Maximum Kick Research Articles

Asymmetry in Ball Kicking Speed between Preferred and Non-preferred Leg in Young Soccer Players

Kicking ability is one of the most important skills in soccer. It is very important to have a good kicking ability with both feet. The main goal of this research was to determine a ball kicking asymmetry (KA) between preferred and non-preferred leg in young soccer players for the U-15 and the U-17 age category. The second goal was to determine differences in kicking asymmetry (KA) between players of different playing positions. 183 young players in U-15 category as well as 87 players from U-17 age category were tested with simple soccer specific test to evaluate kicking velocity (km/h) with preferred and non-preferred leg using Pocket radar. Testing took place on the artificial grass during dry and warm weather and ball was kicked while stationary at the 11-m spot. Results obtained with Student’s T-test showed that differences in the maximum kicking velocity with the preferred and non-preferred leg were statistically significant (p≤0.05) in both age groups (90.2±8.8 km/h /78.5±9.8 km/h for U-15) and (102.7±6.4 km/h /89.5±9.4 km/h for U-17) which confirmed KA is present. Additionally, univariate analysis of variance (ANOVA) showed that there were significant differences in KA between different playing positions in U-17 group (KA=14.57/9.72/14.1 for defenders, midfielders and attackers, respectively). Soccer kicking can be a quality indicator for assessing the soccer kicking ability. By assessing kicking ability, relevant results can be obtained in a fast, and efficient way and can be utilized in the selection process of young talents.

An analytical study on early kick detection and well control considerations for casing while drilling technology

Casing while drilling (CwD) technology is designed to reduce drilling time and expenses by improving the wellbore stability, fracture gradient, and formation damage while reducing the exposure time. However, for the purpose well control, the wellbore geometry and volumes differ from those obtained via a conventional drilling technique, thereby requiring a different approach. This study discusses well control principles for CwD operations. It presents a simplified method for evaluating the maximum kick tolerance and allowable well shut-in time for both conventional and CwD techniques using a mathematical model. Preliminary results revealed that the use of CwD leads to an annulus pressure loss three times higher than that observed in the conventional drilling. In addition, the kick tolerance is reduced by 50% and the maximum allowable well shut-in time is reduced by 65%, making an early kick detection system necessary.

The Influence of Wearable Resistance Loading on Taekwondo Axe Kick Kinematics among Elite Taekwondo Athletes

Wearable resistance (WR) is an alternative proposed to be used in training with the aim to increase sport performance by allowing specific movements to be performed with additional loading. Although the benefits of allowing more sport-specific movement are undeniable, studies conducted on the effects of this WR in Taekwondo sport are scarce. This study aims to determine the acute effects of WR loading on Taekwondo axe kick kinematics. Twenty-four (n=24) state-level taekwondo athletes were recruited and were required to perform axe kick in four conditions by wearing a WR suit on their thigh and shank. Four different loadings were attached at the suit; i) 3% of body mass (3WR), ii) 5% of body mass (5WR), iii) 8% of body mass (8WR) and iv) without load (0WR). During the movement, movement kinematics (maximum kick height, angle between thighs, range of motion (ROM) of hip, ROM of knee, duration of power load, maximum speed of ankle, duration of drive and total time were analyzed for both dominant and non-dominant leg. Cameras attached to motion analysis systems were used to record participant's kicking kinematics. The kinematics data obtained were compared between each loading condition. Results showed that only wearing WR of 3% body mass did not change the kinematics of kicking (except for maximum kick height) as without WR. Wearing WR of 5% and 8% body mass caused significant changes to the movement kinematics when compared to without WR. To conclude, this study has added the knowledge on the alternatives for resistance training that can be performed among Taekwondo athletes. Through the findings of this study, it was found that wearing WR of 3% body mass is suitable for athletes during training session as they can maintain their technical effectiveness while also increase stimulus for body to adapt in long term while a minimum of 5 % body mass might affect the kicking technical efficiency. It is suggested for chronic studies to be conducted to determine the long term effects of WR loadings on the kicking techniques efficiency.

