Jump ability in relation to ball speed during windmill pitching by female softball pitchers:

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.

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Age-Related Differences in Throwing Techniques Used by the Catcher in Baseball

Pediatric Exercise Science ◽

10.1123/pes.6.3.225 ◽

1994 ◽

Vol 6 (3) ◽

pp. 225-235 ◽

Cited By ~ 3

Author(s):

Shinji Sakurai ◽

Bruce Elliott ◽

J. Robert Grove

Keyword(s):

High Speed ◽

High Performance ◽

Age Groups ◽

Three Dimensional ◽

Transformation Method ◽

High Speed Photography ◽

Two Phase ◽

Ball Speed ◽

Age Related ◽

Release Speed

Three-dimensional (3-D) high speed photography was used to record the overarm throwing actions of five open-age, four 18-year-old, six 16-year- old, and six 14-year-old high-performance baseball catchers. The direct linear transformation method was used for 3-D space reconstruction from 2-D images of the catchers throwing from home plate to second base recorded using two phase-locked cameras operating at a nominal rate of 200 Hz. Selected physical capacity measures were also recorded and correlated with ball release speed. In general, anthropometric and strength measures significantly increased through the 14-year-old to open-age classifications, while a range of correlation coefficients from .50 to .84 was recorded between these physical capacities and ball speed at release. While many aspects of the kinematic data at release were similar, the key factors of release angle and release speed varied for the different age groups.

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Muscle Architecture and Maturation Influence Sprint and Jump Ability in Young Boys

The Journal of Strength and Conditioning Research ◽

10.1519/jsc.0000000000003941 ◽

2021 ◽

Vol Publish Ahead of Print ◽

Author(s):

John M. Radnor ◽

Jon L. Oliver ◽

Charlie M. Waugh ◽

Gregory D. Myer ◽

Rhodri S. Lloyd

Keyword(s):

Muscle Architecture ◽

Jump Ability

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Strength Training Using Elastic Bands: Improvement of Muscle Power and Throwing Performance in Young Female Handball Players

Journal of Sport Rehabilitation ◽

10.1123/jsr.2015-0153 ◽

2017 ◽

Vol 26 (3) ◽

pp. 245-252 ◽

Cited By ~ 5

Author(s):

Naryana Cristina Mascarin ◽

Claudio Andre Barbosa de Lira ◽

Rodrigo Luiz Vancini ◽

Alberto de Castro Pochini ◽

Antonio Carlos da Silva ◽

...

Keyword(s):

Strength Training ◽

Outcome Measures ◽

Interaction Effect ◽

Muscle Power ◽

Young Female ◽

Muscle Performance ◽

Significant Group ◽

Ball Speed ◽

Time Interaction ◽

Elastic Bands

Context:Imbalance in shoulder-rotator muscles has been considered a risk factor for injuries in handball. Strength training programs (STPs) may play an important preventive role.Objective:To verify the effects of an STP using elastic bands on shoulder muscles and ball-throwing speed.Design:Randomized and prospective controlled trial.Setting:Exercise physiology laboratory.Participants:Thirty-nine female handball players were randomly assigned to an experimental (EG, n = 21, 15.3 ± 1.1 y) or a control (CG, n = 18, 15.0 ± 0.8 y) group.Intervention:The EG performed the STP with elastic-band progressive exercises for 6 wk before regular handball training, and the CG underwent only their regular training.Main Outcome Measures:Before and after the STP, both groups underwent a ball-throwing-speed test and isokinetic test to assess shoulder internal- (IR) and external-rotator muscle performance.Results:Average power values for IR muscles presented a significant group-vs-time interaction effect (F = 3.9, P = .05); EG presented significantly higher values after the STP (P = .03). Ball speed presented higher values in EG after the STP in standing (P = .04) and jumping (P = .03) throws. IR peak-torque values and balance in shoulder-rotator muscles presented no group-vs-time interaction effect.Conclusions:STP using elastic bands performed for 6 wk was effective to improve muscle power and ball speed for young female handball players.

