scholarly journals Change of Direction Performance Is Influenced by Asymmetries in Jumping Ability and Hip and Trunk Strength in Elite Basketball Players

2020 ◽  
Vol 10 (19) ◽  
pp. 6984
Author(s):  
Filip Ujaković ◽  
Nejc Šarabon
Keyword(s):  
Regression Model ◽  
Range Of Motion ◽  
Sport Performance ◽  
Leg Length ◽  
Basketball Players ◽  
Change Of Direction ◽  
Rate Of Torque Development ◽  
Hip Flexion ◽  
Torque Development ◽  
Trunk Strength

Change of direction (COD) ability is essential for sport performance in high level team sports such as basketball, however, the influence of asymmetries on COD ability is relatively unknown. Forty-three junior and senior level elite basketball players performed isometric hip and trunk strength testing, passive hip and trunk range of motion testing, and unilateral horizontal and vertical jumps, as well as the T-test to measure COD performance. Mean asymmetry values ranged from 0.76% for functional leg length up to 40.35% for rate of torque development during hip flexion. A six-variable regression model explained 48% (R2 = 0.48; p < 0.001) of variation in COD performance. The model included left hip internal/external rotation strength ratio, and inter-limb asymmetries in hip abduction rate of torque development, hip flexion range of motion, functional leg length, single leg triple jump distance, and peak torque during trunk lateral flexion. Results suggest that the magnitude of asymmetries is dependent of task and parameter, and using universal asymmetry thresholds, such as <10 %, is not optimal. The regression model showed the relationship between asymmetries and COD performance. None of tests were sufficient to explain a complex variable like COD performance.

scholarly journals Elbow Extensors and Volar Flexors Strength Capacity and Its Relation to Shooting Performance in Basketball Players—A Pilot Study

2020 ◽  
Vol 10 (22) ◽  
pp. 8206
Author(s):  
Darjan Smajla ◽  
Žiga Kozinc ◽  
Nejc Šarabon
Keyword(s):  
Scaling Factor ◽  
Long Distance ◽  
Basketball Players ◽  
Rate Of Torque Development ◽  
Strength Capacity ◽  
Isometric Torque ◽  
Muscle Groups ◽  
Sufficient Strength ◽  
Torque Development ◽  
Basketball Shooting

Rate of force/torque development scaling factor (RFD-SF/RTD-SF) has been used as a tool for assessing neuromuscular quickness. The aim was to investigate strength capacities of two major shooting muscle groups and their relationship to basketball shooting performance, and to compare the RFD-SF as well as shooting performance between junior and senior basketball players, and finally to examine the differences in RTD-SF between elbow extensors and volar flexors. In 23 male basketball players (13 juniors and 10 seniors) we assessed maximal isometric torque (TMVC), maximal rate of torque development and RTD-SF slope (kRTD-SF) for elbow extensors and volar flexors. The subjects performed 10 throws at 2.3 m (short) and 8.9 m (long) from the basket. Our results showed similar kRTD-SF and TMVC in both groups. Better shooting performance from short distance was observed in senior players. Significant associations between kRTD-SF, TMVC and shooting performance were found only in juniors. Elbow extensors TMVC was found to have a significant positive large association with shooting performance from long distance. It seems that muscle capacity has an important role in shooting performance in junior compared to players. Sufficient strength capacity of major shooting muscles is important for juniors’ shooting performance from a long distance.

scholarly journals Decisive Factors for a Greater Performance in the Change of Direction and Its Angulation in Male Basketball Players

2020 ◽  
Vol 17 (18) ◽  
pp. 6598
Author(s):  
Francisco J. Barrera-Domínguez ◽  
Bartolomé J. Almagro ◽  
Inmaculada Tornero-Quiñones ◽  
Jesús Sáez-Padilla ◽  
Ángela Sierra-Robles ◽  
...  
Keyword(s):  
Total Sample ◽  
Sport Performance ◽  
Vertical Force ◽  
Basketball Players ◽  
Functional Movement ◽  
Performance Variables ◽  
Change Of Direction ◽  
Force Velocity ◽  
The Relationship ◽  
Age Category

