scholarly journals DEVELOPMENT OF IMPACT FORCE IN KICKBOXER TRAINING AT THE STAGE OF IMPROVING SPORTS SKILLS

2021 ◽  
Author(s):  
V.Yu. Filatova ◽  
◽  
I.N. Komarova
Keyword(s):  
Impact Force ◽  
Maximum Power ◽  
Force Development ◽  
Explosive Force ◽  
Sports Skills ◽  
High Level ◽  
Single Knockout

The article presents the results of a study on the development of impact force in kickboxers' training at the stage of improving sports skills. The study showed that the skill of a kickboxer is determined by the ability to realize the existing power potential in battle, and not by the maximum power indicators of his blows. The results obtained make it possible to say that a kickboxer needs a high level of explosive force development to deliver single knockout blows.

A Hierarchical Impact Force Reconstruction Method for Aerospace Composites

2019 ◽  
Vol 812 ◽  
pp. 17-24
Author(s):  
Mario Emanuele de Simone ◽  
Francesco Ciampa ◽  
Michele Meo
Keyword(s):  
Impact Force ◽  
Research Work ◽  
Time History ◽  
Low Velocity Impact ◽  
Reconstruction Method ◽  
Low Velocity ◽  
Force Reconstruction ◽  
Structural Responses ◽  
High Level ◽  
The Impact

This research work presents a hierarchical method able to reconstruct the time history of the impact force on a composite wing stringer-skin panel by using the structural responses measured by a set of surface bonded ultrasonic transducers. Time reversal method was used to identify the impact location by the knowledge of structural responses recorded from a set of excitation points arbitrarily chosen on the plane of the structure. Radial basis function interpolation approach was then used to calculate the transfer function at the impact point and reconstruct the impact force history. Experimental results showed the high level of accuracy of the proposed impact force reconstruction method for a number of low-velocity impact sources and energies.

scholarly journals MPPT Circuit Using Time Exponential Rate Perturbation and Observation for Enhanced Tracking Efficiency for a Wide Resistance Range of Thermoelectric Generator

2021 ◽  
Vol 11 (10) ◽  
pp. 4650
Author(s):  
Jie Miao ◽  
Houpeng Chen ◽  
Yu Lei ◽  
Yi Lv ◽  
Weili Liu ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Thermoelectric Generator ◽  
Complementary Metal Oxide Semiconductor ◽  
Metal Oxide Semiconductor ◽  
Maximum Power ◽  
Oxide Semiconductor ◽  
Cmos Process ◽  
Exponential Rate ◽  
Point Tracking ◽  
High Level

The thermoelectric generator (TEG) stands out among many energy harvesters due to its simple structure, small size, rich thermal energy, and the absence of pollution and noise. However, previous studies have rarely probed into the influence of TEG internal resistances on extracting maximum power from TEGs, and the tracking of efficiency is limited. By analyzing the relationship between the tracking efficiency and the TEG internal resistances, a time exponential rate perturbation and observation (P&O) technology is proposed to achieve maximum power point tracking (MPPT) for a wide resistance range of the TEG. Using the time exponential rate P&O, the MPPT circuit observed the power change by comparing the positive-channel metal-oxide semiconductor (PMOS) on-time and perturbs the power by adjusting the negative-channel metal-oxide semiconductor (NMOS) on-time exponentially. The MPPT circuit was implemented in a 110 nm complementary metal-oxide semiconductor (CMOS) process. The tracking efficiency maintained a high level from 98.9 to 99.5%. The applicable range of the TEG resistance was from 1 to 12 Ω, which reflects an enhancement of at least 2.2 times.

scholarly journals Anthropometric and capacitive analysis of the Ecuadorian senior national women's soccer team (Análisis antropométrico y capacitivo del equipo nacional femenino de fútbol de mayores de Ecuador)

