Showing papers in "British Journal of Sports Medicine in 2017"

Consensus statement on concussion in sport—the 5th international conference on concussion in sport held in Berlin, October 2016

Abstract: The 2017 Concussion in Sport Group (CISG) consensus statement is designed to build on the principles outlined in the previous statements1–4 and to develop further conceptual understanding of sport-related concussion (SRC) using an expert consensus-based approach. This document is developed for physicians and healthcare providers who are involved in athlete care, whether at a recreational, elite or professional level. While agreement exists on the principal messages conveyed by this document, the authors acknowledge that the science of SRC is evolving and therefore individual management and return-to-play decisions remain in the realm of clinical judgement. This consensus document reflects the current state of knowledge and will need to be modified as new knowledge develops. It provides an overview of issues that may be of importance to healthcare providers involved in the management of SRC. This paper should be read in conjunction with the systematic reviews and methodology paper that accompany it. First and foremost, this document is intended to guide clinical practice; however, the authors feel that it can also help form the agenda for future research relevant to SRC by identifying knowledge gaps. A series of specific clinical questions were developed as part of the consensus process for the Berlin 2016 meeting. Each consensus question was the subject of a specific formal systematic review, which is published concurrently with this summary statement. Readers are directed to these background papers in conjunction with this summary statement as they provide the context for the issues and include the scope of published research, search strategy and citations reviewed for each question. This 2017 consensus statement also summarises each topic and recommendations in the context of all five CISG meetings (that is, 2001, 2004, 2008, 2012 as well as 2016). Approximately 60 000 published articles were screened by the expert panels for the Berlin …

Predictors of clinical recovery from concussion: a systematic review

Abstract: Objective A systematic review of factors that might be associated with, or influence, clinical recovery from sport-related concussion. Clinical recovery was defined functionally as a return to normal activities, including school and sports, following injury. Design Systematic review. Data sources PubMed, PsycINFO, MEDLINE, CINAHL, Cochrane Library, EMBASE, SPORTDiscus, Scopus and Web of Science. Eligibility criteria for selecting studies Studies published by June of 2016 that addressed clinical recovery from concussion. Results A total of 7617 articles were identified using the search strategy, and 101 articles were included. There are major methodological differences across the studies. Many different clinical outcomes were measured, such as symptoms, cognition, balance, return to school and return to sports, although symptom outcomes were the most frequently measured. The most consistent predictor of slower recovery from concussion is the severity of a person’s acute and subacute symptoms. The development of subacute problems with headaches or depression is likely a risk factor for persistent symptoms lasting greater than a month. Those with a preinjury history of mental health problems appear to be at greater risk for having persistent symptoms. Those with attention deficit hyperactivity disorder (ADHD) or learning disabilities do not appear to be at substantially greater risk. There is some evidence that the teenage years, particularly high school, might be the most vulnerable time period for having persistent symptoms—with greater risk for girls than boys. Conclusion The literature on clinical recovery from sport-related concussion has grown dramatically, is mostly mixed, but some factors have emerged as being related to outcome.

Exercise to prevent falls in older adults: an updated systematic review and meta-analysis

