Field-testing
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36 stran
- Klíčová slova
- rodina, plánování rodiny, ženské lékařství, porodnost,
- NLK Obory
- gynekologie a porodnictví
- veřejné zdravotnictví
- NLK Publikační typ
- publikace WHO
Purpose: Assisted jumping can supplement resistance training and traditional plyometric training to increase vertical jump performance. However, as coaches may choose to make field-based decisions based on lab-based research, this study determined whether a field-based assisted jumping set-up results in different ground contact times (CT), take off forces (TOF), flight times (FT), and impact forces (IF) compared to a lab-based set-up. Methods: Eighteen active males (24.8 ± 3.0 yr; 178.8 ± 7.8 cm; 77.8 ± 7.8 kg) performed two sessions of assisted jumping: one with each hand holding a commercially available resistance band (1m) that was attached to a pull-up bar (FIELD), and the other with assistance from a custom-built system of ropes, pulleys, and long (3 m) elastic bands (LAB). With each set-up, subjects performed five sets of five countermovement jumps on a force plate. Each set was performed with either bodyweight (BW), 90, 80, 70, or 60% of BW, which was achieved by either grabbing higher or lower on the bands during FIELD, or by being pulled upward via a full-body harness during LAB. The order of each visit was counter-balanced, and the order of jumps within each visit was quasi-randomized. Data from the 90, 80, 70, and 60% trials for each set-up were then expressed relative to the data of BW jumps, and these relative values were then used for analysis. Results: CTFIELD was less than CTLAB at 80, 70, and 60%. FTFIELD was greater than FTLAB at 90 and 80%, but FTLAB became greater at 60%. TOF and IF remained unchanged during LAB, but TOFFIELD was consistently less than TOF during BW, with IFFIELD generally being greater than IFLAB. Conclusion: If the purpose of assisted jumping is to spend less time on the ground without decreasing force, systems with finite adjustments and longer bands like LAB should be used. However, shorter bands similar to FIELD may also be used; but due to the larger variability of assistance throughout the range of motion, such systems may alter the neuromuscular characteristics of the jump in other ways that should be investigated in future research.
- Publikační typ
- časopisecké články MeSH
Introduction: Ice hockey is a power-speed sport played on ice. The surface specification is very different from a normal surface, so it is important to look for the most appropriate measurements and specific off-ice tests that would better define ice-hockey performance. Therefore, the main purpose of this research was to determine the relationship of rate of force development (RFD) in back squat with commonly used off-ice and on-ice tests. Methods: The research involved 15 junior ice-hockey players (181.8 ± 4.1 cm; 80.7 ± 8.8 kg; 18.4 ± 0.9 yrs) playing in the highest competition of Czech hockey. Players performed all tests in one day divided into 2 blocks - off-ice block (OFF) in the morning and on-ice block (ON) in the afternoon, respectively. The OFF contained 30 m sprint test with 15 m split (SP15; SP30), plyometric tests (broad jump - BJ; countermovement jump - CMJ), and a velocity squat protocol (VSP). Finally, in the ON was performed speed and coordination tests - 30 m forward skating with 15 m split (FW15 and FW30); 30 m backward skating with 15 m split (BW15 and BW30); Weave agility test (WAT); Transition test (TT) and Pro-agility test (PAT). Results: No significant results were found between RFD and coordination tests (TT, WAT, PAT) and CMJ. The significant correlations were found between RFD40kg and SP30 (r = -.865; p < .01) and BJ and RFD40kg, respectively (r =.649; p < .05). However, as the back squat loads increase, the correlation strength decreases between RFD and SP30 (r = -.677; p < .01 for RFD50kg and r = -.560; p < .05 for RFD60kg). Moreover, the strong degree of correlation were observed between RFD40kg and FW15 (r = -.699; p < .05) and also FW30 (r = -.705; p < 0.05). Conclusion: The results of the study show a significant relationship between the RFD and commonly used off-ice and on-ice tests.
36 s. : il. ; 32 cm
Pulzná elektroforéza (PFGE- Pulsed-Field Gel Electrophoresis) je metodika, ktorá slúži na delenie dlhých fragmentov DNA v elektrickom poli, ktoré má premenlivý charakter. V stálom elektrickom poh sa fragmenty DNA väčšie ako 50 kilobáz pohybujú rovnakou rýchlosťou a nedajú sa rozlíšiť. Pri pulznej elektroforéze sa smer elektrického poľa periodicky a rovnomerne mení a fragmenty DNA teda putujú nielen priamo, ale aj do strán a dochádza k ich lepšiemu rozdeleniu. Takto sa dajú rozlíšiť aj fragmenty o veľkosti niekoľkých megabáz. Pulzná elektroforéza sa využíva na mapovanie genómov vyšších aj nižších organizmov. Veľmi široké využitie má v mikrobiológii, kde sa používa na typizáciu kmeňov rozličných baktérií porovnávaním elektroforetických proffilov genómovej DNA poštiepenej reštrikčnou endonukleázou s nízkou frekvenciou štiepenia. Využíva sa pritom polymorfizmus dĺžky reštrikčných fragmentov. Mikroorganizmy rôzneho druhu samozrejme poskytnú rozdielne elektroforetické profily. Identické organizmy budú mať identické profily. Organizmy príbuzné ich majú podobné, ale nie identické. Tieto porovnania sa využívajú aj v epidemiologických štúdiách. Po PIGL analýze viacerých vzoriek sa porovnaním ich elektroforetických profilov dá rozhodnúť, či ochorenie vyvolal ten istý kmeň alebo nie. Toto môže byť veími nápomocné v hľadaní zdroja epidémie a sledovaní jej šírenia. Sledujú sa najmä mikroorganizmy dôležité z hľadiska nozokomiálnych nákaz a patogény vyskytujúce sa v potravinách. Takisto sa dá sledovať genetický vývoj mikroorganizmu - hlavné typy, ktoré kolujú v populácii, čo môže byť účinné aj pri prípravách vakcín.
Pulsed-field gel electrophoresis was developed for separating and analyzing of long DNA fragments in alternating electric field. In homogenous electric field, fragments longer than 50 kb run as a broad, unresolved band with high mobility. PFGE separated the DNA by periodicaly changing the direction of electric field. DNA molecules are moving „zig-zag´´ through the gel and they can be better separated. Fragments of several megabases can be resolved using this method. PFGE can be used for genome mapping of microorganisms as well as higher organisms. In microbiology, PFGE is a standard method for typization of bacteria. Comparision of electrophoresis profiles after digestion od DNA from bacterial isolates with restriction endonuclease is a very useful epidemiologists tool. Geneticaly identical organisms have the same PFGE profiles, different strains have different profiles. Related strains have also similar electrophoretic profiles. This enables to determine if the outbreaks are caused by the same strain of microorganism, to locate the source of outbreak and to monitor the spread of the microorganism. The most followed-up are nosocomial and the food-borne pathogens. PFGE can be also used for monitoring genetic evolution of the microorganism and the most prevalent types which circulate in population. This can be very useful for preparation of vaccines.
