Body composition and functional abilities in terms of the quality of professional ballerinas.

The objective of this research was to determine the variability of the sample of professional ballerinas in the space of characteristics of their body composition and some functional characteristics according to the requirements of their roles in ballet. The sample of examinees was comprised of 30 professional ballerinas, members of the Croatian National Theatre Ballet (15 soloists and 15 members of the corps de ballet). The data showed that the soloists were characterized by a significantly larger knee diameter, significantly lower thickness of skin folds on the trunk and the lower fat body mass percentage, as well as by greater grip strength. Aerobic capacity was only moderately more developed than in fit people who participated in physical exercising because of recreational reasons, and there were no differences between soloists and the members of the corps.

Biomechanical analysis of the lumbar spine.

Physiological mobility of the lumbar spine, as a very important feature of this spinal segment biomechanics, has been defined, i.e., physiological instability has been proven on a sample of 35 fresh cadaveric human lumbar spine specimens which were tested in experimental conditions of both centric and eccentric static loads. The presence of physiological instability or physiological mobility of the lumbar spine in the form of so called relative oblique or tangential shifts was already been numerically quantified. The lumbar spine is continuously deformed through the action of static centric and eccentric loads ranging from 0-1000 N(ewton). Using a very sensitive method for detecting the lumbar spine deformities, based on measuring the angle of deflection of the laser beam on the screen, angular shifts of the spinal vertebrae can be defined within the sensitivity range of 0 degree to 1 degree (degree) with a standard error of +/-0.1 degree.

Volume and vascularity of the yolk sac studied by three-dimensional ultrasound and color Doppler.

The aim of our study was to assess the volume of the gestational sac and yolk sac throughout the first trimester of pregnancy, and to establish the relationship between the yolk sac volume measurements and vascularity visualization rates. Eighty women with uncomplicated singleton pregnancies between 5 and 12 weeks were evaluated by three-dimensional and color Doppler ultrasound (Combison 530, Kretztechnik). Regression analysis revealed exponential rise of the gestational sac volume with gestational age throughout the first trimester. An exponential rise of the yolk sac volume was noticed between gestational weeks 5 and 8, followed by gradual increase of the yolk sac volume between the gestational weeks 8 and 10. After reaching the plateau from 10 to 11 weeks, yolk sac volume started to decrease. The highest visualization rates for the yolk sac vessels were obtained between gestational weeks 7 and 8. When yolk sac reached the maximum size between 10 and 11 weeks, reduced vascularity was demonstrated. Three-dimensional ultrasound allowed estimation of the gestational sac and yolk sac volumes throughout the first trimester of pregnancy. Both of these measurements seem to be useful prognostic parameters for the pregnancy outcome. The combination of functional and volumetric data provides much useful information on early human development.

Three-dimensional transvaginal ultrasound improves measurement of nuchal translucency.

The aim of the study was to correlate intra-observer reproducibility of the nuchal translucency measurements by two-dimensional and three-dimensional transvaginal ultrasound. Examinations were performed on 120 women undergoing ultrasound screening at 10 to 14 weeks' gestation. They were examined by two experienced ultrasonographers using both methods two times consecutively. Statistical analysis for the assessment of intra-observer reproducibility was paired t-test. Nuchal translucency measurements were obtained in 100% of cases with three-dimensional sonography compared to only 85% with two-dimensional sonography. Better intra-observer reproducibility was obtained for three-dimensional than for two-dimensional ultrasound. Three-dimensional transvaginal ultrasound improves accuracy of nuchal translucency measurement allowing appropriate mid-sagittal section of the fetus and clear distinction of the nuchal region from the amniotic membrane.