Increasing hip and knee flexion during a drop-jump task reduces tibiofemoral shear and compressive forces: implications for ACL injury prevention training     

Liang-Ching Tsai  Yi-An Ko  Kyle E. Hammond  John W. Xerogeanes  Gordon L. Warren  Christopher M. Powers 《Journal of sports sciences》2017,35(24):2405-2411

Although most ACL injury prevention programmes encourage greater hip and knee flexion during landing, it remains unknown how this technique influences tibiofemoral joint forces. We examined whether a landing strategy utilising greater hip and knee flexion decreases tibiofemoral anterior shear and compression. Twelve healthy women (25.9 ± 3.5 years) performed a drop-jump task before and after a training session (10–15 min) that emphasised greater hip and knee flexion. Peak tibiofemoral anterior shear and compressive forces were calculated using an electromyography (EMG)-driven knee model that incorporated joint kinematics, EMG and participant-specific muscle volumes and patella tendon orientation measured using magnetic resonance imaging (MRI). Participants demonstrated a decrease in peak anterior tibial shear forces (11.1 ± 3.3 vs. 9.6 ± 2.7 N · kg^?1; P = 0.008) and peak tibiofemoral compressive forces (68.4 ± 7.6 vs. 62.0 ± 5.5 N · kg^?1; P = 0.015) post-training. The decreased peak anterior tibial shear was accompanied by a decrease in the quadriceps anterior shear force, while the decreased peak compressive force was accompanied by decreased ground reaction force and hamstring forces. Our data provide justification for injury prevention programmes that encourage greater hip and knee flexion during landing to reduce tibiofemoral joint loading.  相似文献   

Mothers' Perspectives of the Peer-Related Social Development of Young Children with Developmental Delays and Communication Disorders     

Michael J. Guralnick  Robert T. Connor  Brian Neville  Mary A. Hammond 《Early education and development》2002,13(1):59-80

Mothers' perspectives of children's peer-related social development were obtained from matched groups of young children with developmental delays, communicative disorders, and typically developing children. Structured interviews elicited information on numerous issues including mothers' views of the importance of children's social skills development, rationales with respect to why children succeed or had difficulties on specific social tasks, and the socialization strategies mothers employ to promote children's peer-related social development. Mothers also reported on their efforts to arrange play with peers for their child and the degree to which they monitored that play. Results indicated that mothers rated children's social development as highly important, offered primarily internal rationales (e.g., traits, dispositions) for success or difficulties in achieving social tasks, and endorsed moderate and low power socialization strategies. Differences across the three groups were minimal. Mothers arranged play with peers least often for children with developmental delays and communication disorders, but monitored play more extensively for children with delays. These finding were discussed in terms of mothers adopting a developmental orientation to understand children's social development and their implications for maternal participation in peer competence intervention programs.  相似文献   

Christian Higher Education in the United States: The Crisis of Evangelical Identity     

Michael D. Hammond 《Christian Higher Education》2019,18(1-2):3-15

The Council for Christian Colleges & Universities (CCCU) is the most successful higher education organization to emerge from the modern American evangelical movement. Especially within the context of the United States, higher education has been a key element of neo-evangelicalism since the 1940s. Rather than choosing between biblical truth and cultural outreach, post–World War II neo-evangelicals called the church toward a thoughtful approach to address the needs of the world. The early movement was focused not only on evangelistic ministry efforts, but also on education as a primary means for shaping the culture. As modern evangelicalism took shape in the 1950s, the movement struggled to find a consistent moral voice. From early challenges related to the civil rights movement to current debates over poverty and immigration, evangelicals have engaged with cultural issues, but with a wide variety of strategies and viewpoints. Political issues have brought evangelicals into public life, and some leaders have used elections as the primary means for promoting moral concerns. Consequently, the public may often view U.S. evangelicals as activists concerned with political voting rather than as sincere followers of Christ who are committed to social ethics. Yet, the Christian college represents a significant platform for sustaining evangelical thought in public life. Evangelicalism has suffered a fracturing in the last decade or so, and the term now carries a negative connotation in some circles. Many colleges in the CCCU are searching for a new way to describe their evangelical identity. The historical meaning of the term evangelical focused on gospel proclamation and social reform. A return to this emphasis, as well as an alignment with the international focus of evangelical movement, can provide a more accurate and consistent legacy for evangelical institutions.  相似文献   

