scholarly journals Advancing the pro-agility test to provide better change of direction speed diagnostics

2021 ◽  
Vol 5 (2) ◽  
Keyword(s):  
Change Of Direction

scholarly journals Greater Power but Not Strength Gains Using Flywheel Versus Equivolumed Traditional Strength Training in Junior Basketball Players

2021 ◽  
Vol 18 (3) ◽  
pp. 1181
Author(s):  
Marko D. M. Stojanović ◽  
Mladen Mikić ◽  
Patrik Drid ◽  
Julio Calleja-González ◽  
Nebojša Maksimović ◽  
...  
Keyword(s):  
Strength Training ◽  
Training Group ◽  
T Test ◽  
Control Group ◽  
Basketball Players ◽  
Significant Group ◽  
Sprint Time ◽  
Change Of Direction ◽  
Time Interaction ◽  
And Control

The main aim of the present study was to compare the effects of flywheel strength training and traditional strength training on fitness attributes. Thirty-six well trained junior basketball players (n = 36; 17.58 ± 0.50 years) were recruited and randomly allocated into: Flywheel group (FST; n = 12), traditional strength training group (TST; n = 12) and control group (CON; n = 12). All groups attended 5 basketball practices and one official match a week during the study period. Experimental groups additionally participated in the eight-week, 1–2 d/w equivolume intervention conducted using a flywheel device (inertia = 0.075 kg·m−2) for FST or free weights (80%1 RM) for TST. Pre-to post changes in lower limb isometric strength (ISOMET), 5 and 20 m sprint time (SPR5m and SPR20m), countermovement jump height (CMJ) and change of direction ability (t-test) were assessed with analyses of variance (3 × 2 ANOVA). Significant group-by-time interaction was found for ISOMET (F = 6.40; p = 0.000), CMJ (F = 7.45; p = 0.001), SPR5m (F = 7.45; p = 0.010) and T test (F = 10.46; p = 0.000). The results showed a significantly higher improvement in CMJ (p = 0.006; 11.7% vs. 6.8%), SPR5m (p = 0.001; 10.3% vs. 5.9%) and t-test (p = 0.045; 2.4% vs. 1.5%) for FST compared to the TST group. Simultaneously, th FST group had higher improvement in ISOMET (p = 0.014; 18.7% vs. 2.9%), CMJ (p = 0.000; 11.7% vs. 0.3%), SPR5m (p = 0.000; 10.3% vs. 3.4%) and t-test (p = 0.000; 2.4% vs. 0.6%) compared to the CON group. Players from the TST group showed better results in CMJ (p = 0.006; 6.8% vs. 0.3%) and t-test (p = 0.018; 1.5% vs. 0.6%) compared to players from the CON group. No significant group-by-time interaction was found for sprint 20 m (F = 2.52; p = 0.088). Eight weeks of flywheel training (1–2 sessions per week) performed at maximum concentric intensity induces superior improvements in CMJ, 5 m sprint time and change of direction ability than equivolumed traditional weight training in well trained junior basketball players. Accordingly, coaches and trainers could be advised to use flywheel training for developing power related performance attributes in young basketball players.

scholarly journals Analyzing the Magnitude of Interlimb Asymmetries in Young Female Soccer Players: A Preliminary Study

2021 ◽  
Vol 18 (2) ◽  
pp. 475
Author(s):  
Javier Raya-González ◽  
Filipe Manuel Clemente ◽  
Daniel Castillo
Keyword(s):  
Range Of Motion ◽  
Muscle Mass ◽  
Injury Risk ◽  
Young Female ◽  
Asymmetry Index ◽  
Lower Limbs ◽  
Soccer Players ◽  
Countermovement Jump ◽  
Change Of Direction ◽  
Jump Ability

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.

scholarly journals Change-of-Direction Deficit vs. Deceleration Deficit: A Comparison of Limb Dominance and Inter-limb Asymmetry between Forwards and Backs in Elite Male Rugby Union Players

2020 ◽  
pp. 1-8
Author(s):  
Chris Bishop ◽  
Richard Clarke ◽  
Tomás T. Freitas ◽  
Ademir F. S. Arruda ◽  
Aristide Guerriero ◽  
...  
Keyword(s):  
Rugby Union ◽  
Change Of Direction ◽  
Limb Asymmetry ◽  
Limb Dominance

Changes in selected locomotor skills of young runners after one athletic season: Influence of sex and age

2021 ◽  
pp. 174795412110066
Author(s):  
Josune Rodriguez-Negro ◽  
Iñaki Llodio ◽  
Daniel Castillo ◽  
Estibaliz Romaratezabala ◽  
Javier Yanci
Keyword(s):  
Athletic Training ◽  
Countermovement Jump ◽  
Training School ◽  
Change Of Direction ◽  
Age And Sex

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.

scholarly journals Associations between Inter-Limb Asymmetries in Jump and Change of Direction Speed Tests and Physical Performance in Adolescent Female Soccer Players

2021 ◽  
Vol 18 (7) ◽  
pp. 3474
Author(s):  
Elena Pardos-Mainer ◽  
Chris Bishop ◽  
Oliver Gonzalo-Skok ◽  
Hadi Nobari ◽  
Jorge Pérez-Gómez ◽  
...  
Keyword(s):  
Physical Performance ◽  
Age Groups ◽  
Soccer Players ◽  
Adolescent Female ◽  
Specific Training ◽  
Countermovement Jump ◽  
Change Of Direction ◽  
Percentage Difference ◽  
Hop Test ◽  
Physical Tests

