Coordinative patterns require experience and learning to be acquired, producing movements that offer efficient solutions to various situations and involving certain degree of variability. This coordination variability implies functionality in movement, but it can be impacted by the type of sport practice from early years. The purpose of this work is to analyze the coordination variability and coordination patterns in a specific action such as single-leg landing in children practicing gymnastics, volleyball and non-sporting children. Thirty children (15 girls) performed 10 successful trials of single-leg landing from a height of 25 cm. A motion capture system (9 cameras) was used to capture 3D thigh and shank kinematics. To identify the significant effect of children's groups on coordination and coordination variability during single-leg landing, one-dimensional Statistical Parametric Mapping (SPM) was used. Regarding the coordination patterns, in the frontal plane, during the attenuation phase of single-leg landing, the control group exhibited a higher frequency of Anti-Phase with proximal dominancy compared to the sport groups (i.e., gymnastics, and volleyball). In addition, in the sagittal plane during the second peak phase, volleyball players exhibited a higher coordination variability than the gymnastics. The children in the control group showed a greater frequency of antiphasic movements, which indicates the influence of training at an early age, being a determining factor in the increase or not of variability.
- MeSH
- bérec fyziologie MeSH
- biomechanika MeSH
- dítě MeSH
- gymnastika * MeSH
- lidé MeSH
- motorické dovednosti fyziologie MeSH
- pohyb MeSH
- psychomotorický výkon fyziologie MeSH
- volejbal * MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
PURPOSE: To examine the influence of growth and maturation in the trajectory of stretch-shortening cycle capability. METHOD: Using a mixed-longitudinal design, absolute and relative leg stiffness and reactive strength index (RSI) were measured 3 times over a 3-year period in 44 youth team-sport players. Maturation was determined as maturity offset and included within the Bayesian inference analysis as a covariate alongside chronological age. RESULTS: Irrespective of age and maturation, there was no change in absolute leg stiffness, however relative leg stiffness decreased over time. Maturation and age reduced this decline, but the decline remained significant (Bayesian factor [10] = 5097, model averaged R2 = .61). The RSI increased over time and more so in older more mature youth players (Bayesian factor [10] = 9.29e8, model averaged R2 = .657). CONCLUSION: In youth players who are at/post peak height velocity, relative leg stiffness appears to decline, which could have an impact on both performance and injury risk. However, RSI increases during this period, and these data reinforce that leg stiffness and RSI reflect different components of stretch-shortening cycle capability. Practitioners should consider these differences when planning training to maximize stretch-shortening cycle capability during growth and maturation in athletes on the developmental performance pathway.
- MeSH
- Bayesova věta MeSH
- bérec fyziologie MeSH
- kosterní svaly fyziologie MeSH
- lidé MeSH
- longitudinální studie MeSH
- mladiství MeSH
- sport pro děti a mládež MeSH
- sportovci * MeSH
- svalová kontrakce * MeSH
- svalová síla MeSH
- týmové sporty MeSH
- Check Tag
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Although a number of different methods have been proposed to assess the time to stabilization (TTS), none is reliable in every axis and no tests of this type have been carried out on children. The purpose of this study was thus to develop a new computational method to obtain TTS using a time-scale (frequency) approach [i.e. continuous wavelet transformation (WAV)] in children. Thirty normally-developed children (mean age 10.16 years, SD = 1.52) participated in the study. Every participant performed 30 single-leg drop jump landings with the dominant lower limb (barefoot) on a force plate from three different heights (15cm, 20cm and 25cm). Five signals were used to compute the TTS: i) Raw, ii) Root mean squared, iii) Sequential average processing, iv) the fitting curve of the signal using an unbounded third order polynomial fit, and v) WAV. The reliability of the TTS was determined by computing both the Intraclass Correlation Coefficient (ICC) and the Standard Error of the Measurement (SEM).In the antero-posterior and vertical axes, the values obtained with the WAV signal from all heights were similar to those obtained by raw, root mean squared and sequential average processing. The values obtained for the medio-lateral axis were relatively small. This WAV provided substantial-to-good ICC values and low SEM for almost all the axes and heights. The results of the current study thus suggest the WAV method could be used to compute overall TTS when studying children's dynamic postural stability.
The number and type of landings performed after blocking during volleyball matches has been related to the potential risk of ACL injury. The aim of the present study was to determine whether gender affects the frequency of specific blocking landing techniques with potential risk of ACL injury from the perspective of foot contact and subsequent movement after the block used by volleyball players during competitive matches. Three matches involving four female volleyball teams (fourteen sets) and three matches involving four male volleyball teams (thirteen sets) in the Czech Republic were analyzed for this study. A Pearson chi-square test of independence was used to detect the relationship between gender and different blocking techniques. The results of the present study showed that gender affected single-leg landings with subsequent movement in lateral direction and double-leg landings. Although the total number of landings was lower for male athletes than for female athletes, a larger portion of male athletes demonstrated single leg landings with a subsequent movement than female athletes. Single leg landings with a subsequent movement have a higher potential risk of ACL injury.
