Accuracy of human motion capture systems for sport applications; state-of-the-art review

Objective: Sport research often requires human motion capture of an athlete. It can, however, be labour-intensive and difficult to select the right system, while manufacturers report on specifications which are determined in set-ups that largely differ from sport research in terms of volume, environment and motion. The aim of this review is to assist researchers in the selection of a suitable motion capture system for their experimental set-up for sport applications. An open online platform is initiated, to support (sport)researchers in the selection of a system and to enable them to contribute and update the overview. Design: systematic review; Method: Electronic searches in Scopus, Web of Science and Google Scholar were performed, and the reference lists of the screened articles were scrutinised to determine human motion capture systems used in academically published studies on sport analysis. Results: An overview of 17 human motion capture systems is provided, reporting the general specifications given by the manufacturer (weight and size of the sensors, maximum capture volume, environmental feasibilities), and calibration specifications as determined in peer-reviewed studies. The accuracy of each system is plotted against the measurement range. Conclusion: The overview and chart can assist researchers in the selection of a suitable measurement system. To increase the robustness of the database and to keep up with technological developments, we encourage researchers to perform an accuracy test prior to their experiment and to add to the chart and the system overview (online, open access).     

Development,construct validity and test–retest reliability of a field-based wheelchair mobility performance test for wheelchair basketball

The aim of this study was to develop and describe a wheelchair mobility performance test in wheelchair basketball and to assess its construct validity and reliability. To mimic mobility performance of wheelchair basketball matches in a standardised manner, a test was designed based on observation of wheelchair basketball matches and expert judgement.

Forty-six players performed the test to determine its validity and 23 players performed the test twice for reliability. Independent-samples t-tests were used to assess whether the times needed to complete the test were different for classifications, playing standards and sex. Intraclass correlation coefficients (ICC) were calculated to quantify reliability of performance times.

Males performed better than females (P < 0.001, effect size [ES] = ?1.26) and international men performed better than national men (P < 0.001, ES = ?1.62). Performance time of low (≤2.5) and high (≥3.0) classification players was borderline not significant with a moderate ES (P = 0.06, ES = 0.58). The reliability was excellent for overall performance time (ICC = 0.95).

These results show that the test can be used as a standardised mobility performance test to validly and reliably assess the capacity in mobility performance of elite wheelchair basketball athletes. Furthermore, the described methodology of development is recommended for use in other sports to develop sport-specific tests.     

Secondary students’ modelling conceptualisation in situations related to particle dynamics: a clinical perspective

This study investigates the modelling conceptualisation of secondary school students in two situations related to particle dynamics: pendulum’s motion and horizontal motion. We performed in-depth clinical interviews with secondary school students (N?=?10). Participants’ ideas about properties which are not ‘given’ in empirical observations were explored in order to investigate signs of abstractions and idealisations in their reasoning processes. We proposed contributions to modelling in science education based on Mario Bunge’s epistemology and we employed his basic concepts as the axis to analyse our results: (1) abstractions and idealisations, considered as thought processes required to build conceptual counterparts of concrete objects; (2) theoretical models, meaning hypothetico-deductive systems concerning those conceptual objects; and (3) general theoretical frameworks that allow us to derive those theoretical models. We developed our analysis viewing the ideas presented by participants as concepts-in-action and theorems-in-action as regarded by Gérard Vergnaud’s Theory of Conceptual Fields. Results indicated a gradation in the concepts-in-action mobilised in terms of levels of idealisation and showed that participants do not spontaneously recognise the use of a general theory as a possible way to obtain a theoretical model. These results suggest that science education practices must pay better attention to make abstractions and idealisations explicit in scientific concepts formation, as well as to the heuristic role of theories in model construction.     

