THE RELATIONSHIP BETWEEN TECHNICAL AND TACTICAL ELEMENTS OF DIRECT POINTS WITH REGARD TO THE QUALIFICATIONS FOR THE 2018 VOLLEYBALL WOMEN’S WORLD CHAMPIONSHIP

The goal of this paper is to analyse the relationships and differences among volleyball teams, participants of the 2018 World Cup in Japan, divided into three categories by their final standings (1st to 4th place, 5th to 8th place and others), based on the elements of situation-based efficiency. For the purposes of this paper, information from the official match reports (p 2 report) related to the way of winning points in the match was used, and these data were analysed using the program Volleyball Information System (VIS). The data obtained were analysed in relation to the team category and the outcome of the match. The data were obtained using descriptive and comparative statistical procedures. The survey sample includes all the women’s volleyball championship games played in Japan in 2018. Based on the final standings, the teams were divided into three groups: 1) the teams who reached the 3rd stage of the tournament (6 teams, from 1st to 6th place); 2) the teams that finished the competition in phase 2 (10 national teams, ranking 7th to 16th); 3) national teams that finished the competition in phase 1 (8 national teams, ranking 17th to 24th). The results obtained indicate that the teams had an equally good performance of the block and serve game elements; statistically these were not significant for the match outcome, but they rather serve as an aid for the overall game and for the final outcome of the match. The results of this research also highlight the spike as the key element affecting the positive end result of the match. It is important to emphasize that the opponent errors are a factor that depends exclusively on the opponent, but they also determine the overall score of the winning team

The content and composition of humus in pseudogleys of slopes and plains in South Mačva and Pocerina

The scope of this paper was to examine the influence of two subtypes of pseudogley soil (of planes and of slopes) and three different land uses (forest, grassland and arable land) on the content and composition of humus in south Mačva and Pocerina. The humus content was determined by dichromate method, and hu­mus components were measured using the method proposed by Kononova and Bel­cikova. The studied soils are mostly characterized by low humus content. Humus content is significantly higher in pseudogleys of plains compared to pseudogleys of slopes. Pseudogleys under grass and crops have significantly lower content of humus compared to the pseudogleys under forest. Important characteristic of hu­mus composition of surface horizon is dominant portion of fulvic over humic acids. Pseudogleys of plains have statistically significant higher amount of humic acids. The composition of humus is significantly different in pseudogley under forest compared to pseudogleys under grass and crops: it has more fulvic acids, less humin, and lower Ch:Cf ratio. Changes in pseudogley land use have produced better humus quality

Isometric strength in volleyball players of different age

Physical abilities modelling has a profound connection with long-term athlete development and talent identification. There is not enough data to support evidence about age-related changes in volleyball players’ isometric strength. This study aimed to define the age-related model of volleyball players multidimensional muscles’ contractile characteristics. The participants were divided according to gender (male n = 112, female n = 371) and according to age into four groups: under 15 (U15), under 17 (U17), under 19 (U19), and under 21 (U21) years old. Participants performed three isometric strength tests: handgrip, lumbar extensors, and ankle extensors. Maximal force and rate of force development results from all three tests were transformed into a single Score value as a representation of contractile potentials using principal component analysis. The main findings were that Score values of both genders showed significant differences between age groups (male: F = 53.17, p < 0.001Female: F = 41.61, p < 0.001). Trends of those yearly changes were slightly more balanced for female subjects (3.9%) compared to male subjects (6.3%). These findings could help in strength training adjustments when working with volleyball players of a certain age, and enable coaches to detect ones that stand out positively, considering them as strong in regard to their age