The authors investigate the ways in which varied postural responses to translating platform perturbations are associated with the variables of strength and power. Twenty-four physically active and 27 sedentary young adults were exposed to a set of postural perturbations at varied velocities (10 and 20 cm/s) and the respective accelerations (6.4 and 6.9 m/s2), constant distance (6 cm), and 4 directions of platform motion (forward, backward, left-lateral, and right-lateral). They also performed maximum voluntary isometric contraction (MVC) and chair rising/chair jumping tests. The analysis of variance revealed significant interaction effect for peak center of pressure displacement, direction by velocity: F3,129= 24.43, p = .002; and direction by acceleration: F3,129= 34.18, p = .001. There were no significant correlations between peak center of pressure displacements and peak force and peak rate of force development measured during MVC in either standing (r = .27-57) or sitting positions (r = .12-51) and peak power during chair jumping (r = .47-.59) in all participants. As such, only a small proportion of variance was explained (9-39%, 3-23%, and 23-41%, respectively). In conclusion, interaction effects indicate that the composition of stimuli strongly influences compensatory responses and this effect is more pronounced in sedentary than in physically active young adults. Nevertheless, the dynamic balance is not associated with muscle strength and power in either group.
- MeSH
- dospělí MeSH
- lidé MeSH
- mladý dospělý MeSH
- postura těla fyziologie MeSH
- posturální rovnováha fyziologie MeSH
- sedavý životní styl MeSH
- svalová síla fyziologie MeSH
- tělesná výkonnost MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
This study compares postural and trunk responses to translating platform perturbations of varied velocities and directions. A group of 18 young and physically active subjects were exposed to a set of postural perturbations at varied velocities (5, 10, 15, and 20 cm/s) and directions of platform movement (forward, backward, left-lateral, and right-lateral). The center of pressure (CoP) displacement measurement, in addition to the trunk motion (representing the center of mass (CoM) displacement), were both monitored. Results identified that the CoP displacement increased from slow to faster velocities of platform motion more widely in both anterior and posterior directions (50.4 % and 48.4 %) as compared to the CoM displacement (17.8 % and 14.9 %). However a greater increase in the peak CoM velocity (70.3 % and 69.6 %) and the peak CoM acceleration (60.5 % and 53.1 %) was observed. The values in the anterior and posterior direction only differed significantly at the highest velocity of platform motion (i.e. 20 cm/s). A similar tendency was observed in the medio-lateral direction, but there were no significant differences in any parameter in the left-lateral and right-lateral direction. The velocity of the platform motion highly correlated with peak velocity (r=0.92-0.97, P<0.01) and moderately with amplitude of trunk displacement (r=0.56-0.63, P<0.05). These findings indicate that the velocity of perturbation alters peak CoM velocity rather than the magnitude of CoM displacement. The effect of the direction of perturbations on the trunk response emerges only at a high velocity of platform motion, such that the peak CoM velocity and peak CoM acceleration are significantly greater in anterior than posterior direction.
- MeSH
- dospělí MeSH
- lidé MeSH
- mladý dospělý MeSH
- posturální rovnováha fyziologie MeSH
- trup fyziologie MeSH
- zdraví dobrovolníci pro lékařské studie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
OBJECTIVE: Postural control is a complex skill based on the interaction of dynamic sensorimotor processes. This study assessed the effect of lateral perturbations on postural re-stabilization regarding lower limb preference. METHODS: A group of 14 physically active individuals (9 male, 5 female) randomly underwent postural perturbations in lateral-left and lateral-right directions at a velocity of 0.2 m.s-1 and a platform shift of 6 cm. Perturbation to the preferred limb side (PS) was noted when the contralateral body movement was primarily controlled by the preferred limb and perturbation to the non-preferred limb side (NS) was noted when the contralateral body movement was primarily controlled by the non-preferred (stabilizing) limb. Prior to, during and after the perturbation centre of pressure (CoP) was registered using a computerized motor driven FiTRO Dynamic Posturography System based on force plate (Fitro Sway Check) with a sampling rate of 100 Hz. The basic stabilographic parameters of peak displacement (Peak 1), peak-to-peak displacement (Peak 2), time to peak displacement (Time 1), time to peak-to-peak displacement (Time 2) and re-stabilization time (Time 3) were analyzed. RESULTS: Results showed significantly larger Time 3 on PS than on NS (2.81 ± 1.32 s and 1.73 ± 1.10 s; p=0.02). However, there were no significant differences in other parameters between PS and NS. CONCLUSION: It may be concluded that the observed shorter re-stabilization time at NS was due to the stabilization role of the non-preferred limb.
- MeSH
- dolní končetina fyziologie MeSH
- dospělí MeSH
- funkční lateralita fyziologie MeSH
- lidé MeSH
- mladý dospělý MeSH
- postura těla fyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Monitoring of heart rate variability (HRV) and oxygen saturation is important in medicine as well as training of top athletes. Our work describes the implementation of pulse oximetry functions in sensor system for measurement of biosignals. It allows us to follow along even pulse biosignal and the flow rate of blood.
Je prezentován případ 42leté ženy operované ve 23 letech pro ileus podezřením na Crohnovu chorobu. Pooperační vyšetření resekátu ukázalo však aktinomykózu a nemocná byla léčena antibiotiky s dobrým efektem. Po mnoha letech se objevily příznaky ileu a nemocná byla znovu operována. V tomto případě byla v operačním resekátu potvrzena Crohnova choroba, což předoperační vyšetření nezjistilo. Konečná diagnóza byla stanovena až vyšetřením operačního preparátu, protože ostatní testy selhaly.
We present a case of 42-years old woman, operated in age of 23 because of obstruction, with a suspicion of Crohn's disease. Unexpectedly, postoperative pathological examination revealed actinomycosis and the patient received antibiotics with a good effect. Many years later, according to the recurrence of symptoms of obstruction the patient was operated again. This time, a pathological evaluation of postoperative issues confirmed Crohn's disease, however preoperative tests did now allow to establish the reason of obstruction. Our case shows difficulties in diagnosis of Crohn's disease and actinomycosis. The final diagnosis was established after postoperative pathological examination and all other tests usually helpful in recognition of Crohn's disease were ineffective.
- MeSH
- aktinomykóza chirurgie mikrobiologie MeSH
- Crohnova nemoc chirurgie komplikace MeSH
- diferenciální diagnóza MeSH
- ileus etiologie chirurgie mikrobiologie MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