Abstract: Objective Previous meta-analyses have found that exercise prevents falls in older people. This study aimed to test whether this effect is still present when new trials are added, and it explores whether characteristics of the trial design, sample or intervention are associated with greater fall prevention effects. Design Update of a systematic review with random effects meta-analysis and meta-regression. Data sources Cochrane Library, CINAHL, MEDLINE, EMBASE, PubMed, PEDro and SafetyLit were searched from January 2010 to January 2016. Study eligibility criteria We included randomised controlled trials that compared fall rates in older people randomised to receive exercise as a single intervention with fall rates in those randomised to a control group. Results 99 comparisons from 88 trials with 19 478 participants were available for meta-analysis. Overall, exercise reduced the rate of falls in community-dwelling older people by 21% (pooled rate ratio 0.79, 95% CI 0.73 to 0.85, p<0.001, I2 47%, 69 comparisons) with greater effects seen from exercise programmes that challenged balance and involved more than 3 hours/week of exercise. These variables explained 76% of the between-trial heterogeneity and in combination led to a 39% reduction in falls (incident rate ratio 0.61, 95% CI 0.53 to 0.72, p<0.001). Exercise also had a fall prevention effect in community-dwelling people with Parkinson's disease (pooled rate ratio 0.47, 95% CI 0.30 to 0.73, p=0.001, I2 65%, 6 comparisons) or cognitive impairment (pooled rate ratio 0.55, 95% CI 0.37 to 0.83, p=0.004, I2 21%, 3 comparisons). There was no evidence of a fall prevention effect of exercise in residential care settings or among stroke survivors or people recently discharged from hospital. Summary/conclusions Exercise as a single intervention can prevent falls in community-dwelling older people. Exercise programmes that challenge balance and are of a higher dose have larger effects. The impact of exercise as a single intervention in clinical groups and aged care facility residents requires further investigation, but promising results are evident for people with Parkinson's disease and cognitive impairment.

The Sport Concussion Assessment Tool 5th Edition (SCAT5): Background and rationale.

Abstract: This paper presents the Sport Concussion Assessment Tool 5th Edition (SCAT5), which is the most recent revision of a sport concussion evaluation tool for use by healthcare professionals in the acute evaluation of suspected concussion. The revision of the SCAT3 (first published in 2013) culminated in the SCAT5. The revision was based on a systematic review and synthesis of current research, public input and expert panel review as part of the 5th International Consensus Conference on Concussion in Sport held in Berlin in 2016. The SCAT5 is intended for use in those who are 13 years of age or older. The Child SCAT5 is a tool for those aged 5–12 years, which is discussed elsewhere.

Effects of high-intensity interval training on cardiometabolic health: a systematic review and meta-analysis of intervention studies

Abstract: The current review clarifies the cardiometabolic health effects of high-intensity interval training (HIIT) in adults. A systematic search (PubMed) examining HIIT and cardiometabolic health markers was completed on 15 October 2015. Sixty-five intervention studies were included for review and the methodological quality of included studies was assessed using the Downs and Black score. Studies were classified by intervention duration and body mass index classification. Outcomes with at least 5 effect sizes were synthesised using a random-effects meta-analysis of the standardised mean difference (SMD) in cardiometabolic health markers (baseline to postintervention) using Review Manager 5.3. Short-term (ST) HIIT (<12 weeks) significantly improved maximal oxygen uptake (VO2 max; SMD 0.74, 95% CI 0.36 to 1.12; p<0.001), diastolic blood pressure (DBP; SMD −0.52, 95% CI −0.89 to −0.16; p<0.01) and fasting glucose (SMD −0.35, 95% CI −0.62 to −0.09; p<0.01) in overweight/obese populations. Long-term (LT) HIIT (≥12 weeks) significantly improved waist circumference (SMD −0.20, 95% CI −0.38 to −0.01; p<0.05), % body fat (SMD −0.40, 95% CI −0.74 to −0.06; p<0.05), VO2 max (SMD 1.20, 95% CI 0.57 to 1.83; p<0.001), resting heart rate (SMD −0.33, 95% CI −0.56 to −0.09; p<0.01), systolic blood pressure (SMD −0.35, 95% CI −0.60 to −0.09; p<0.01) and DBP (SMD −0.38, 95% CI −0.65 to −0.10; p<0.01) in overweight/obese populations. HIIT demonstrated no effect on insulin, lipid profile, C reactive protein or interleukin 6 in overweight/obese populations. In normal weight populations, ST-HIIT and LT-HIIT significantly improved VO2 max, but no other significant effects were observed. Current evidence suggests that ST-HIIT and LT-HIIT can increase VO2 max and improve some cardiometabolic risk factors in overweight/obese populations.

A systematic review of potential long-term effects of sport-related concussion.

