The aim of this cross-sectional study was to examine relationships of external load variables between beach and indoor volleyball amongst individual positions on the team. The movements of eight beach and fourteen indoor female volleyball players were recorded during elite playoff matches; in total, 2,336 three-dimensional trajectories were analyzed. Time-outs and intervals between rallies or sets were excluded from active play time. In both beach and indoor volleyball, 80% of rallies lasted up to 10 s, and players covered 4.5 to 10 m of court during 60% of rally play. Differences in dependent variables of external load were found between independent variables of sports and player positions (p < 0.05). The distance covered in beach volleyball rallies and Player LoadTM parameters was significantly higher by up to 23%. The unstable court surface with sand in beach volleyball elevated explosive Player LoadTM (accelerations in all three orthogonal planes of motion higher than 3.5 m/s3) in beach volleyball players compared to those of players on stable flooring in indoor. While beach volleyball blocker and defender positions showed no significant difference in parameters between each other, they differed in all parameters when compared to player positions in indoor volleyball. Indoor blocker and libero reached higher loads than setter, outside and opposite positions in various parameters. Factors that influence external load include the larger relative court areas covered by each player in beach volleyball, complexity of players' roles, and game strategy. This data adds to the knowledge of elite match demands in female volleyball. Specified agility-drill distances and times are essential for training optimization and must be supported by scientific observation. Researchers, coaches, and conditioning specialists should find this helpful for achieving a higher degree of training regulation.

• MeSH
• lidé MeSH
• operantní podmiňování MeSH
• průřezové studie MeSH
• volejbal * MeSH
• výbušné látky * MeSH
• zrychlení MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

We examined the compositional associations between the intensity spectrum derived from incremental acceleration intensity bands and the body mass index (BMI) z-score in youth, and investigated the estimated differences in BMI z-score following time reallocations between intensity bands. School-aged youth from 63 schools wore wrist accelerometers, and data of 1453 participants (57.5% girls) were analysed. Nine acceleration intensity bands (range: 0-50 mg to ≥700 mg) were used to generate time-use compositions. Multivariate regression assessed the associations between intensity band compositions and BMI z-scores. Compositional isotemporal substitution estimated the differences in BMI z-score following time reallocations between intensity bands. The ≥700 mg intensity bandwas strongly and inversely associated with BMI z-score (p < 0.001). The estimated differences in BMI z-score when 5 min were reallocated to and from the ≥700 mg band and reallocated equally among the remaining bands were -0.28 and 0.44, respectively (boys), and -0.39 and 1.06, respectively (girls). The time in the ≥700 mg intensity band was significantly associated with BMI z-score, irrespective of sex. When even modest durations of time in this band were reallocated, the asymmetrical estimated differences in BMI z-score were clinically meaningful. The findings highlight the utility of the full physical activity intensity spectrum over a priori-determined absolute intensity cut-point approaches.

• MeSH
• cvičení * MeSH
• dítě MeSH
• index tělesné hmotnosti MeSH
• lidé MeSH
• mladiství MeSH
• sedavý životní styl * MeSH
• školy MeSH
• zrychlení MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

While the existing research provides a wealth of information about the static properties of RTK receivers, less is known about their dynamic properties, although it is clear that the vast majority of field operations take place when the machine is moving. A new method using a MRA for the evaluation of RTK receivers in movement with a precise circular reference trajectory (r = 3 m) was proposed. This reference method was developed with the greatest possible emphasis on the positional, time and repeatable accuracy of ground truth. Four phases of the measurement scenario (static, acceleration, uniform movement and deceleration) were used in order to compare four different types of RTK receiver horizontal operation accuracy over three measurement days. The worst result of one of the receivers was measured at SSR = 13.767% in dynamic movement. Since the same "low-cost" receiver without an INS unit had SSR = 98.14% in previous static measurements, so it can be assumed that the motion had a very significant effect on the dynamic properties of this receiver. On the other hand, the best "high-end" receiver with an INS unit had SSR = 96.938% during the dynamic testing scenarios. The median values of the deviations were always better during uniform movements than during acceleration or braking. In general, the positioning accuracy was worse in the dynamic mode than in the static one for all the receivers. Error indicators (RMSerr and Me) were found several times higher in the dynamic mode than in the static one. These facts should be considered in the future development of modern agricultural machinery and technology.

