Abdominal muscle response to a simulated weight-bearing task by elite Australian Rules football players

The aim of this study was to examine the automatic recruitment of the deep abdominal muscles during a unilateral simulated weight-bearing task by elite Australian Rules football (AFL) players with and without low back pain (LBP). An observational cross-sectional study was conducted using ultrasound imaging to measure the thickness of the internal oblique (IO) and transversus abdominis (TrA) muscles. Thirty-seven elite male AFL players participated. Repeated measures factors included 'force level' (rest, 25% and 45% of body weight), 'leg' (dominant or non-dominant kicking leg) and 'side' (ultrasound side ipsilateral or contralateral to the leg used for the weight-bearing task). The dependent variables were thickness of the IO and TrA muscles. The results of this study showed that thickness of the IO (p<.0001) and TrA (p<.0001) muscles increased in response to 'force level'. During the task, the thickness of the IO muscle on the contralateral side of the trunk relative to the leg being tested, increased more in participants with current LBP (p=.034). This pattern was more distinct on the non-dominant kicking leg. Altered abdominal muscle recruitment in elite athletes with low back pain may be an attempt by the central nervous system (CNS) to compensate for inadequate lumbo-pelvic stability.     

Subjectivity in psychological science: From problem to prospect

The problem of subjectivity within psychological research has long been recognized. The practices of scientific psychology, however, continue to assume that objectivity is desirable, even if not completely possible, and that subjectivity is a source of bias that must be minimized or eliminated. Such a dispassionate stance has offered and continues to offer a range of benefits, not least a tight focus on participants' relevant responses. Nonetheless, in this article, we question the wisdom of always or automatically working to minimize participant and researcher subjectivity, and we invite psychological researchers to consider the benefits of a more, what we term, reflexive scientific attitude. We turn in particular to recent theoretical and methodological innovations within qualitative research in order to help us progress toward a more reflexive psychological science where subjectivity is re-viewed as a resource that can be tapped in order to contextualize and enrich the psychological research process and its products. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Habit strength moderates the strength of within-person relations between weekly self-reported and objectively-assessed physical activity

ObjectivesPhysical activity (PA) habit strength influences how people control their PA and may also influence how people encode, store, or recall their PA. This study evaluated whether individual differences in PA habit strength moderated the magnitude of within-person associations between weekly self-reported PA and step counts.DesignLongitudinal.MethodAfter an initial assessment of PA habit strength, university students wore pedometers for four weeks and completed four self-reports of weekly mild, moderate, and strenuous PA.ResultsOn average, people's weekly step counts and self-reported PA across time were weakly-to-moderately associated, but there was substantial variability in the magnitude of these associations across people. People with strong PA habits had weaker within-person associations between deviations from their average self-reported PA and step counts than those with weak PA habits.ConclusionsThese results may indicate that PA habit strength influences the sensitivity of self-report PA measures to change in objectively-measured PA.     

The dark side of career preference: dark side traits,motives, and values

Over 2000 people completed two validated questionnaires: one measuring “dark side” personality traits and the other a measure of values and preferences that indicates the type of work that an individual would like to do and is best suited for. Dark side variables (and demographics) accounted for between 11% (science) and 46% (affiliation) variance in specific vocation related values. Factor analysis suggested three overall value/vocation factors (enterprising, traditional, and social) and three dark side variables (moving against, away from, and toward others). The three dark side factors predicted around a third of the variance in favoring enterprising and social occupations. Implications for vocational guidance and limitations of the study are considered.     

Modelling mechanisms with causal cycles

Mechanistic philosophy of science views a large part of scientific activity as engaged in modelling mechanisms. While science textbooks tend to offer qualitative models of mechanisms, there is increasing demand for models from which one can draw quantitative predictions and explanations. Casini et al. (Theoria 26(1):5–33, 2011) put forward the Recursive Bayesian Networks (RBN) formalism as well suited to this end. The RBN formalism is an extension of the standard Bayesian net formalism, an extension that allows for modelling the hierarchical nature of mechanisms. Like the standard Bayesian net formalism, it models causal relationships using directed acyclic graphs. Given this appeal to acyclicity, causal cycles pose a prima facie problem for the RBN approach. This paper argues that the problem is a significant one given the ubiquity of causal cycles in mechanisms, but that the problem can be solved by combining two sorts of solution strategy in a judicious way.