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Background: In recent years, there has been a large expansion in literature pertaining to the game of Australian football (AF). Furthermore, there have been a number of rule changes that are likely to have changed the demands of the game. Based on these advances and changes, it seemed important to conduct a review assessing the scientific literature surrounding the sport.Objective: The review evaluates the match demands of AF, the qualities required for success, and the impact training and competition have on adaptation, injury and fatigue.Methods: A systematic search of PubMed, CINAHL, SPORTDiscus, Web of Science and Scopus for AF literature was conducted; studies investigating match demands, physical qualities, training practices and injury were included. Weighted means and standard deviations were calculated for match demands and physical and anthropometric profiles across playing standards.Results: A total of 1830 articles were retrieved in the initial search, with 888 removed as duplicates, 626 removed for being non-relevant and a further 152 removed for being AF papers but not relevant to the review. As such, 164 AF papers were included in the review. Due to the intermittent high-intensity nature of match-play, players need a wide range of physical and technical qualities to excel, with speed, aerobic fitness, reactive agility and well-developed lean mass being central to success. Training for AF at the elite level is associated with high workloads, with players engaging in numerous training modalities; even altitude and heat training camps have been utilised by Australian Football League (AFL) teams to further augment fitness improvements. While high chronic workloads can be tolerated and are needed for improving physical qualities, careful planning and monitoring of internal and external workloads is required to minimise sharp spikes in load that are associated with injury.Conclusions: There is a complex interaction between numerous contextual factors that influence the match demands that are discussed in this review. Whilst players must have the physical capacities to cope with the intense physical demands of AF matches, the successful execution of technical skills during match-play is central to success. To develop these skills and attributes, specific and carefully planned and monitored training must be performed over a number of years. [ABSTRACT FROM AUTHOR]

Background: Soccer is the most popular sport worldwide, with a long history and currently more than 500 million active participants, of whom 300 million are registered football club members. On the basis of scientific findings showing positive fitness and health effects of recreational soccer, FIFA (Fédération Internationale de Football Association) introduced the slogan 'Playing football for 45 min twice a week-best prevention of non-communicable diseases' in 2010. Objective: The objective of this paper was to perform a systematic review and meta-analysis of the literature to determine the effects of recreational soccer on maximal oxygen uptake ( $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ ). Methods: Six electronic databases (MEDLINE, PubMed, SPORTDiscus, Web of Science, CINAHL and Google Scholar) were searched for original research articles. A manual search was performed to cover the areas of recreational soccer, recreational physical activity, recreational small-sided games and $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ using the following key terms, either singly or in combination: recreational small-sided games, recreational football, recreational soccer, street football, street soccer, effect, maximal oxygen uptake, peak oxygen uptake, cardiorespiratory fitness, $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ . The inclusion criteria were divided into four sections: type of study, type of participants, type of interventions and type of outcome measures. Probabilistic magnitude-based inferences for meta-analysed effects were based on standardised thresholds for small, moderate and large changes (0.2, 0.6 and 1.2, respectively) derived from between-subject standard deviations for baseline fitness. Results: Seventeen studies met the inclusion criteria and were included in the systematic review and meta-analysis. Mean differences showed that $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ increased by 3.51 mL/kg/min (95 % CI 3.07-4.15) over a recreational soccer training programme in comparison with other training models. The meta-analysed effects of recreational soccer on $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ compared with the controls of no exercise, continuous running and strength training were most likely largely beneficial [effect size (ES) = 1.46; 95 % confidence interval (CI) 0.91, 2.01; I = 88.35 %], most likely moderately beneficial (ES = 0.68; 95 % CI 0.06, 1.29; I = 69.13 %) and most likely moderately beneficial (ES = 1.08; 95 % CI −0.25, 2.42; I = 71.06 %), respectively. In men and women, the meta-analysed effect was most likely largely beneficial for men (ES = 1.22) and most likely moderately beneficial for women (ES = 0.96) compared with the controls. After 12 weeks of recreational soccer with an intensity of 78-84 % maximal heart rate (HR), healthy untrained men improved their $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ by 8-13 %, while untrained elderly participants improved their $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ by 15-18 %. Soccer training for 12-70 weeks in healthy women resulted in an improvement in $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ of 5-16 %. Significant improvements in $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ have been observed in patients with diabetes mellitus, hypertension and prostate cancer. Conclusion: Recreational soccer produces large improvements in $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ compared to strength training and no exercise, regardless of the age, sex and health status of the participants. Furthermore, recreational soccer is better than continuous endurance running, albeit the additional effect is moderate. This kind of physical activity has great potential for enhancing aerobic fitness, and for preventing and treating non-communicable diseases, and is ideal for addressing lack of motivation, a key component in physical (in)activity. [ABSTRACT FROM AUTHOR]