• MeSH
• pohyb těles MeSH
• pohyb MeSH
• roboticky asistované výkony * MeSH
• záznamy jako téma MeSH
• zrychlení MeSH
• Publikační typ
• časopisecké články MeSH

Nowadays, gait assessment in the real life environment is gaining more attention. Therefore, it is desirable to know how some factors, such as surfaces (natural, artificial) or dual-tasking, influence real life gait pattern. The aim of this study was to assess gait variability and gait complexity during single and dual-task walking on different surfaces in an outdoor environment. Twenty-nine healthy young adults aged 23.31 ± 2.26 years (18 females, 11 males) walked at their preferred walking speed on three different surfaces (asphalt, cobbles, grass) in single-task and in two dual-task conditions (manual task-carrying a cup filled with water, cognitive task-subtracting the number 7). A triaxial inertial sensor attached to the lower trunk was used to record trunk acceleration during gait. From 15 strides, sample entropy (SampEn) as an indicator of gait complexity and root mean square (RMS) as an indicator of gait variability were computed. The findings demonstrate that in an outdoor environment, the surfaces significantly impacted only gait variability, not complexity, and that the tasks affected both gait variability and complexity in young healthy adults.

• MeSH
• chůze (způsob) * MeSH
• chůze * MeSH
• lidé MeSH
• mladý dospělý MeSH
• rychlost chůze MeSH
• trup MeSH
• zrychlení MeSH
• Check Tag
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

The article deals with the measurement of dynamic effects that are transmitted to the driver (passenger) when driving in a car over obstacles. The measurements were performed in a real environment on a defined track at different driving speeds and different distributions of obstacles on the road. The reaction of the human organism, respectively the load of the cervical vertebrae and the heads of the driver and passenger, was measured. Experimental measurements were performed for different variants of driving conditions on a 28-year-old and healthy man. The measurement's main objective was to determine the acceleration values of the seats in the vehicle in the vertical movement of parts of the vehicle cabin and to determine the dynamic effects that are transmitted to the driver and passenger in a car when driving over obstacles. The measurements were performed in a real environment on a defined track at various driving speeds and diverse distributions of obstacles on the road. The acceleration values on the vehicle's axles and the structure of the driver's and front passenger's seats, under the buttocks, at the top of the head (Vertex Parietal Bone) and the C7 cervical vertebra (Vertebra Cervicales), were measured. The result of the experiment was to determine the maximum magnitudes of acceleration in the vertical direction on the body of the driver and the passenger of the vehicle when passing a passenger vehicle over obstacles. The analysis of the experiment's results is the basis for determining the future direction of the research.

• MeSH
• automobily * MeSH
• dopravní nehody MeSH
• dospělí MeSH
• krční obratle MeSH
• lidé MeSH
• řízení motorových vozidel * MeSH
• zrychlení MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

We developed a swing arm device for acoustic measurement of food texture, which resolved difficulties of food texture evaluation. The device has a structure of balance-style and a probe in the device is moved downward along with motion of swing arm according to the balance of weights at both ends of the swing arm. The probe was inserted into a food sample. The device measured displacement and acceleration of the probe on food fracture by probe insertion with high precision until the probe stops inserting into a food sample. Using the displacement and acceleration of the probe on fracture, we calculated three parameters to determine food texture. Energy texture index (ETI) which is probe kinetic energy of acoustic vibration was evaluated by the vibration on food fracture. Audible energy texture index (aETI) could be introduced as food texture perceived by human sense of hearing, which was obtained by multiplying ETI by human hearing sensitivity. It was found that the ETI and aETI can be used for measurement of characteristic food texture detected at a tooth and perceived in brain, respectively. Food friction index (FFI) to explain the friction strength of a probe against a food sample was theoretically formulated under the condition of probe motion in the device. FFI was found to be useful not only for crispy food like biscuit but for soft food. The measured FFI indicated characteristic of smoothness of probe insertion into food sample. PRACTICAL APPLICATIONS: The swing arm device can be used to estimate food texture by measuring probe vibration energy on food fracture. Energy texture index (ETI) and Audible energy texture index (aETI) are introduced into measurements of food with crispness which emits sounds on fracture by probe insertion. ETI is an index to estimate probe vibration energy, while aETI is one to estimate food texture by human sense of hearing that was corrected by human hearing sensitivity as human hearing sensitivity is highest around sound frequency ranging from 1,000 to 4,000 Hz. Food friction index (FFI) was also obtained by the device to evaluate smoothness of probe insertion into a food sample. ETI, aETI, and FFI can be useful parameters for food texture of water melon, pear, persimmon, apple, cookie, potato chips, and biscuit. FFI is especially suitable for evaluation of soft food such as banana, avocado, mango, melon, peach, pudding, or bread.