Abstract: Objective Systematic review of possible long-term effects of sports-related concussion in retired athletes. Data sources Ten electronic databases. Study selection Original research; incidence, risk factors or causation related to long-term mental health or neurological problems; individuals who have suffered a concussion; retired athletes as the subjects and possible long-term sequelae defined as >10 years after the injury. Data extraction Study population, exposure/outcome measures, clinical data, neurological examination findings, cognitive assessment, neuroimaging findings and neuropathology results. Risk of bias and level of evidence were evaluated by two authors. Results Following review of 3819 studies, 47 met inclusion criteria. Some former athletes have depression and cognitive deficits later in life, and there is an association between these deficits and multiple prior concussions. Former athletes are not at increased risk for death by suicide (two studies). Former high school American football players do not appear to be at increased risk for later life neurodegenerative diseases (two studies). Some retired professional American football players may be at increased risk for diminishment in cognitive functioning or mild cognitive impairment (several studies), and neurodegenerative diseases (one study). Neuroimaging studies show modest evidence of macrostructural, microstructural, functional and neurochemical changes in some athletes. Conclusion Multiple concussions appear to be a risk factor for cognitive impairment and mental health problems in some individuals. More research is needed to better understand the prevalence of chronic traumatic encephalopathy and other neurological conditions and diseases, and the extent to which they are related to concussions and/or repetitive neurotrauma sustained in sports.

Blood flow restriction training in clinical musculoskeletal rehabilitation: a systematic review and meta-analysis

Abstract: Background and objective Low-load exercise training with blood flow restriction (BFR) can increase muscle strength and may offer an effective clinical musculoskeletal (MSK) rehabilitation tool. The aim of this review was to systematically analyse the evidence regarding the effectiveness of this novel training modality in clinical MSK rehabilitation. Design This is a systematic review and meta-analysis of peer-reviewed literature examining BFR training in clinical MSK rehabilitation (Research Registry; researchregistry91). Data sources A literature search was conducted across SPORTDiscus (EBSCO), PubMed and Science Direct databases, including the reference lists of relevant papers. Two independent reviewers extracted study characteristics and MSK and functional outcome measures. Study quality and reporting was assessed using the Tool for the assEssment of Study qualiTy and reporting in EXercise. Eligibility Search results were limited to exercise training studies investigating BFR training in clinical MSK rehabilitation, published in a scientific peer-reviewed journal in English. Results Twenty studies were eligible, including ACL reconstruction (n=3), knee osteoarthritis (n=3), older adults at risk of sarcopenia (n=13) and patients with sporadic inclusion body myositis (n=1). Analysis of pooled data indicated low-load BFR training had a moderate effect on increasing strength (Hedges’ g=0.523, 95% CI 0.263 to 0.784, p Conclusion Compared with low-load training, low-load BFR training is more effective, tolerable and therefore a potential clinical rehabilitation tool. There is a need for the development of an individualised approach to training prescription to minimise patient risk and increase effectiveness.

What is the difference in concussion management in children as compared with adults? A systematic review

Abstract: Aim To evaluate the evidence regarding the management of sport-related concussion (SRC) in children and adolescents. The eight subquestions included the effects of age on symptoms and outcome, normal and prolonged duration, the role of computerised neuropsychological tests (CNTs), the role of rest, and strategies for return to school and return to sport (RTSp). Design Systematic review. Data sources MEDLINE (OVID), Embase (OVID) and PsycInfo (OVID). Eligibility criteria for selecting studies Studies were included if they were original research on SRC in children aged 5 years to 18 years, and excluded if they were review articles, or did not focus on childhood SRC. Results A total of 5853 articles were identified, and 134 articles met the inclusion criteria. Some articles were common to multiple subquestions. Very few studies examined SRC in young children, aged 5–12 years. Summary/conclusions This systematic review recommends that in children: child and adolescent age-specific paradigms should be applied; child-validated symptom rating scales should be used; the widespread routine use of baseline CNT is not recommended; the expected duration of symptoms associated with SRC is less than 4 weeks; prolonged recovery be defined as symptomatic for greater than 4 weeks; a brief period of cognitive and physical rest should be followed with gradual symptom-limited physical and cognitive activity; all schools be encouraged to have a concussion policy and should offer appropriate academic accommodations and support to students recovering from SRC; and children and adolescents should not RTSp until they have successfully returned to school, however early introduction of symptom-limited physical activity is appropriate. Systematic review registration PROSPERO 2016:CRD42016039184