Background: Ankle sprain is one of the most common musculoskeletal injuries, yet a contemporary review and meta-analysis of prospective epidemiological studies investigating ankle sprain does not exist. Objective: Our aim is to provide an up-to-date account of the incidence rate and prevalence period of ankle sprain injury unlimited by timeframe or context activity. Methods: We conducted a systematic review and meta-analyses of English articles using relevant computerised databases. Search terms included Medical Search Headings for the ankle joint, injury and epidemiology. The following inclusion criteria were used: the study must report epidemiology findings of injuries sustained in an observed sample; the study must report ankle sprain injury with either incidence rate or prevalence period among the surveyed sample, or provide sufficient data from which these figures could be calculated; the study design must be prospective. Independent extraction of articles was performed by two authors using pre-determined data fields. Results: One-hundred and eighty-one prospective epidemiology studies from 144 separate papers were included. The average rating of all the included studies was 6.67/11, based on an adapted version of the STROBE (STrengthening the Reporting of OBservational studies in Epidemiology) guidelines for rating observational studies. 116 studies were considered high quality and 65 were considered low quality. The main findings of the meta-analysis demonstrated a higher incidence of ankle sprain in females compared with males (13.6 vs 6.94 per 1,000 exposures), in children compared with adolescents (2.85 vs 1.94 per 1,000 exposures) and adolescents compared with adults (1.94 vs 0.72 per 1,000 exposures). The sport category with the highest incidence of ankle sprain was indoor/court sports, with a cumulative incidence rate of 7 per 1,000 exposures or 1.37 per 1,000 athlete exposures and 4.9 per 1,000 h. Low-quality studies tended to underestimate the incidence of ankle sprain when compared with high-quality studies (0.54 vs 11.55 per 1,000 exposures). Ankle sprain prevalence period estimates were similar across sub-groups. Lateral ankle sprain was the most commonly observed type of ankle sprain. Conclusions: Females were at a higher risk of sustaining an ankle sprain compared with males and children compared with adolescents and adults, with indoor and court sports the highest risk activity. Studies at a greater risk of bias were more likely to underestimate the risk of ankle sprain. Participants were at a significantly higher risk of sustaining a lateral ankle sprain compared with syndesmotic and medial ankle sprains. [ABSTRACT FROM AUTHOR]

Background: The adolescent 'growth spurt' results in rapid growth of the skeletal system. It has been theorised that absence of a concomitant increase in muscular adaptations in female athletes may predispose them to an increased risk of anterior cruciate ligament injuries. Objectives: To determine if sex differences exist in landing biomechanics and postural stability of adolescent athletes; with a further objective of determining if such differences are propagated during adolescence. Data sources: The following databases were searched: MEDLINE, EMBASE, CINAHL, PEDro, PubMed, SPORTDiscus and Web of Science. Research papers were identified by including search terms for neuromuscular control, lower limb and pubertal development. Inclusion Criteria: Studies were required to be written in English; report on biomechanical analyses; include landing or postural control tasks; be cross-sectional or longitudinal; and include healthy adolescent/pubertal subjects. Study Appraisal and Synthesis Methods: A modified version of the Strengthening the Reporting of Observational studies in Epidemiology checklist was used to rate methodological quality. Meta-analyses were performed when more than one study reported on an outcome measure. Results: Sixteen articles were included. The overall methodological quality of evaluated studies was low (mean score = 5.75/10 points). Adolescent females exhibited increased knee valgus with increasing maturity. There was no consensus on sex differences in postural stability. Conclusions: With increasing maturation, females are characterized by increased knee valgus during landing tasks. To date, no research has longitudinally investigated postural stability development during adolescence in females, despite the importance of postural control training in injury prevention programmes. Therefore, further research on this topic is warranted. [ABSTRACT FROM AUTHOR]

Background: Although injuries to the head represent a small proportion of all sport injuries, they are of great concern due to their potential long-term consequences, which are even suspected in mild traumatic brain injuries.Objective: The aim of this review was to compare the incidence of concussions and other head injuries in elite level football, rugby, ice hockey and American Football.Methods: Four electronic databases (CINAHL, PsycINFO, Web of Science, PubMed) were searched. Prospective cohort studies on the incidence of concussion in elite athletes aged 17 years or older that were published in an English-language peer-reviewed journal since 2000 were included. Two authors independently evaluated study eligibility and quality. The extracted data on concussions were pooled in a meta-analysis using an inverse-variance fixed-effects model. The extracted data on head injuries were reported in a narrative and tabular summary.Results: The search yielded 7673 results of which 70 articles were included in the qualitative and 47 in the quantitative analysis. In our meta-analysis, we found the highest concussion incidences in rugby match play (3.89 and 3.00 concussions per 1000 h and athletic exposures (AEs), respectively), and the lowest in men’s football training (0.01 and 0.08 per 1000 h and AEs, respectively). Overall, concussions and all head injuries were rare in training when compared to match play. Female players had an increased concussion risk in football and ice hockey when compared to male players.Conclusion: Future research should focus on concussion in women’s contact sports, as there is little evidence available in this area. Methodological deficits are frequent in the current literature, especially regarding sample size and study power, and should be avoided. [ABSTRACT FROM AUTHOR]