MPD Well-Design Process Optimizes Design, Delivery of Deepwater Well

This article, written by JPT Technology Editor Judy Feder, contains highlights of paper SPE 200504, “Using MPD Well-Design Process To Optimize Design and Delivery of a Deepwater Exploration Well,” by Sharief Moghazy, SPE, Wilmer Gaviria, SPE, and Roger Van Noort, SPE, Shell, et al., prepared for the 2020 SPE/IADC Managed Pressure Drilling and Underbalanced Operations Conference and Exhibition, originally scheduled to be held in Denver, Colorado, 21-22 April. The paper has not been peer reviewed. The complete paper presents a case for using managed pressure drilling (MPD), and the full capabilities of its associated well-design process, to optimize all aspects of the well-delivery process in deep water, including design, safety, and subsurface data acquisition. The process was used to design and drill a deepwater exploration well with an expected pressure ramp and narrow drilling margins while acquiring valuable subsurface data. Introduction The operator’s only offset well in the area faced many challenges including a pressure ramp, resulting in narrow drilling margins. The team experienced several margin-related issues, such as kicks and losses, that resulted in permanent abandonment of the well without reaching the objectives. Given those results, and the subsurface uncertainty, the operator determined that the use of MPD would have mitigated many of the risks and non-productive-time events experienced in that well. The drilling contractor procured a rig fitted with an MPD system to drill a new exploratory well. MPD and the MPD well-design process were employed to increase the likelihood of drilling the well to total depth (TD) safely and successfully by providing the capability to accomplish the following: Account for pore pressure/fracture gradient (PPFG) uncertainty and navigate the expected pressure ramp and narrow margin sections safely by holding a constant bottomhole pressure and adjusting as needed during drilling operations Optimize the location of the casing/liner shoes by identifying the pressure profile based on real-time pore pressure data to potentially eliminate casing/liners, streamline the well design, and retain contingency strings in the event of a more-aggressive pore-pressure ramp Enable early kick and loss-detection capabilities and dynamic influx management to identify, react, and address downhole issues more quickly Use dynamic formation integrity tests (DFIT), dynamic leakoff tests, and dynamic pore-pressure tests (DPPT) to identify the extremes of the drilling margin, derisk subsurface uncertainty, and make decisions while drilling The process used hydraulics modeling to assess the feasibility of several potential scenarios and to understand the deepest possible casing points for a particular PPFG case, mud weight (MW), and well-design scheme. After a base-case well design was created, the maximum allowable kick tolerance was determined using an influx management envelope (IME) analysis, which was used as an input for an MPD operations matrix to be used during the operational phase. During the drilling of the well, the use of the MPD system and the calibration of the hydraulics model to the actual subsurface information allowed the team to continue drilling through more-benign conditions and optimize the well-design configuration.

Effects of plyometric jump training on the physical fitness of young male soccer players: Modulation of response by inter-set recovery interval and maturation status

ABSTRACTThe effects of plyometric jump training on the physical fitness of male youth (age = 10–17 years) soccer players was examined in relation to inter-set recovery intervals and the maturity of the players in a single-blind, randomized-and controlled crossover trial. Jumping tests and kicking velocities were measured before (T0), after a 6 week control period (T1), after 6 weeks of plyometrics (T2), after 6 weeks of wash-out (T3), and after a further 6 weeks of plyometrics (T4). Subjects were divided into pre- and post- peak-height-velocity (PHV) groups, and were randomly assigned to 30 s or 120 s inter-set intervals during periods T2 and T4. Any changes in jumping and maximum kicking velocities during T1 and T3, had trivial effect sizes (0.01–0.15), but small to moderate improvements (effect size = 0.20–0.99) were observed in both groups during T2 and T4. Gains in pre-PHV players were similar for the two inter-set intervals, but gains in post-PHV players were greater (p < 0.05) with an inter-set recovery of 120 s than with a 30 s recovery. We conclude that plyometric jump training improves the physical fitness of adolescents, irrespective of their maturity, but that in older individuals gains are greater with a longer inter-set recovery interval.

