Markovic, G., D. Dizdar, I. Jukic, and M. Cardinale. Reliability and factorial validity of squat and countermovement jump tests. J. Strength Cond. Res. 18(3):551-555. 2004.-The primary aim of this ...study was to determine reliability and factorial validity of squat (SJ) and countermovement jump (CMJ) tests. The secondary aim was to compare 3 popular methods for the estimation of vertical jumping height. Physical education students (n = 93) performed 7 explosive power tests: 5 different vertical jumps (Sargent jump, Abalakow's jump with arm swing and without arm swing, SJ, and CMJ) and 2 horizontal jumps (standing long jump and standing triple jump). The greatest reliability among all jumping tests (Cronbach's alpha = 0.97 and 0.98) had SJ and CMJ. The reliability alpha coefficients for other jumps were also high and varied between 0.93 and 0.96. Within-subject variation (CV) in jumping tests ranged between 2.4 and 4.6%, the values being lowest in both horizontal jumps and CMJ. Factor analysis resulted in the extraction of only 1 significant principal component, which explained 66.43% of the variance of all 7 jumping tests. Since all jumping tests had high correlation coefficients with the principal component (r = 0.76-0.87), it was interpreted as the explosive power factor. The CMJ test showed the highest relationship with the explosive power factor (r = 0.87), that is, the greatest factorial validity. Other jumping tests had lower but relatively homogeneous correlation with the explosive power factor extracted. Based on the results of this study, it can be concluded that CMJ and SJ, measured by means of contact mat and digital timer, are the most reliable and valid field tests for the estimation of explosive power of the lower limbs in physically active men.
Explosive lower body strength in volleyball is a constant challenge for every coach and physical trainer who is involved in training a team. The concern is mostly important not only due to the ...vertical jump but also due to the movement in the field. During the game of volleyball, because of the small dimension of the court, the first 2-3 steps, the starting steps are crucial in the successful execution of each phase during the game. Methods. To determine the area of interest in a representative volleyball team, we applied two tests using the optojump device, as follows: 15 sec jumps test and 30 sec jumps test. Objective. These two tests were performed at the beginning of the training season in order to see the level of explosive strength parameters Results. These parameters were analyzed for each subject, as well as for the entire tested team. The average height reached by the center of gravity for the entire team during the 15 sec jumps test is 20.1 cm, while the average jumps in the 30 sec jumps test is 16.6 cm. Analyzing the explosive force parameters shows the direction in which the team’s physical training should be designed. Keywords: volleyball, optojump, explosive power
The study purpose was to investigate the relationship between sprint ability at elementary school and leg length, jump height and leg explosive power. Sports coaching starting at the school level, ...where students are led and trained to have a strong, skilled, nimble, and agile mentality, athletic is very appropriate. One factor, specifically leg length (anatomy), jump height, and leg explosive power (physiology) in sprinting, affects an athlete's performance. The method Cross-sectional quantitative descriptive research is the method used in this study. A total of 61 male students between the ages of 10 and 12 made up the research sample. Measurements of leg length, jump height, leg explosive power, and a 40-meter sprint are used to obtain data. The normality test, correlation test, and table presentation were used in the descriptive data analysis. The results The results stated that the average leg length was 83.46 ± 5.43 cm, the average jump height was 17.91 ± 5.52 cm, the average explosive power of leg was 1451.61 ± 399.45 watts, and the average speed was 8.70 ± 1.61 m/s. If the calculated r value is less than the r table value, then there is a very weak correlation between the leg length variable and the speed variable. The results of the correlation test between leg length and speed obtained r count 0.137 and r table 0.254. There is a weak correlation between the leg explosive power variable and the speed variable, is evidenced by the correlation test results between leg power and speed, which were r count -0.369 and r table 0.254. There is a strong correlation between the jump height variable and the speed variable, as evidenced by the correlation value test results between the jump height value and the speed value, which show a correlation coefficient value of -0.715 and a sig value of 0.000, which is smaller than 0.05. According to the study's findings, sprint students at elementary school have a correlation between leg length, leg muscle explosive power, and jump height.
Keywords: Leg length, Explosive Power, Jump Height, and Sprint
Study purpose. Determination of the peculiarities of the manifestation of strength in competitive exercises of highly qualified armwrestlers with different strength abilities.
Materials and methods. ...The study involved the 4 best armwrestlers in the world weighing from 80 to 100 kg (m = 87.50 ± 2.47 kg) in 2017–2020. Four power test exercises have been identified that ensure the performance of a competitive action in armwrestling: flexion of the fingers, stretch with a hammer, hook and bending the hand. Strength indicators in all test exercises were measured with an FL1K 0.5N, 1000N electric strain gauge dynamometer, Kern & Sohn GmbH (China), fixed on the armwrestling table using an author’s block device.
