Test UHCJ20m-Measurement Procedure Standardization and Metric Characteristics Determination.

The purpose of the research study was to standardize the measurement procedure and determine the reliability, homogeneity, and sensitivity of a 20 m unilateral horizontal cyclic jump test (UHCJ20m) whose intentional (assumed) measurement aim is the lower extremities' explosive strength. The subject sample consisted of 31 students from Zagreb University (20.68 ± 1.96 years of age, height 185.16 ± 7.19 cm, body mass 79.48 ± 9.23 kg) actively involved in various sports events. The UHCJ20m test was performed three times using a dominant (take-off) leg with an active rest of 15 min between the repetitions. The results showed that the UHCJ20m test had satisfactory sensitivity and a very high reliability: Cronbach α = 0.95, intraclass correlation coefficient (ICC) = 0.94 and homogeneity average intertrial correlation (AVR) = 0.88. Future research studies should be aimed at determining the metric characteristics of the UHCJ20m test with a population of athletes in sports characterized by start acceleration and maximum speed running.

Performance prediction models based on anthropometric, genetic and psychological traits of Croatian sprinters.

Elite athletes differ from each other in their characteristics according to their discipline. This study aimed to identify performance predictors in elite Croatian sprinters taking into consideration their anthropometric, psychological and genetic characteristics. One hundred and four elite Croatian sprinters (68 males and 36 females) participated in this study. Of them, 38 are currently competing in the 100-metre dash. The others are former sprinters. The participants underwent direct anthropometric assessment. Participants were also tested by means of the Competitive State Anxiety Inventory-2 and for ACE and ACTN3 polymorphisms. Multiple linear regression analysis was applied to identify the best model for performance prediction. Different models were developed for males and females. Anthropometric traits accounted for 44% of the variance in performance for males, 62% for females. Once other traits (psychological for females) were entered into the model, no additional contribution to the variance was observed. The most significant predictors of higher running velocity were bicristal diameter and foot dimensions in males, and leg length and clean one-repetition maximum in females. The findings suggest that performance in sprinters is associated with anthropometric characteristics, with biomechanical implications that may be used to provide a more complete evaluation of sprinters' performance.

Comparison of clinical assessment and multifrequency bioimpedance analysis as methods of estimating volume status in peritoneal dialysis patients - A single-center experience
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INTRODUCTION: Clinical assessment (CA) is frequently used for the evaluation of volume status in peritoneal dialysis (PD) patients despite its subjectivity. Multiple-frequency bioelectrical impedance analysis (MF-BIA) is objective, accurate, and quick, proving to be a promising technique for measuring volume status. The aim of this study was to assess volume status in PD patients using CA and MF-BIA and to compare results. MATERIALS AND METHODS: Incident PD patients were prospectively analyzed between January 1, 2014, and January 1, 2016, at the Clinical Hospital Center of -Rijeka, Croatia. Volume status measurements were performed once a month for 6 consecutive months. The presence of symptoms and signs associated with hyper- or hypovolemia were detected by CA. Euvolemia was defined as a symptom-free state or up to 2 symptoms maximum. Patients lacking up to 1.2 L of volume or with up to 1.2 L in excess were considered euvolemic, as measured by MF-BIA. RESULTS: A total of 45 PD patients were analyzed; 51% were men, 27% were diabetic, the mean age was 52 ± 26 years, and PD duration was 11.5 ± 6.5 months. In comparison to MF-BIA, CA showed a significant difference in detected hypervolemia between baseline and follow-up (p = 0.708 vs. p = 0.01, respectively) and among all measurements (p < 0.01). Contrary to CA, volume status measured by MF-BIA correlated significantly with systolic and diastolic blood pressure (R = 0.29; p ≤ 0.01 and R = 0.26; p ≤ 0.01, respectively). CA showed low sensitivity (0.24) and high specificity (0.92) in detecting hypervolemia. CONCLUSION: MF-BIA is an effective, objective, and safe method for assessing volume status in PD patients. Longitudinal monitoring of body composition changes - including hydration state - leading to adequate therapeutic intervention is a promising and potential application of MF-BIA along with CA.

Body composition and size in sprint athletes.