Kicking ability and kicking deficit in young elite soccer players

Kicking ability in soccer has been evaluated predominantly by the maximum ball velocity. The kicking deficit (KD) may be defined as the percentage of the difference between the maximum ball velocity each player achieved by the non-preferred leg kick in relation to the preferred leg kick. This study aimed to compare: side-to-side kicking velocity, vertical jumps and anthropometrics between the younger (G-14) and older (G+14) than 14 years soccer players. An additional aim was to investigate associations among these variables. Participants were 92 young elite soccer players from the development programme of a top Spanish division club. They were divided into two age groups according to their growth and motor development stages (10.80-13.55 years, n=46; 14.02-16.39 years, n=46). Student’s t-test showed that the maximum kicking velocity with the preferred and non-preferred leg, jumping performance, and all anthropometric measurements were significantly (p&amp;lt;.01) higher in G+14 compared with G-14. In contrast, KD values remained stable (15.31%- 15.83%) without significant differences between the groups. Pearson’s correlation analysis revealed that vertical jump tests and anthropometric measurements correlated with kicking ball velocity produced by the preferred and non-preferred leg. Our results demonstrate that kicking skills are still not consolidated and power factors may be determinant for kicking performance in young soccer players. In addition, the KD may be a constant element for both the under and above 14 years soccer players and could result from an unequal and greater use of the preferred leg in comparison with the non-preferred leg.

Diferencias cinemáticas del golpeo de fútbol entre futbolistas expertos y sujetos inexpertos (Soccer kick kinematic differences between experienced and non-experienced soccer players)

Objetivo: Examinar las diferencias cinemáticas del golpeo con empeine entre futbolistas expertos y sujetos inexpertos. Sujetos: Se analizaron 17 hombres de 17 a 21 años. Metodología: Se utilizó un sistema de fotogrametría 3D con cuatro cámaras. Los sujetos ejecutaron golpeos con el empeine a máxima potencia. Se analizó la Velocidad del Pie en el Impacto, la Máxima Extensión de Cadera, la Máxima Flexión de Rodilla y la Duración de las Fases del gesto. Resultados: Se hallaron diferencias significativas en la Velocidad del Pie de la pierna no hábil en el momento del impacto (m/s) (Expertos: 14,5±.52, Inexpertos: 12.5±.5; p&lt;.001) y Máxima Extensión de Cadera (grados) (Expertos: 39.2±1.3, Inexpertos: 34.28±3.2; p&lt;.001). También hubo diferencias significativas en la Duración de la Fase 2 en ambas piernas (p&lt;.05). Conclusiones: El golpeo con el empeine total en fútbol presenta diferencias significativas entre grupos de diferente nivel tan solo en la pierna no dominante. Palabra clave: golpeo, fútbol, biomecánica, empeine.Abstract: T; Purpose: to examine kinematic differences of instep soccer kick between experienced and non-experienced soccer players. Subjects: 17 men between 17 and 21 years old. Methodology: a 3D film system with 4 cameras was used. Maximum power instep kicks were executed. It was analyzed feet velocity in the impact, maximum hip extension, maximum knee flexion and kick phases duration. Results: were found significant differences in feet velocity with non-dominant leg in the impact moment (m/s) (Experienced: 14.5±.52, Non-experienced: 12.5±.5; p&lt;.001) and maximum hip extension (degrees) (Experienced: 39.2 ± 1.3, Non-experienced: 34.28±3.2; p&lt;.001). Also were significant differences in the second phase duration in both legs (p&lt;.05). Conclusions: Maximum instep soccer kick show significant differences between groups of different level only in non-dominant leg.Key words: kick, soccer, biomechanics, instep.