A study was made to initially evaluate whether the age category directly could influence anthropometric measurements, functional movement tests, linear sprint (30 m) and strength. Moreover, and as the main purpose, this study aimed to examine the relationship between the time execution and angles in different changes of direction (COD) test with the analyzed sport performance variables. A total sample of 23 basketball players (age: 17.5 ± 2.42 years; height: 184.6 ± 6.68 cm; body weight: 78.09 ± 11.9 kg). Between-groups’ comparison explored the differences between basketball categories (Junior, n = 12; Senior, n = 11). The COD variables were divided by the time execution into low responders (LR) and high responders (HR) to establish comparisons between groups related to COD time execution. Pearson’s correlation coefficient was used to establish correlations between different CODs and sport performance variables. The results showed a greater influence of age category upon COD performance, especially when the cutting angle was sharper (7.05% [Confidence limits (CL) 90%: 2.33; 11.99]; Quantitative chances (QC) 0/2/98), in which athletes need greater application of strength. Moreover, the sharper the angle or the larger the number of cuts made, the greater the relationship with the vertical force–velocity profile (−42.39 [CL 90%: −57.37; −22.16]; QC 100/0/0%). Thus, the usefulness of the f–v profile to implement training programs that optimize the f–v imbalance and the improvement of the COD performance in basketball players is suggested.

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.

Knee flexor strength, rate of torque development and flexibility in women and men with patellofemoral pain: Relationship with pain and the single leg bridge test

2021 ◽  
Author(s):  
Matheus Henrique Maiolini Ducatti ◽  
Marina Cabral Waiteman ◽  
Ana Flávia Balotari Botta ◽  
Helder dos Santos Lopes ◽  
Neal Robert Glaviano ◽  
...  
Keyword(s):  
Patellofemoral Pain ◽  
Knee Flexor ◽  
Rate Of Torque Development ◽  
Torque Development ◽  
Flexor Strength

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.

Blockade of 5-HT2 receptors suppresses rate of torque development and motor unit discharge rate during rapid contractions

2021 ◽  
Author(s):  
Benjamin Ian Goodlich ◽  
Sean A Horan ◽  
Justin J Kavanagh
Keyword(s):  
Motor Unit ◽  
Unit Activity ◽  
Repeated Measures ◽  
Discharge Rate ◽  
Voluntary Contraction ◽  
Unit Discharge ◽  
Motor Unit Activity ◽  
Rate Of Torque Development ◽  
Motor Unit Discharge ◽  
Torque Development

Serotonin (5-HT) is a neuromodulator that is critical for regulating the excitability of spinal motoneurons and the generation of muscle torque. However, the role of 5-HT in modulating human motor unit activity during rapid contractions has yet to be assessed. Nine healthy participants (23.7 ± 2.2 yr) ingested 8 mg of the competitive 5-HT2 antagonist cyproheptadine in a double-blinded, placebo-controlled, repeated-measures experiment. Rapid dorsiflexion contractions were performed at 30%, 50% and 70% of maximal voluntary contraction (MVC), where motor unit activity was assessed by high-density surface electromyographic decomposition. A second protocol was performed where a sustained, fatigue-inducing dorsiflexion contraction was completed prior to undertaking the same 30%, 50% and 70% MVC rapid contractions and motor unit analysis. Motor unit discharge rate (p < 0.001) and rate of torque development (RTD; p = 0.019) for the unfatigued muscle were both significantly lower for the cyproheptadine condition. Following the fatigue inducing contraction, cyproheptadine reduced motor unit discharge rate (p < 0.001) and RTD (p = 0.024), where the effects of cyproheptadine on motor unit discharge rate and RTD increased with increasing contraction intensity. Overall, these results support the viewpoint that serotonergic effects in the central nervous system occur fast enough to regulate motor unit discharge rate during rapid powerful contractions.

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