International criteria for electrocardiographic interpretation in athletes: Consensus statement

Abstract: Sudden cardiac death (SCD) is the leading cause of mortality in athletes during sport. A variety of mostly hereditary, structural or electrical cardiac disorders are associated with SCD in young athletes, the majority of which can be identified or suggested by abnormalities on a resting 12-lead electrocardiogram (ECG). Whether used for diagnostic or screening purposes, physicians responsible for the cardiovascular care of athletes should be knowledgeable and competent in ECG interpretation in athletes. However, in most countries a shortage of physician expertise limits wider application of the ECG in the care of the athlete. A critical need exists for physician education in modern ECG interpretation that distinguishes normal physiological adaptations in athletes from distinctly abnormal findings suggestive of underlying pathology. Since the original 2010 European Society of Cardiology recommendations for ECG interpretation in athletes, ECG standards have evolved quickly, advanced by a growing body of scientific data and investigations that both examine proposed criteria sets and establish new evidence to guide refinements. On 26-27 February 2015, an international group of experts in sports cardiology, inherited cardiac disease, and sports medicine convened in Seattle, Washington (USA), to update contemporary standards for ECG interpretation in athletes. The objective of the meeting was to define and revise ECG interpretation standards based on new and emerging research and to develop a clear guide to the proper evaluation of ECG abnormalities in athletes. This statement represents an international consensus for ECG interpretation in athletes and provides expert opinion-based recommendations linking specific ECG abnormalities and the secondary evaluation for conditions associated with SCD.

What is the physiological time to recovery after concussion? A systematic review.

Abstract: Aim or objective The aim of this study is to consolidate studies of physiological measures following sport-related concussion (SRC) to determine if a time course of postinjury altered neurobiology can be outlined. This biological time course was considered with respect to clinically relevant outcomes such as vulnerability to repeat injury and safe timing of return to physical contact risk. Design Systematic review. Data sources PubMed, CINAHL, Cochrane Central, PsychINFO. Eligibility criteria for selecting studies Studies were included if they reported original research on physiological or neurobiological changes after SRC. Excluded were cases series Results A total of 5834 articles were identified, of which 80 were included for full-text data extraction and review. Relatively few longitudinal studies exist that follow both physiological dysfunction and clinical measures to recovery. Summary/conclusions Modalities of measuring physiological change after SRC were categorised into the following: functional MRI, diffusion tensor imaging, magnetic resonance spectroscopy, cerebral blood flow, electrophysiology, heart rate, exercise, fluid biomarkers and transcranial magnetic stimulation. Due to differences in modalities, time course, study design and outcomes, it is not possible to define a single ‘physiological time window’ for SRC recovery. Multiple studies suggest physiological dysfunction may outlast current clinical measures of recovery, supporting a buffer zone of gradually increasing activity before full contact risk. Future studies need to use generalisable populations, longitudinal designs following to physiological and clinical recovery and careful correlation of neurobiological modalities with clinical measures.

5th International Conference on Concussion in Sport (Berlin)

Abstract: Sport-related concussion (SRC) has received much media coverage over the past 5 years. In the face of misinformation about this injury in the minds of parents, coaches and athletes, it is critical that all involved stakeholders receive scientifically sound and up-to-date information regarding SRC and its potential consequences. One of the most significant developments in SRC over the past two decades has been the establishment of the Concussion In Sport Group (CISG). This group has organised the key consensus meetings in this field and has published assessment tools that have …

Sports injury and illness incidence in the Rio de Janeiro 2016 Olympic Summer Games: A prospective study of 11274 athletes from 207 countries