Moderate Effort Instep Kick in Futsal

In futsal matches players do not perform maximum kicking effort all the time. There are situations when the player needs to perform a moderate effort kick to achieve certain kicking objectives. In instep kicks, the kicking leg's ankle condition is one of the important parameters influencing the quality of the kick. In maximum effort instep kicks, ankle rigidity is associated with successful kicking effort. This study was focused on the kicking leg's ankle influence on ball velocity during moderate effort kicks in futsal. The focus was on the ankle condition at pre and post impact phase between the foot and the ball. Video analyses were performed on trials of the instep soccer kick with moderate effort to produce low foot velocity during kicking. Seven (n=7) skilled futsal players were selected to perform the kick. Test subject's motions during kicking trials were analyzed by the motion analysis package, Kinovea. The raw data of displacement obtained from the video analysis were then filtered by a single cut-off frequency using 4th order low-pass zero-phase-shift Butterworth filter at 11Hz. Velocity of the ankle and foot before the foot-ball impact and also the ball velocity after the foot-ball impact were calculated from the filtered data using the finite (forward) difference method. Results showed that the ankle influenced kicking outcome. This study also indicated that players focused less on ankle rigidity during ankle-foot plantar flexion during moderate effort kicks. This was based on low ankle-foot velocity ratio prior to ball impact and low coefficient of restitution as compared to maximum kick effort.

When Skeletons Are Geared for Speed: The Morphology, Biomechanics, and Energetics of Rapid Animal Motion

A skeleton amplifies the minute contractions of muscles to animate the body of an animal. The degree that a muscular contraction displaces an appendage is determined by the gearing provided by the joints of a skeleton. Species that move rapidly commonly possess joints with relatively high gears that produce a large output displacement. However, the speed of an appendage can depend on dynamics that obscure how this motion is influenced by the skeleton. The aim of this review is to resolve mechanical principles that govern the relationship between the gearing and speed of skeletal joints. Forward dynamic models of three rapid force-transmission systems were examined with simulations that varied the gearing of a joint. The leg of a locust, the raptorial appendage of a mantis shrimp, and the jaw of a toad are all driven by the conversion of stored elastic energy into kinetic energy. A locust achieves this conversion with high efficiency when it kicks and thereby applies nearly all stored energy into fast movement. This conversion is unaffected by differences in the leverage of the knee joint, as demonstrated by a maximum kicking speed that was found to be independent of gearing. In contrast, the mantis shrimp creates drag as it strikes toward a prey and thereby loses energy. As a consequence, high gears displace the raptorial appendage relatively far and yield slower motion than do low gears. The muscle that opens a toad's jaw also dissipates energy during ballistic capture of prey. This loss of energy is reduced when jaw opening occurs from the slower muscle contraction produced by a high gear within the jaw. Therefore, the speed of these lever systems is dictated by how gearing affects the efficiency of the conversion of potential energy into kinetic energy. In this way, the energetics of force transmission mediate the relationship between the gearing of a skeletal joint and the maximum speed of its motion.

Enhancing Foot Velocity in Football Kicking: The Role of Strength Training

In all codes of football, it is advantageous to be able to achieve a high ball speed or distance in a kick. An important determinant of ball speed and kick distance is the velocity of the foot at impact with the ball. Therefore, it is of interest to strength and conditioning practitioners to identify training programs that can increase foot velocity. The purpose of this review is to identify the factors influencing kicking performance and the research evidence relating to resistance training designed to enhance foot velocity in kicking. The review has been divided into 3 main sections. The first addresses the biomechanics of kicking to provide insights into the physical demands. The second section reviews the relationships between various measures of strength with performance indicators of maximum kicking, and the third part explores the research investigating the effects of resistance training on maximum kicking performance. Kicking can be described as a skill involving proximal-to-distal muscle activation. Foot velocity is determined by a complex sequencing of hip flexor and knee extensor concentric contractions and also involves hip extensor and knee flexor activation to assist with movement control. Research reporting correlations between strength and kicking performance support the importance of hip flexor and quadriceps strength. Although unclear, there is some evidence that adequate strength of the support leg, trunk muscles, hip adductors, and the muscles that control pelvic rotations are important. Strength training studies have shown that foot velocity and kicking performance can be enhanced by supplementary programs to regular football training, especially in nonelite athletes. Potentially valuable training includes plyometrics, exercises that simulate the whole kicking action, and kicking weighted balls. Exercises that isolate parts of the kicking action are not recommended because these do not appear to transfer well to kicking performance. There are many unanswered questions that await future research.

