88 research outputs found

    A Review of the Internal and External Physiological Demands Associated With Batting in Cricket

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    Cricket is a popular international team sport with various game formats ranging from long-duration multiday tests to short-duration Twenty20 game play. The role of batsmen is critical to all game formats, with differing physiological demands imposed during each format. Investigation of the physiological demands imposed during cricket batting has historically been neglected, with much of the research focusing on bowling responses and batting technique. A greater understanding of the physiological demands of the batting role in cricket is required to assist strength and conditioning professionals and coaches with the design of training plans, recovery protocols, and player-management strategies. This brief review provides an updated synthesis of the literature examining the internal (eg, metabolic demands and heart rate) and external (eg, activity work rates) physiological responses to batting in the various game formats, as well as simulated play and small-sided-games training. Although few studies have been done in this area, the summary of data provides important insight regarding physiological responses to batting and highlights that more research on this topic is required. Future research is recommended to combine internal and external measures during actual game play, as well as comparing different game formats and playing levels. In addition, understanding the relationship between batting technique and physiological responses is warranted to gain a more holistic understanding of batting in cricket, as well as to develop appropriate coaching and training strategies

    CHANGES IN BACK SQUAT BAR VELOCITY AND PERCEIVED MUSCLE SORENESS FOLLOWING A STANDARDISED RUGBY LEAGUE MATCH SIMULATION

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    This study examined changes in back squat bar velocity and perceived muscle soreness following a rugby league match simulation protocol. Twenty male rugby league players (age: 19.8 ± 0.7 yrs) were recruited for this study. Back squat bar velocity and perceived muscle soreness of the lower body were collected on four days surrounding a match simulation: -24 h (prior to match simulation), +0 h (after the match simulation), +24 h and +48 h. Compared to baseline (-24h), there were non-significant decreases in maximum (dz=-0.50, moderate) back squat bar velocity +0 h. There was a significant increase in perceived muscle soreness at +0h only (p=0.003). Results suggest that elevated muscle soreness may not indicate impaired neuromuscular performance and highlight the importance of monitoring fatigue via multiple measures to ensure appropriate coaching decisions are made

    VALIDATION OF TWO MOBILE APPS TO PREDICT MAXIMAL STRENGTH

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    Through recent advances in smartphone technology, two mobile applications (apps), LizaPlus and PowerLift, have been developed to monitor strength training and predict 1RM based on maximal concentric velocity during submaximal exercises. The aim of this study was to assess the validity of the two apps to predict 1RM using the bench press exercise. Strong correlations were found between actual 1RM and predicted 1RM values (r-values: 0.80 to 0.86, p \u3c 0.001). Bland and Altman plots show a systematic bias such that predicted 1RMs tend to be higher than actual 1RM for both apps. Results indicate both apps are valid in predicting 1RM but there appears to be systematic bias to overestimate actual 1RM. Caution should be used when basing training loads on these predicted 1RM values as there is an increased risk of injury through prescription of excessive training load

    MEASURING INSTANTANEOUS VELOCITY IN FOUR SWIM STROKES USING AN AUTOMATIC HEAD TRACKING SYSTEM: A COMPARISON STUDY

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    This study compared instantaneous swimming velocity from an automated video-based system to a tethered speedometer. Twenty-two state- and national-level swimmers (7 M, 15 F; 14.5 ± 2.5 yrs) swam 25 m of each stroke at maximal intensity. Bland-Altman plots showed good agreement between systems for backstroke and freestyle but poorer agreement for butterfly and breaststroke. The RMS error was also lower in backstroke and freestyle compared to butterfly and breaststroke. The differences in systems may be explained by the different body segments tracked by each system (head vs hips) and with differences being more apparent during butterfly and breaststroke due to the wave-like motion of these strokes. While the automated video-based system is suitable for measuring instantaneous swimming velocity, coaches, sports scientists, and swimmers should be aware of larger discrepancies between systems when assessing butterfly and breaststroke

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

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    Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

    A multi-country test of brief reappraisal interventions on emotions during the COVID-19 pandemic.

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    The COVID-19 pandemic has increased negative emotions and decreased positive emotions globally. Left unchecked, these emotional changes might have a wide array of adverse impacts. To reduce negative emotions and increase positive emotions, we tested the effectiveness of reappraisal, an emotion-regulation strategy that modifies how one thinks about a situation. Participants from 87 countries and regions (n = 21,644) were randomly assigned to one of two brief reappraisal interventions (reconstrual or repurposing) or one of two control conditions (active or passive). Results revealed that both reappraisal interventions (vesus both control conditions) consistently reduced negative emotions and increased positive emotions across different measures. Reconstrual and repurposing interventions had similar effects. Importantly, planned exploratory analyses indicated that reappraisal interventions did not reduce intentions to practice preventive health behaviours. The findings demonstrate the viability of creating scalable, low-cost interventions for use around the world

    Comparison of static and dynamic balance training on muscle activation, static balance, jumping and sprint performance