BACKGROUND: The aims of the present study were to assess competitive sprinters' body size and composition and to determine their impact on performance. METHODS: Ninety-eight competitive male sprinters (100 m) participated in this cross-sectional study. A series of measurements was directly taken and data on muscular strength and power tests were self-reported. Body composition was assessed by skinfold method and somatotype was calculated by the Heath-Carter anthropometric method. Sprinters were classified into three groups depending on their personal best time and comparisons were performed between the athletes in the top and in the bottom tertiles. Relationships between anthropometric traits and performance were assessed by Pearson's correlation coefficients. RESULTS: Top sprinters had significantly greater body mass index, relaxed and contracted upper arm girths, thigh and calf girths, fat free mass and fat free mass index, and lower ectomorphy than the lowest tertile. Strength and power were significantly higher. Personal best time was significantly correlated with several anthropometric traits and indices of lean body mass. CONCLUSIONS: Body size, composition and somatotype differ between performance levels in speed running. Being less ectomorphic, with a greater fat free mass and strength, can explain significant differences in sprinting performances. The results presented in this study provide a point of reference about sprinter characteristics, which can help coaches and sport scientists to improve sprinter performance.

[NONALCOHOLIC FATTY LIVER DISEASE ­ A MULTISYSTEM DISEASE?].

With the increasing incidence of obesity and metabolic syndrome the incidence of nonalcoholic fatty liver ­disease (NAFLD) is increasing as well. These patients have a significant risk of progression to the end-stage liver disease, but also these patients are at increased risk of developing hepatocellular carcinoma. In recent years there is a growing ­number of publications that support the idea that NAFLD is not just a disease that is limited to the liver, but is associated with a number of extrahepatic manifestations. For example, NAFLD increases the risk of type 2 diabetes mellitus, cardiovascular diseases and chronic kidney disease. Consequently NAFLD has become a growing public health problem. A number of sub-specialists as well as primary care physicians should be aware of these potential extrahepatic associations, given the availability of numerous methods for screening in clinical practice. The above approach is important in order to recognize potentially modifiable events in the early stages, and thus manage them and at least prevent the progression of certain diseases.

Differences in Some Kinematic Parameters between Two Qualitatively Different Groups of Pole Vaulters.

The basic aim of this research was to determine the differences of kinematic parameters in two qualitatively different groups of young pole vaulters. With this purpose, a research was conducted in which the video records from a competition were acquired. The sample of entities (N = 71) consisted of successful vaults of 30 pole vaulters, whose attempts were recorded at the European Junior Championship in Novi Sad, held on 23-26th July 2009. The examinees performed the vaults as a part of the elimination competition for the finals, and during the final part of the competition. The age of examinees was from 17 to 19 years, and the span of their best results was from 4.70 to 5.30 meters. The kinematic analysis was conducted according to the standards of APAS procedure (Ariel Performance Analysis System, USA), determining 25 kinematic variables necessary for further analysis. The entities (vaults) were divided into two categories (qualitative classes) based on the expert knowledge. Group 1 consisted of successful vaults up to 4.90 m (N = 46), while group 2 consisted of successful vaults whose height was more than 4.90 m (N = 25). The discrimination analysis determined the parameters differentiating the vaults of different quantitative classes. Also, it was confirmed that the result efficiency in pole vault was primarily determined by the variables defined by motor abilities, as well as the indicators determining the vault performance technique.

The Influence of Anthropometric Characteristics on Kinematic Parameters of Children's Sprinter's Running.

Children's sprinters running differs from the adults' one primarily in their motoric abilities, anthropometric characteristics, physiological and biochemical characteristics, as well as psychological and sociological characteristics. This research's aim was to examine the influence of anthropometric characteristics on kinematic parameters of children's sprinter's running. The sample of variables consisted of variables which determine anthropometric characteristics (14 anthropometric characteristics) and of 5 kinematic parameters'variables of sprinter's running. Kinematic parameters of sprinter's running in the phase of maximal speed have been collected by applying the Optojump technology (Microgate, Italy) and the sprinter's running times were measured every 5 meters on a 50 m lap. The results obtained from the multiple regression analysis between the group of anthropometric characteristics and the 50 m running results indicate that the percentage of fatty tissue is a statistically significant variable with boys, while the same variable with girls is near the limit of statistical significance. In the factor structure of anthropometric characteristics two factors have been set apart with boys and three with girls. The first factor set apart with both boys and girls is the factor of body voluminosity, the second factor with boys is the factor of longitudinal dimensionality, while with girls it is the factor of fatty tissue quantity. The factor of longitudinal dimensionality is the third girls' factor. For most variables a negative correlation has been determined with a higher percentage of fat or a higher quantity of subcutaneous fatty tissue with both boys and girls. Boys having a lower quantity of subcutaneous fatty tissue achieve better results in 50 m running, they have a shorter duration of contact with the pad, a longer duration of the flight phase and a longer step length when compared to boys with a higher quantity of subcutaneous fatty tissue. Boys with a bigger body muscular mass achieve a shorter duration of the contact, a longer duration of the flight and a longer step length. Girls who have a lower quantity of subcutaneous fatty tissue achieve a better 50 m running time, have a shorter duration of contact with the pad and a longer step length. It has been established that taller boys have a longer step length, and longer feet significantly influence the longer duration of contact with the pad and the lowering of the step frequency.

