Comparison of Morphological Profiles and Performance Variables between Female Volleyball Players of the First and Second Division in Portugal.

Knowledge of players' anthropometric profiles may contribute to a better understanding of the differences between their performance levels. For example, vertical jump height, which is a major indicator of a volleyball player's performance, is influenced by favorable anthropometric variables. This study's aim was to describe anthropometric profiles of elite female volleyball players competing in the 1st and 2nd divisions in Portugal and to link these profiles with performance skills such as jump height obtained during blocking and spiking actions. Fifty-nine volleyball players were analyzed according to their competitive level, forming three independent groups: GA (n = 20, A1 division, ranked first), GB (n = 21, A1 division, ranked last) and GC (n = 18, A2 division). Anthropometric data collected included body mass and height, arm span, seven skinfolds (triceps, biceps, subscapular, suprailiac, abdominal, thigh and calf), four body perimeters (relaxed brachial, contracted brachial, thigh and calf), and two body diameters (humeral and femoral). Performance data included the height obtained during block and spike actions. Significant differences were found between groups (GA/GB from A1 and GC from A2). Players in the GA had the highest body mass (68.05 ± 6.62 kg, p < 0.05), body height (176.35 ± 6.21 cm, p < 0.05), arm span (177.59 ± 6.09 cm, p < 0.05), lean mass (53.51 ± 4.94 kg, p < 0.05) and vertical jump heights (block: 0.36 ± 0.06 m and spike: 0.43 ± 0.05 m, p < 0.05). As expected, the fat mass percentage of GA players was the lowest (21.30 ± 2.61%). The results suggest that anthropometric profiles of volleyball players may vary according to the competitive level. The higher body mass, body height, arm span, and lean mass presented by GA players in comparison with GC players suggest these variables are important for top-level performance, since these athletes also exhibited higher jump heights. Variables such as height and arm span have a considerable genetic influence and could be important for early talent identification in volleyball. Other variables such as body mass, lean mass and vertical jump performance are more complex, since they also reflect the effects of environmental and training conditions.

Effects of noise on postural stability when in the standing position.

BACKGROUND: Loss of postural stability may result in postural imbalance and can increase the risk of slips and falls in the workplace. OBJECTIVE: This study intended to provide new insight into the effects of noise on postural stability when in the standing position. METHODS: Twenty healthy subjects voluntarily participated in this study. Their postural stability was analysed using a baropodometry platform under 4 different sets of conditions: i) standing position, without any noise and without wearing ear protectors; ii) standing position, without any noise and wearing ear protectors; iii) standing position, with noise and without wearing ear protectors; iv) standing position, with noise and wearing ear protectors. RESULTS: The results showed that noise at different sound frequencies (400, 2000, 4000 and 8000 Hz) at a level of 95-100 dBA did not affect the participants' postural stability when in the standing position. CONCLUSIONS: No significant differences were found in postural balance when participants were exposed to sound with or without ear protectors. Short duration, sensory inputs (i.e. vision) and the absence of physical workloads appear to facilitate postural stability.

Evaluating injury risk in first and second league professional Portuguese soccer: muscular strength and asymmetry.

Strength imbalances between the hamstrings and quadriceps are an essential predictor for hamstring strain in soccer. The study aimed to investigate and compare the muscle strength imbalances of professional soccer players of different performance levels. One hundred and fifty nine senior male professional soccer players from first (n = 75) and second league (n = 84) Portuguese clubs participated in this study. Muscle strength was evaluated with a REV9000 isokinetic dynamometer. Maximal peak torque data were used to calculate quadriceps and hamstrings strength during concentric and eccentric actions, bilateral asymmetry, conventional strength ratios and dynamic control ratios. Second league athletes produced slightly lower conventional strength ratios in the right and left legs (ES = 0.22, p = 0.17 and ES = 0.36, p = 0.023, respectively) compared to the first league athletes. No significant differences were found in dynamic control ratios or in bilateral asymmetry among first and second league athletes. These findings do not show a clear link between the competitive level and injury risk in soccer players. However, some of the differences found, particularly in conventional strength ratios, highlight the importance of performing off-season and pre-season strength assessments to prescribe and adjust individual strength training programs among professional soccer players.

