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1.
Irwin G Kerwin DG 《Sports biomechanics / International Society of Biomechanics in Sports》2007,6(2):131-144
This study focused on identifying the most effective skill progression for developing the longswing on high bar in men's artistic gymnastics. Building on previous work by Irwin and Kerwin, in which a method to rank progressions based on their angular kinematics was developed, this study aimed to use the method to quantify similarities in inter-segmental coordination between selected progressions and the longswing on high bar. Video images of four members of the UK men's national gymnastics squad performing three series of five longswings and eight progressions were recorded at 50Hz. Two-dimensional direct linear transformation techniques were used to determine the real-world coordinates from the digitized data. Inter-segmental coordination of the hip and shoulder joints during the functional phases of the longswing was assessed using continuous relative phase. Similarity between the longswing and each progression was represented by a "specificity score", which was also used to rank the progressions. Each progression's specificity score was calculated by combining a "difference score" (root mean squared difference between the continuous relative phase profiles of the longswing and the progression) and a "variability score" (standard deviation of the continuous relative phase profiles for each progression). The progressions that were most similar to the longswing included the looped bar longswing and layaway swing down (ranked 1st and 2nd), with specificity scores of 9% and 10% respectively. In contrast, the least similar progressions were the looped bar "no action" longswing (51%) and pendulum swing (63%) (ranked 7th and 8th). Establishing effective skill learning pathways is recognized as a key component of the coaching process and ranking progressions based on their specificity score provided a mechanism to identify progressions with similar inter-segmental coordination profiles to the key skill on the high bar, the longswing. 相似文献
2.
Myat Noe Hsu Rongcong Luo Kerwin Zeming Kwek Yong Chen Por Yong Zhang Chia-Hung Chen 《Biomicrofluidics》2015,9(5)
The poor solubility of many newly discovered drugs has resulted in numerous challenges for the time-controlled release of therapeutics. In this study, an advanced drug delivery platform to encapsulate and deliver hydrophobic drugs, consisting of poly (lactic-co-glycolic acid) (PLGA) nanoparticles incorporated within poly (ethylene glycol) (PEG) microgels, was developed. PLGA nanoparticles were used as the hydrophobic drug carrier, while the PEG matrix functioned to slow down the drug release. Encapsulation of the hydrophobic agents was characterized by fluorescence detection of the hydrophobic dye Nile Red within the microgels. In addition, the microcomposites prepared via the droplet-based microfluidic technology showed size tunability and a monodisperse size distribution, along with improved release kinetics of the loaded cargo compared with bare PLGA nanoparticles. This composite system has potential as a universal delivery platform for a variety of hydrophobic molecules. 相似文献
3.
Williams G Irwin G Kerwin DG Newell KM 《Sports biomechanics / International Society of Biomechanics in Sports》2012,11(1):20-33
The purpose of this study is to provide evidence of technique changes during learning a sports-specific skill, the looped bar longswing (LLS). Thirteen male participants with no previous high bar experience took part in a training study. Kinematic data were collected using a CODA motion analysis system (200 Hz) during eight weekly testing sessions. Analyses focused on the amplitude of swing and the functional phase (FP) actions, defined by the rapid flexion to extension of the shoulders and extension to flexion of the hips as the performer passed through the lower vertical. Three groups were identified based on the number of sessions it took each participant to perform the LLS (G1: most successful, G2: intermediate, and G3: least successful). All participants were able to significantly increase swing amplitude over the training period (p < 0.05). For each participant the hip FP started significantly: later for G1, earlier for G2, and did not change for G3. Extension actions at the shoulders were dissimilar to those reported for elite gymnasts performing the longswing. The FP of the hips provides a mechanism to distinguish between the learners of different skill levels. The study has provided support for a single-subject design when investigating technique changes during learning. 相似文献
4.
George B. Cunningham Sheranne Fairley Lesley Ferkins Shannon Kerwin Daniel Lock Sally Shaw Pamela Wicker 《Sport Management Review》2018,21(1):1-6
The purpose of this article is to add to the conceptual discussion on eSport, analyze the role of eSport within sport management, and suggest avenues for future eSport research. The authors suggest that debates surround the degree to which eSport represents formal sport, and disagreements likely stem from conceptualizations of sport and context. Irrespective of one’s notion of eSport as formal sport, the authors suggest the topic has a place in sport management scholarship and discourse. Such a position is consistent with the broad view of sport adopted by Sport Management Review, the perspective that eSport represents a form of sportification, and the association among eSport and various outcomes, including physical and psychological health, social well-being, sport consumption outcomes, and diversity and inclusion. Finally, the authors conclude that eSport scholarship can advance through the study of its governance, marketing, and management as well as by theorizing about eSport. 相似文献
5.
Michael Barnes Robert G. Kelly Maureen Kerwin 《Library Collections, Acquisitions, and Technical Services》2010,34(2-3):57-65
Identifying and evaluating the oldest published content held by the library using a set of transfer criteria provided a means to systematically evaluate and, if necessary, move rare or unusual content into a more secure location. The process enabled us to correct cataloging errors, identify and address items with condition issues, be familiar with the library's unique holdings and finally, to identify and add content distinctly associated with EMU's history to the University Archives and Special Collections. 相似文献
6.