Athletic Engagement and Athletic Identity in Top Croatian Sprint Runners.

The aim of the research was to determine construct validity and reliability for two questionnaires (Athlete Engagement Questionnaire-AEQ and Athletic Identity Measurement Scale-AIMS), applied on elite Croatian athletes-sprinters, as well as the correlations among the dimensions in these measuring instruments. Then, we have determined the differences in the dimensions of sport engagement and sport identity, according to gender, education level and winning medals on international competitions. A total of 71 elite athletes-sprinters (former and still active) are examined, from which 27 (38%) females and 44 (62%) males. The results of factor analyses revealed the existence of dimensions very similar as in the original instruments, which showed moderate to-high reliabilities. A small number of statistically significant correlations have been found between the dimensions of sport engagement and sport identity, mainly in male sprinter runners. Small number of statistically significant differences in the dimensions of sport engagement and sport identity have been found according to the gender, education level and winning medals on the international competitions. The most reasonable explanation of these differences could be given in terms of very similar characteristics of elite athletes on the same level of sport excellence.

Influence of kinematic parameters on pole vault results in top juniors.

The aim of this research was to analyse the kinematic parameters and to ascertain the influence of those parameters on the pole vault result. The entity sample of the research consisted of successful vaults of 30 athletes, whose attempts were recorded at the European Junior Athletics Championships. The examinees performed the vaults as part of the qualification competition for the finale and the finale of the competition itself The examinees were 17-19 years old, and the range of their top results was from 4.90 to 5.30 m. The results of the regression analysis showed a significant influence of the predictor variables on the effective pole vault height. The centre of body mass height was mostly influenced by the following variables: TS - takeoff velocity, LSS - last step velocity, PSS - penultimate step velocity, TAPR - trunk angle at the moment of the pole release. The following variables had lesser, but still a significant influence: CBMDM - centre of body mass distance at the pole release moment, and MCMVV - time of pole straightening. Generally, the information gained by this research indicates the significant influence of the kinematic parameters on the pole vault result. Therefore, the conclusion is that the result efficacy in the pole vault is primarily determined by the variables defined by the motor capabilities, but also by the indicators determining the vault activity realization technique. The variables that define the body position during the pole release (trunk angle and centre of mass distance) have heomost significant influence on the vault performance technique, while the motor capabilities influence the last two run up steps velocity, take off speed and the time of pole straightening.

Influence of kinematic parameters on result efficiency in javelin throw.

The aim of the research was to define the influence of the kinematic parameters in the javelin throw success in the top junior athletes at the European Junior Athletics Championships in Novi Sad. A set, consisting of 17 kinematic variables, was applied on a sample of 16 athletes, and the same variables were registered at the 2009 Novi Sad European Junior Championships. The criteria variable was the achieved throw length (javelin throw). The subjects were represented by 113 successful javelin throws. The results of the chosen kinematic variables correlation analysis showed the existence of multiple significant relations between the observed variables. Based on the observed kinematic variables correlation analysis, the next conclusion can be made: the javelin release speed has the most important role, followed by the fast front support leg placing. The results are expected and logical, and can be used in kinesiology practice, especially in the process of young throwers' technique learning and in development of motor abilities relevant for this athletic discipline.

The effect of intraocular pressure on visual field after trabeculectomy in patients with primary open angle glaucoma.

