The X-Factor: An evaluation of common methods used to analyse major inter-segment kinematics during the golf swing

Abstract

A common biomechanical feature of a golf swing, described in various ways in the literature, is the interaction between the thorax and pelvis, often termed the X-Factor. There is no consistent method used within golf biomechanics literature however to calculate these segment interactions. The purpose of this study was to examine X-factor data calculated using three reported methods in order to determine the similarity or otherwise of the data calculated using each method. A twelve-camera three-dimensional motion capture system was used to capture the driver swings of 19 participants and a subject specific three-dimensional biomechanical model was created with the position and orientation of each model estimated using a global optimisation algorithm. Comparison of the X-Factor methods showed significant differences for events during the swing (P < 0.05). Data for each kinematic measure were derived as a times series for all three methods and regression analysis of these data showed that whilst one method could be successfully mapped to another, the mappings between methods are subject dependent (P <0.05). Findings suggest that a consistent methodology considering the X-Factor from a joint angle approach is most insightful in describing a golf swing.     

Stress and performance: An application of Gray's three‐factor arousal theory to basketball free‐throw shooting

The suitability of Gray's (1975) three‐factor arousal theory as a model of human performance under stress was investigated in a study of basketball free‐throw shooting. Free‐throw attempts, made by members of an NCAA Division I men's varsity team, were videotaped during one full season. On the basis of Gray's theory, we predicted that increased stress (assumed to be present in games as opposed to practices) would be associated with longer pre‐shot preparations and a greater incidence of overthrow shots. The prediction was confirmed by the results. Moreover, we found that free‐throws were more frequently overthrown when attempted during crucial rather than non‐crucial game situations. Further tests of the utility of Gray's theory are suggested.     

The university in the global age: reconceptualising the humanities and social sciences for the twenty-first century.

Abstract

By any metric, the twentieth century university was a successful institution. However, in the twenty-first century, ongoing neoliberal educational reform has been accompanied by a growing epistemological crisis in the meaning and value of the humanities and social sciences (HaSS). Concerns have been expressed in two main forms. The governors of tertiary education systems—governments, private investors, university managers and consultancy firms—have focused on how HaSS can adapt to the perceived research needs of the 21st century. At the same time, a competing set of discourses has been generated by scholars and researchers employed within the critical HaSS themselves. This article considers what these differing perspectives mean for reconceptualising HaSS for the twenty-first century. After surveying the contemporary climate, this article examines the findings of key reports on the future of the humanities from the United States, the United Kingdom and Australia. Alongside those of Western Europe, these university systems are arguably the key drivers for the global university system. It is argued that these reports provide an opportunity for emerging universities to reflect on their research priorities and developmental strategies. The article concludes with some reflections on the wider consequences of the globalising of the university system, the increase of China's influence in Asia, and ponders the prospect of post-human/ist futures of the humanities.     

The Development of Critical Consciousness and its Relation to Academic Achievement in Adolescents of Color

Critical consciousness, the process by which individuals come to understand, analyze, and take action against systems of oppression, is associated with several positive youth outcomes. However, little research has considered how the core components of critical consciousness (critical reflection, political agency, critical action) are associated with academic achievement. The present study explored the extent to which the developing critical consciousness of adolescents of color (N = 364) over 4 years of high school predicted academic achievement, as measured by grade point average (GPA) and the Scholastic Aptitude Test (SAT). Results demonstrated that adolescents’ critical reflection and critical action intercepts predicted SAT scores whereas critical reflection and critical action slopes predicted GPAs. Political agency was not predictive of either academic outcome.     

The importance of duration and magnitude of force application to sprint performance during the initial acceleration,transition and maximal velocity phases

ABSTRACT

Successful sprinting depends on covering a specific distance in the shortest time possible. Although external forces are key to sprinting, less consideration is given to the duration of force application, which influences the impulse generated. This study explored relationships between sprint performance measures and external kinetic and kinematic performance indicators. Data were collected from the initial acceleration, transition and maximal velocity phases of a sprint. Relationships were analysed between sprint performance measures and kinetic and kinematic variables. A commonality regression analysis was used to explore how independent variables contributed to multiple-regression models for the sprint phases. Propulsive forces play a key role in sprint performance during the initial acceleration (r = 0.95 ± 0.03) and transition phases (r = 0.74 ± 0.19), while braking duration plays an important role during the transition phase (r = ?0.72 ± 0.20). Contact time, vertical force and peak propulsive forces represented key determinants (r = ?0.64 ± 0.31, r = 0.57 ± 0.35 and r = 0.66 ± 0.30, respectively) of maximal velocity phase performance, with peak propulsive force providing the largest unique contribution to the regression model for step velocity. These results clarified the role of force and time variables on sprinting performance.     

Rural Public Library Outreach Services and Elder Users: A Case Study of the Washington County (VA) Public Library

ABSTRACT

Outreach services provided by rural public libraries are crucial to fulfilling their mission to provide information access to the widest array of user groups. Particular socioeconomic and geographic factors in rural areas present challenges of access to information resources, yet there exists only a limited amount of published scholarly work examining outreach services provided specifically by rural public libraries. This case study of outreach services to elder users offers contextual evidence for the centrality of social equity and access to the larger work of rural public libraries. Primary data were collected through four semi-structured focus group meetings conducted with elder users of the agency’s outreach services as well as through narrative interviews with six agency staff members. Principal findings showed that elder users had particular information needs related to entertainment and intellectual stimulation, challenges of transportation, and a limited access to technology and internet service. WCPL outreach services were found to positively impact the lives and general well-being of elder users by providing vital social and community connections and serving as a key link for elder users to an institution understood to be central to the life of the community in general.