Learning from human cadaveric prosections: Examining anxiety in speech therapy students

Human anatomy education often utilizes the essential practices of cadaver dissection and examination of prosected specimens. However, these exposures to human cadavers and confronting death can be stressful and anxiety‐inducing for students. This study aims to understand the attitudes, reactions, fears, and states of anxiety that speech therapy students experience in the dissection room. To that end, a before‐and‐after cross‐sectional analysis was conducted with speech therapy students undertaking a dissection course for the first time. An anonymous questionnaire was administered before and after the exercise to understand students' feelings and emotions. State‐Trait Anxiety Inventory questionnaires (STAI‐S and STAI‐T) were used to evaluate anxiety levels. The results of the study revealed that baseline anxiety levels measured using the STAI‐T remained stable and unchanged during the dissection room experience (P > 0.05). Levels of emotional anxiety measured using the STAI‐S decreased, from 15.3 to 11.1 points (P < 0.05). In the initial phase of the study, before any contact with the dissection room environment, 17% of students experienced anxiety, and this rate remained unchanged by end of the session (P > 0.05). A total of 63.4% of students described having thoughts about life and death. After the session, 100% of students recommended the dissection exercise, giving it a mean score of 9.1/10 points. Anatomy is an important subject for students in the health sciences, and dissection and prosection exercises frequently involve a series of uncomfortable and stressful experiences. Experiences in the dissection room may challenge some students' emotional equilibria. However, students consider the exercise to be very useful in their education and recommend it. Anat Sci Educ 10: 487–494. © 2017 American Association of Anatomists.     

The Elusive Relationship Between Teacher Characteristics and Student Academic Growth: A Longitudinal Multilevel Model for Change

Teacher characteristics and student achievement growth are currently a significant topic of investigation in the educational accountability arena. Given the environment of high-stakes accountability associated with the No Child Left Behind (NCLB) legislation and state accountability systems, staffing all classrooms with highly qualified teachers is a critical national concern. A new era of research is needed to understand the complexity of teacher quality when defined by student learning growth. The present study evaluated the effects of teacher characteristics (i.e., experience, education, and race) in high school reading achievement gains using a multi-level growth model in an urban school district in Kentucky. Findings showed significant effects of time, but non-significant effects of teacher characteristics in high school reading achievement growth. Implications for educational policy and future research are discussed.     

Evaluating Teacher-Leaders for Careers as Administrators: Effects of Job Attributes, Teacher Leader Role, and Teaching Assignment Area

Recruitment of public school administrators is an important issue due to the shortage of qualified job applicants nationwide. The shortage of applicants requires school districts to evaluate their internal pools of potential applicants for administrative vacancies. This evaluation research addressed the recruitment of teacher-leaders to serve as assistant principals (APs) using a recruitment simulation technique. The participants were secondary school teacher-leaders who were counselors, school council members, department chairs, or resource teachers. The evaluation technique used involved an innovative experimental design approach. Teacher-leaders, whose current or past primary teaching assignment was in the core content areas (e.g., English/language arts, mathematics, science, social studies), rated the job of AP highest. Resource teachers rated the job significantly higher when the AP job emphasized instruction than when the job emphasized discipline. Implications for recruitment practice and future research are discussed.     

How to Analyze Interpersonal and Individual Effects in Peer-Tutored Reading Intervention

Reading strategy interventions relying upon peer tutoring are a common way to foster poor readers' comprehension skills. Those interventions are based on the assumption that tutees benefit from the (higher) reading skills of their tutors. However, this interpersonal effect has not yet been tested explicitly because the effectiveness of peer tutoring is commonly analyzed separately for tutees and tutors or with aggregated data. The present study illustrates how interpersonal and individual effects of a peer-tutored reading strategy intervention can be estimated using dyads as units of analysis in structural equation modeling. To demonstrate the application of the model, data from an experimental intervention study comparing the effects of a peer-tutored reading strategy training and a control condition in Grade 4 (N = 68 dyads) were analyzed.     

Deprivation level and choice in pigeons: a test of within-trial contrast

Within-trial contrast has been proposed as a mechanism underlying preferences for stimuli that follow relatively more aversive events over stimuli that follow less aversive events. In this study, we manipulated deprivation level to test within-trial contrast predictions. In Experiment 1, pigeons encountered two discriminative stimuli, one presented when they were deprived and the other when they were prefed. When later given a choice between the two stimuli, pigeons strongly preferred the stimulus encountered when deprived, independently of their deprivation level at test. In Experiment 2, pigeons learned two simultaneous discriminations, one when deprived and the other when prefed. Here, subsequent tests between the two S⁺ or the two S⁻ stimuli revealed no consistent preferences. These contrasting findings suggest that differential aversiveness is necessary but not sufficient to induce preferences via within-trial contrast.