The aim of this paper was to present a review on the role that movement variability (MV) plays in the analysis of sports movement and in the monitoring of the athlete's skills. MV has been traditionally considered an unwanted noise to be reduced, but recent studies have re-evaluated its role and have tried to understand whether it may contain important information about the neuro-musculo-skeletal organisation. Issues concerning both views of MV, different approaches for analysing it and future perspectives are discussed. Information regarding the nature of the MV is vital in the analysis of sports movements/motor skills, and the way in which these movements are analysed and the MV subsequently quantified is dependent on the movement in question and the issues the researcher is trying to address. In dealing with a number of issues regarding MV, this paper has also raised a number of questions which are still to be addressed.

Results provided additional information about movement patterns compared to traditional approaches and identified the first half of stance as the most relevant period in injury occurrence. The study showed evidence that variability is related to the presence of injury in this clinical population. Further FDA focusing on within-subject variation is recommended to gain greater insight into the role of variability in injury occurrence.

Background Rugby union is a physically demanding, fullcontact team sport that has gained worldwide popularity. The incidence of injury in rugby union has been widely reported in the literature. While comprehensive injury surveillance and prevention programmes have been implemented within the professional game, there is a need for similar strategies in the amateur game. Despite recent increases in the volume of research in rugby, there is little consensus regarding the true incidence rate of match and training injuries in senior amateur male rugby union players. Objective The aim of the current review was to systematically review the available evidence on the epidemiology of time-loss injuries in senior amateur male rugby union players and to subsequently conduct a meta-analysis of the findings. Methods A comprehensive search of the PubMed, Scopus, SportDiscus and Google Scholar electronic databases was performed using the following keywords; ('rugby' OR 'rugby union') AND ('amateur' OR 'community') AND ('injur*' OR 'pain*'). Six articles regarding the incidence of injury in senior amateur male rugby union players, in both matches and training, were retrieved and included in the meta-analysis to determine the overall incidence rate of match injury, with descriptive analyses also provided for other reported variables. Results The overall incidence rate of match injuries within senior amateur rugby union players was 46.8/1000 player hours [95% confidence interval (CI) 34.4-59.2]. Contact events accounted for the majority of injuries, with the tackler more at risk than the player being tackled, and with respective incidence rates of 15.9/1000 player hours (95% CI 12.4-19.5) and 12.2/1000 player hours (95% CI 9.3-15.1). Conclusion This meta-analysis found that the incidence rate of injury in amateur rugby union players was lower than that in professional players, but higher than the incidences reported in adolescent and youth rugby players. By understanding the true incidence and nature of injuries in rugby, injury prevention strategies can best be implemented. Future prevention strategies may best be aimed towards the tackle area, specifically to the tackler, in order to minimize injury risk. 2. The incidence rate of injury in senior male amateur rugby union players appears to be lower than that in professional players, but higher than the incidences reported in adolescent and youth rugby players.3.

BackgroundTumor cell motility and invasion is governed by dynamic regulation of the cortical actin cytoskeleton. The actin-binding protein cortactin is commonly upregulated in multiple cancer types and is associated with increased cell migration. Cortactin regulates actin nucleation through the actin related protein (Arp)2/3 complex and stabilizes the cortical actin cytoskeleton. Cortactin is regulated by multiple phosphorylation events, including phosphorylation of S405 and S418 by extracellular regulated kinases (ERK)1/2. ERK1/2 phosphorylation of cortactin has emerged as an important positive regulatory modification, enabling cortactin to bind and activate the Arp2/3 regulator neuronal Wiskott-Aldrich syndrome protein (N-WASp), promoting actin polymerization and enhancing tumor cell movement.Methodology/Principal FindingsIn this report we have developed phosphorylation-specific antibodies against phosphorylated cortactin S405 and S418 to analyze the subcellular localization of this cortactin form in tumor cells and patient samples by microscopy. We evaluated the interplay between cortactin S405 and S418 phosphorylation with cortactin tyrosine phosphorylation in regulating cortactin conformational forms by Western blotting. Cortactin is simultaneously phosphorylated at S405/418 and Y421 in tumor cells, and through the use of point mutant constructs we determined that serine and tyrosine phosphorylation events lack any co-dependency. Expression of S405/418 phosphorylation-null constructs impaired carcinoma motility and adhesion, and also inhibited lamellipodia persistence monitored by live cell imaging.Conclusions/SignificanceCortactin phosphorylated at S405/418 is localized to sites of dynamic actin assembly in tumor cells. Concurrent phosphorylation of cortactin by ERK1/2 and tyrosine kinases enables cells with the ability to regulate actin dynamics through N-WASp and other effector proteins by synchronizing upstream regulatory pathways, confirming cortactin as an important integration point in actin-based signal transduction. Reduced lamellipodia persistence in cells with S405/418A expression identifies an essential motility-based process reliant on ERK1/2 signaling, providing additional understanding as to how this pathway impacts tumor cell migration.

These data support the early introduction of clinical skills teaching, backed up by a fully integrated clinically relevant curriculum with continued assessment, in preparing students and reducing levels of anxiety before they start full-time clinical attachments. These course design differences appear to be more important than any differences in maturity between the 2 groups.

