Optimising the front foot contact phase of the cricket fast bowling action

Cricket fast bowling is a dynamic activity in which a bowler runs up and repeatedly delivers the ball at high speeds. Experimental studies have previously linked ball release speed and several technique parameters with conflicting results. As a result, computer simulation models are increasingly being used to understand the effects of technique on performance. This study evaluates a planar 16-segment whole-body torque-driven simulation model of the front foot contact phase of fast bowling by comparing simulation output with the actual performance of an elite fast bowler. The model was customised to the bowler by determining subject-specific inertia and torque parameters. Good agreement was found between actual and simulated performances with a 4.0% RMS difference. Varying the activation timings of the torque generators resulted in an optimised simulation with a ball release speed 3.5 m/s faster than the evaluation simulation. The optimised technique used more extended front ankle and knee kinematics, increased trunk flexion and a longer delay in the onset of arm circumduction. These simulations suggest the model provides a realistic representation of the front foot contact phase of fast bowling and is suitable to investigate the limitations of other kinematic or kinetic variables on fast bowling performance

Respiratory syncytial virus hospitalization in middle-aged and older adults

BACKGROUND: The importance of Respiratory Syncytial Virus (RSV) is increasingly recognized in hospitalized adults, but mainly in those ≥ 65 years. OBJECTIVES: We sought to describe the epidemiology and clinical severity of RSV compared to influenza in hospitalized adults ≥18 years. STUDY DESIGN: Adults hospitalized with acute respiratory illnesses (ARI) of ≤10days duration were prospectively enrolled from two Michigan hospitals during two influenza seasons. Collected specimens were tested for RSV and influenza by real-time, reverse transcription polymerase chain reaction (RT-PCR). Viral load and subtype were determined for RSV-positive specimens. We evaluated factors associated with RSV and outcomes of infection using multivariable logistic regression. RSV-positive patients were separately compared to two reference groups: RSV-negative and influenza-negative, and influenza-positive patients. RESULTS: RSV was detected in 84 (7%) of 1259 hospitalized individuals (55 RSV-B, 29 RSV-A). The highest prevalence was found in 50-64year olds (40/460; 8.7%); 98% of RSV cases in this age group had at least one chronic comorbidity. RSV detection was associated with obesity (OR: 1.71 95% CI: 0.99-3.06, p=0.03). Individuals with RSV were admitted to the hospital later in their illness and had a higher median Charlson comborbidity index (3 vs 2 p\u3c0.001) compared to those with influenza. Clinical severity of RSV-associated hospitalizations was similar to influenza-associated hospitalizations. DISCUSSION: In this study we observed the highest frequency of RSV-associated hospitalizations among adult 50-64 years old; many of whom had chronic comorbidities. Our results suggest the potential benefit of including these individuals in future RSV vaccination strategies

Severe morbidity among hospitalised adults with acute influenza and other respiratory infections: 2014-2015 and 2015-2016

Our objective was to identify predictors of severe acute respiratory infection in hospitalised patients and understand the impact of vaccination and neuraminidase inhibitor administration on severe influenza. We analysed data from a study evaluating influenza vaccine effectiveness in two Michigan hospitals during the 2014-2015 and 2015-2016 influenza seasons. Adults admitted to the hospital with an acute respiratory infection were eligible. Through patient interview and medical record review, we evaluated potential risk factors for severe disease, defined as ICU admission, 30-day readmission, and hospital length of stay (LOS). Two hundred sixteen of 1119 participants had PCR-confirmed influenza. Frailty score, Charlson score and tertile of prior-year healthcare visits were associated with LOS. Charlson score \u3e2 (OR 1.5 (1.0-2.3)) was associated with ICU admission. Highest tertile of prior-year visits (OR 0.3 (0.2-0.7)) was associated with decreased ICU admission. Increasing tertile of visits (OR 1.5 (1.2-1.8)) was associated with 30-day readmission. Frailty and prior-year healthcare visits were associated with 30-day readmission among influenza-positive participants. Neuraminidase inhibitors were associated with decreased LOS among vaccinated participants with influenza A (HR 1.6 (1.0-2.4)). Overall, frailty and lack of prior-year healthcare visits were predictors of disease severity. Neuraminidase inhibitors were associated with reduced severity among vaccine recipients

Influenza Vaccine Effectiveness in the Inpatient Setting; Evaluation of Potential Bias in the Test Negative Design by use of Alternate Control Groups

The test negative design is validated in outpatient but not inpatient studies of influenza vaccine effectiveness. The prevalence of chronic pulmonary disease among inpatients may lead to nonrepresentative controls. Test negative design estimates are biased if vaccine administration is associated with incidence of non-influenza viruses. We evaluated whether control group selection and effects of vaccination on non-influenza viruses biased vaccine effectiveness in our study. Subjects were enrolled at the University of Michigan and Henry Ford hospitals during the 2014-15 and 2015-16 seasons. Patients presenting with acute respiratory infection were enrolled and tested for respiratory viruses. Vaccine effectiveness was estimated using three control groups: influenza negative, other respiratory virus positive, and pan-negative individuals; it was also estimated for other common respiratory viruses. In 2014-15, vaccine effectiveness was 41.1% (95% CI: 1.7%, 64.7%) using influenza negative, 24.5% (95% CI: -42.6%, 60.1%) using other-virus positive, and 45.8% (95% CI: 5.7%, 68.9%) using pan-negative controls. In 2015-16, vaccine effectiveness was 68.7% (95% CI: 44.6%, 82.5%) using influenza negative, 63.1% (95% CI: 25.0%, 82.2%) using other-virus positive, and 71.1% (46.2%, 84.8%) using pan-negative controls. Vaccination did not alter odds of other respiratory viruses. Results support use of the test negative design among inpatients