Background: Team bat-or-stick sports, including cricket, softball and hockey, are popular among women. However, little is known about the injury profile in this population.Objective: The aim was to describe the incidence, nature and anatomical location of injuries in bat-or-stick sports played by women in a competitive league.Methods: This review was prospectively registered (PROSPERO CRD42015026715). CINAHL, MEDLINE, PsycINFO, PubMed, SPORTDiscus were systematically searched from January 2000 to September 2016, inclusive. Peer-reviewed original research articles reporting the incidence, nature and anatomical location of injuries sustained by women aged 18 + years in competitive bat-or-stick sports were included. Two meta-analyses based on injury incidence proportions (injury IP) and injury rates per 1000 person-days of athletic exposure (AE) were performed.Results: A total of 37 studies satisfied the inclusion criteria, and five had low risk of bias. The weighted injury IP was 0.42 [95% confidence interval (CI) 0.39–0.45]. The weighted injury rate was 6.12 (95% CI 6.05–6.18) overall, and greater in games [15.79 (95% CI 15.65–15.93)] than in practice [3.07 (95% CI 2.99–3.15)]. The ankle was the most commonly injured anatomical location, followed by the hand (including wrist and fingers), knee and head. Soft tissue and ligament injuries were most common types of injuries.Conclusion: Injury prevention in women’s sports is a novel and emerging field of research interest. This review highlights that injury incidence is high among female bat-or-stick players, but little information is known about direct causal mechanisms. This review clearly establishes the need for enhancements to injury data collection. Without this information, it will not be possible to develop evidence-based injury prevention interventions. [ABSTRACT FROM AUTHOR]

Background: Many factors are thought to contribute to chronic ankle instability (CAI). Multiple systematic reviews have synthesised the available evidence to identify the primary contributing factors. However, readers are now faced with several systematic reviews that present conflicting findings. Objective: The aim of this systematic review and meta-analysis was to establish the statistical significance and effect size of primary factors contributing to CAI and to identify likely reasons for inconsistencies in the literature. Methods: Relevant health databases were searched: CINAHL, MEDLINE, PubMed, Scopus and SPORTDiscus. Systematic reviews were included if they answered a focused research question, clearly defined the search strategy criteria and study selection/inclusion and completed a comprehensive search of the literature. Included reviews needed to be published in a peer-reviewed journal and needed to review observational studies of factors and/or characteristics of persons with CAI, with or without meta-analysis. There was no language restriction. Studies using a non-systematic review methodology (e.g. primary studies and narrative reviews) were excluded. Methodological quality of systematic reviews was assessed using the modified R-AMSTAR tool. Meta-analysis on included primary studies was performed. Results: Only 17% of primary studies measured a clearly defined CAI population. There is strong evidence to support the contribution of dynamic balance, peroneal reaction time and eversion strength deficits and moderate evidence for proprioception and static balance deficits to non-specific ankle instability. Conclusions: Evidence from previous systematic reviews does not accurately reflect the CAI population. For treatment of non-specific ankle instability, clinicians should focus on dynamic balance, reaction time and strength deficits; however, these findings may not be translated to the CAI population. Research should be updated with an adequately controlled CAI population. Systematic review registration: PROSPERO 2016, CRD42016032592. [ABSTRACT FROM AUTHOR]

Background: Late-stage rehabilitation programs often incorporate 'sport-specific' demands, but may not optimally simulate the in-game volume or intensity of such activities as sprinting, cutting, jumping, and lateral movement. Objective: The aim of this review was to characterize, quantify, and compare straight-line running and multi-directional demands during sport competition. Data Sources: A systematic review of PubMed, CINAHL, SPORTDiscus, and Cochrane Central Register of Controlled Trials databases was conducted. Study Eligibility Criteria: Studies that reported time-motion analysis data on straight-line running, accelerations/decelerations, activity changes, jumping, cutting, or lateral movement over the course of an entire competition in a multi-directional sport (soccer, basketball, lacrosse, handball, field hockey, futsal, volleyball) were included. Study Appraisal and Synthesis Methods: Data was organized based on sport, age level, and sex and descriptive statistics of the frequency, intensity, time, and volume of the characteristics of running and multi-directional demands were extracted from each study. Results: Eighty-one studies were included in the review ( n = 47 soccer, n = 11 basketball, n = 9 handball, n = 7 field hockey, n = 3 futsal, n = 4 volleyball). Variability of sport demand data was found across sports, sexes, and age levels. Specifically, soccer and field hockey demanded the most volume of running, while basketball required the highest ratio of high-intensity running to sprinting. Athletes change activity between 500 and 3000 times over the course of a competition, or once every 2-4 s. Studies of soccer reported the most frequent cutting (up to 800 per game), while studies of basketball reported the highest frequency of lateral movement (up to 450 per game). Basketball (42-56 per game), handball (up to 90 per game), and volleyball (up to 35 per game) were found to require the most jumping. Limitations: These data may provide an incomplete view of an athlete's straight-line running load, considering that only competition and not practice data was provided. Conclusions: Considerable variability exists in the demands of straight-line running and multi-directional demands across sports, competition levels, and sexes, indicating the need for sports medicine clinicians to design future rehabilitation programs with improved specificity (including the type of activity and dosage) to these demands. [ABSTRACT FROM AUTHOR]