Equilibrium and duality in electromagnetic field problems     

P. Hammond 《Journal of The Franklin Institute》1978,306(2):133-157

Electromagnetic fields can be treated as systems in which the field equations are the equations of equilibrium. This formulation draws the subject into the unified approach of mechanics. Close analogies to potential and kinetic energy exist and these can be used to provide double bounds to the electromagnetic energy.  相似文献   

Helping the One You Hurt: Toddlers’ Rudimentary Guilt,Shame, and Prosocial Behavior After Harming Another          下载免费PDF全文

Jesse D. K. Drummond  Stuart I. Hammond  Emma Satlof‐Bedrick  Whitney E. Waugh  Celia A. Brownell 《Child development》2017,88(4):1382-1397

This study explored the role of guilt and shame in early prosocial behavior by extending previous findings that guilt‐ and shame‐like responses can be distinguished in toddlers and, for the first time, examining their associations with helping. Toddlers (n = 32; M_age = 28.9 months) were led to believe they broke an adult's toy, after which they exhibited either a guilt‐like response that included frequently confessing their behavior and trying to repair the toy; or a shame‐like response that included frequently avoiding the adult and seldom confessing or attempting to repair the toy. In subsequent prosocial tasks, children showing a guilt‐like response helped an adult in emotional distress significantly faster and more frequently than did children showing a shame‐like response.  相似文献   

Differences in Brain Activation Between Novices and Experts in Science During a Task Involving a Common Misconception in Electricity     

Steve Masson  Patrice Potvin  Martin Riopel  Lorie‐Marlène Brault Foisy 《Mind, Brain, and Education》2014,8(1):44-55

Science education studies have revealed that students often have misconceptions about how nature works, but what happens to misconceptions after a conceptual change remains poorly understood. Are misconceptions rejected and replaced by scientific conceptions, or are they still present in students' minds, coexisting with newly acquired scientific conceptions? In this study, we use functional magnetic resonance imaging (fMRI) to compare brain activation between novices and experts in science when they evaluate the correctness of simple electric circuits. Results show that experts, more than novices, activate brain areas involved in inhibition when they evaluate electric circuits in which a bulb lights up, even though there is only one wire connecting it to the battery. These findings suggest that experts may still have a misconception encoded in the neural networks of their brains that must be inhibited in order to answer scientifically.  相似文献   

Stability, change, and correlates of the peer relationships of young children with mild developmental delays     

Guralnick MJ  Hammond MA  Connor RT  Neville B 《Child development》2006,77(2):312-324

The peer relationships of young children with mild developmental (cognitive) delays recruited at 4-6 years of age were examined in a longitudinal study across a 2-year period. Results revealed only modest increases in children's peer interactions, a high degree of intraindividual stability, and the existence of a poorly organized and conflict-prone pattern of peer interactions. Child cognitive and language levels as well as family stress and support were associated with children's peer interactions. A subgroup was identified of initially low interactors who were at especially high risk for future peer interaction problems. These findings further underscore the importance of designing and implementing early intervention programs in the area of peer relationships for children with mild developmental delays.  相似文献   

2006 AECT Membership Salary Survey     

James A. Pershing CPT  PhD  Christopher D. Ryan  Nichole M. Harlin  Timothy D. Hammond 《TechTrends》2006,50(5):10-19

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Researcher vulnerability: implications for educational research and practice     

Lionel C. Howard  Shane P. Hammond 《International journal of qualitative studies in education》2019,32(4):411-428

This paper explores the concept of researcher vulnerability through a review of the extant research literature and each author’s feelings of vulnerability connected to their research with vulnerable populations while exploring both sensitive and seemingly innocuous, yet important, topics in education using qualitative methodology. Specifically, a reflection of our respective study of the academic and social transitions of student combat veterans, and the academic and gender socialization of adolescent African American males is presented as means of illustrating the phenomena of researcher vulnerability. Implications of vulnerability for research, practice, and theory are discussed.  相似文献   

Considered evaluation of clinical placements in a new medical school     

Jerry Booth  Sarah Collins  Anna Hammond† 《Assessment & Evaluation in Higher Education》2009,34(1):17-29

This article suggests that quality assessment in the UK has been largely set apart from learning and teaching and reports on a pilot project at the Hull York Medical School which attempted to integrate students’ evaluation of their clinical placements into the curriculum. It outlines the operational demands of this integrated method and compares the student experience of different evaluation methods. It argues that, when properly prepared and considered, evaluation can help students to practise useful skills and suggests that integrating this type of evaluation into the curriculum could be a step towards encouraging academic staff to engage with quality processes.  相似文献