Abstract: Objective To describe the pattern of injuries and illnesses sustained during the Games of the XXXI Olympiad, hosted by Rio de Janeiro from 5 to 21 August 2016. Methods We recorded the daily incidence of athlete injuries and illnesses (1) through the reporting of all National Olympic Committee (NOC) medical teams and (2) in the polyclinic and medical venues by the Rio 2016 medical staff. Results In total, 11 274 athletes (5089 women, 45%; 6185 men, 55%) from 207 NOCs participated in the study. NOC and Rio 2016 medical staff reported 1101 injuries and 651 illnesses, equalling 9.8 injuries and 5.4 illnesses per 100 athletes over the 17-day period. Altogether, 8% of the athletes incurred at least one injury and 5% at least one illness. The injury incidence was highest in BMX cycling (38% of the athletes injured), boxing (30%), mountain bike cycling (24%), taekwondo (24%), water polo (19%) and rugby (19%), and lowest in canoe slalom, rowing, shooting, archery, swimming, golf and table tennis (0%–3%). Of the 1101 injuries recorded, 40% and 20% were estimated to lead to ≥1 and >7 days of absence from sport, respectively. Women suffered 40% more illnesses than men. Illness was generally less common than injury, with the highest incidence recorded in diving (12%), open-water marathon (12%), sailing (12%), canoe slalom (11%), equestrian (11%) and synchronised swimming (10%). Illnesses were also less severe; 18% were expected to result in time loss. Of the illnesses, 47% affected the respiratory system and 21% the gastrointestinal system. The anticipated problem of infections in the Rio Olympic Games did not materialise, as the proportion of athletes with infectious diseases mirrored that of recent Olympic Games (3%). Conclusion Overall, 8% of the athletes incurred at least one injury during the Olympic Games, and 5% an illness, which is slightly lower than in the Olympic Summer Games of 2008 and 2012.

Accumulated workloads and the acute:chronic workload ratio relate to injury risk in elite youth football players

Abstract: Aim The purpose of this study was to investigate the relationship between physical workload and injury risk in elite youth football players. Methods The workload data and injury incidence of 32 players were monitored throughout 2 seasons. Multiple regression was used to compare cumulative (1, 2, 3 and 4-weekly) loads and acute:chronic (A:C) workload ratios (acute workload divided by chronic workload) between injured and non-injured players for specific GPS and accelerometer-derived variables:total distance (TD), high-speed distance (HSD), accelerations (ACC) and total load. Workloads were classified into discrete ranges by z-scores and the relative risk was determined. Results A very high number of ACC (≥9254) over 3 weeks was associated with the highest significant overall (relative risk (RR)=3.84) and non-contact injury risk (RR=5.11). Non-contact injury risk was significantly increased when a high acute HSD was combined with low chronic HSD (RR=2.55), but not with high chronic HSD (RR=0.47). Contact injury risk was greatest when A:C TD and ACC ratios were very high (1.76 and 1.77, respectively) (RR=4.98). Conclusions In general, higher accumulated and acute workloads were associated with a greater injury risk. However, progressive increases in chronic workload may develop the players9 physical tolerance to higher acute loads and resilience to injury risk.

What is the association between sedentary behaviour and cognitive function? A systematic review.

Abstract: Aim The increasing rate of all-cause dementia worldwide and the lack of effective pharmaceutical treatments emphasise the value of lifestyle approaches as prevention strategies. Emerging evidence suggests sedentary behaviour is associated with impaired cognitive function. A better understanding of this association would significantly add to our knowledge of how to best promote healthy cognitive ageing. Thus, we conducted a systematic review ascertaining the contribution of sedentary behaviour towards associated changes in cognitive function over the adult lifespan. Study design Systematic review of peer-reviewed literature examining the association of sedentary behaviour with cognition. Data sources We searched PubMed, PsycINFO, EBSCO and Web of Science, and reference lists of relevant reviews on sedentary behaviour. Two independent reviewers extracted (1) study characteristics and (2) information regarding measurement of sedentary behaviour and cognitive function. We also assessed study quality using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist. Eligibility criteria We limited search results to adults ≥40 years, observational studies published in English since 1990 and studies investigating associations between sedentary behaviour and cognitive function. Results 8 studies examined the association of sedentary behaviour with cognitive function. 6 studies reported significant negative associations between sedentary behaviour and cognitive function. 8 different measures of sedentary behaviour and 13 different measures of cognitive function were used across all eight studies. Summary Sedentary behaviour is associated with lower cognitive performance, although the attributable risk of sedentary time to all-cause dementia incidence is unclear. Our systematic review provides evidence that limiting sedentary time and concomitantly engaging in regular moderate-to-vigorous physical activity may best promote healthy cognitive ageing.