Is it important to know the load mass in lifting tasks to prevent falls?

BACKGROUND: Lifting objects without knowing its weight may result in postural imbalances and be a risk factor for falls. OBJECTIVE: The aim of this study was to examine the influence of the load knowledge in postural balance when lifting different weight loads. METHODS: Thirteen male subjects (23.8 ± 3.1 years; 73.5 ± 7.8 kg; 179.1 ± 7.5 cm; foot length, 25.7 ± 1.2 cm) participated in the study. The effect of the weight overestimation on the postural stability was measured by the Index of Proximity to Stability Boundary (IPSB) and through the anterior-posterior and medio-lateral lengths displacements of the Center of Pressure (CoP). RESULTS: The results showed an increase in the IPSB when the 5 kg lifting task was performed with load knowledge. Moreover, the length of the antero-posterior and medio-lateral CoP displacement was reduced in the 5 kg lift with knowledge. CONCLUSIONS: Results showed that the lack of the loads' knowledge may lead to balance loss. Thus, when the preparation processes are not adequate, picking up similar objects with different loads may increase the risk of fall, mainly when a light weight is suddenly lifted up after a heavy one.

Effect of a short time concentric versus eccentric training program on electromyography activity and peak torque of quadriceps.

The purpose of this study was to examine the effect of an 8-week concentric (CON) versus eccentric (ECC) isokinetic training program on the electromyography (EMG) signal amplitude of vastus medialis (VM), vastus lateralis (VL) and rectus femoris (RF). Also, the isometric (ISO) and dynamic maximum strength of the knee extensors were assessed. Eighteen physically healthy male subjects (age 22 ± 1 years, body height 177 ± 4 cm, body mass 73 ± 7 kg) performed four weeks of unilateral CON isokinetic training for the quadriceps of the dominant leg on a REV9000 dynamometer. At the end of the fourth week, the sample was divided into two groups, with one group performing additional four weeks of unilateral ECC training and the other continuing with CON training. The training sessions consisted of three sets of ten maximal repetitions at a velocity of 60ºs-1, three days per week for eight weeks. The results showed that CON and ECC groups improved the peak torque in all types of contractions. Also, both groups presented increases in the avgEMG for VL, VM and RF. The present investigation showed that CON training elicited increases of the ISO peak torque and VM avgEMG in the CON contraction. Additionally, significant gains were reported after the ECC training on the VM avgEMG in all contractions and RM avgEMG in CON contraction.

Effects of Strength Training Combined with Specific Plyometric exercises on body composition, vertical jump height and lower limb strength development in elite male handball players: a case study.

The purpose of the present study was to identify the effects of a strength training program combined with specific plyometric exercises on body composition, vertical jump (VJ) height and strength development of lower limbs in elite male handball players. A 12-week program with combined strength and specific plyometric exercises was carried out for 7 weeks. Twelve elite male handball players (age: 21.6 ± 1.73) competing in the Portuguese Major League participated in the study. Besides the anthropometric measurements, several standardized jump tests were applied to assess VJ performance together with the strength development of the lower limbs in an isokinetic setting. No significant changes were found in body circumferences and diameters. Body fat content and fat mass decreased by 16.4 and 15.7% respectively, while lean body mass increased by 2.1%. Despite small significance, there was in fact an increase in squat jump (SJ), counter movement jump (CMJ) and 40 consecutive jumps after the training period (6.1, 3.8 and 6.8%, respectively). After the applied protocol, peak torque increased in lower limb extension and flexion in the majority of the movements assessed at 90ºs-1. Consequently, it is possible to conclude that combining general strength-training with plyometric exercises can not only increase lower limb strength and improve VJ performance but also reduce body fat content.

A new notosuchian from the Late Cretaceous of Brazil and the phylogeny of advanced notosuchians.

