Biomechanical characterization of the Junzuki karate punch: indexes of performance

The aims of this study were: (i) to determine kinematic, kinetic, and electromyographic characteristics of Junzuki karate punch in professional karate athletes; (ii) to identify biomechanical parameters that correlate with punch force and lead to a higher punching performance; (iii) to verify the presence of muscle co-activation in the upper limb, trunk, and lower limb muscles. Data were collected from nine experienced karatekas from the Accademia Italiana Karate e Arti Marziali during the execution of the specific punch. Mean punch forces (181.2?N) delivered to the target, the range of motion of both right and left knees (1.13 and 0.82?rad) and right elbow (1.49?rad) joints, and the angles at impact (knee: 0.81 and 0.91?rad; elbow: 1.19?rad) in the sagittal plane were computed. Furthermore, the trunk rotational angular acceleration (63.1?rad^?s^?2), force related to the lower limbs (550.2 and 425.1?N), and co-activation index for the upper limb (36.1% and 34.7%), trunk (24.5% and 16%), and lower limbs (16.0% and 16.1%) muscles were evaluated bilaterally. Significant positive correlations were found between the punch force and both right and left knee flexion at the instant of impact and right and left leg force. Significant negative correlation was found between the punch force and maximum trunk angular acceleration. Significant differences (p?=?.03) in the co-activation index among the upper limb, trunk, and lower limbs muscles highlighted a rostro-caudal gradient on both body sides. This research could be of use to performers and coaches when considering training preparations.     

Kinetics and kinematics analysis of incremental cycling to exhaustion

Technique changes in cyclists are not well described during exhaustive exercise. Therefore the aim of the present study was to analyze pedaling technique during an incremental cycling test to exhaustion. Eleven cyclists performed an incremental cycling test to exhaustion. Pedal force and joint kinematics were acquired during the last three stages of the test (75%, 90% and 100% of the maximal power output). Inverse dynamics was conducted to calculate the net joint moments at the hip, knee and ankle joints. Knee joint had an increased contribution to the total net joint moments with the increase of workload (5-8% increase, p < 0.01). Total average absolute joint moment and knee joint moment increased during the test (25% and 39%, for p < 0.01, respectively). Increases in plantar flexor moment (32%, p < 0.01), knee (54%, p < 0.01) and hip flexor moments (42%, p = 0.02) were found. Higher dorsiflexion (2%, for p = 0.03) and increased range of motion (19%, for p = 0.02) were observed for the ankle joint. The hip joint had an increased flexion angle (2%, for p < 0.01) and a reduced range of motion (3%, for p = 0.04) with the increase of workload. Differences in joint kinetics and kinematics indicate that pedaling technique was affected by the combined fatigue and workload effects.     

Cruising through the stacks: Developing tools to rapidly and economically mass-produce stack end signage: A case study

The purpose of this article is to describe a case study that addresses issues related to stack end signage in a university library. Poor stack end signage can negatively influence patrons' ability to navigate the library and locate physical materials. At the Monsignor William Barry Memorial Library, a tool was developed using Microsoft Excel and Microsoft Word to quickly and inexpensively mass-produce effective and user-friendly stack end signage. This article details the specific steps taken to develop, implement, and utilize this instrument.     

Three-dimensional kinematics of competitive and recreational cyclists across different workloads during cycling

Although the link between sagittal plane motion and exercise intensity has been highlighted, no study assessed if different workloads lead to changes in three-dimensional cycling kinematics. This study compared three-dimensional joint and segment kinematics between competitive and recreational road cyclists across different workloads. Twenty-four road male cyclists (12 competitive and 12 recreational) underwent an incremental workload test to determine aerobic peak power output. In a following session, cyclists performed four trials at sub-maximal workloads (65, 75, 85 and 95% of their aerobic peak power output) at 90?rpm of pedalling cadence. Mean hip adduction, thigh rotation, shank rotation, pelvis inclination (latero-lateral and anterior–posterior), spine inclination and rotation were computed at the power section of the crank cycle (12 o'clock to 6 o'clock crank positions) using three-dimensional kinematics. Greater lateral spine inclination (p?p?p?相似文献   

Public education and student movements: the Chilean rebellion under a neoliberal experiment