- MeSH
- bérec fyziologie MeSH
- biomechanika MeSH
- kompetitivní chování fyziologie MeSH
- lidé MeSH
- motorické dovednosti fyziologie MeSH
- noha (od hlezna dolů) fyziologie MeSH
- pohyb fyziologie MeSH
- poranění předního zkříženého vazu patofyziologie prevence a kontrola MeSH
- rizikové faktory MeSH
- sexuální faktory MeSH
- studie pohybu a času MeSH
- videozáznam MeSH
- volejbal zranění fyziologie MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
The purpose of this study was to determine the relation between posturally increased intra-abdominal pressure and lower/upper esophageal sphincter pressure changes in patients with gastroesophageal reflux disease. We used high resolution manometry to measure pressure changes in lower and upper esophageal sphincter during bilateral leg rise. We also examined whether the rate of lower and upper esophageal sphincter pressure would increase during leg raise differentially in individuals with versus without normal resting pressure. Fifty eight patients with gastroesophageal reflux disease participated in the study. High resolution manometry was performed in relaxed supine position, then lower and upper esophageal sphincter pressure was measured. Finally, the subjects were instructed to keep their legs lifted while performing 90-degree flexion at the hips and knees and the pressure was measured again. Paired t-test and independent samples t-test were used. There was a significant increase in both lower (P < 0.001) and upper esophageal sphincter pressure (P = 0.034) during leg raise compared to the initial resting position. Individuals with initially higher pressure in lower esophageal sphincter (>10 mmHg) exhibited a greater pressure increase during leg raise than those with initially lower pressure (pressure ≤10 mmHg; P = 0.002). Similarly individuals with higher resting upper esophageal sphincter pressure (>44 mmHg) showed a greater pressure increase during leg raise than those with lower resting pressure (≤44 mmHg; P < 0.001). The results illustrate the influence of postural leg activities on intraesophageal pressure in patients with gastroesophageal reflux disease, indicating by means of high resolution manometry that diaphragmatic postural and sphincter function are likely interrelated in this population.
- MeSH
- bérec fyziologie MeSH
- dolní jícnový svěrač fyziologie MeSH
- dospělí MeSH
- gastroezofageální reflux patofyziologie MeSH
- horní jícnový svěrač fyziologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- manometrie MeSH
- postura těla MeSH
- senioři MeSH
- svalová kontrakce fyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- autologní štěp MeSH
- bércové vředy * diagnóza ošetřování terapie MeSH
- bérec fyziologie patofyziologie MeSH
- destičkový růstový faktor * fyziologie MeSH
- fibroblasty fyziologie MeSH
- granulační tkáň fyziologie MeSH
- hojení ran fyziologie MeSH
- kotník fyziologie patofyziologie MeSH
- lidé MeSH
- plazma bohatá na destičky * MeSH
- regenerace kůže s využitím plazmy trendy využití MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- separace buněk metody MeSH
- trombocyty fyziologie metabolismus MeSH
- výsledek terapie MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
PURPOSE: Dynamic phosphorus magnetic resonance spectroscopy ((31)P MRS) during and after acute exercise enables the noninvasive in vivo determination of the mitochondrial capacity of skeletal muscle. Nevertheless, the lack of standardization in experimental setups leads to significant variations in published values of maximal aerobic capacity, even in the population of healthy volunteers. Thus, in this study, we aimed to assess the impact of the ergometer type (pneumatic and mechanical resistance construction), radiofrequency (RF)-coil diameter, and different magnetic field strengths (3 and 7 T) on the metabolic parameters measured by dynamic (31)P MRS during a plantar flexion isotonic exercise protocol within the same group of healthy volunteers. METHODS: Dynamic (31)P MRS measurements of the calf muscle in 11 volunteers (mean age, 36 ± 13 yrs; mean BMI, 23.5 ± 2.5 kg/m(2)), on a 3 T MR system with a custom-made mechanical ergometer in the first research laboratory (RL1) and on 3 and 7 T MR systems equipped with a commercial pneumatic ergometer in the second research laboratory (RL2), were performed at three different workloads. RF-coils differed slightly between the sites and MR systems used. The repeatability of the experimental protocol was tested in every setup. The basal concentrations of phosphocreatine (PCr), exercise-induced depletion of PCr (ΔPCr), initial PCr resynthesis rate (VPCr), and mitochondrial capacity (Qmax) were calculated and compared between the research sites and field strengths. RESULTS: High repeatability of the measurement protocol was found in every experimental setup. No significant differences at any workload were found in these metabolic parameters assessed at different magnetic field strengths (3 T vs 7 T), using the same ergometer (in RL2) and a similar RF-coil. In the inter-research laboratory comparison at the same field strength (3 T), but with using different ergometers and RF-coils, differences were found in the concentration of PCr measured at rest and in the drop in PCr signal intensity. These differences translated into difference in the value of mitochondrial capacity at a workload of 15% of maximal voluntary contraction (MVC) force (0.45 ± 0.16 mM/s vs 0.31 ± 0.08 mM/s, in the RL1 and RL2, respectively). CONCLUSIONS: Metabolic parameters measured during exercise challenge by dynamic (31)P MRS do not depend upon the magnetic field strength used. For multicenter studies with different ergometers, it is important to set the same workload, measurement, and evaluation protocols, especially when the effects of very mild exercise (15% MVC) are to be compared. However, a higher workload (24% MVC) decreases the influence of imperfections and intersite differences for the assessed value of maximal mitochondrial capacity.