Background: In professional senior soccer, training load monitoring is used to ensure an optimal workload to maximize physical fitness and prevent injury or illness. However, to date, different training load indicators are used without a clear link to training outcomes. Objective: The aim of this systematic review was to identify the state of knowledge with respect to the relationship between training load indicators and training outcomes in terms of physical fitness, injury, and illness. Methods: A systematic search was conducted in four electronic databases (CINAHL, PubMed, SPORTDiscus, and Web of Science). Training load was defined as the amount of stress over a minimum of two training sessions or matches, quantified in either external (e.g., duration, distance covered) or internal load (e.g., heart rate [HR]), to obtain a training outcome over time. Results: A total of 6492 records were retrieved, of which 3304 were duplicates. After screening the titles, abstracts and full texts, we identified 12 full-text articles that matched our inclusion criteria. One of these articles was identified through additional sources. All of these articles used correlations to examine the relationship between load indicators and training outcomes. For pre-season, training time spent at high intensity (i.e., >90 % of maximal HR) was linked to positive changes in aerobic fitness. Exposure time in terms of accumulated training, match or combined training, and match time showed both positive and negative relationships with changes in fitness over a season. Muscular perceived exertion may indicate negative changes in physical fitness. Additionally, it appeared that training at high intensity may involve a higher injury risk. Detailed external load indicators, using electronic performance and tracking systems, are relatively unexamined. In addition, most research focused on the relationship between training load indicators and changes in physical fitness, but less on injury and illness. Conclusion: HR indicators showed relationships with positive changes in physical fitness during pre-season. In addition, exposure time appeared to be related to positive and negative changes in physical fitness. Despite the availability of more detailed training load indicators nowadays, the evidence about the usefulness in relation to training outcomes is rare. Future research should implement continuous monitoring of training load, combined with the individual characteristics, to further examine their relationship with physical fitness, injury, and illness. [ABSTRACT FROM AUTHOR]

Background: Cardiorespiratory fitness (CRF) among people with severe mental illness (SMI) (i.e., schizophrenia, bipolar disorder, and major depressive disorder) is a critical clinical risk factor given its relationship to cardiovascular disease and premature mortality. Objectives: This study aimed to: (1) investigate the mean CRF in people with SMI versus healthy controls; (2) explore moderators of CRF; and (3) investigate whether CRF improved with exercise interventions and establish if fitness improves more than body mass index following exercise interventions. Methods: Major electronic databases were searched systematically. A meta-analysis calculating Hedges' g statistic was undertaken. Results: Across 23 eligible studies, pooled mean CRF was 28.7 mL/kg/min [95 % confidence interval (CI) 27.3 to 30.0 mL/kg/min, p < 0.001, n = 980]. People with SMI had significantly lower CRF compared with controls ( n = 310) (Hedges' g = −1.01, 95 % CI −1.18 to −0.85, p < 0.001). There were no differences between diagnostic subgroups. In a multivariate regression, first-episode ( β = 6.6, 95 % CI 0.6-12.6) and inpatient ( β = 5.3, 95 % CI 1.6-9.0) status were significant predictors of higher CRF. Exercise improved CRF (Hedges' g = 0.33, 95 % CI = 0.21-0.45, p = 0.001), but did not reduce body mass index. Higher CRF improvements were observed following interventions at high intensity, with higher frequency (at least three times per week) and supervised by qualified personnel (i.e., physiotherapists and exercise physiologists). Conclusion: The multidisciplinary treatment of people with SMI should include a focus on improving fitness to reduce all-cause mortality. Qualified healthcare professionals supporting people with SMI in maintaining an active lifestyle should be included as part of multidisciplinary teams in mental health treatment. [ABSTRACT FROM AUTHOR]