BackgroundAs the use of self-reported data to classify obesity continues, the temporal change in the accuracy of self-report measurement when compared to clinical measurement remains unclear. The objective of this study was to examine temporal trends in misclassification patterns, as well as sensitivity and specificity, of clinically measured versus self-report based body mass index (BMI) from three national lifestyle surveys over a 10-year period.MethodsThe Surveys of Lifestyle Attitudes and Nutrition (SLÁN) were interview based cross-sectional survey/measurements involving nationally representative samples in 1998, 2002 and 2007. Data from a subsample of both self-reported and measured height and weight were available from 66 men and 142 women in 1998, 147 men and 184 women in 2002 and 909 men and 1128 women in 2007. Respondents were classified into the BMI categories normal (< 25 kg m-2), overweight (25- < 30 kg m-2) and obese (≥ 30 kg m-2).ResultsUnderreporting of BMI increased across the three surveys (14%→21%→24%; p = 0.002). Sensitivity scores for the normal category exceeded 94% in all three surveys but decreased for the overweight (75%→68%→66%) and obese categories (80%→64%→53%). Simultaneously, specificity levels remained high.ConclusionsBMI values based on self-reported determinations of height and weight in population samples are underestimating the true prevalence of the obesity epidemic and this underestimation is increasing with time. The decreased sensitivity and consistently high specificity scores in the obese category across time, highlights the limitation of self-report based BMI classifications and the need for simple, readily comprehensible indicators of obesity.

SummaryThe proto-oncogene Src tyrosine kinase (Src) is overexpressed in human cancers and is currently a target of anti-invasive therapies. Activation of Src is an essential catalyst of invadopodia production. Invadopodia are cellular structures that mediate extracellular matrix (ECM) proteolysis, allowing invasive cell types to breach confining tissue barriers. Invadopodia assembly and maturation is a multistep process, first requiring the targeting of actin-associated proteins to form pre-invadopodia, which subsequently mature by recruitment and activation of matrix metalloproteases (MMPs) that facilitate ECM degradation. We demonstrate that active, oncogenic Src alleles require the presence of a wild-type counterpart to induce ECM degradation at invadopodia sites. In addition, we identify the phosphorylation of the invadopodia regulatory protein cortactin as an important mediator of invadopodia maturation downstream of wild-type Src. Distinct phosphotyrosine-based protein-binding profiles in cells forming pre-invadopodia and mature invadopodia were identified by SH2-domain array analysis. These results indicate that although elevated Src kinase activity is required to target actin-associated proteins to pre-invadopodia, regulated Src activity is required for invadopodia maturation and matrix degradation activity. Our findings describe a previously unappreciated role for proto-oncogenic Src in enabling the invasive activity of constitutively active Src alleles.

Cellular invasion into local tissues is a process important in development and homeostasis. Malregulated invasion and subsequent cell movement is characteristic of multiple pathological processes, including inflammation, cardiovascular disease and tumor cell metastasis 1 . Focalized proteolytic degradation of extracellular matrix (ECM) components in the epithelial or endothelial basement membrane is a critical step in initiating cellular invasion. In tumor cells, extensive in vitro analysis has determined that ECM degradation is accomplished by ventral actin-rich membrane protrusive structures termed invadopodia 2,3 . Invadopodia form in close apposition to the ECM, where they moderate ECM breakdown through the action of matrix metalloproteinases (MMPs). The ability of tumor cells to form invadopodia directly correlates with the ability to invade into local stroma and associated vascular components 3 .Visualization of invadopodia-mediated ECM degradation of cells by fluorescent microscopy using dye-labeled matrix proteins coated onto glass coverslips has emerged as the most prevalent technique for evaluating the degree of matrix proteolysis and cellular invasive potential 4,5 . Here we describe a version of the standard method for generating fluorescently-labeled glass coverslips utilizing a commercially available Oregon Green-488 gelatin conjugate. This method is easily scaled to rapidly produce large numbers of coated coverslips. We show some of the common microscopic artifacts that are often encountered during this procedure and how these can be avoided. Finally, we describe standardized methods using readily available computer software to allow quantification of labeled gelatin matrix degradation mediated by individual cells and by entire cellular populations. The described procedures provide the ability to accurately and reproducibly monitor invadopodia activity, and can also serve as a platform for evaluating the efficacy of modulating protein expression or testing of anti-invasive compounds on extracellular matrix degradation in single and multicellular settings. Video LinkThe video component of this article can be found at http://www.jove.com/video/4119/ Protocol Production of Oregon Green 488-gelatin Coated Coverslips1. Prepare an unlabeled 5% (w/w) stock gelatin/sucrose solution by adding 1.25 g gelatin and 1.25 g sucrose in PBS to a final volume of 50 ml.Warm the stock gelatin solution to 37 °C and ensure it is entirely melted before use. Store the final mixture at 4 °C. 2. Clean 13 mm diameter #1 glass coverslips by placing an individual coverslip into each well of a 24 well plastic tissue culture plate. Add 500 μl of 20% nitric acid to each well and incubate for 30 min. Aspirate the nitric acid solution and wash coverslips three times with deionized water. 3. Coat coverslips with 500 μl of 50 μg/ml poly-L-lysine (prepared from 0.1% stock solution and diluted in deionized water) to each well for 20 min at room temperature. Aspirate the solution and wash three times with PBS. Poly-L-lysine coa...