EFFECTS OF FATIGUE ON RUGBY PLACE KICKING TECHNIQUE AND PERFORMANCE

The aim of this study was to identify differences in place kicking performance and technique following a rugby-specific fatigue protocol. Three skilled place kickers performed four blocks of the protocol, between which they took three place kicks from a challenging pitch location. The success of the kicks, measures of physical exertion and lower body and torso kinematic variables were measured. Kicking success dropped following blocks 2 and 4 of the protocol, all missed kicks were wide of the goalposts. Individual differences were apparent. After block 2 the kickers demonstrated greater upper body motion, potentially a strategy to obtain fast foot velocity but at a detriment to accuracy. After block 4, collapse of the stance leg was observed which may have impacted the kickers’ stability. Further research with more participants and a specific focus on muscular fatigue is required

The Effect of Attentional Focus Instructions on Performance and Technique in a Complex Open Skill

External focus of attention has been shown to promote more automatic motor control, yielding better performance and more efficient technique, than an internal focus (Wulf, 2013). However, most research has used closed-skill tasks in novices. The extent to which the reported pattern of findings generalises to more complex, time-constrained tasks requires further investigation. In this study we investigated the effect of attentional focus instructions on performance and technique in an open-skill task in skilled performers. Thirteen skilled cricket batters batted from a ball projector in four conditions, receiving instructions to focus on the movement of their hands (internal focus), the movement of their bat (proximal external focus), the flight of the ball (distal external focus), or no instruction (control). Performance and technique were measured by quality of bat-ball contacts and step length/knee flexion, respectively, whilst playing straight drives. Compared to external focus and control conditions, focusing internally yielded significantly worse batting performance and shorter step lengths, with the largest effects observed between internal and distal external focus conditions. Quality of bat-ball contact data suggested that participants’ ability to protect the wicket (as evidenced by more miss/edge shots) was more negatively affected by focusing internally than their ability to play shots to score runs (as evidenced by fewer good bat-ball contacts). Findings suggest that, for skilled performance of open-skill tasks, a distal external focus yields more effective performance and technique compared with focusing internally. Findings highlight the need for further research on attentional focus effects between different skills within specific sports

Extension and stress during continental breakup: seismic anisotropy of the crust in Northern Afar

Studies that attempt to simulate continental rifting and subsequent breakup require detailed knowledge of crustal stresses, however observational constraints from continental rifts are lacking. In addition, a knowledge of the stress field around active volcanoes can be used to detect sub-surface changes to the volcanic system. Here we use shear wave splitting to measure the seismic anisotropy of the crust in Northern Afar, a region of active, magma-rich continental breakup. We combine shear wave splitting tomography with modelling of gravitational and magmatic induced stresses to propose a model for crustal stress and strain across the rift. Results show that at the Ethiopian Plateau, seismic anisotropy is consistently oriented N–S. Seismic anisotropy within the rift is generally oriented NNW–SSE, with the exception of regions north and south of the Danakil Depression where seismic anisotropy is rift-perpendicular. These results suggest that the crust at the rift axis is characterized by rift-aligned structures and melt inclusions, consistent with a focusing of tectonic extension at the rift axis. In contrast, we show that at regions within the rift where extension rate is minimal the seismic anisotropy is best explained by the gravitationally induced stress field originating from variations in crustal thickness. Seismic anisotropy away from the rift is controlled by a combination of inherited crustal structures and gravitationally induced extension whereas at the Dabbahu region we show that the stress field changes orientation in response to magmatic intrusions. Our proposed model provides a benchmark of crustal stress in Northern Afar which will aid the monitoring of volcanic hazard. In addition we show that gravitational forces play a key role in measurements of seismic anisotropy, and must be considered in future studies. We demonstrate that during the final stages of continental rifting the stress field at the rift axis is primarily controlled by tectonic extension, but that gravitational forces and magmatic intrusions can play a key role in the orientation of the stress field

Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

SummaryBackground Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatoryactions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19.Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospitalwith COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients wererandomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once perday by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatmentgroups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment andwere twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants andlocal study staff were not masked to the allocated treatment, but all others involved in the trial were masked to theoutcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treatpopulation. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) wereeligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomlyallocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall,561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days(rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days(rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, nosignificant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilationor death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24).Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or otherprespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restrictedto patients in whom there is a clear antimicrobial indication