Abstract

Chile is recognized in the educational policy field as one of the first laboratories of neoliberal initiatives. These policies, initiated under the dictatorship of Augusto Pinochet, did not change with the new democratic governments after 1990. This characteristic led international organizations to promote the Chilean policies in different contexts in Latin America and beyond. In 2006, a high school student movement occupied public and private schools, demystifying the outcomes of these policies. A new wave of demonstrations took place in 2011, with a college student leadership that paralyzed a significant amount of universities and schools throughout the country. After both waves of mobilizations, the political system opened the process of policy-making that considered the demands of social movements. In this article, we explore the dynamics between educational policies and social student movements in Chile, and the possibilities of change in favor of public education.     

Outcome evaluation of a community center-based program for mothers at high psychosocial risk

OBJECTIVE: This study reported the outcome evaluation of the "Apoyo Personal y Familiar" (APF) program for poorly-educated mothers from multi-problem families, showing inadequate behavior with their children. APF is a community-based multi-site program delivered through weekly group meetings in municipal resource centers. METHOD: A total of 340 mothers referred by the municipal social services of Tenerife, Spain were assessed; 185 mothers participated in the APF program that lasted 8 months, and 155 mothers were in the control group. Pre-post test comparisons for the intervention group and post-test comparisons with the control group on self-rating measures of maternal beliefs, personal agency and child-rearing practices were performed. Multivariate tests, t tests and effect sizes (ES) were calculated to determine the program effectiveness on the outcome measures. RESULTS: Mothers' support of nurturist and nativist beliefs and the reported use of Neglect-permissive and Coercive practices significantly decreased after program completion whereas the reported use of Inductive practices significantly increased. Increases in self-efficacy, internal control and role difficulty were also significant in relation to those of the control group. The program was especially effective for older mothers, with fewer children, living in a two-parent family, in urban areas and with either low or medium educational levels. CONCLUSION: The program was very effective in changing the mothers' perceived competences and modestly effective in changing their beliefs about child development and education and reported child-rearing practices. Changes in personal agency are very important for at-risk parents who feel helpless and with no control over their lives.     

Resilience does not predict academic performance in gross anatomy

Few studies have evaluated resilience in an academic environment as it relates to academic success or failure. This work sought to assess resilience in regular and remedial students of gross anatomy during the first and second semesters of medical school and to correlate this personal trait with academic performance. Two groups of students were compared: the first group included first‐year medical students in the regular course, and the second group included first‐year medical students who did not pass the regular anatomy course and so were enrolled in the remedial course. Both groups completed anonymous surveys designed to gather demographic data and establish scores on the Connor‐Davidson resilience scale, which includes 25 statements rated zero to four on a Likert scale (maximum score 100). The average resilience score was the same for both groups, 80 ± 9. The average anatomy grades differed significantly between regular students (67± 15.0) and remedial students (61 ± 12.0). While there was no overall correlation between resilience score and anatomy grade, regular students with resilience scores of 75 or greater showed slightly better academic performance than their classmates. Similarly, remedial students with resilience scores of 87 or greater faired better academically. Resilience does not predict academic performance in gross anatomy, and further work is necessary to identify those intrinsic and extrinsic factors that influence students' achievements. Anat Sci Educ. © 2010 American Association of Anatomists.     

Measuring Space and Furniture Occupancy in Academic Libraries: From Data Gathering to Visualization

Abstract

Academic libraries are a vital space for collaboration, socialization, research, and quiet study. To support these needs, they must offer a variety of environments, noise levels, and furniture to support varying student needs. However, it can be difficult to understand these specific needs and properly balance the types of spaces and seating alternatives to optimally meet them. This article describes a space usage study undertaken to determine patron needs and preferences and the resulting visualization of the data using Tableau Public. The project provided important insights into patron space preferences and use, and the methodology can be replicated at other institutions.     

Teaching skills to promote clinical reasoning in early basic science courses

Basic and superior reasoning skills are woven into the clinical reasoning process just as they are used to solve any problem. As clinical reasoning is the central competence of medical education, development of these reasoning skills should occur throughout the undergraduate medical curriculum. The authors describe here a method of teaching reasoning skills in a clinical context during a human anatomy course. Anat Sci Educ 3:267–271, 2010. © 2010 American Association of Anatomists.