A comparison of isokinetic knee strength and power output ratios between female basketball and volleyball players

Abstract

Purpose. Tests such as the counter movement jump (cMJ) and squat jump (sJ) allow for determining the ratio of maximal power output generated during sJ to cMJ (s/c). The isokinetic peak torque ratio of the hamstrings contracting eccentrically to the quadriceps contracting concentrically (H/Q) is defined as functional H/Q. The purpose of this study was to compare the s/c and functional H/Q between female basketball and volleyball players. Methods. The total of 14 female basketball players (age, 19.8 ± 1.4 years) and 12 female volleyball players (age, 22.3 ± 4.2 years) participated in the study. A piezoelectric force platform was used for the cMJ and sJ. Moreover, isokinetic tests of the hamstrings and quadriceps muscle torque during eccentric and concentric contraction were performed. Results. The results of the s/c and functional H/Q at 90 deg · s -1 /60 deg · s -1 velocities were higher in basketball players (87.3 ± 9.1% and 91.4 ± 9.3%, respectively) than in volleyball players (83.1 ± 9.8% and 83.6 ± 16.5%, respectively). No significant differences in s/c or functional H/Q values between the two groups were found (p > 0.05). Conclusions. Decreasing the s/c may result from an improvement in the power output during cMJ and a better utilization of the stretch-shortening cycle effect. Balancing the functional H/Q through increasing the eccentric hamstrings strength can provide dynamic knee joint stabilization.

The competitive activity structure of highly skilled basketball players on the basis of factor analysis methods

“…According to the authors who studied the competitive activity structure of qualified basketball players using factor analysis [6,8], these methods are quite effective. Problematic questions for the researchers are the rather high complexity of the selection of competitive activity indicators and the interpretation of the results obtained by using methods of factor analysis.…”

“…Such approaches are not completely new, but have high practical and theoretical signifi-cance and involve a number of problems that do not have a final conclusion, as well as common points of view among both scientists and practitioners in the field of team sports games that are very popular and have a spectator interest. Significant scientific studies in this area include the work of Kozina [5], Kozina et al [6], okazaki and rodacki [7], Kabaciński et al [8]. these studies, using the material of team sports games (volleyball, handball) and applying factor analysis methods, investigated the athletes' physical preparedness structure and determined the factor models of game activity.…”

“…A similar methodological principle was employed by Kozina et al [14], who made an attempt to determine the individual characteristics of the complex athletes' preparedness with the help of mathematical modelling and multivariate statistical analysis methods. Hopkins [17] and Koryahin et al [18] proposed an algorithm for selecting the most optimal test tasks for determining the level of various aspects of preparedness of qualified basketball players [8] with the use of multidimensional statistical analysis methods, which is based on the hierarchy of both indicators of athletic preparedness and their significance from the point of view of test theory. A similar study was conducted by Karpowicz and Karpowicz [19] among young Polish basketball players aged 15-16 years observed for a long time.…”

Examination of Balance and Isokinetic Strength in Female Volleyball Players

“…In the literature, it is possible to come across the researches in which the isokinetic knee strength of different sports branches and volleyball players was determined (Cheung, Smith, & Wong, 2012;Kabaciński et al, 2017). In these researches, the focus was mostly on the H/Q ratio.…”

Absolute and relative peak power during pneumatic squat exercise using different percentages of loads in elite soccer players

“…the difference of ± 39% in the maximal peak power between squat exercises with the pneumatic resistance equipment vs. smith machine may be related to improvements in peak power and power endurance owing to the requirement of pneumatic resistance equipment in eccentric muscle actions of the exercise and an increase of the hip and thigh power production during the concentric phase [15,16]. A greater eccentric muscle action in leg muscle contributes to a better transition of the extensor muscles to explosive power [22,23]. the performance improvement may occur by lower limb resistance training and a control of the training load [24].…”