A combined estimate of injuries within a specific sport through pooled analysis provides more precise evidence and meaningful information about the sport, whilst controlling for between-study variation due to individual sub-cohort characteristics. The objective of this analysis was to review all published rugby league studies reporting injuries from match and training participation and report the pooled data estimates for rugby league concussion injury epidemiology. A systematic literature analysis of concussion in rugby league was performed on published studies from January 1990 to October 2015. Data were extracted and pooled from 25 studies that reported the number and incidence of concussions in rugby league match and training activities. Amateur rugby league players had the highest incidence of concussive injuries in match activities (19.1 per 1000 match hours) while semi-professional players had the highest incidence of concussive injuries in training activities (3.1 per 1000 training hours). This pooled analysis showed that, during match participation activities, amateur rugby league participants had a higher reported concussion injury rate than professional and semi-professional participants. Semi-professional participants had nearly a threefold greater concussion injury risk than amateur rugby league participants during match participation. They also had nearly a 600-fold greater concussion injury risk than professional rugby league participants during training participation. [ABSTRACT FROM AUTHOR]

Background: A number of resistance training (RT) program variables can be manipulated to maximize muscular hypertrophy. One variable of primary interest in this regard is RT frequency. Frequency can refer to the number of resistance training sessions performed in a given period of time, as well as to the number of times a specific muscle group is trained over a given period of time. Objective: We conducted a systematic review and meta-analysis to determine the effects of resistance training frequency on hypertrophic outcomes. Methods: Studies were deemed eligible for inclusion if they met the following criteria: (1) were an experimental trial published in an English-language refereed journal; (2) directly compared different weekly resistance training frequencies in traditional dynamic exercise using coupled concentric and eccentric actions; (3) measured morphologic changes via biopsy, imaging, circumference, and/or densitometry; (4) had a minimum duration of 4 weeks; and (5) used human participants without chronic disease or injury. A total of ten studies were identified that investigated RT frequency in accordance with the criteria outlined. Results: Analysis using binary frequency as a predictor variable revealed a significant impact of training frequency on hypertrophy effect size ( P = 0.002), with higher frequency being associated with a greater effect size than lower frequency (0.49 ± 0.08 vs. 0.30 ± 0.07, respectively). Statistical analyses of studies investigating training session frequency when groups are matched for frequency of training per muscle group could not be carried out and reliable estimates could not be generated due to inadequate sample size. Conclusions: When comparing studies that investigated training muscle groups between 1 to 3 days per week on a volume-equated basis, the current body of evidence indicates that frequencies of training twice a week promote superior hypertrophic outcomes to once a week. It can therefore be inferred that the major muscle groups should be trained at least twice a week to maximize muscle growth; whether training a muscle group three times per week is superior to a twice-per-week protocol remains to be determined. [ABSTRACT FROM AUTHOR]

Background: The FIFA Medical and Research Centre (F-MARC) has designed a comprehensive warm-up program targeting muscular strength, body kinaesthetic awareness, and neuromuscular control during static and dynamic movements to decrease injury risk for soccer players. Prior studies have investigated the effectiveness of the F-MARC programs, but have not consistently reported a statistically significant reduction in injury and reduction in time loss due to injury from utilizing the program. Objective: The purpose of this study was to conduct a systematic review and meta-analysis of randomized controlled trials and interventional studies that evaluated the efficacy of the F-MARC injury prevention programs in soccer. Methods: Two independent researchers searched the relevant article databases. The keyword domains used during the search were 'F-MARC', 'FIFA 11+', 'the 11+', 'injury prevention programs', 'soccer', and variations of these keywords. The initial search resulted in 4299 articles which were filtered to nine articles that met the inclusion criteria. Main inclusion criteria were randomized controlled trials or interventional studies, use of F-MARC injury prevention programs, and the primary outcome measuring overall and lower extremity injuries. Extracted data were entered and analyzed using Comprehensive Meta-Analysis software, version 2 (CMA.V2). Results: The pooled results based on total injuries per 1000 h of exposure showed that F-MARC injury prevention programs had a statistically significant reduction in the overall injury risk ratio of 0.771 (95 % CI 0.647-0.918, p = 0.003) and the lower extremity injury risk ratio of 0.762 (95 % CI 0.621-0.935, p = 0.009). Moreover, FIFA '11+' had a statistically significant reduction in the overall injury risk ratio to 0.654 (95 % CI 0.537-0.798, p < 0.001) and the lower extremity injury risk ratio of 0.612 (95 % CI 0.475-0.788, p < 0.001). However, FIFA '11' did not reach significance for the lower extremity and overall injury reduction. It can be suggested that teams involved in the FIFA '11+' warm-up program will reduce injury rates by between 20 and 50 % in the long term compared with the teams that do not engage in F-MARC programs. Conclusions: This systematic review and meta-analysis indicated that use of F-MARC injury prevention programs, particularly the '11+' program, decreases the risk of injuries among soccer players. These data also support the case for the development and introduction of sport-specific programs. [ABSTRACT FROM AUTHOR]