- MeSH
- bérec fyziologie MeSH
- cvičení fyziologie MeSH
- design vybavení MeSH
- dospělí MeSH
- ergometrie přístrojové vybavení metody MeSH
- fosfokreatin metabolismus MeSH
- isotonická kontrakce fyziologie MeSH
- izotopy fosforu MeSH
- kosterní svaly metabolismus MeSH
- lidé MeSH
- magnetická rezonanční spektroskopie přístrojové vybavení metody MeSH
- magnetické pole MeSH
- mitochondrie metabolismus MeSH
- reprodukovatelnost výsledků MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- multicentrická studie MeSH
- práce podpořená grantem MeSH
- Klíčová slova
- skok, svalový výkon, jumping mechanography, mechanografie, QCT, poskok na jedné noze,
- MeSH
- absorpční fotometrie MeSH
- antropometrie MeSH
- bérec fyziologie MeSH
- biomechanika MeSH
- denzitometrie MeSH
- dítě MeSH
- elektrická impedance MeSH
- kosterní svaly * fyziologie MeSH
- kosti a kostní tkáň fyziologie MeSH
- kostní denzita * MeSH
- lidé MeSH
- mladiství MeSH
- počítačová rentgenová tomografie MeSH
- pohyb fyziologie MeSH
- pohybová aktivita * fyziologie MeSH
- svalová síla - dynamometr MeSH
- svalová síla * fyziologie MeSH
- tělesná námaha fyziologie MeSH
- tělesná výkonnost fyziologie MeSH
- zátěžový test * metody přístrojové vybavení MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mladiství MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
Proper subtraction and visualization of contrast-enhanced blood vessels in lower extremities using computed tomography angiography (CTA) is based on precise masking of all non-contrasted structures in the area, and it is the main prerequisite for correct diagnosis and decision on treatment for peripheral arterial occlusive disease (PAOD). Because of possible motion of patients during the CTA examination, precise elimination of non-contrasted tissues, including bones, calcifications, and soft tissue, is still very challenging for lower legs, that is, from knees to toes. We propose novel registration-based framework for detection and correction of the motion in lower legs, which typically occurs between and during CTA pre-contrast and post-contrast acquisitions. Within the framework, two registration cores are proposed as alternatives, and resulting CTA subtraction images are compared with Advanced Vessel Analysis considered one of the reference commercial tools among clinical applications for CTA of lower extremities. The CTA subtraction images of 55 patients examined for PAOD are evaluated visually by four expert observers on the Philips Extended Brilliance Workspace using four criteria assessing the overall robustness of tested methods. According to the complex evaluation, the proposed framework enabled valuable improvements of CTA examination of lower legs.
- MeSH
- algoritmy MeSH
- bérec fyziologie radiografie MeSH
- digitální subtrakční angiografie metody MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- počítačová rentgenová tomografie metody MeSH
- počítačové zpracování obrazu metody MeSH
- pohyb fyziologie MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
In contemporary science, the analysis of human walking is extensively used. The prediction of leg motion, as well as rehabilitation, can be usable for orthosis and prosthesis programing. Our work is focused on predicting of human walking by angle-angle diagrams, also called cyclograms. The applications of cyclograms in conjunction with artificial intelligence offers wide area of applications in medicine. But until now, this approach has not been studied or applied in practice.
- MeSH
- analýza hlavních komponent MeSH
- bérec fyziologie MeSH
- bioinženýrství metody MeSH
- biologické modely MeSH
- biomechanika MeSH
- chůze fyziologie MeSH
- infračervené záření MeSH
- koleno fyziologie MeSH
- kotník fyziologie MeSH
- kyčel fyziologie MeSH
- lidé MeSH
- neuronové sítě MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
