ENERGY FLOW AND IMPULSE PREDICTORS OF BAT SPEED DURING BASEBALL TEE BATTING USING THE LEAST ABSOLUTE SHRINKAGE AND SELECTION OPERATOR (LASSO) REGRESSION

The purposes of this study were to examine how energy is generated, absorbed, and transferred through the pelvis during the baseball swing and to identify the best model of ground reaction force (GRF) and energy flow (EF) predictors of bat speed using a LASSO regression, which reduced the dataset to a model of four EF and two impulse variables that best predicts bat speed. The findings indicate that the mechanical energy flows from the trunk to the lead leg via the pelvis as these segments rotate during the swing. It is hoped that these findings will aid coaches and athletes in better understanding which elements of the swing movement are most closely related to bat speed. Thus, coaches may be able to develop and implement training strategies accordingly to improve bat speed and player performance

DIFFERENCES IN THE ENERGY FLOW, GROUND REACTION FORCE, AND IMPULSE DURING BASEBALL TEE BATTING BETWEEN HIGH SCHOOL AND COLLEGIATE BASEBALL PLAYERS

The purposes of this study were to examine the differences in the peak impulses and ground reaction forces (GRF) of the lead and back legs as well as how energy flows (energy absorption, generation, and transfer) in the back hip, front hip, and L5S1 joints during the baseball swing phases between high school and collegiate baseball players. The findings indicate that the mechanical energy flows down the chain from the L5S1 joint to the pelvis into the lead leg during the bat acceleration phase of the swing in both participant groups. It is hoped that these findings may help coaches and athletes understand which kinetic components of the swing improve bat speed. Thus, coaches may develop training strategies to improve bat speed and player performance

ENERGY FLOW AND GROUND REACTION FORCE PREDICTORS OF BAT SWING SPEED DURING PITCHED BALL BATTING IN PROFESSIONAL BASEBALL PLAYERS

The purposes of this study are to determine how mechanical energy is absorbed, generated, and transferred during baseball hitting for professional athletes. This study also aims to identify which ground reaction force and energy flow variables influence bat speed. The findings of this study suggest that energy flows from the trunk to the lead leg as the pelvis rotates towards the pitcher. The results of this study emphasize the crucial role of the back leg and trunk during acceleration as well as eccentric contraction of muscles in the lead leg and trunk to decelerate during follow-through. Training strategies that improve muscular strength and mobility of the trunk and hips can be implemented to potentially increase bat speed

Bias estimation in study design: a meta-epidemiological analysis of transcatheter versus surgical aortic valve replacement

Background: Paucity of RCTs of non-drug technologies lead to widespread dependence on non-randomized studies. Relationship between nonrandomized study design attributes and biased estimates of treatment effects are poorly understood. Our purpose was to estimate the bias associated with specific nonrandomized study attributes among studies comparing transcatheter aortic valve implantation with surgical aortic valve replacement for the treatment of severe aortic stenosis. Results: We included 6 RCTs and 87 nonrandomized studies. Surgical risk scores were similar for comparison groups in RCTs, but were higher for patients having transcatheter aortic valve implantation in nonrandomized studies. Nonrandomized studies underestimated the benefit of transcatheter aortic valve implantation compared with RCTs. For example, nonrandomized studies without adjustment estimated a higher risk of postoperative mortality for transcatheter aortic valve implantation compared with surgical aortic valve replacement (OR 1.43 [95% CI 1.26 to 1.62]) than high quality RCTs (OR 0.78 [95% CI 0.54 to 1.11). Nonrandomized studies using propensity score matching (OR 1.13 [95% CI 0.85 to 1.52]) and regression modelling (OR 0.68 [95% CI 0.57 to 0.81]) to adjust results estimated treatment effects closer to high quality RCTs. Nonrandomized studies describing losses to follow-up estimated treatment effects that were significantly closer to high quality RCT than nonrandomized studies that did not. Conclusion: Studies with different attributes produce different estimates of treatment effects. Study design attributes related to the completeness of follow-up may explain biased treatment estimates in nonrandomized studies, as in the case of aortic valve replacement where high-risk patients were preferentially selected for the newer (transcatheter) procedure

