The purpose of this study was to evaluate the intersession and the intrasession reliability of maximal handgrip strength test in young wrestlers. Twenty-seven prepubertal (9.49 ± 0.96yrs) and twenty-seven pubertal (14.60 ± 0.50yrs) male wrestlers performed two assessment sessions separated by one day. Both assessments included a testing protocol consisted of three maximal isometric contractions, on both hands using a hydraulic dynamometer (Jamar). The intersession and intrasession reliability was high for both prepubertal and pubertal wrestlers (ICC = 0.87−0.99). The single trial as well as the best of two and three trials of handgrip strength were slightly less reliable (ICC = 0.87−0.94) than the mean of two and three trials in prepubertal (ICC = 0.95−0.97). The present results indicate that maximum handgrip strength can be measured reliably, using the Jamar dynamometer, in young wrestlers. A single trial as well as the two trials can be used as reliable, less-tiring and less time-consuming methods for the evaluation of handgrip strength than the three trials.
Vassilis Gerodimos and Konstantina Karatrantou
Vassilis Gerodimos, Andreas Zafeiridis, Stefanos Perkos, Konstantina Dipla, Vassiliki Manou and Spiros Kellis
This study examined from childhood to adulthood: (1) the effects of countermovement (use of stretch-shortening cycle-SSC) and arm-swing (AS) on vertical jumping (VJ) performance and (2) the ability to use the SSC and AS during VJ. Male basketball players (n = 106) were divided according to their age into: children (12.0 ± 0.23), young adolescents (14.5 ± 0.41), old adolescents (16.9 ± 0.27), and adults (21.9 ± 0.32). Each participant executed three maximal squat jumps (SJ), countermovement jumps without arms (CMJ) and with arms (CMJA). The contribution of SSC and AS was calculated by the augmentation (difference and percent change) in performance between CMJ and SJ, and CMJA and CMJ, respectively. CMJA performance was significantly (p < .05) higher than CMJ and SJ, and CMJ was higher than SJ within all age-groups. There were no significant differences (p > .05) among children, young and old adolescents, and adults in the percent contribution of SSC and AS to VJ performance. The variability in the contribution of SSC and AS to VJ performance was about twofold higher in children vs. adults. It appears that the ability to use the SSC and AS is not affected by the maturation process in males, trained in basketball.