1036 Int. J. Morphol., 32(3):1036-1042, 2014. Lumbar and Abdominal Muscles Isometric Potential in Volleyball Cadets Potencial Isometrico de Músculos Lumbares y Abdominales en Cadetes de Voleibol Zoran Bogdanovic * ; Miroslav Smajic ** ; Damjan Jaksic ** ; Zoran Milosevic ** ; Borislav Obradovic ** ; Aleksandra Gogic *** ; Hadzi Milos Vidakovic * ; Milija Ljubisavljevic **** ; Vesko Draskovic ***** ; Svetlana Visnjic ****** ; Hasim Mekic * ; Ratko Stankovic ******* ; Goran Ivancic ******** & Stevo Popovic ********* BOGDANOVIC, Z.; SMAJIC, M.; JAKSIC, D.; MILOSEVIC, Z.; OBRADOVIC, B.; GOGIC, A.; VIDAKOVIC, H. M.; LJUBISAVLJEVIC, M.; DRASKOVIC, V.; VISNJIC, S.; MEKIC, H.; STANKOVIC, R.; IVANCIC, G. & POPOVIC, S. Lumbar and abdominal muscles isometric potential in volleyball cadets. Int. J. Morphol., 32(3):1036-1042, 2014. SUMMARY: Given that a volleyball game requires a certain level of individual anthropological characteristics of young volleyball players to successfully act on situational conditions, and that interdisciplinary approach in the science study is the principal methodological orientation, subject of study in the field of sports is the anthropological status. The aim of this study was to analyze the possible differences in spinal lumbar and abdominal muscles isometric potential of prospective male and female. Sample included 42 subjects (15 male and 27 female subjects), male and female volleyball players, the cadet selection of Serbia, aged 14±0.5 years. Isometric muscle potential assessment was conducted using four standardized motor movement tasks, covering the following areas: static contraction of the flexors of the torso, static contraction of the extensors of the torso, static contraction of the left flexor of the torso, and static contraction of the right flexor of the torso. In addition to the descriptive statistics used, as basis statistics, the t-test for independent samples was used, to compare the mean values of parameters measured in two different groups of athletes – volleyball players (girls – boys). Descriptive indicators of the sample suggest greater values of deep spinal muscles isometric potential with boys in all study variables. Study results gained by the t-test of independent samples indicate that statistically significant difference exists between their mean results in variables of trunk flexor static contractions and trunk extensor static contractions, at the level 0.001. With other two variables, the values indicate that difference between genders is not significant but accidental. The results of this study regarding static contraction of the right and left lateral flexors of the torso show the lack of statistical significance between male and female cadet volleyball players. KEY WORDS: Muscle Strength; Trunk; Volleyball Players. INTRODUCTION Structure of motor requests which are characteristic for a volleyball game, consists of frequent changes of direction, numerous jumps, spike jumps etc. (Hadzic et al., 2012). The above-mentioned characteristics require adequate preparation and high performance in terms of sporting techniques and specific physical preparation (Micoogulları et al., 2012). On the other hand, in the area of motor movement there are three basic forms of muscle strain expression, i.e. manifestation of muscular energy (potential): isometric muscle potential, ballistic muscle potential and repetitive muscle potential. Isometric muscle potential is expressed through the static mode that is reflected in the ability of enduring and maximum maintaining of the muscle strength (Akpinar et al., 2012) while there is no movement and muscle belly approximation. Typical motor activities for this mode of expressing the strength are various endurance, balance, standstill, holding movement or great load positions. Mechanisms of strength manifestation, * State University of Novi Pazar, Department of Biomedical Sciences, Novi Pazar, Serbia. ** University of Novi Sad, Faculty of Sport and Physical Education, Novi Sad, Serbia. *** Military Medical Academy, Institute for Scientific Information, Belgrade, Serbia. **** Ministry of Interior, Internal Affairs Sector, Novi Beograd, Serbia. ***** Alfa University, Faculty of Sports Management, Belgrade, Serbia. ****** Center for Sports, Recreation and Physical Education “Studio No1”, Belgrade, Serbia. ******* University of Nis, Faculty of Sport and Physical Education, Nis, Serbia. ******** Futsal Club “Tvdrava”, Novi Sad, Serbia. ********* University of Montenegro, Faculty for Sport and Physical Education, Niksic, Montenegro.