A realist analysis of hospital patient safety in Wales:Applied learning for alternative contexts from a multisite case study

Background: Hospital patient safety is a major social problem. In the UK, policy responses focus on the introduction of improvement programmes that seek to implement evidence-based clinical practices using the Model for Improvement, Plan-Do-Study-Act cycle. Empirical evidence that the outcomes of such programmes vary across hospitals demonstrates that the context of their implementation matters. However, the relationships between features of context and the implementation of safety programmes are both undertheorised and poorly understood in empirical terms. Objectives: This study is designed to address gaps in conceptual, methodological and empirical knowledge about the influence of context on the local implementation of patient safety programmes. Design: We used concepts from critical realism and institutional analysis to conduct a qualitative comparative-intensive case study involving 21 hospitals across all seven Welsh health boards. We focused on the local implementation of three focal interventions from the 1000 Lives+ patient safety programme: Improving Leadership for Quality Improvement, Reducing Surgical Complications and Reducing Health-care Associated Infection. Our main sources of data were 160 semistructured interviews, observation and 1700 health policy and organisational documents. These data were analysed using the realist approaches of abstraction, abduction and retroduction. Setting: Welsh Government and NHS Wales. Participants: Interviews were conducted with 160 participants including government policy leads, health managers and professionals, partner agencies with strategic oversight of patient safety, advocacy groups and academics with expertise in patient safety. Main outcome measures: Identification of the contextual factors pertinent to the local implementation of the 1000 Lives+ patient safety programme in Welsh NHS hospitals. Results: An innovative conceptual framework harnessing realist social theory and institutional theory was produced to address challenges identified within previous applications of realist inquiry in patient safety research. This involved the development and use of an explanatory intervention–context–mechanism–agency–outcome (I-CMAO) configuration to illustrate the processes behind implementation of a change programme. Our findings, illustrated by multiple nested I-CMAO configurations, show how local implementation of patient safety interventions are impacted and modified by particular aspects of context: specifically, isomorphism, by which an intervention becomes adapted to the environment in which it is implemented; institutional logics, the beliefs and values underpinning the intervention and its source, and their perceived legitimacy among different groups of health-care professionals; and the relational structure and power dynamics of the functional group, that is, those tasked with implementing the initiative. This dynamic interplay shapes and guides actions leading to the normalisation or the rejection of the patient safety programme. Conclusions: Heightened awareness of the influence of context on the local implementation of patient safety programmes is required to inform the design of such interventions and to ensure their effective implementation and operationalisation in the day-to-day practice of health-care teams. Future work is required to elaborate our conceptual model and findings in similar settings where different interventions are introduced, and in different settings where similar innovations are implemented. Funding: The National Institute for Health Research Health Services and Delivery Research programme

Spoken-word recognition in foreign-accented speech by L2 listeners

Item does not contain fulltextTwo cross-modal priming studies investigated the recognition of English words spoken with a foreign accent. Auditory English primes were either typical of a Dutch accent or typical of a Japanese accent in English and were presented to both Dutch and Japanese L2 listeners. Lexical-decision times to subsequent visual target words revealed that foreign-accented words can facilitate word recognition for L2 listeners if at least one of two requirements is met: the foreign-accented production is in accordance with the language background of the L2 listener, or the foreign accent is perceptually confusable with the standard pronunciation for the L2 listener. If neither one of the requirements is met, no facilitatory effect of foreign accents on L2 word recognition is found. Taken together, these findings suggest that linguistic experience with a foreign accent affects the ability to recognize words carrying this accent, and there is furthermore a general benefit for L2 listeners for recognizing foreign-accented words that are perceptually confusable with the standard pronunciation