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    The role of balance and balance training in athletic performance: -- Balance has long been recognized as an important factor in a number of sports (such as gymnastics, and figure skating) and more recently has been regarded as important in other sports as well. Lack of balance has been shown to be detrimental to optimal performance through decreases in strength and force production, increased fatigue as well as predisposition to injury. Much of the research regarding balance training focuses on injury rehabilitation and prevention with little focus on examining the effects of short and long term balance training on athletic performance. The purpose of this paper is therefore to provide a comprehensive review of literature regarding balance, short and long term effects of balance training and its possible beneficial effects on athletic performance. -- The objective of this study was to determine the effects static balance and dynamic balance training on muscle activation strategies, static balance, jump and sprint performance. Twenty-four recreationally active females were tested pre- and post-training (static balance training, n= 11, dynamic balance training, n = 7 and control group, n = 6). Experimental subjects completed either static or dynamic balance exercises 4 times per week for 6 weeks. Surface electromyography (EMG) was used to assess preparatory and reactive muscle activity of the rectus femoris (RF), biceps femoris (BF), and the soleus during one- and two-foot landings. Maximum vertical jump, static balance and sprint times were also examined. A 3-way ANOVA revealed a significant (p<.05) increase in reactive rectus femoris activity, as well as a group by time interaction for the reactive rectus femoris activity. The static balance group showed a 33% increase in reactive rectus femoris activity (p<.01). There was also significantly less reactive hamstring to quadriceps coactivation following training (p<.05). The group by time interaction for the static balance and maximum vertical jump height performance (p<.05) were also significant. The static balance training group showed a 33% improvement in static balance and 9% improvement in jump height performances. Based on the finding from this study, it appears that balance training is specific to task and therefore training programs should be designed to mimic the demands of the sport or activity

    Effects of a modified shoe on knee load in people with and those without knee osteoarthritis

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    OBJECTIVE: To evaluate the effects of a modified shoe that incorporates both lateral wedging and a variable-stiffness sole on knee joint loading in 3 populations: individuals with symptomatic and radiographic knee osteoarthritis (OA), asymptomatic overweight individuals, and asymptomatic healthy weight individuals. METHODS: Ninety participants (30 per group) underwent a 3-dimensional gait analysis across 3 test conditions: modified shoes, standard control shoes, and barefoot. For each condition, the first peak knee adduction moment (KAM) and knee flexion moment (KFM) (both expressed as Nm/[body weight x height]%) as well as the KAM impulse (expressed as Nm.s/[body weight x height]%) were determined. RESULTS: The modified shoes significantly reduced the peak KAM as compared to the control shoes in both the OA (P = 0.002) and the overweight (P = 0.03) groups. In the OA group, there was no significant difference in peak KAM when walking in the modified shoe as compared to walking barefoot. In the overweight and the healthy weight groups, the peak KAM when walking in the modified shoe was significantly higher than that when walking barefoot (P < 0.001). Irrespective of group, the KAM impulse was significantly reduced when walking in the modified shoe as compared to the control shoe (P < 0.001) and was significantly higher during both shoe conditions as compared to walking barefoot (P < 0.001). There was no change in the KFM between walking conditions for any group. CONCLUSION: The findings illustrate that a shoe incorporating both a lateral wedge and a variable-stiffness sole can significantly reduce medial knee joint load. Further research examining the effects of these shoes on pain, function, and structural changes in the joint is warrante

    Modified walking shoes for knee osteoarthritis mechanisms for reductions in the knee adduction moment /

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    The objective of this study was to examine mechanisms underpinning the reduction in knee adduction moment (KAM) and changes in frontal plane knee-ground reaction force (GRF) lever arm with a modified shoe that incorporates both a variable-stiffness sole and lateral wedging. Thirty individuals with symptomatic knee osteoarthritis (OA) and 30 overweight asymptomatic individuals underwent gait analyses wearing modified and standard shoes. In both groups, there was a decrease in the lever arm (p<0.001), and a lateral shift in the center of pressure (COP) offset (p</=0.001). There was no change in frontal plane or medial-lateral GRF magnitudes, lateral trunk lean or stance duration in either group. There was no significant change in the frontal plane hip-knee-ankle angle in the OA group but a significant decrease in the overweight group (p=0.003). In both groups, changes in lever arm and frontal plane GRF magnitude predicted change in peak KAM (p<0.01), but only change in lever arm predicted change in KAM impulse (p<0.001). In the OA group, changes in COP offset and medial-lateral GRF magnitude predicted change in lever arm (p<0.05), whereas changes in trunk lean and hip-knee-ankle angle predicted change in lever arm in the overweight group (p=0.01). In conclusion, the change in lever arm contributed the most to explaining change in KAM parameters with modified shoes. The change in the lever arm was driven by changes evident at the foot in the OA participants (COP and medial-lateral GRF), and by more proximal changes (hip-knee-ankle angle and trunk lean) in the overweight group
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