The association between asymmetries in jump and change of direction (COD) with physical performance in several sports show inconclusive results. The purposes of this study were to: (1) measure inter-limb asymmetries in three distinct groups in adolescent female soccer players and, (2) to determine the association between inter-limb asymmetries and physical performance in different age groups. Fifty-four players were distributed in three age groups: U-18, U-16 and U-14. All of them performed a series of jumps, sprints and change of direction speed tests. Asymmetries were assessed as the percentage difference between limbs, with the equation: 100/Max value (right and left) * in value (right and left) * −1 + 100. Mean inter-limb asymmetries were 2.91%, 4.82% and 11.6% for 180° COD, single leg hop and single leg countermovement jump tests respectively, but higher percentages of asymmetries were observed in many players individually. U-18 and U-16 showed significant differences on 180° left COD compared to U-14. Effect size (ES): 0.80 and 0.74, respectively; U-18 presented differences on single left leg hop test compared to U-14, ES: −0.72; U-16 also showed differences on 40 m speed compared to U-14, ES 0.87 (All p < 0.05). Jumping and COD physical tests show asymmetries in adolescent female soccer players, but these asymmetries do not interfere with physical performance. The largest asymmetry was observed in the single leg countermovement jump, and no asymmetries between groups were found. Due to the high variability in the direction of asymmetries, it is recommended to consider players’ individual asymmetries for designing specific training programs.

scholarly journals Change of direction in pairwise neutrino conversion physics: The effect of collisions

2021 ◽  
Vol 103 (6) ◽  
Author(s):  
Shashank Shalgar ◽  
Irene Tamborra
Keyword(s):  
Change Of Direction

Influence of upper-limb muscle strength on the repeated change of direction ability in international-level wheelchair basketball players

2021 ◽  
pp. 1-17
Author(s):  
Aitor Iturricastillo ◽  
Ibai Garcia-Tabar ◽  
Raul Reina ◽  
Adrian Garcia-Fresneda ◽  
Gerard Carmona ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Upper Limb ◽  
Limb Muscle ◽  
International Level ◽  
Wheelchair Basketball ◽  
Basketball Players ◽  
Change Of Direction

scholarly journals Relationship between Asymmetries Measured on Different Levels in Elite Basketball Players

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1436
Author(s):  
Filip Ujaković ◽  
Nejc Šarabon
Keyword(s):  
Return To Play ◽  
Basketball Players ◽  
Change Of Direction ◽  
Vertical Jumping ◽  
Hip Abduction ◽  
Golden Standard ◽  
Comprehensive Picture ◽  
Skill Change ◽  
Different Levels ◽  
Complex Movement

In this study, we investigated the association of magnitude and agreement in direction between asymmetries measured on single-joint (hip and trunk), complex movement (jumping), and skill (change of direction (CoD)) levels. The study sample comprised 43 junior- and senior-level (age = 20.5 ± 6.0 years; height = 194.5 ± 7.2 cm; body mass = 86.8 ± 10.1 kg) elite male basketball players. Both limbs/sides were tested in hip and trunk isometric strength; passive range of motion (RoM); unilateral, horizontal, and vertical jumping; and CoD tests, from which asymmetry indexes were calculated. The associations between asymmetry magnitudes were calculated with Spearman’s ρ correlation coefficient. The agreement between the direction of asymmetries on different levels was calculated with Cohen’’s Kappa (κ) coefficient. The average magnitude of asymmetry varied substantially (2.9–40.3%). Most associations between asymmetry magnitudes measured on different levels were small and statistically non-significant, with a few exceptions of moderate and large associations. Asymmetry in single-leg countermovement jump parameters was strongly associated with hip abduction maximal strength (ρ = 0.58 and 0.50, p < 0.01). Agreement between asymmetry directions was slight to fair, with a few moderate exceptions. Results indicate that multiple tests are needed to obtain a comprehensive picture of athletes’ asymmetries and that universal thresholds and golden standard tests for return to play should be reconsidered and reinvestigated.

scholarly journals Maximizing Acceleration and Change of Direction in Sport: A Case Series to Illustrate How the Force-Velocity Profile Provides Additional Information to That Derived from Linear Sprint Time

2021 ◽  
Vol 18 (11) ◽  
pp. 6140
Author(s):  
Andrés Baena-Raya ◽  
Manuel A. Rodríguez-Pérez ◽  
Pedro Jiménez-Reyes ◽  
Alberto Soriano-Maldonado
Keyword(s):  
Mechanical Properties ◽  
Case Series ◽  
Relevant Information ◽  
Maximal Power Output ◽  
Sprint Time ◽  
Change Of Direction ◽  
Training Interventions ◽  
Additional Information ◽  
Technical Report ◽  
Force Velocity

Sprint running and change of direction (COD) present similar mechanical demands, involving an acceleration phase in which athletes need to produce and apply substantial horizontal external force. Assessing the mechanical properties underpinning individual sprint acceleration might add relevant information about COD performance in addition to that obtained through sprint time alone. The present technical report uses a case series of three athletes with nearly identical 20 m sprint times but with different mechanical properties and COD performances. This makes it possible to illustrate, for the first time, a potential rationale for why the sprint force-velocity (FV) profile (i.e., theoretical maximal force (F0), velocity (V0), maximal power output (Pmax), ratio of effective horizontal component (RFpeak) and index of force application technique (DRF)) provides key information about COD performance (i.e., further to that derived from simple sprint time), which can be used to individualize training. This technical report provides practitioners with a justification to assess the FV profile in addition to sprint time when the aim is to enhance sprint acceleration and COD performance; practical interpretations and advice on how training interventions could be individualized based on the athletes’ differential sprint mechanical properties are also specified.

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