Rest and treatment/rehabilitation following sport-related concussion: a systematic review

Abstract: Aim or objective The objective of this systematic review was to evaluate the evidence regarding rest and active treatment/rehabilitation following sport-related concussion (SRC). Design Systematic review. Data sources MEDLINE (OVID), CINAHL (EbscoHost), PsycInfo (OVID), Cochrane Central Register of Controlled Trials (OVID), SPORTDiscus (EbscoHost), EMBASE (OVID) and Proquest DissertationsandTheses Global (Proquest) were searched systematically. Eligibility criteria for selecting studies Studies were included if they met the following criteria: (1) original research; (2) reported SRC as the diagnosis; and (3) evaluated the effect of rest or active treatment/rehabilitation. Review articles were excluded. Results Twenty-eight studies met the inclusion criteria (9 regarding the effects of rest and 19 evaluating active treatment). The methodological quality of the literature was limited; only five randomised controlled trials (RCTs) met the eligibility criteria. Those RCTs included rest, cervical and vestibular rehabilitation, subsymptom threshold aerobic exercise and multifaceted collaborative care. Summary/conclusions A brief period (24-48 hours) of cognitive and physical rest is appropriate for most patients. Following this, patients should be encouraged to gradually increase activity. The exact amount and duration of rest are not yet well defined and require further investigation. The data support interventions including cervical and vestibular rehabilitation and multifaceted collaborative care. Closely monitored subsymptom threshold, submaximal exercise may be of benefit. Systematic review registration PROSPERO 2016:CRD42016039570.

What tests and measures should be added to the SCAT3 and related tests to improve their reliability, sensitivity and/or specificity in sideline concussion diagnosis? A systematic review

Abstract: Objectives Several iterations of the Sport Concussion Assessment Tool (SCAT) have been published over the past 16 years. Our goal was to systematically review the literature related to the SCAT and provide recommendations for improving the tool. To achieve this goal, five separate but related searches were conducted and presented herein. Design Systematic literature review. Data sources Medline, Embase, PsycINFO, Cumulative Index of Nursing and Allied Health Literature (CINAHL), Cochrane Central Register of Controlled Trials, SPORTDiscus and PubMed. Eligibility criteria Original, empirical, peer-reviewed findings published in English and included sports-related concussion (SRC). Review papers, case studies, editorials and conference proceedings/abstracts were excluded. The age range for the ChildSCAT was 5–12 years and for the Adult SCAT was 13 years and above. Results Out of 2961 articles screened, a total of 96 articles were included across the five searches. Searches were not mutually exclusive. The final number of articles included in the qualitative synthesis for each search was 21 on Adult SCAT, 32 on ChildSCAT, 21 on sideline, 8 on video/observation and 14 on oculomotor. Summary/conclusions The SCAT is the most widely accepted and deployable sport concussion assessment and screening tool currently available. There is some degree of support for using the SCAT2/SCAT3 and ChildSCAT3 in the evaluation of SRC, with and without baseline data. The addition of an oculomotor examination seems indicated, although the most valid method for assessing oculomotor function is not clear. Video-observable signs of concussion show promise, but there is insufficient evidence to warrant widespread use at this time.

