  
Michael Ludwig ◽  
Regine von Klitzing

Complete interaction force profiles of charged surfaces across confined suspensions were successfully described using a superposition of double layer and structural forces.


2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0017
Author(s):  
Sophia M. Ulman ◽  
Laura Saleem ◽  
Kirsten Tulchin-Francis

Background: The Functional Movement Screen (FMS) is a tool designed to establish a baseline for fundamental movement capacity, highlight limitations and limb asymmetries, and identify potential injury risk. Previous research has shown that individual components of the screen are also indicative of injury risk, as well as potential predictors of athletic performance unlike the FMS composite scores. However, this literature is limited and lacks statistical power. Identifying which component scores are predictive of injury risk and athletic performance would provide a quick, powerful tool for coaches and trainers to evaluate athletes. Purpose: To determine if individual component scores of the FMS are associated with athletic performance in highly-active youth athletes. Methods: Youth athletes participated in the Specialized Athlete Functional Evaluation (SAFE) Program. Data collection was extensive, however, for the purpose of this abstract, only a selection of data was analyzed – age, BMI, years played, total number of past injuries, isokinetic knee strength, 10- and 20-meter sprint, single-leg hop (SLH) distance, and FMS scores. Seated knee flexion/extension strength was collected at 120°/second using a Biodex System 4, and peak torque was normalized by body weight. The maximum distance of three SLHs was recorded for each leg and normalized to leg length. FMS scores used for analysis included the total composite and component scores, including the deep squat, hurdle step, in-line lunge, shoulder mobility, active straight-leg raise, trunk stability push-up, and rotary stability. Wilcoxon Signed Ranks Tests were used to determine side-to-side differences, and Kruskal-Wallis tests were performed to determine differences in athletic performance based on FMS scores ( α<0.05). Results: A total of 38 highly-active, youth athletes (26F; 15.4±2.6 years; BMI 21.0±5.3) were tested. Participants reported playing organized sports for 8.7±3.4 years, having 2.0±1.2 past sports-related injuries, and 74% reported specializing in a single sport. No side-to-side differences were found. While the composite FMS score significantly differed by number of past injuries ( p=0.036), it was not associated with athletic performance. Alternatively, left knee strength, sprint speeds, and right hop distance significantly differed by the hurdle step component score (Table 1). Conclusion: While the composite FMS score was not an indicator of athletic performance, the hurdle step component score was associated with strength, speed, and jump performance. This individual task could be a beneficial tool for coaches and trainers when evaluating athletic ability and injury risk of athletes. Tables/Figures: [Table: see text]


Author(s):  
Javier Raya-González ◽  
Filipe Manuel Clemente ◽  
Daniel Castillo

Although asymmetries in lower limbs have been linked with players’ performance in male soccer players, literature that has been published addressing female soccer is scarce. Thus, the aim of this study was twofold: (i) describe the asymmetries of women soccer players during jumping, change-of-direction and range-of-motion tests; and (ii) test possible relationships between asymmetries and injury risk in female soccer players. Sixteen female players (15.5 ± 1.5 years) performed a battery of fitness tests (i.e., jump ability, change-of-direction ability and passive range-of-motion) and muscle mass analysis via dual-energy X-ray absorptiometry, through which the specific asymmetry index and the related injury risk were calculated. Significant (p < 0.05) lower asymmetries in the change-of-direction test were observed in comparison to those observed in jumping and range-of-motion tests; significant (p < 0.05) lower asymmetries in muscle mass were also reported compared to those found in the change-of-direction and countermovement jump tests. Additionally, increased injury risk for countermovement jump and hip flexion with extended knee range-of-motion (relating to asymmetry values) and for ankle flexion with flexed knee range-of-motion in both legs (relating to reference range-of-motion values), as well as increased individual injury risk values, were observed across all tests. These findings suggest the necessity to implement individual approaches for asymmetry and injury risk analyses.


Author(s):  
Eduardo Guimarães ◽  
José A. R. Maia ◽  
Mark Williams ◽  
Filipa Sousa ◽  
Eduardo Santos ◽  
...  

Although successful performance in basketball requires high levels of muscular strength during adolescence, its development is confounded by the effects of normal growth. We examine the timing, intensity and sequence of muscular strength according to biological age (years from peak height velocity (PHV)) and hypothesize that young basketball players attain their peak muscular strength spurts around PHV. A total of 160 adolescent male basketballers, aged 11–15 years, were followed bi-annually over 3 consecutive years. The years from attainment of PHV and peak weight velocity (PWV) were estimated and five muscular strength measures (sit-ups, handgrip, seated medicine ball throw, squat jump and countermovement jump) were aligned to years from PHV in 3-month intervals. Strength velocities were estimated using a non-smooth mathematical model. The mean ages at-PHV and at-PWV were 13.90 ± 1.40 years and 13.90 ± 1.79 years, respectively. Maximal velocity in sit-ups was attained 6 months prior to attainment of PHV (intensity = 10.69 repetitions·year−1), whereas maximal velocity in squat jump occurred 6 months after-PHV (intensity = 3.93 cm·year−1). Handgrip strength, seated medicine ball throw and countermovement jump maximal velocity peaked at-PHV (intensity = 8.47 kgf·year−1, intensity = 0.75 m·year−1, intensity = 5.59 cm·year−1, respectively). In general, maximal velocity spurts did not differ in their timing, with the velocities reaching a peak concurrent with PHV and PWV or within 6 months of its attainment. Basketball coaches, as well as strength and conditioning trainers, should consider individual differences in strength development and be aware of rapid periods of growth in stature when planning and designing muscular strength training regimes.


Author(s):  
Josune Rodriguez-Negro ◽  
Iñaki Llodio ◽  
Daniel Castillo ◽  
Estibaliz Romaratezabala ◽  
Javier Yanci

The aim of the present research was to describe the changes in the locomotor competence [i.e. sprint, change of direction ability (CODA) and jump capacity] of young runners from an athletic training school after one season, according to runners’ sex and age. Two hundred and forty-one young runners from an athletic training school were divided by sex (boys, n = 107, and girls, n = 134) and age [under 8 years old (U8, n = 70), under 10 years old (U10, n = 68), under 12 years old (U12, n = 45), under 14 years old (U14, n = 39) and under 16 years old (U16, n = 19)]. At the start of the training season (PRE) and at the end of the season (POST), the runners performed different tests in order to assess their locomotor competence. The results showed that boys and girls improved their performance during the season in the 5 m sprint ( p = 0.000, ES = -0.58 to -0.74) and horizontal countermovement jump (HCMJ) ( p = 0.000, ES = 0.51 to 1.02), and decreased it in the 15 m sprint test ( p = 0.011 or p = 0.006, ES = 0.27 to 0.31), and only girls improved in change of direction ability (CODA) ( p = 0.000, ES = -0.22 to -0.27). In addition, with respect to age categories, all groups improved their performance in the HCMJ ( p = 0.000 - 0.005, ES > 0.40) and the 5 m sprint tests ( p = 0.000 - 0.002, ES = -0.68 to -1.24). Although in the 505 test no group improved its result ( p = 0.184 - 0.314, ES = -0.25 to 0.01), the U8 and U10 groups improved in the modified agility test (MAT) ( p = 0.000 or p = 0.003, ES = -0.38 to -0.41). In conclusion, there are differences in the changes in the locomotor competence according to runners’ sex and age, so perhaps age- and sex-dependent specialization in training is necessary.


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