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981.
The field hockey hit is an important but poorly understood stroke. In this study, we investigated the planarity of the stickface motion during the downswing to better characterize the kinematics and to assess the suitability of planar pendulum models for simulating the hit. Thirteen experienced female field hockey players were filmed executing hits with a single approach step, and the kinematics of the centre of the stickface were measured. A method was developed for identifying how far back from impact the stickface motion was planar. Orthogonal regression was used to fit least-squares planes to the stickface path during sections of the downswing of varying length, with each section ending at impact. A section was considered planar if the root mean square residual between the stickface path and the fitted plane was less than 0.25% of the distance travelled by the stickface during that period. On average, the stickface motion was planar for the last 83 ± 12% of its downswing path, with the length of the planar section ranging from 1.85 m to 2.70 m. The suitability of a planar model for the stickface motion was supported, but further investigation of the stick and arm kinematics is warranted. 相似文献
982.
Many of the socio-cultural lifestyle and dietary changes that take place during Ramadan may affect the risk of injury in athletes, but little evidence is available. The aim of the present study was to examine the effects over two consecutive years of the holy month of Ramadan on injury rates in 42 professional players of a Tunisian top-level professional soccer team. Players were retrospectively organized into fasting and non-fasting groups and monitored for 3 months: 4 weeks before Ramadan, during the month of Ramadan (4 weeks), and 4 weeks after Ramadan each year. During Ramadan, training started at 22.00 h. The circumstances (training/match) and mechanism of injury (traumatic/overuse) were recorded. No significant differences between the three periods were observed for weekly mean training load, training strain, training duration, and Hooper's Index (quality of sleep, and quantities of stress, delayed-onset muscle soreness, and fatigue). Compared with non-fasting players, fasters had a lower (P < 0.05) Hooper's Index and stress during and after Ramadan. No significant difference in injury rates was observed between fasting and non-fasting players. Nevertheless, the rates of non-contact (6.8 vs. 0.6 and 1.1) and training overuse (5.6 vs. 0.6 and 0.5) injuries were significantly higher in fasting players during the month of Ramadan than before or after Ramadan. In conclusion, Ramadan, along with the corresponding changes in nutritional habits, sleeping schedule, and socio-cultural and religious events, significantly increased overuse and non-contact injuries in fasting players despite the fact that the training load, strain, and duration were maintained. 相似文献
983.
Francisco P. Romero Ismael CaballeroJesus Serrano-Guerrero Jose A. Olivas 《Information processing & management》2012
Nowadays, new ways of managing and accessing to health-care information are continuously appearing. Web-based Personal Health Records (web PHRs) have the potential to make data about health-care available to clinicians, researchers and students in different medical contexts and applications. Therefore, the amount of web PHRs accessible through Internet has grown enormously and as a result health-care professionals are currently burdened with more and more data. It’s probable that these data, unfortunately, have not always the adequate levels of quality, making that their work cannot always be as successful as expected. As a way of alleviating this fact, the present work is focused on improving the document filtering results in the context of web PHRs management. To achieve this goal, a new kind of document filtering model is proposed. This model is based on fuzzy prototypes which are defined by means of conceptual prototypes. These prototypes are obtained by using a data quality analysis of documents. This analysis guarantees that filtered information will be relevant enough for the information user. The complete model provides an efficient strategy of document filtering that can be very useful when it is necessary to deal with a constant flow of new information. 相似文献
984.
985.
Drawing on institutional theory, we examine how institutions have influenced technology development trends in the U.S. since the mid-19th century. Based on an inductive analysis of the history of technology development and corporate R&D, we show that both formal and informal institutional rules and constraints played a role in the initial rise of markets for technology, their decline during the early-20th century, and their eventual return at the end of the 20th century. We also find that formal and informal institutions influenced the widespread adoption of in-house R&D labs during the mid-20th century. Our study integrates insights from both the economics and sociology branches of institutional theory. This perspective is particularly useful to analyze historical phenomenon and shifts in trends across long time periods. 相似文献
986.
Meera S. Ghadge Purva P. Naik Bijaynath P. Tiwari Ruprekha M. Hegde Tanaji J. Matale 《Indian journal of clinical biochemistry : IJCB》2012,27(1):97-99
Breast cancer is one of the most frequent malignancies in the world. Available staging procedures to detect breast cancer
are bone scan, chest X-ray, liver ultrasonography, computerized tomography, estimation of tumor markers like carbohydrate
antigen (CA15-3) and carcino embryonic antigen. These procedures are expensive and may not be required in all cases. Out of
70 patients studied, 55 had normal CA15-3 and 15 had elevated levels of Ca15-3. Eight (14.5%) of the 55 patients with normal
CA15-3 had abnormal bone scan. Fifteen patients had CA15-3 levels above the normal range and among these 9 (60%) had abnormal
bone scan. While prime facie it would appear that a high level of CA15-3 correlate with abnormal bone scan, it is also true
that the numbers are small at present and conclusions about the validity of CA15-3 as marker of bone metastasis may be premature. 相似文献
987.
988.
989.
Erich Petushek Chris Richter David Donovan William P. Ebben Phillip B. Watts Randall L. Jensen 《Sports Engineering》2012,15(3):159-166
Quantifying countermovement jump (CMJ) and landing knee flexion angle is important for performance and injury risk assessment. The purpose of the study was to compare electrogoniometer (El-Gon)- and video-derived CMJ and landing knee flexion angle. Twenty-two adults performed three CMJs while knee flexion angle was simultaneously assessed using an El-Gon and video. The average systematic offset (RMSE) of the El-Gon-derived knee flexion angle throughout the entire movement was 7.03°?±?2.69°. Excellent reliability was demonstrated by the El-Gon (ICCavg?=?0.92). Countermovement knee flexion angle, maximum landing knee flexion angle and flexion angle at maximum vertical ground reaction force were 12.0°, 10.9°, and 5.7° higher, respectively, when assessed using El-Gon (p?<?0.001), compared to video. Errors between instruments are likely due to El-Gon crosstalk, misalignment and/or axis determination. The El-Gon is a cost-effective and time-efficient alternative to video analysis for the assessment of knee flexion angle if the error is accounted for and the sensor is precisely attached. 相似文献
990.
Empirical data on the development of interaction, communication, and language in deafblind children is very rare. To fill this gap, a case study was conducted in which the interaction between a teacher and a deafblind boy age 3 years 4 months was analyzed. Sequential analysis of their interaction confirmed some general clinical impressions about interaction with deafblind children, and provided the basis for suggestions on how the interaction pattern might be changed. 相似文献