Retos ◽  
2021 ◽  
Vol 44 ◽  
pp. 716-727
Author(s):  
Richard Manuel Manangón Pesantez ◽  
Lisbet Guillen Pereira ◽  
Daniela Alexandra Guevara Sánchez ◽  
Pablo Pablo Rendon Morales ◽  
Yaxel Ale De la Rosa Fuente ◽  
...  
Keyword(s):  
Normal Distribution ◽  
Muscle Mass ◽  
International Society ◽  
Lower Extremities ◽  
Soccer Players ◽  
National Team ◽  
Explosive Force ◽  
Morphological Diagnosis ◽  
Soccer Team ◽  
High Level

  The development of women's football worldwide points to the resignification of the approach to team preparation, where anthropometric and capacitive variables play an important role. Ecuador shows no precedent for studies in high-level female soccer players. Accordingly, the objective focused on analyzing the state of anthropometric and capacitive variables of 22 soccer players of the Ecuadorian senior women's national team, which represent 100% of the population. It started from the morphological diagnosis of equipment applying 19 measurements under the protocol of marking and measurement of the International Society for the development of Kineanthropometry (ISAK), the evaluation of the explosive force through three jumps (Tests SJ, CMJ and Abalakob ( AB) and speed (35 meters), The data were subjected to normality criteria (Shapiro-Wilk test), the result of which indicated that the values ​​did not follow a normal distribution, therefore the non-parametric ANOVA test of a Kruskal - Wallis Factor for independent samples. The study was preceded by three research hypotheses. It is shown that there are no significant differences in the variables analyzed by position, being p> 0.05, H0 is accepted in all cases. The results allowed to characterize the team morphologically with a Meso-Endomorph somatotype, irregularities were found in some variables of the morphology of the soccer players (IDG / IMO), suggesting how conclusion a nutritional dietary planning, and enhance muscle mass in the lower extremities from the management of physical direction.  Resumen. El desarrollo del fútbol femenino a nivel mundial, apunta hacia la resignificación del enfoque de la preparación de los equipos, donde juega un rol importante las variables antropométricas y capacitivas. Ecuador no muestra precedentes de estudios en mujeres futbolistas de alto nivel. En concordancia el objetivo se centró en analizar el estado de variables antropométricas y capacitivas de 22 futbolistas del equipo nacional femenino de mayores de Ecuador, las cuales representan el 100% de la población. Se partió del diagnóstico morfológico de equipo aplicando 19 mediciones bajo el protocolo de marcaje y medición de la Sociedad Internacional para el desarrollo de la Cineantropometría (ISAK), la evaluación de la fuerza explosiva a través de tres saltos (Tests SJ, CMJ y Abalakob (AB) y la rapidez (35 metros), Los datos se sometieron a criterios de normalidad (test de Shapiro-Wilk), cuyo resultado indicó que los valores no siguen una distribución normal, en virtud de ello se empleó la prueba no paramétrica ANOVA de un Factor de Kruskal - Wallis para muestras independiente. El estudio estuvo precedido por tres hipótesis de investigación. Se demuestra que no existen diferencias significativas en las variables analizadas por posición; al ser p>0,05 se acepta H0 en todos los casos. Los resultados permitieron caracterizar morfológicamente al equipo con un somatotipo Meso-Endomorfo, se comprueba irregularidades en algunas variables de la morfología de las futbolistas (IDG/ IMO) sugiriendo como conclusión una planificación dietético nutricional, y potenciar la masa muscular en las extremidades inferiores desde la gestión de la dirección física.