Results. The results of the correlation analysis of the relationships between the studied indicators confirm the presence of a difference in the direction and strength of the relationships between the strength and time characteristics of the efforts of athletes with different strength and speed-strength abilities. Thus, out of 36 correlation indicators, the data of armwrestlers 1 and 2 have 11 modules with very high connection strength (r = 0.926–0.999), of which 7 modules are with time and 4 modules are with force characteristics of efforts. Athletes 3 and 4 also have 3 modules with very strong connections (r = 0.916–0.948) and 8 modules with strong connections (r = 0.739–0.886), of which 7 modules are with strength indicators and 4 modules are related to time characteristics. But the other correlation indicators have very weak (r < 0.29) and weak (r = 0.3–0.5) levels of relationships.
Conclusions. Analysis of the time and force characteristics of the manifestation of force in the process of achieving boundary resistance allows us to clearly establish the genetically determined speed and strength abilities of the explosive, fast and slow force of armwrestlers.
ABSTRACTDobbs, WC, Tolusso, DV, Fedewa, MV, and Esco, MR. Effect of postactivation potentiation on explosive vertical jumpa systematic review and meta-analysis. J Strength Cond Res 33(7)2009–2018, ...2019—The primary aim of this systematic review and meta-analysis was to quantify the magnitude of the effect of postactivation potentiation (PAP) on explosive vertical power while accounting for the nesting of multiple effects within each study. This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Statement (PRISMA). Original research articles published by January 18, 2018, were located using an electronic search of 4 databases and yielded 759 original publications. Data were extracted and independently coded by 2 authors (W.C.D. and D.V.T.). The standardized mean effect size (ES) was calculated by subtracting the pre-treatment mean from the post-treatment mean and dividing by the pooled SD, adjusting for small sample bias. Multilevel random-effects model was used to aggregate a mean ES and 95% confidence interval (CI) for PAP on vertical jump performance. The cumulative results of 179 effects gathered from 36 studies indicate that PAP does not improve vertical jump performance (ES = 0.08, 95% CI −0.04 to 0.21, p = 0.197), with moderate heterogeneity. Moderator analysis indicated that rest intervals between 3 and 7 minutes provided favorable performance outcomes (ES = 0.18, 95% CI 0.05 to 0.31, p = 0.007). Conversely, rest intervals less than 3 minutes (ES = −0.15, 95% CI −0.31 to 0.01, p = 0.052) or performing isometric contractions (ES = −0.52, 95% CI −0.89 to −0.14, p = 0.007) may be detrimental to performance. Meta-regression indicated that rest interval was the only moderator significantly associated with ES (β = −0.04, 95% CI −0.57 to −0.02, R = 14.31%, p < 0.001). When appropriate PAP guidelines are followed, an increase in vertical jump performance may be achieved.
Purpose. To determine the features of the manifestation of strength and speed-strength indicators in the components of the competitive exercise of leading armwrestlers of different weight categories. ...Material and Methods. The study involved 3 of the best armwrestlers in the world in different weight categories: athlete 1 (weight 62 kg; age 39 years) - multiple world champion (Ukraine), athlete 2 (weight 90 kg, age 36 years) - multiple world champion (Ukraine) , athlete 3 (weight 136 kg, age 34 years) – multiple world champion (Ukraine). The strength characteristics of athletes were determined in four test exercises that ensure the performance of a competitive action in armwrestling: flexion of the fingers, stretch with a hammer, hook and bending the hand. These exercises were performed with the left and right hands. Strength indicators in all test exercises were measured with an FL1K 0.5N, 1000N electric strain gauge dynamometer, Kern & Sohn GmbH (China) with an accuracy class of up to 50 g, fixed on a specialized armwrestling table using a specially made an author's block device. In the course of statistical analysis, the following parameters were determined and calculated: maximum (F) and relative (F1 = ƩF / m) strength, kg; total strength index in four strength exercises (ƩF = F1 + F2 + F3 + F4), kg; time to reach maximum strength (Ʃt = t1 + t2 + t3 + t4), s; speed-strength index (J = ƩF / Ʃt), kg*ms-1; average strength, index of four exercises ( = ƩF / 4), kg; total strength gradient of four exercises (Ʃt0,5F), ms; speed-strength index in the first 500 ms (J500 = ƩF500 / Ʃt500), kg*ms-1; time to reach 1 kg force (t1 = Ʃt0.5F / (0.5×F)), ms*kg-1. Results. Athlete 1, weighing 62 kg, reached the maximum value of the strength of the left arm, equal to 181.8 kg, in 4.8 s, and in the right – after 4.4 s and reached 170.0 kg. The speed-force index when reaching maximum strength was, respectively, 0.038 kg*ms-1 and 0.039 kg*ms-1. For athlete 2, weighing 90 kg, the maximum strength values were determined after 5.3 s with the left hand and after 5.5 s with the right hand and, respectively, amounted to 233.8 kg and 260.5 kg. At the same time, the speed-strength index reached 0.044 kg*ms-1 with the left hand, and 0.047 kg*ms-1 with the right hand. The achievements of the maximum strength value of the heaviest athlete 3, weighing 136 kg, of both left and right arms were significantly better and reached 248.1 kg and 275.4 kg, respectively. At the same time, the time characteristics for reaching the limiting force values are relatively low and amounted to 4.9 s and 5.1 s. In this regard, noticeably high speed-strength index values are observed: left arm – 0.051 kg*ms-1; right – 0.054 kg*ms-1. Conclusions. The study made it possible to establish that the heaviest athlete 3 has the highest overall maximum strength, but in the test exercises, which are elements of performing competitive hook and hammer pull movements, the lighter athlete 2 demonstrated a higher result. The lightest athlete 1, whose weight is 62 kg, has a high result in the relative strength indicator. The heaviest athlete 3 has significantly higher levels of explosive, fast, slow and maximum strength and, as a result, a higher speed-strength index, due to which he wins quick victories in competitions. Athletes 1 and 2, who have lower body weight, according to such time characteristics as force gradient, time to reach 1 kg of force, speed-strength indicator at the last second, have respectively better results. This indicates that athletes 1 and 2 achieve their victories in competitions due to these very characteristics.