Sprint push-off technique is fundamental to sprint performance and joint stiffness has been identified as a performance-related variable during dynamic movements. However, joint stiffness for the push-off and its relationship with performance (times and velocities) has not been reported. The aim of this study was to quantify and explain lower limb net joint moments and mechanical powers, and ankle stiffness during the first stance phase of the push-off. One elite sprinter performed 10 maximal sprint starts. An automatic motion analysis system (CODA, 200 Hz) with synchronized force plates (Kistler, 1000 Hz) collected kinematic profiles at the hip, knee, and ankle and ground reaction forces, providing input for inverse dynamics analyses. The lower-limb joints predominately extended and revealed a proximal-to-distal sequential pattern of maximal extensor angular velocity and positive power production. Pearson correlations revealed relationships (P < 0.05) between ankle stiffness (5.93 ± 0.75 N x m x deg(-1)) and selected performance variables. Relationships between negative power phase ankle stiffness and horizontal (r = -0.79) and vertical (r = 0.74) centre of mass velocities were opposite in direction to the positive power phase ankle stiffness (horizontal: r = 0.85; vertical: r = -0.54). Thus ankle stiffness may affect the goals of the sprint push-off in different ways, depending on the phase of stance considered. 相似文献
7.
Knowledge of external forces acting on an athlete is often required to study performance and injury mechanisms, but direct
measurements are difficult to obtain. While transducers in the rings cables typically measure external forces experienced
by gymnasts performing static balances and swinging movements on rings, this solution is not always acceptable and an accurate
technique that does not hinder the gymnasts’ performances is desirable. This study evaluates a video-based technique for estimating
cable tension on the rings apparatus. Static loading of a rings frame coupled with a planar video analysis of the mandatory
damped elastic devices (DEDs) provided a tension-deflection calibration curve. Three-dimensional video and cable tension data
were obtained for two male gymnasts performing static balances and dynamic swinging movements. Cable tension was measured
using a force link while a planar video analysis determined time histories of the DED deflections. Combined cable tension
time histories were estimated fromrelative DED deflections coupled with the tension-deflection calibration curve and the orientation of the rings cables, and were compared
to measured values to evaluate the proposed technique. For static balances the RMS difference between measured and estimated
combined cable tension was 83 N. For dynamic swinging movements the maximum RMS difference was 189 N, equivalent to a 4% difference
when expressed as a percentage of the peak value. The indirect video-based technique developed in this study accurately estimates
combined cable tension throughout movements on rings and may be considered for studies where a remote measurement is required.
There is potential for the technique to be extended to other sporting situations, where indirect accurate estimates of external
forces acting on an athlete are needed. 相似文献
8.
In this study, we examined the methods used and knowledge required by 16 elite men's gymnastic coaches in the development of skill progressions. Following in-depth interviews, a conceptual model representing the process of skill progression development was generated. We found that: (1) elite gymnastic coaches developed skill progressions through experimental practice, reflection and critical inquiry; (2) the development of skill progressions was underpinned by the coaches acquiring a mindset based on four further sub-components (i.e. skill progression refinement, current coaching knowledge, mental imagery and biomechanical understanding); and (3) coaches identified the importance of replication of the spatial and temporal characteristics of the final skill. The results are consistent with task analysis, reflective practice and the principle of specificity. Practically, these findings suggest the need to develop coaches with a more objective approach to skill progression development and a greater understanding of the controlling mechanisms inherent in such practices. 相似文献
9.
In the kinematic and kinetic analysis of human movement, an accurate assessment of the inertial properties of the body segments under investigation is often essential. Statistical and geometric models of the segments of the upper limb were examined to determine their ability to predict the moments of inertia of these segments. The cadaver data of Chandler et al. (1975) were used as the criteria with which computed values were compared. The regression equations of Hinrichs (1985) gave the most accurate results; the geometric models appeared to offer the greatest flexibility. 相似文献
10.
Hegemonic masculinity would suggest that sport fandom is the exclusive domain of men and women are subordinate. Yet, it is apparent that women make up a significant portion of the professional sport spectator market. As such, it is important to systematically examine the role of hegemonic masculinity in the female sport fan experience. The purpose of this paper was to document, explore, and reflect upon personal experiences of female sport fans using a collaborative self-ethnography approach. Over a period of 3 months, we documented our experiences attending professional sport events (e.g., Major League Baseball, Canadian Football League) in the United States and Canada. Analysis of the data occurred through a process of sharing and critical reflection of our narratives. We identified three common themes that defined our experiences as female sport fans: (a) negotiating our definition of being a sport fan, (b) female sport fan as “the outsider”, and (c) marginalisation of other women. Our work provides some insight into the lived experiences of female sport fans. Discussion of the findings is intended to shed light on the conversation regarding hegemonic masculinity within the sport fan literature. 相似文献