Background: The vertical jump (VJ) is considered a key indicator of lower limb explosive strength. Previous research has established that rate of force development and time to peak force are linked closely to athletic ability and hence the ability to extract these accurately is of significance. Objectives: The objectives of this study were to (1) review the literature to ascertain what methods are currently used to extract jump phases from the force platform data and (2) compare identified methods on neutral data. Methods: In Part 1, an electronic search was conducted using PubMed, Central, and EBSCO host (January 1965 to April 2014). Articles were included if they (1) detailed how VJ phases from the force platform data were identified and (2) used only force platform data in the analysis. Additionally, study design and quality was independently examined. In Part 2, the three common methodologies identified were used to analyze a neutral pool of data to determine if any variance existed. Results: For Part 1, a total of 19 studies met the inclusion criteria. Meta-analysis determined three methods of phase identification used in the literature from which to extract force-time variables. In Part 2, a one-way analysis of variance and Scheffe's post-hoc tests showed significant differences ( p < 0.01) for force-time variables (eccentric phase time, concentric phase time, time to peak force, rate of force development) between methods. Conclusion: The results demonstrate that three common methods exist for determination of the VJ phases from force platform data. Consequently, each produce different values for force-time variables when used on a neutral data pool. There is a clear need for a robust agreed method for VJ analysis. [ABSTRACT FROM AUTHOR]

Background: The promotion of sport and physical activity (PA) for children is widely recommended to support a healthy lifestyle, but being engaged in sport bears the risk of sustaining injuries. Injuries, in turn, can lead to a reduction in current and future involvement in PA and, therefore, may negatively affect future health as well as quality of life. Thus, sports injury prevention is of particular importance in youth. Objective: The aim of this systematic review was to quantify the effectiveness of exercise-based injury prevention programs in child and adolescent sport in general, and with respect to different characteristics of the target group, injury prevention program, and outcome variables. Data Sources: An Internet-based literature search was conducted in six databases (CINAHL, Cochrane, EMBASE, ISI Web of Science, PubMed, SPORTDiscus) using the following search terms with Boolean conjunction: (sport injur* OR athletic injur* OR sport accident*) AND (prevent* OR prophylaxis OR avoidance) AND (child* OR adolescent OR youth). Study Selection: Randomized controlled trials and controlled intervention studies in organized sport, published in English in a peer-reviewed journal, analyzing the effects of an exercise-based injury prevention program in athletes younger than 19 years of age. Data Extraction: Two reviewers evaluated eligibility and methodological quality. Main outcome extracted was the rate ratio (RR). Statistical analyses were conducted using the inverse-variance random effects model. Results: Twenty-one trials, conducted on a total of 27,561 athletes (median age 16.7 years [range 10.7-17.8]), were included. The overall RR was 0.54 (95 % CI 0.45-0.67) [ p < 0.001]. Girls profited more from injury prevention than boys ( p = 0.05). Both prevention programs with a focus on specific injuries (RR 0.48 [95 % CI 0.37-0.63]) and those aiming at all injuries (RR 0.62 [95 % CI 0.48-0.81]) showed significant reduction effects. Pre-season and in-season interventions were similarly beneficial ( p = 0.93). Studies on programs that include jumping/plyometric exercises showed a significant better ( p = 0.002) injury preventive effect (RR 0.45 [95 % CI 0.35-0.57], Z = 6.35, p < 0.001) than studies without such exercises (RR 0.74 [95 % CI 0.61-0.90], Z = 3.03, p = 0.002). Conclusions: The results provide good evidence and clearly demonstrate beneficial effects of exercise-based injury prevention programs in youth sports as they can result in statistically significant and practically relevant injury reduction. In particular, multimodal programs including jumping/plyometric exercises can be recommended. However, there is a considerable lack of data for children (under 14 years of age) and for individual sports in general. Future research should include these groups and focus on the effect of specific exercises and compliance. [ABSTRACT FROM AUTHOR]