• MeSH
• akustika * MeSH
• analýza potravin přístrojové vybavení   metody   MeSH
• design vybavení MeSH
• kinetika MeSH
• lidé MeSH
• manipulace s potravinami přístrojové vybavení   metody   MeSH
• sluchové testy MeSH
• teoretické modely MeSH
• vibrace MeSH
• zrychlení MeSH
• zvuk MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

PURPOSE: It is well known that postural stability is influenced by visual stimuli. The influence of saccadic eye movement on postural control has been described, however, a specific response of different body segments has not been studied yet. Therefore, the aim of this study was to assess the effect of horizontal and vertical saccadic eye movements on postural stability with specific focus on upper trunk, lower trunk and lower limbs movement variability and complexity. METHODS: Eighteen elderly participants (age 70.3 ± 7.7 years) stood in bipedal stance in three visual conditions - horizontal saccades, vertical saccades and fixation. Accelerometers were attached to their lower back, sternum and shanks. Movement variability of each body segment was described by root-mean-square and sample entropy of acceleration. RESULTS: The results of the present study revealed significant influence of saccadic eye movements on anterior-posterior and vertical shanks, and vertical lower trunk movement variability described by root-mean-square. CONCLUSIONS: The correlations between results of the observed segments showed segment-specific variability patterns but generalised complexity pattern.

• MeSH
• biomechanika MeSH
• entropie MeSH
• lidé MeSH
• lidské tělo * MeSH
• neparametrická statistika MeSH
• pohyb MeSH
• postura těla fyziologie   MeSH
• sakadické oční pohyby fyziologie   MeSH
• senioři MeSH
• zrychlení MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Metaxas, T, Mandroukas, A, Michailidis, Y, Koutlianos, N, Christoulas, K, and Ekblom, B. Correlation of fiber-type composition and sprint performance in youth soccer players. J Strength Cond Res 33(10): 2629-2634, 2019-The aim of this study was to examine the correlation between muscle fiber type and sprint performance in elite young soccer players of different age groups of the same team. Twenty-eight young players participated in this study (group U15, n = 8; group U13, n = 9; and group U11, n = 11). Anthropometric assessments, acceleration (10 m), and Bangsbo modified sprint test (30 m) were performed. Muscle biopsies were obtained from the vastus lateralis, and after that, fiber-type composition was determined by immunohistochemistry. No significant correlations were found between the sprint test and muscle fiber distribution for the groups U13 and U11 (p > 0.05). Also, no correlations were found between cross-sectional areas in the types of fibers with the sprint test in all groups (p > 0.05). A positive correlation was found between type I fibers and the performance in the acceleration test (10 m) (r = 0.77, p < 0.05) was found only in group U15 and a negative correlation between type IIA fibers and the performance in the acceleration test (10 m) (r = -0.89, p < 0.05). The correlations were observed only in group U15, which may indicate that the duration and the intensity of the soccer systematic training can affect the plasticity of the muscle fibers. Specific soccer training in youth is one of the factors that can affect fiber-type plasticity. The specific training programs and status of U15 are more intensive, and the exercises are oriented more to improve physical fitness.

• MeSH
• antropometrie MeSH
• běh fyziologie   MeSH
• čtyřhlavý sval stehenní cytologie   MeSH
• cvičení fyziologie   MeSH
• dítě MeSH
• fotbal fyziologie   MeSH
• lidé MeSH
• mladiství MeSH
• plasticita buňky MeSH
• sportovní výkon fyziologie   MeSH
• svalová síla MeSH
• svalová vlákna typu I cytologie   fyziologie   MeSH
• svalová vlákna typu II cytologie   fyziologie   MeSH
• zátěžový test MeSH
• zrychlení MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

