Simspetterson8783

© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.Background Coaches have the potential to support athlete mental wellness, but many are unsure what to do and concerned they may unintentionally engage in behaviours that negatively impact their athletes. Education has the potential to help coaches engage in primary, secondary and tertiary preventive behaviours related to athlete mental health; however, there exists no empirical or consensus basis for specifying the target behaviours that should be included in such education. Objective The aim of this research was to review extant literature about the role of sport coaches in mental health prevention and promotion, and obtain expert consensus about useful, appropriate and feasible coach behaviours. Design Modified Delphi methodology with exploration (ie, narrative review) and evaluation phase. Data sources Twenty-one articles from PubMed, PsycINFO and ProQuest, and grey literature published by prominent sport organisations. Eligibility criteria for selecting studies All studies were English-language articles that focused on the role of coaches as they relate to (1) culture setting in sport, (2) addressing athlete mental health and (3) providing ongoing support to athletes with mental health concerns. No study design, publication date limits or sport characteristics were applied. Results The coach's role should include fostering team cultures that support athlete mental health, encouraging care-seeking and supporting athletes currently receiving mental healthcare. Summary/Conclusion The behaviours specified herein have implications for coach education programme development. This study is the first to use a structured Delphi process to develop specific recommendations about the role coaches can play in supporting athlete mental health. © Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.Objective The purpose of this study was to determine the effect of fatigue level and sex on the range of motions of the lower extremities and impulses during the jump-landing phase after performing bilateral fatiguing tasks. Methods In total, 41 healthy young adults volunteered for this study. Participants' jump-landing trajectories were monitored using nine cameras, and ground reaction forces were measured using a force plate. Participants performed five maximal bilateral countermovement jumps as prefatiguing tasks. The fatiguing tasks consisted of maximal effort contractions of the knee extensor at 60°/s on a dynamometer until task failure, defined as the inability to reach 50% of the peak knee extension torque for three consecutive times. The post-task maximal bilateral jumps were immediately captured after the participants failed the fatiguing task. Participants were asked to perform this cycle again, performing the fatiguing contraction task until failure to reach 30% of the peak knee extension torque. Results and conclusion It was found that the knee joint was more extended in the post-30% fatiguing task, which was due to the reduction of the flexion angle of the hip and knee joints in response to fatigue level. The impulses for both sexes were reduced at the severe fatigue level. Fatigability altered jump-landing kinematics, jump heights and impulses in response to fatigue level. The post-30% fatiguing task elicited more fatigue than the post-50% fatiguing task. © Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY. Published by BMJ.Objectives Our aim of this study was to quantify the physical demands of elite rugby union players by each position as a step towards designing position-specific training programme using a Global Positioning System/accelerometer system. Methods This study was performed as a retrospective observational study. Data were obtained from 45 official matches. The sample size used for the analysis was 298. The per-match total distances, accelerations and impacts were calculated and statistically compared for the forwards and backs and for individual positions. Results Total distances for the forwards and backs were 5731.1±507.8 and 6392.1±646.8 m, respectively. The high-velocity running distances (>18.0 km/hour) covered by the forwards and backs were 317.4±136.9 and 715.0±242.9 m, respectively. The number of accelerations (>1.5 m/s2) for the forwards and backs were 76.3±18.9 and 100.8±19.6 times, respectively, and the number of high impacts (>10 g) were 48.0±46.9 and 35.6±28.3 times for the forwards and backs, respectively. All characteristics were significantly different between the forwards and backs (p less then 0.05). The per-position characteristics were also calculated. Within the backs, scrum half (SH) and wingers (WTBs) covered high-velocity running significantly higher distance than fly-half (SH d=2.571, WTBs d=1.556) and centres (SH d=1.299, WTBs d=0.685) (p less then 0.05). Conclusion By clarifying the physical demands according to the positions, it will be possible to create optimised position-specific training programmes. © Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.Objectives Non-tackle American football is growing in popularity, and it has been proposed as a safer alternative for young athletes interested in American football. Little is known about the nature of head contact in the sport, which is necessary to inform the extent to which protective headgear is warranted. The objective of this study was to identify the location, types and frequency of head and body contacts in competitive 7v7 non-tackle American football. Endoxifen Methods Video analysis was used to document the type, frequency and mechanism of contacts across a series of under 12, under 14 and high school non-tackle tournament games. A subset of impacts was quantitatively analysed via 3-D model-based image matching to calculate the preimpact and postimpact speed of players' heads and the change in resultant translational and rotational velocities. Results The incidence rate of head contact was found to be low (3.5 contacts per 1000 athlete-plays). Seventy-five per cent of head contacts were caused by a head-to-ground impact.