Background: Skeletal muscle plays an important role in maintaining the stability of the lumbar region. However, there is conflicting evidence regarding the effects of exercise on trunk muscle morphology. Objective: To systematically review the literature on the effects of exercise training on lower trunk muscle morphology to determine the comparative effectiveness of different exercise interventions. Data Source and Study Selection: A systematic search strategy was conducted in the following databases: PubMed, SportDiscus, CINAHL, the Cochrane Library and PEDro. We included full, peer-reviewed, prospective longitudinal studies, including randomized controlled trials and single-group designs, such as pre- to post-intervention and crossover studies, reporting on the effect of exercise training on trunk muscle morphology. Study Appraisal and Synthesis: Study quality was assessed with the Cochrane risk-of-bias tool. We classified each exercise intervention into four categories, based on the primary exercise approach: motor control, machine-based resistance, non-machine-based resistance or cardiovascular. Treatment effects were estimated using within-group standardized mean differences (SMDs). Results: The systematic search identified 1,911 studies; of which 29 met our selection criteria: motor control ( n = 12), machine-based resistance ( n = 10), non-machine-based resistance ( n = 5) and cardiovascular ( n = 2). Fourteen studies (48 %) reported an increase in trunk muscle size following exercise training. Among positive trials, the largest effects were reported by studies testing combined motor control and non-machine-based resistance exercise (SMD [95 % CI] = 0.66 [0.06 to 1.27] to 3.39 [2.80 to 3.98]) and machine-based resistance exercise programmes (SMD [95 % CI] = 0.52 [0.01 to 1.03] to 1.79 [0.87 to 2.72]). Most studies investigating the effects of non-machine-based resistance exercise reported no change in trunk muscle morphology, with one study reporting a medium effect on trunk muscle size (SMD [95 % CI] = 0.60 [0.03 to 1.16]). Cardiovascular exercise interventions demonstrated no effect on trunk muscle morphology (SMD [95 % CI] = −0.16 [−1.14 to 0.81] to 0.09 [−0.83 to 1.01]). Limitations: We excluded studies published in languages other than English, and therefore it is possible that the results of relevant studies are not represented in this review. There was large clinical heterogeneity between the included studies, which prevented data synthesis. Among the studies included in this review, common sources of potential bias were random sequence generation, allocation concealment and blinding. Finally, the details of the exercise parameters were poorly reported in most studies. Conclusion: Approximately half of the included studies reported an increase in lower trunk muscle size following participation in an exercise programme. Among positive trials, studies involving motor control exercises combined with non-machine-based resistance exercise, as well as machine-based resistance exercises, demonstrated medium to large effects on trunk muscle size. Most studies examining the effect of non-machine-based resistance exercise and all studies investigating cardiovascular exercise reported no effect on trunk muscle morphology. However, these results should be interpreted with caution because of the substantial risk of bias and suboptimal reporting of exercise details in the included studies. Additional research, using methods ensuring a low risk of bias, are required to further elucidate the effects of exercise on trunk muscle morphology. [ABSTRACT FROM AUTHOR]

Background and Objective: Skeletal muscle wasting resulting in reduced muscular strength and health-related quality of life (HR-QOL) is common in chronic kidney disease (CKD) and may be reversed with progressive resistance training (PRT). Therefore, we systematically assessed the effect of PRT on measures of skeletal muscle hypertrophy, muscular strength and HR-QOL in this cohort to inform clinical practice and guidelines. Design: We performed a systematic review and meta-analysis. Inclusion Criteria: We included randomised controlled trials (RCTs) that investigated the independent effect of PRT (>6 weeks) on measures of skeletal muscle hypertrophy [muscle mass or cross-sectional area (CSA)], muscular strength and/or HR-QOL in adults with CKD. Data Extraction and Analysis: The standardised mean difference (SMD) from each study was pooled to produce an overall estimate of effect and associated 95 % confidence interval (95 % CI) between treatment and control groups on primary outcomes. Results: Seven RCTs in 271 patients with Stage 3-5 CKD yielded seven studies on muscular strength ( N = 249), six studies on total body muscle mass ( N = 200) and six studies on HR-QOL ( N = 223). PRT significantly improved standardised muscular strength [SMD 1.15 (95 % CI 0.80-1.49)] and HR-QOL [SMD 0.83 (95 % CI 0.51-1.16)], but not total body muscle mass [SMD 0.29 (95 % CI −0.27 to 0.86)] in our primary analysis. However, secondary analysis of six studies showed that PRT induced significant muscle hypertrophy of the lower extremities (leg mass, or mid-thigh or quadriceps CSA) [SMD 0.43 (95 % CI 0.11-0.76)], a pertinent analysis given that most studies implemented lower-body PRT only. Conclusions: Robust evidence from RCTs indicates that PRT can induce skeletal muscle hypertrophy and increase muscular strength and HR-QOL outcomes in men and women with CKD. Therefore, clinical practice guidelines should be updated to inform clinicians on the benefits of PRT in this cohort. [ABSTRACT FROM AUTHOR]