This study aimed to find out the differences between the effects of plyometric and conventional exercises on the explosive power of the spark. This study used an experimental method where the sample ...is given treatment. The subjects in this study were 4th semester students of the STKIP Setiabudhi Sports Education study program. The sampling technique used cluster random sampling, so a sample of 40 students was obtained. The study was conducted for 14 meetings with a training frequency of twice a week. The sample was given treatment in the form of plyometric training to increase the explosive power of the sickle kick. The data obtained was analyzed using the SPSS version 26 application. The results of the comparison between plyometric and conventional exercises for low hand-foot coordination were reviewed. The study indicated that the value of Qcount = 12.96 exceeded Qtable = 4.90, or Qcount > Qtable, suggesting significant differences, with the plyometric exercise method proving superior to conventional exercise. Further, the results of the comparison of plyometric and conventional exercises were reviewed for high hand-foot coordination and the results showed that the value of Qcount = 6.65 was greater than Qtable = 4.90, or Qcount > Qtable, indicating significant differences favoring the plyometric exercise method over conventional exercise. The plyometric training method and the conventional training method have an influence on the explosive power of the sickle kick. However, the plyometric training method is more influential, effective, and good for the explosive power of the sickle kick than the conventional training method.
The purpose of this study was to determine the relationship between limb length, leg muscle explosive power and the ability to run 100 meters sprint in male students of class X in SMAN 2 Seluma. This ...type of research is multiple correlation research. The population in this study were the sons of class X at SMAN 2 Seluma totaling 65 students. sampling technique is purposive sampling the number of samples is 40 people. The instruments used were leg length measurement, vertical jump test and sprint 100 meterFrom the calculation results, the conclusion in this study is that there is a very strong relationship between leg length and the ability to run sprint 100 meterThere is a very strong relationship between leg muscle explosive power and the ability to run sprint 100 metersthere is a very strong relationship between leg length, leg muscle explosive power and the ability to run sprint in male students of class X at SMAN 2 Seluma.
Aim:
To determine the most effective dose of the box jump exercise for increasing explosive leg muscle strength in adolescents, as measured by vertical jump height.
Methods:
This study is a field ...experimental study using a randomized control group pretest-posttest design by providing different doses of jump-to-box exercise. The experiment was conducted on Buqa’tum Mubarakah Junior High School students in Makassar, Indonesia, on February 16 to August 16, 2022 and obtained a total sample size of 60 male subjects aged 15-16 years. The participants were randomly divided into four experimental groups, each consisting of 15 people who were given jump-to-box exercises with different doses.
Results:
The results of the ANOVA test analysis showed that training with a loading dose of 24 cm and 5 minutes duration had a significant effect on increasing leg muscle explosive power with a p-value = 0.005. The other three groups did not show statistically significant improvements in jump height.
Conclusion:
The jump-to-box exercise with the box height of 24 cm and training duration of 5 minutes resulted in the highest average vertical jumping ability compared to other dose groups. This exercise protocol has an optimal effect on vertical jumping ability and limb explosive power in adolescents compared to other protocols.
This research uses the Survey Research Method, a quantitative research type approach meaning research that is comparative or different. The population and sample in this study were water skiers and ...wakeboard athletes as many as 30 people consisting of male and female athletes. Data collection techniques using tests and measurements: physical condition tests; For leg muscle explosiveness by using a vertical jump measuring instrument and a chronojump. Data analysis using quantitative descriptive analysis techniques, overall The data analysis technique used is a t-test at a significant level of 5%. To obtain the results of this study, which one better results from the explosive power of leg muscles in Water Ski and Wakeboard Athletes of DKI Jakarta Province using Vertical jump and Chronojump? The results of this study showed that: There was a difference in leg explosive power in terms of the use of vertical jump and chronojump tools in Water Ski and Wakeboard athletes with an average value between the two groups, wherein the vertical jump group with an initial test average value of 47.50, the chronojump group with an average value of 27.97. This means that the vertical jump group is better than the chronojump group. However, further research is needed related to the environmental, psychosocial, and psychological factors of athletes and those related to improving athlete performance.