The article focuses on designing methods for quantitative assessment of the postural stability in a quiet stance by measuring segments of the appendicular skeleton, namely upper and forearms by inertial measurement units (IMU). Although an array of quantitative analysis methods assessing data of postural stability in the quiet stance exist by measuring the head and trunk movement, these methods have not been used to date to assess the behavior of appendicular skeleton segments, namely the upper limbs. The applicability of methods assessing arm movement during the quiet stance has been verified by comparing the values of healthy subjects performing various stance tasks. The tests determined the quantitative evaluation of acceleration measured on individual anatomical axes. The quantities included: the volume of a convex polyhedron (PV), the volume of confidence ellipsoid (EV) and average velocity (AV) obtained by plotting three accelerations against each other. The most important findings in this study concern significant differences of PV and AV between dominant and non-dominant upper extremities and significant differences of EV, PV and AV between the data measured with a subject';s eyes closed and open. Higher values of indicators were in the non-dominant extremities when subjects were measured with closed eyes. Statistically significant differences between dominant and non-dominant arm movements were documented in PV and AV cases. This is due to the PV calculation being more sensitive to random deviations, i.e. the range of measured data, since the polyhedron bounds all the measured data, as opposed to the method, where the ellipse bounds only 95% of the measured data. In the case of the AV method, it is due to higher sensitivity to movements corresponding with arm tremors; the AV calculation relates not only to the range of measured data but, above all, to the intensity of data changes in the segment measured in a particular space and time interval. These conclusions demonstrate that it is possible to apply the proposed methods in the assessment of arm movement during a quiet stance since the differences between individual stance tasks and the dominant and non-dominant arms in specific cases of quiet stance have been identified. These conclusions also indicate a potentially more extensive medical application of the proposed quantitative data evaluation obtained from IMU, for example, within the rehabilitation process of injured appendicular skeleton segments. The use of cheaper IMU methods in mobile phones or watches can be of significant benefit in measuring the segmental movement of the appendicular skeleton in quiet stance. The methods outlined in this paper have potential in the field of telemedicine.

• MeSH
• kineziologie aplikovaná metody   MeSH
• lidé MeSH
• mladý dospělý MeSH
• paže MeSH
• posturální rovnováha * MeSH
• výzkum MeSH
• zrychlení MeSH
• Check Tag
• lidé MeSH
• mladý dospělý MeSH
• Publikační typ
• práce podpořená grantem MeSH

OBJECTIVES: This retrospective study aimed to analyze the trend of mortality due to thoracic aortic ruptures caused by deceleration injuries that occurred within the catchment area of Hradec Kralove University Hospital. MATERIALS AND METHODS: The study sample comprised 175 patients who had sustained thoracic aortic ruptures caused by deceleration injuries and were transported to Hradec Kralove University Hospital in 2009-2014. The small proportion of patients enrolled in this retrospective study were diagnosed and treated at the emergency department (ED). However, the overwhelming majority of the sample comprised of patients who died at the accident scene and later underwent an autopsy at the Institute of Forensic Medicine in our hospital. RESULTS: Of 175 patients, 150 underwent an autopsy. Of these, 139 individuals (79%) died at the incident scene, and 11 (6%) were transported to the ED and later died of their injuries. A total of 36 patients were admitted to the hospital; 29 were admitted primary (11 later died), and 7 were transferred. No deaths occurred in the group of secondary admissions. Thus, 31% of all patients hospitalized died following transport to the hospital. Of 175 patients, 15% (or 69% of all hospitalized patients) survived their injuries. Among patients who died as a result of thoracic aortic injury, no unexpected deaths were recorded (i.e., no deaths among patients with survival probability more than 50% = PS > 0.5). CONCLUSION: Our results suggested that the lethality of thoracic aortic injuries might be minimized by transporting triage-positive patients directly to trauma centers. Accurate diagnoses and treatments were supported by admission chest X-rays, a massive transfusion protocol, and particularly, CT angiography, which is not routinely included in primary surveys. An additional prognostic parameter was clinical collaboration between an experienced trauma surgeon, an interventional radiologist, and a vascular or thoracic surgeon.

• MeSH
• aorta thoracica diagnostické zobrazování   zranění   MeSH
• dopravní nehody mortalita   statistika a číselné údaje   MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• rentgendiagnostika MeSH
• retrospektivní studie MeSH
• ruptura aorty diagnostické zobrazování   epidemiologie   etiologie   mortalita   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• traumatologická centra statistika a číselné údaje   MeSH
• zpomalení škodlivé účinky   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Hongkong MeSH