Background: Resistance and aerobic exercises are both recommended as effective treatments for people with type 2 diabetes. However, the optimum type of exercise for the disease remains to be determined to inform clinical decision-making and facilitate personalized exercise prescription. Objectives: Our objective was to investigate whether resistance exercise is comparable to aerobic exercise in terms of effectiveness and safety in people with type 2 diabetes. Data sources: PubMed, EMBASE, CENTRAL, CINAHL, and SPORTdiscus were systematically searched up to March 2013. The reference lists of eligible studies and relevant reviews were also checked. Study Selection: We used the following criteria to select studies for inclusion in the review: (i) the study was a randomized controlled trial; (ii) the participants were people with type 2 diabetes aged 18 years or more; (iii) the trial compared resistance exercise with aerobic exercise for a duration of at least 8 weeks, with pre-determined frequency, intensity, and duration; and (iv) the trial provided relevant data on at least one of the following: glycaemic control, blood lipids, anthropometric measures, blood pressure, fitness, health status, and adverse events. Study Appraisal and Synthesis Methods: The assessment of study quality was based on the Cochrane Risk of Bias tool. For effectiveness measures, differences (resistance group minus aerobic group) in the changes from baseline with the two exercises were combined, using a random-effects model wherever possible. For adverse events, the relative risks (resistance group vs. aerobic group) were combined. Results: Twelve trials ( n = 626) were included. Following the exercise interventions, there was a greater reduction of glycosylated hemoglobin with aerobic exercise than with resistance exercise (difference 0.18 % (1.97 mmol/mol), 95 % confidence interval (CI) 0.01, 0.36). This difference became non-significant with sensitivity analysis ( p = 0.14). The differences in changes from baseline were also statistically significant for body mass index (difference 0.22, 95 % CI 0.06, 0.39), peak oxygen consumption (difference −1.84 mL/kg/min, 95 % CI −3.07, −0.62), and maximum heart rate (difference 3.44 beats per minute, 95 % CI 2.49, 4.39). Relative risks for adverse events (all) and serious adverse events were 1.17 (95 % CI 0.77, 1.79) and 0.89 (95 % CI 0.18, 4.39), respectively. Limitations: Most included trials were short term (8 weeks to 6 months), and seven had important methodological limitations. Additionally, the meta-analyses for some of the secondary outcomes had a small number of participants or substantial statistical heterogeneity. Conclusions: Although differences in some diabetic control and physical fitness measures between resistance exercise and aerobic exercise groups reached statistical significance, there is no evidence that they are of clinical importance. There is also no evidence that resistance exercise differs from aerobic exercise in impact on cardiovascular risk markers or safety. Using one or the other type of exercise for type 2 diabetes may be less important than doing some form of physical activity. Future long-term studies focusing on patient-relevant outcomes are warranted. [ABSTRACT FROM AUTHOR]

Background: Although a series of meta-analyses demonstrated neuromuscular training (NMT) is an effective intervention to reduce anterior cruciate ligament (ACL) injury in female athletes, the potential existence of a dosage effect remains unknown. Objective: Our objective was to systematically review previously published clinical trials and evaluate potential dosage effects of NMT for ACL injury reduction in female athletes. Design: This study took the form of a meta- and sub-group analysis. Setting: The keywords 'knee', 'anterior cruciate ligament', 'ACL', 'prospective', 'neuromuscular', 'training', 'female', and 'prevention' were utilized in PubMed and EBSCO host for studies published between 1995 and May 2012. Participants: Inclusion criteria set for studies in the current analysis were (i) recruited female athletes as subjects, (ii) documented the number of ACL injuries, (iii) employed an NMT intervention aimed to reduce ACL injuries, (iv) had a control group, (v) used a prospective control trial design, and (vi) provided NMT session duration and frequency information. Main outcome measures: The number of ACL injuries and female athletes in each group (control and intervention) were compared based on duration, frequency, and volume of NMT via odds ratios (ORs). Results: A total of 14 studies were reviewed. Analyses that compared the number of ACL injuries with short versus long NMT duration showed greater ACL injury reduction in female athletes who were in the long NMT duration group (OR 0.35, 95 % CI 0.23-0.53, p = 0.001) than in those in the short NMT duration group (OR 0.61, 95 % CI 0.41-0.90, p = 0.013). Analyses that compared single versus multi NMT frequency indicated greater ACL injury reduction in multi NMT frequency (OR 0.35, 95 % CI 0.23-0.53, p = 0.001) compared with single NMT frequency (OR 0.62, 95 % CI 0.41-0.94, p = 0.024). Combining the duration and frequency of NMT programs, an inverse dose-response association emerged among low (OR 0.66, 95 % CI 0.43-0.99, p = 0.045), moderate (OR 0.46, 95 % CI 0.21-1.03, p = 0.059), and high (OR 0.32, 95 % CI 0.19-0.52, p = 0.001) NMT volume categories. Conclusions: The inverse dose-response association observed in the subgroup analysis suggests that the higher the NMT volume, the greater the prophylactic effectiveness of the NMT program and increased benefit in ACL injury reduction among female athletes. [ABSTRACT FROM AUTHOR]