The Association Between Motor Skill Competence and Physical Fitness in Young Adults

We examined the relationship between competence in three fundamental motor skills (throwing, kicking, and jumping) and six measures of health-related physical fitness in young adults (ages 18–25). We assessed motor skill competence using product scores of maximum kicking and throwing speed and maximum jumping distance. A factor analysis indicated the 12-min run/walk, percent body fat, curl-ups, grip strength, and maximum leg press strength all loaded on one factor defining the construct of “overall fitness.” Multiple regression analyses indicated that the product scores for jumping (74%), kicking (58%), and throwing (59%) predicted 79% of the variance in overall fitness. Gender was not a significant predictor of fitness. Results suggest that developing motor skill competence may be fundamental in developing and maintaining adequate physical fitness into adulthood. These data represent the strongest to date on the relationship between motor skill competence and physical fitness.

Understanding the mechanisms of shaft deflection in the golf swing

An understanding of shaft dynamics during the golf swing was gained through a series of theoretical simulations, using a 3D forward dynamics model. By resolving the resultant force applied at the grip end of the club into a tangential and a radial (centripetal) component, the mechanisms of shaft deflection were quantified. It was determined that radial force plays an important role in producing the toe-down and lead-deflections recorded in all golf swings made with a driver. However, the simulations also revealed that the recoil of the shaft, from its previously toe-up and lag deflected position during the downswing (due to tangential forces), plays at least an equally important role in determining the position and orientation of the clubhead at impact. It was further demonstrated that, due to the influence of the radial force component, maximum kick velocity is reached after the clubhead has passed beyond the neutral shaft position.

Binary black hole mergers: Large kicks for generic spin orientations

We present results from several simulations of equal mass black holes with spin. The spin magnitudes are $S/{m}^{2}=0.8$ in all cases, but we vary the spin orientations arbitrarily, inside and outside the orbital plane. We find that in all but one case the final merged black hole acquires a kick of more than $1000\text{ }\text{ }\mathrm{km}/\mathrm{s}$, indicating that kicks of this magnitude are likely to be generic and should be expected for mergers with general spin orientations. The maximum kick velocity we find is $2500\text{ }\text{ }\mathrm{km}/\mathrm{s}$ and occurs for initial spins which are antialigned in the initial orbital plane.

Supermassive Recoil Velocities for Binary Black-Hole Mergers with Antialigned Spins

Recent calculations of the recoil velocity in binary black-hole mergers have found the kick velocity to be of the order of a few hundred km/s in the case of nonspinning binaries and about 500 km/s in the case of spinning configurations, and have lead to predictions of a maximum kick of up to 1300 km/s. We test these predictions and demonstrate that kick velocities of at least 2500 km/s are possible for equal-mass binaries with antialigned spins in the orbital plane. Kicks of that magnitude are likely to have significant repercussions for models of black-hole formation, the population of intergalactic black holes, and the structure of host galaxies.

Alignment of the Spins of Supermassive Black Holes Prior to Coalescence

Recent numerical relativistic simulations of black hole coalescence suggest that in certain alignments the emission of gravitational radiation can produce a kick of several thousand kilometers per second. This exceeds galactic escape speeds, hence unless there a mechanism to prevent this, one would expect many galaxies that had merged to be without a central black hole. Here we show that in most galactic mergers, torques from accreting gas suffice to align the orbit and spins of both black holes with the large-scale gas flow. Such a configuration has a maximum kick speed <200 km/s, safely below galactic escape speeds. We predict, however, that in mergers of galaxies without much gas, the remnant will be kicked out several percent of the time. We also discuss other predictions of our scenario, including implications for jet alignment angles and X-type radio sources.