A new notosuchian crocodyliform from the Late Cretaceous Bauru Group found in the southeastern State of São Paulo (Brazil) is described here. The new taxon, Caipirasuchus stenognathus, is referred as a new species of the recently erected genus Caipirasuchus within the clade Sphagesauridae based on a phylogenetic analysis of basal mesoeucrocodylians. Caipirasuchus stenognathus is represented by an almost complete skull and lower jaw that has autapomorphic characters that distinguish it from other species of Sphagesauridae. These autapomorphies include: maxilla forming part of the orbital margin (absence of lacrimal-jugal contact), nasal with smooth depressions on the posterior region close to the contact with the maxilla and lacrimal, postorbital with posterior palpebral facet that extends posteriorly underneath the ear-flap groove, and a distinct anterior process of the medial flange of the retroarticular process. Additionally, the new taxon lacks autapomorphic features described in other sphagesaurids. The phylogenetic analysis results in a monophyletic genus Caipirasuchus, that is the sister group of a clade fomed by Sphagesaurus huenei, Caryonosuchus pricei, and Armadillosuchus arrudai. Sphagesaurids also include a basal clade formed by Adamantinasuchus navae and Yacarerani boliviensis. Other notosuchian taxa, such as Mariliasuchus amarali, Labidiosuchus amicum, Notosuchus terrestris, and Morrinhosuchus luziae are successive sister taxa of Sphagesauridae, forming a clade of advanced notosuchians that are restricted to the Late Cretaceous of South America. These results contrast with most previous phylogenetic hypotheses of the group that depicted some members of Sphagesauridae as more closely related to baurusuchids, or found Asian (e.g., Chimaerasuchus) or African (Malawisuchus, Pakasuchus) forms nested within advanced notosuchians that are, according to our analysis, endemic of the Late Cretaceous of South America.

A complete skull of an early cretaceous sauropod and the evolution of advanced titanosaurians.

Advanced titanosaurian sauropods, such as nemegtosaurids and saltasaurids, were diverse and one of the most important groups of herbivores in the terrestrial biotas of the Late Cretaceous. However, little is known about their rise and diversification prior to the Late Cretaceous. Furthermore, the evolution of their highly-modified skull anatomy has been largely hindered by the scarcity of well-preserved cranial remains. A new sauropod dinosaur from the Early Cretaceous of Brazil represents the earliest advanced titanosaurian known to date, demonstrating that the initial diversification of advanced titanosaurians was well under way at least 30 million years before their known radiation in the latest Cretaceous. The new taxon also preserves the most complete skull among titanosaurians, further revealing that their low and elongated diplodocid-like skull morphology appeared much earlier than previously thought.

Aspectos sociológicos do acidente do trabalho / Sociological aspects of occupational accidents

Comentam-se os limites da legislaçäo acidentária, discutindo-se brevemente as transformaçöes técnicas e sociais, a partir do momento em que o homem passou a modificar seu ecossistema. Comenta-se também o modelo de prática médica adotado no País, incluindo a medicina preventiva dentro dos objetivos estratégicos de melhores condiçöes de saúde para a populaçäo

Barulho e desempenho: aspectos ergonômicos / Noise and performance: ergonomic aspects

Procura-se estudar a interferência do barulho na transmissäo da informaçäo num sistema cibernético, verificando-se os possíveis danos causados nos sistemas ergonômicos Homem-Homem, Homem-Máquina e Homem-Ambiente. Säo passados em revista os fenômenos fisiológicos inatos do comportamento do aparelho auditivo e suas vias de conduçäo, bem como as transformaçöes psicológicas na esfera mental. As noçöes de carga mental e sua medida mostram a importância da interferência do barulho na tomada de decisöes em tarefas de triagem. Enumeram-se as principais açöes de deterioraçäo do desempenho em tarefas de vigilância, de precisäo e mentais. Mostra-se a açäo de ativaçäo do barulho em outros tipos de tarefas, como as de automatizaçäo, e a reaçäo geral inespecífica ao barulho, conhecida como "reaçäo de alarme"