30 research outputs found
A KINEMATIC ANALYSIS OF FINGER MOTION IN ARCHERY
This paper examines finger motion during the bow string release in archery. METHOD: Fifty-six shots from one athlete were captured with an infrared motion tracking system. Kinematics for index, third and ring fingers were calculated. Two different kinematic variables were defined, related to the proximal interphalangeal joint (PIP) of the third finger: maximum angular velocity (MAX) and minimum angular velocity (MIN). For statistical analysis shots were separated into two groups (very good shots: shots which hit the innermost score area and bad shots: score of 8 or less; shots which achieved a nine or a ten were excluded). A Mann-Whitney test was used. RESULTS: No significant differences were found in the variables MAX and MIN between very good and bad shots (p > 0.05). CONCLUSION: Findings in this study show that there are no significant differences in angular velocity (related to the PIP joint) between very good and bad shots, but that reproducibility of kinematic characteristics are possible crucial factors in archer’s performance
A KINEMATIC ANALYSIS OF THE NAERYO-CHAGI TECHNIQUE IN TAEKWONDO
The purpose of this study was to investigate the influence of selected kinematic parameters on the performance of the naeryo-chagi technique in taekwondo. Performance was quantified by the vertical velocity of the ankle at initial target contact (VIMP). METHOD: A sample of 19 competitive taekwondo athletes (17 males and 2 females) aged from 17 to 30 years (mean age = 19 ± 4), who were able to accomplish a correct naeryo-chagi technique, participated in this study. After warm up, participants were asked to perform several series of five naeryo-chagi kicks with their front leg at a kicking pad which was mounted on a frame at chin height. For data acquisition a motion tracking system comprising eight infrared cameras and a force plate were used. Only that series, which included the trial with the highest ankle velocity at initial target contact, was further processed. RESULTS: Significant differences between the best and worst performed kick of each athlete (p = 0.025) were found for the extension of the hip joint during the pull down phase (EHIP). No significant differences were found for the maximum ankle velocity during the strike out phase (AVSO; p = 0.28). Considering the best trials of each athlete only, Pearson correlation between EHIP and VIMP was significant (r = 0.542; p = 0.017), that between AVSO and VIMP was not (r = 0.354, p = 0.137). CONCLUSION: The magnitude of change of the hip flexion angle during the pull down movement seems to be an important factor for performing a kick featuring high velocity at initial target contact
The effects of a strength and neuromuscular exercise programme for the lower extremity on knee load, pain and function in obese children and adolescents: study protocol for a randomised controlled trial
First records of the introduced slug Deroceras panormitanum (Lessona et Pollonera, 1882) from the Czech Republic (Mollusca: Gastropoda: Agriolimacidae)
First findings of the non-native slug Deroceras panormitanum from the Czech Republic are reported. First anatomically identified specimens were collected in a greenhouse in SW Bohemia. In N Moravia the species was however found in a natural habitat already in 1996
Bythinella hansboetersi Gloer et Pesic, 2006 (Gastropoda: Rissooidea) in Bulgaria: Its morphology, molecular distinctness, and phylogeography
For five populations of Bythinella from Bulgaria the shell, penis, and female reproductive organs are figured and briefly described. 27 sequences of COI (mtDNA), and 14 of ITS-1 (rRNA) are used to infer phylogenetic relationships among the studied populations and five Central European Bythinella species. All five studied populations belong to the same species: B. hansboetersi Glöer et Pestic 2006, which is morphologically and molecularly distinct from B. austriaca earlier reported from Bulgaria. NCA analysis for the COI data revealed a pattern of restricted gene flow with isolation by distance
The second site of Pupilla alpicola (Charpentier, 1837) and the first recent record of Pupilla pratensis (Clessin, 1871) in Poland
The second site of Pupilla alpicola (Charpentier) was found in Poland in 2010. It is a treeless alkaline fen located close to the village of Czarny Dunajec (Nowy Targ region, S. Poland). The site is the north-western extension of the Western Carpathian distribution of the species, being more than 30 km away from the previously known Polish site near Niedzica village and also from its known sites in Slovakia. The first recent record of Pupilla pratensis (Clessin) in Poland was found in the north-eastern most part of Poland close to the border with Lithuania, in the vicinity of the village of Rowele. It is an extension of the species' distribution in NW. Europe and also the eastern most known record of this taxon. Both species are exclusive inhabitants of calcareous fensand fen meadows, highly endangered and mostly isolated, and deserve attention of nature conservation agencies.They seem to be very rare in Poland, because no further population was documented at 25 suitable alkaline fen sites sampled mainly in 2010 and 2011 across the southern and eastern part of Poland
Oxychilus (Mediterranea) hydatinus (Gastropoda: zonitidae) new for Slovakia, with notes on its distribution in Hungary
The first records of Oxychilus hydatinus (Rossmässler, 1838) from Slovakia are reported. The material was identified based on a detailed comparative study of shell morphology and internal structure of penis. The Slovak sites represent the northernmost occurrence of this species
Checklist of the molluscs (Mollusca) of the Slovak Republic
The checklist of 245 mollusc species known so far from the Slovak Republic is presented, plus 11
species limited to greenhouses or thermal waters. Critical comments on species erroneously mentioned in recent
publications from Slovakia are included
Variation in the shell colour and banding polymorphism of Cepaea nemoralis (L.) in rural areas around Wroclaw
105 samples of Cepaea nemoralis (L.) were made in rural locations around the city of Wrocław in 2008-10. Variation in the shell colour and banding polymorphism showed no relationship to habitat, nor were there any large-scale geographical patterns. In some morphs, there were strong frequency correlations between samples close to one another, but these never extended beyond 20 km, and usually involved much shorter distances. Relative to populations within the city, these populations vary more among themselves, but are individually less polymorphic. Linkage disequilibria in common between city and country suggest a common origin. These results suggest that rural populations have a more recent origin, and that they are more isolated from one another than those in the city. A process of recent passive dispersal by humans, with some local spread appears to account for the pattern of variation observed