Treatment and prevention of acute and recurrent ankle sprain: an overview of systematic reviews with meta-analysis

Abstract: Background Ankle sprains are highly prevalent with high risk of recurrence. Consequently, there are a significant number of research reports examining strategies for treating and preventing acute and recurrent sprains (otherwise known as chronic ankle instability (CAI)), with a coinciding proliferation of review articles summarising these reports. Objective To provide a systematic overview of the systematic reviews evaluating treatment strategies for acute ankle sprain and CAI. Design Overview of intervention systematic reviews. Participants Individuals with acute ankle sprain/CAI. Main outcome measurements The primary outcomes were injury/reinjury incidence and function. Results 46 papers were included in this systematic review. The reviews had a mean score of 6.5/11 on the AMSTAR quality assessment tool. There was strong evidence for bracing and moderate evidence for neuromuscular training in preventing recurrence of an ankle sprain. For the combined outcomes of pain, swelling and function after an acute sprain, there was strong evidence for non-steroidal anti-inflammatory drugs and early mobilisation, with moderate evidence supporting exercise and manual therapy techniques. There was conflicting evidence regarding the efficacy of surgery and acupuncture for the treatment of acute ankle sprains. There was insufficient evidence to support the use of ultrasound in the treatment of acute ankle sprains. Conclusions For the treatment of acute ankle sprain, there is strong evidence for non-steroidal anti-inflammatory drugs and early mobilisation, with moderate evidence supporting exercise and manual therapy techniques, for pain, swelling and function. Exercise therapy and bracing are supported in the prevention of CAI.

How do training and competition workloads relate to injury? The workload—injury aetiology model

Abstract: Injury aetiology models that have evolved over the previous two decades highlight a number of factors which contribute to the causal mechanisms for athletic injuries. These models highlight the pathway to injury, including (1) internal risk factors (eg, age, neuromuscular control) which predispose athletes to injury, (2) exposure to external risk factors (eg, playing surface, equipment), and finally (3) an inciting event, wherein biomechanical breakdown and injury occurs. The most recent aetiological model proposed in 2007 was the first to detail the dynamic nature of injury risk, whereby participation may or may not result in injury, and participation itself alters injury risk through adaptation. However, although training and competition workloads are strongly associated with injury, existing aetiology models neither include them nor provide an explanation for how workloads alter injury risk. Therefore, we propose an updated injury aetiology model which includes the effects of workloads. Within this model, internal risk factors are differentiated into modifiable and non-modifiable factors, and workloads contribute to injury in three ways: (1) exposure to external risk factors and potential inciting events, (2) fatigue, or negative physiological effects, and (3) fitness, or positive physiological adaptations. Exposure is determined solely by total load, while positive and negative adaptations are controlled both by total workloads, as well as changes in load (eg, the acute:chronic workload ratio). Finally, we describe how this model explains the load-injury relationships for total workloads, acute:chronic workload ratios and the training load-injury paradox.

Effect of specific exercise-based football injury prevention programmes on the overall injury rate in football: a systematic review and meta-analysis of the FIFA 11 and 11+ programmes

Abstract: Objective To investigate the effect of FIFA injury prevention programmes in football (FIFA 11 and FIFA 11+). Design Systematic review and meta-analysis. Eligibility criteria for selecting studies Randomised controlled trials comparing the FIFA injury prevention programmes with a control (no or sham intervention) among football players. Data sources MEDLINE via PubMed, EMBASE via OVID, CINAHL via Ebsco, Web of Science, SportDiscus and Cochrane Central Register of Controlled Trials, from 2004 to 14 March 2016. Results 6 cluster-randomised controlled trials had assessed the effect of FIFA injury prevention programmes compared with controls on the overall football injury incidence in recreational/subelite football. These studies included 2 specific exercise-based injury prevention programmes: FIFA 11 (2 studies) and FIFA 11+ (4 studies). The primary analysis showed a reduction in the overall injury risk ratio of 0.75 (95% CI 0.57 to 0.98), p=0.04, in favour of the FIFA injury prevention programmes. Secondary analyses revealed that when pooling the 4 studies applying the FIFA 11+ prevention programme, a reduction in the overall injury risk ratio (incidence rate ratio (IRR) 0.61; 95% CI 0.48 to 0.77, p Conclusions An injury-preventing effect of the FIFA injury prevention programmes compared with controls was shown in football. This effect was induced by the FIFA 11+ prevention programme which has a substantial injury-preventing effect by reducing football injuries by 39%, whereas a preventive effect of the FIFA 11 prevention programme could not be documented. Trial registration number PROSPERO CRD42015024120.