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Modeling and Optimization of an Indirect Coil Gun for Launching Non-Magnetic Projectiles

Actuators ◽

10.3390/act8020039 ◽

2019 ◽

Vol 8 (2) ◽

pp. 39 ◽

Cited By ~ 3

Author(s):

Valentin Gies ◽

Thierry Soriano

Keyword(s):

Initial Position ◽

Fine Tuning ◽

Model Coupling ◽

Ball Speed ◽

Limited Size ◽

Modeling And Optimization ◽

Electromagnetic Models

This article focuses on indirect coil guns used for launching non-magnetic objects. A mechatronic model, coupling electrical, mechanical, and electromagnetic models, is proposed. This model is applied to the optimization of a kicking system used on limited size robots for propelling real soccer balls at the RoboCup. Working with an existing coil gun, we show that fine tuning its setup, especially the initial position and the length of the non-magnetic plunger extension, leads to an increase in the ball speed of 30 % compared to previous results.

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PENGARUH LATIHAN LARI KIJANG DAN LARI GAWANG TERHADAP KEMAMPUAN LOMPAT JAUH DITINJAU DARI DAYA LEDAK OTOT TUNGKAI PADA SISWA KELAS VIII SMP NEGERI 4 GOLEWA

IMEDTECH (Instructional Media, Design and Technology) ◽

10.38048/imedtech.v2i1.158 ◽

2018 ◽

Vol 2 (1) ◽

Author(s):

Josep Marsianus Rewo

Keyword(s):

Student Performance ◽

Random Sampling ◽

Performance Test ◽

Control Group ◽

Limb Muscle ◽

Design Data ◽

Control Group Design ◽

Equivalent Control ◽

Long Jump ◽

Jump Ability

Penelitian ini merupakan kuasi eksperimen yang menggunakan non-equivalent control group design. Data yang dikumpulkan dalam penelitian ini adalah tes unjuk kerja lompat jauh siswa. Penelitian ini bertujuan untuk mengetahui dan menganalisis pengaruh latihan lari kijang dan lari gawang untuk meningkatkan kemampuan lompat jauh siswa di tinjau dari daya ledak otot tungkai. Sampel penelitian berjumlah 84 orang siswa kelas VIII yang dipilih dengan teknik random sampling. Data dikumpulkan dengan tes, kemudian dianalisis dengan analisis varian (Anava dua jalur). Hasil penelitian menemukan sebagai berikut. (1) terdapat perbedaan kemampuan lompat jauh antara siswa yang mengikuti model latihan lari kijang dengan siswa yang mengikuti model latihan lari gawang (Fhitung= 4,06>Ftabel(a=5%)) = 4,00, signifikan). (2) Terdapat pengaruh interaksi antara model latihan dengan daya ledak otot tungkai terhadap lompat jauh (Fhitung= 23,39>Ftabel(a=5%) = 4,00, signifikan). (3) Tidak terdapat perbedaan lompat jauh antara siswa yang mengikuti latihan lari kijang dan lari gawang untuk siswa yang memiliki daya ledak otot tungkai tinggi (Qhitung= 16,43>Qtabel = 4,00 signifikan). (4) Terdapat perbedaan lompat jauh antara siswa yang mengikuti model latihan lari kijang dan lari gawang untuk siswa yang memiliki daya ledak otot tungkai rendah (Qhitung = 5,919 >Qtabel= 4,00 signifikan).This study was quasi experiment used non-equivalent control design. The data collected in this study was the student performance test of long jump. This study aims to determine and analyze the influence of the practice of lari kijang and lari gawang to improve students' long jump ability in review of the explosive muscle limb power. The sample of the study was 84 students of grade VIII chosen by random sampling technique. The data was collected by test then analyzed with variant analysis (ANAVA) two ways) and t-test. The result of the study showed that: (1) There is a difference in long jump ability between students who follow the model of lari kijang training with students who follow the model of lari gawang (Fhitung= 4,06 >Ftabel(a=5%)) = 4,00, significant) (2) There is an interaction effect between the exercise model and the explosive muscle limb power against the long jump (Fhitung= 23,39 >Ftabel(a=5%) = 4,00, significant). (3) There is no difference in long jump between students who follow lari kijang and lari gawang for students who have high limb muscle explosive power (Qhitung= 16,43>Qtabel = 4,00 significant) (4) There is a long jump difference between students who follow the model of lari kijang and lari gawang for students who have low limb muscle explosiveness (Qhitung = 5,919 >>Qtabel = 4,00 significant).

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