Lower Limb Kinetics and Kinematics during Two Different Jumping Methods

2015 ◽  
Vol 22 ◽  
pp. 29-35 ◽  
Author(s):  
Yang Shu ◽  
Dong Sun ◽  
Qiu Li Hu ◽  
Yan Zhang ◽  
Jian She Li ◽  
...  
Keyword(s):  
Lower Limb ◽  
Impact Force ◽  
Vertical Jump ◽  
Lower Limbs ◽  
Countermovement Jump ◽  
Kinematic Parameters ◽  
Squat Jump ◽  
High Level ◽  
Vertical Jumps ◽  
Kinematics Parameters

The purpose of the study is to investigate into the dynamic and kinematic parameters of lower limbs about two types of jump high-level basketball athlete doing: countermovement jump and squat jump. There were distinctively different in jump height between two types. Kinetics and kinematics parameters of squat jump were less than countermovement jump. Using Vertical Jumps countermovement jump can increase the height of vertical jump effectively. These jumps all can cushion the pressure of impact force in landing phase.

scholarly journals The Effects of a Maximal Power Training Cycle on the Strength, Maximum Power, Vertical Jump Height and Acceleration of High-Level 400-Meter Hurdlers

2013 ◽  
Vol 36 (1) ◽  
pp. 119-126 ◽  
Author(s):  
Carlos Balsalobre-Fernández ◽  
Carlos Mª Tejero-González ◽  
Juan del Campo-Vecino ◽  
Dionisio Alonso-Curiel
Keyword(s):  
Training Program ◽  
Vertical Jump ◽  
Training Session ◽  
Maximum Power ◽  
Jump Height ◽  
Power Training ◽  
Vertical Jump Height ◽  
Training Cycle ◽  
Power Load ◽  
High Level

The aim of this study was to determine the effects of a power training cycle on maximum strength, maximum power, vertical jump height and acceleration in seven high-level 400-meter hurdlers subjected to a specific training program twice a week for 10 weeks. Each training session consisted of five sets of eight jump-squats with the load at which each athlete produced his maximum power. The repetition maximum in the half squat position (RM), maximum power in the jump-squat (W), a squat jump (SJ), countermovement jump (CSJ), and a 30-meter sprint from a standing position were measured before and after the training program using an accelerometer, an infra-red platform and photocells. The results indicated the following statistically significant improvements: a 7.9% increase in RM (Z=-2.03, p=0.021, δc=0.39), a 2.3% improvement in SJ (Z=-1.69, p=0.045, δc=0.29), a 1.43% decrease in the 30-meter sprint (Z=-1.70, p=0.044, δc=0.12), and, where maximum power was produced, a change in the RM percentage from 56 to 62% (Z=-1.75, p=0.039, δc=0.54). As such, it can be concluded that strength training with a maximum power load is an effective means of increasing strength and acceleration in high-level hurdlers.

Mechanisms for the mechanical plasticity of tracheal smooth muscle

1995 ◽  
Vol 268 (5) ◽  
pp. C1267-C1276 ◽  
Author(s):  
S. J. Gunst ◽  
R. A. Meiss ◽  
M. F. Wu ◽  
M. Rowe
Keyword(s):  
Smooth Muscle ◽  
Stimulus Intensity ◽  
Isometric Force ◽  
Muscle Length ◽  
Muscle Stiffness ◽  
Force Development ◽  
Cross Bridges ◽  
High Level ◽  
Cellular Components ◽  
The Relationship

In smooth muscle tissues, the relationship between muscle or cell length and active force can be modulated by altering the cell or tissue length during stimulation. Mechanisms for this mechanical plasticity were investigated by measuring muscle stiffness during isometric contractions in which contractile force was graded by changing stimulus intensity or muscle length. Stiffness was significantly higher in contracted than in resting muscles at comparable forces; however, the relationship between stiffness and force during force development was curvilinear and independent of muscle length and stimulus intensity. This suggests that muscle stiffness during force development reflects properties of cellular components other than cross bridges which contribute to the series elasticity only during activation. During the tonic phase of isometric contraction, muscle stiffness increased while force remained constant. A step decrease in the length of a contracted muscle resulted in a high level of stiffness relative to force during isometric force redevelopment following the length step. We propose that the arrangement of the cytoskeleton can adjust to changes in the conformation of resting smooth muscle cells but that the organization of the cytoskeleton becomes more fixed upon contractile activation and is modulated very slowly during a sustained contraction. This may provide a mechanism for optimizing force development to the physical conformation of the cell at the time of activation.

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