PURPOSE: To compare the mean intraocular pressure (IOP), peak IOP and percentage reduction in IOP in the first five years following trabeculectomy between the patients with progressed visual field loss and the patients with stable visual fields. MATERIAL AND METHODS: Thirty-six eyes of 36 patients were followed for five years after their first trabeculectomy with tonometry and automated perimetry (Octopus 500EZ, program G1). The rate of change of the visual field was measured by linear regression analysis of the mean sensitivity value (dB) of each field test versus time (month). Based on the statistical significance of the slope of the regression line (Spearman p value of the correlation coefficient less than 0.05), patients were divided into two groups: with significant negative slope of the regression line (group with progressed visual field loss) and with non-significant slope of the regression line (group with stable visual field). The mean IOP values and percentage of IOP reduction at the end of each of the first five years after surgery were compared between the group with progressed field loss and group with stable fields by using Mann-Whitney U test. RESULTS: Patients with progressed visual field loss had higher mean IOP, higher peak IOP and less reduction in pressure after the operation than patients with stable visual field. The mean IOP at end of the two year postoperative period was significantly higher in patients with progressed visual field loss (21.98 +/- 3.38 mmHg) than in those with stable fields (17.48 +/- 4.80 mmHg). The mean percentage reduction in IOP at the end of two year postoperative period was significantly less in patients that showed progression of field loss (21.84%) than in those with stable fields (41.0%). CONCLUSION: Prognosis for further field loss seems to be better if postoperative pressure is at lower levels and greater percent reduction of IOP is obtained after surgery. The data that predict better prognosis is the mean postoperative IOP value of approximately 18 mmHg or less resulting from at least 35% of IOP reduction.

Anthropometric characteristics and gait transition speed in human locomotion.

The purpose of this study was to investigate the relationship between anthropometric parameters and the preferred transition speed (PTS) in human locomotion, in both genders. Previous studies exploring body measures as possible determinants of the PTS were biased toward longitudinal body dimensions, while the relationship between the PTS and transverse body dimensions has so far not been examined. Longitudinal and transverse anthropometric parameters were measured in 48 physical education students (21 males, 27 females), and an exercise test was performed for determination of the PTS. The relationship between the PTS and the anthropometric variables was determined using Pearson product-moment correlations and stepwise multiple regression analysis. Weak to moderate correlations between several body size and body shape variables and the PTS were found. In males, significant negative correlations (p<.05) between transverse body dimensions scaled to body height (calf girth, shoulder, bicristal and bitrochanteric diameters) and the PTS were found (r=-.51 to -.63). In females, calf girth and thigh girth scaled to height were significantly negatively correlated with the PTS (r=-.61 and -.42, respectively; p<.05). The results of the study suggest that gait transition speed in humans is related to both transverse and longitudinal body dimensions, and that sexual dimorphism in body size and shape should be taken into consideration for a proper interpretation of the PTS.

Development of biomotor characteristics and sprint and throw athletic abilities in six- to eight-year-old girls.

The aim of the study was to assess the effect of programmed physical education on biomotor changes in girls, and the impact of these changes on relations between the set of morphological and motor variables, and athletic variables evaluating the sprint and throw abilities. Study sample included 310 six- to eight-year-old girls, elementary school first-graders from the Split area, divided into control group (n = 138) attending regular physical education classes and experimental group (n = 172) attending programmed physical education classes based on the elements of athletics, apparatus gymnastics, games and general preparatory exercises. Relations between the predictor set of variables consisting of 4 morphological measures and 6 motor tests, and the sprint and ball throw criteria were determined by regression correlation analysis at the beginning and at the end of the academic year. Both groups achieved favorable quantitative result improvement between the two measurement points, however, the improvement was considerably more pronounced in experimental group, especially in the motor abilities of coordination, flexibility, movement frequency, and explosive, repetitive and static strength. On final measurement, the number of significant predictors for the criterion variables of sprint and ball throw increased from the initial measurement in both experimental and control group of subjects. In control group, trunk strength, explosive strength and movement frequency as motor abilities and body height as a morphological characteristic were found to be the best result predictors in sprint. In experimental group, coordination, flexibility, static arm strength and trunk strength as motor abilities were the best result predictors in sprint. In the study sample as a whole, explosive strength and trunk strength were identified as the best predictors of ball throw as a criterion variable. In experimental group, it was accompanied by muscle mass development and adipose tissue reduction. Based on comparison of these results and those obtained in previous studies, a new model of work in the athletics events of sprint and throw in elementary school physical education is proposed.