Large Merger Recoils and Spin Flips from Generic Black Hole Binaries

We report the first results from evolutions of a generic black-hole binary, i.e. a binary containing unequal mass black holes with misaligned spins. Our configuration, which has a mass ratio of 2:1, consists of an initially non-spinning hole orbiting a larger, rapidly spinning hole (specific spin a/m = 0.885), with the spin direction oriented -45 degrees with respect to the orbital plane. We track the inspiral and merger for ~2 orbits and find that the remnant receives a substantial kick of 454 km/s, more than twice as large as the maximum kick from non-spinning binaries. The remnant spin direction is flipped by 103 degrees with respect to the initial spin direction of the larger hole. We performed a second run with anti-aligned spins, a/m = +-0.5 lying in the orbital plane that produces a kick of 1830 km/s off the orbital plane. This value scales to nearly 4000 km/s for maximally spinning holes. Such a large recoil velocity opens the possibility that a merged binary can be ejected even from the nucleus of a massive host galaxy.

Maximum Kick from Nonspinning Black-Hole Binary Inspiral

When unequal-mass black holes merge, the final black hole receives a kick due to the asymmetric loss of linear momentum in the gravitational radiation emitted during the merger. The magnitude of this kick has important astrophysical consequences. Recent breakthroughs in numerical relativity allow us to perform the largest parameter study undertaken to date in numerical simulations of binary black-hole inspirals. We study nonspinning black-hole binaries with mass ratios from q=M1/M2=1 to q=0.25 (eta=q/(1+q)2 from 0.25 to 0.16). We accurately calculate the velocity of the kick to within 6%, and the final spin of the black holes to within 2%. A maximum kick of 175.2+/-11 km s(-1) is achieved for eta=0.195+/-0.005.

The relationship between occlusal support and physical exercise ability.

This study was conducted to elucidate the relationship between the presence of occlusal support in edentulous subjects and their ability for physical exercise. Ten complete denture wearers were selected and instructed to jump vertically while standing on a force plate with and without occlusal support (i.e. dentures). On the curve recorded by the force plate (1) reaction time (latency) (2) jump elevation time and (3) maximum kicking force were analysed. The reaction time, which is an index of physical quickness, was significantly prolonged when the subjects lost their occlusal support. This result suggests that reconstruction of occlusal support at a desirable mandibular position has significance not only for the restoration of masticatory function but also for the maintenance of physical exercise.

Very fast kicker with high repetition rate for accelerator applications

We describe a very fast kicker with unique combination of high repetition rate and short pulse width. Constructionally, the device is a counter traveling wave strip-line kicker fed by semiconductor high-voltage pulse generator. Experimentally tested kicker has a full pulse width of about 7 ns, 1.4 MHz repetition rate and maximum kick strength of the order of 3 G m. Recent achievements in high-voltage semiconductor field-effect-transistors (FET) technology and goal-specific optimization of the kicker parameters allow many-fold increase of the strength, and the kicker can be a very useful tool for bunch-by-bunch injection/extraction and other accelerator applications.

Measurement and Analysis of the Overnight Small Package Shipping Environment for Federal Express and United Parcel Service

Abstract The purpose of this study was to measure and characterize the various impacts (free fall drops, lateral kicks, and tosses) received by packages in the overnight small parcel environments found at Federal Express and United Parcel Service. Packages instrumented with tri-axial shock data recorders were repeatedly sent through UPS “Next Day Air” and Federal Express “Priority Overnight” services and shipped from East Lansing, MI to five destinations: Monterey, CA; Atlanta, GA; Rochester, NY; Portland, OR; and Memphis, TN. A total of 100 trips were monitored and 2394 impact events recorded that measured over the trigger threshold level of 10 G. The data show that a package encounters an average of 24 shock events throughout a one-way trip consisting of 31% drops, 43.6% kicks, and 25.4% tosses. The highest free-fall drop height measured was 1.97 m (77.8 in.). The maximum kick level was 5.91 m/s (233 in./s), and the highest equivalent drop height in a toss was 0.79 m (31.4 in.). The results indicate that 95% of all drops were from less than 0.40 m (16 in.), 95% of all kicks were from less than 3.42 m/sec (135 in./s), and 95% of all tosses were from less than 0.26 m (10.5 in.) equivalent drop height. The packages received 51.1% of total impacts on edges, 42% on corners, and only 6.9% on the six flat faces. Erratum to this paper appears in 24(6).