Infographic: 2016 Consensus statement on return to sport from the First World Congress in Sports Physical Therapy, Bern.

Abstract: Infographic: 2016 Consensus statement on return to sport from the First World Congress in Sports Physical Therapy, Bern

Evidence-based framework for a pathomechanical model of patellofemoral pain: 2017 patellofemoral pain consensus statement from the 4th International Patellofemoral Pain Research Retreat, Manchester, UK: part 3.

Abstract: The aetiology of patellofemoral pain (PFP) is a complex interplay among various anatomical, biomechanical, psychological, social and behavioural influences. Numerous factors associated with PFP have been reported in the literature, but the interaction between these proposed risk factors and the clinical entity of PFP remains unclear (figure 1). Figure 1 Schematic overview of potential pathways to elevated patellofemoral joint (PFJ) stress, a proposed contributor to patellofemoral pain. The goal of this consensus document is to place known associated factors within the context of a pathomechanical model of PFP. An underlying assumption of the proposed pathomechanical model is that PFP is associated with abnormal loading of the patellofemoral joint (elevated joint stress). In this model, abnormal loading could affect the various patellofemoral structures that can contribute to nociception (ie, subchondral bone, infrapatellar fat pad, retinaculum and ligamentous structures); however, the specific tissue sources related to PFP are not known. The experience of PFP is not just nociception.1 Persons with persistent PFP exhibit abnormal nociceptive processing (ie, widespread mechanical hyperalgesia, impaired pain modulation),2–5 altered somatosensory processing (implying neuropathic pain),6 impaired sensorimotor function (ie, proprioception and balance)7–10 and certain psychological factors (ie, catastrophising and kinesiophobia).11 The amount and quality of research in the non-‘patho-mechanical’ pathways to PFP are evolving, and will be included in future consensus statements emanating from the International Patellofemoral Pain Research Retreats. At the 4th International Patellofemoral Pain Research Retreat,12 Dr Christopher Powers presented a draft framework of the pathomechanical model, which was based on prior consensus statements from the three previous Patellofemoral Pain Research Retreats.13–15 At the meeting, all attendees (clinician-researchers and research scientists) participated in a comprehensive discussion of the draft model, and agreed on the overall framework (Figure 1). Following the retreat, the authors conducted a thorough review of pertinent literature related to …

Impact of the Nordic hamstring and hip extension exercises on hamstring architecture and morphology: implications for injury prevention

Abstract: Background The architectural and morphological adaptations of the hamstrings in response to training with different exercises have not been explored. Purpose To evaluate changes in biceps femoris long head (BFLH) fascicle length and hamstring muscle size following 10-weeks of Nordic hamstring exercise (NHE) or hip extension (HE) training. Methods 30 recreationally active male athletes (age, 22.0±3.6 years; height, 180.4±7 cm; weight, 80.8±11.1 kg) were allocated to 1 of 3 groups: (1) HE training (n=10), NHE training (n=10), or no training (control, CON) (n=10). BFLH fascicle length was assessed before, during (Week 5) and after the intervention with a two-dimensional ultrasound. Hamstring muscle size was determined before and after training via MRI. Results Compared with baseline , BFLH fascicles were lengthened in the NHE and HE groups at mid-training (d=1.12–1.39, p<0.001) and post-training (d=1.77–2.17, p<0.001) and these changes did not differ significantly between exercises (d=0.49–0.80, p=0.279–0.976). BFLH volume increased more for the HE than the NHE (d=1.03, p=0.037) and CON (d=2.24, p<0.001) groups. Compared with the CON group, both exercises induced significant increases in semitendinosus volume (d=2.16–2.50, ≤0.002) and these increases were not significantly different (d=0.69, p=0.239). Conclusion NHE and HE training both stimulate significant increases in BFLH fascicle length; however, HE training may be more effective for promoting hypertrophy in the BFLH.

Step training improves reaction time, gait and balance and reduces falls in older people: a systematic review and meta-analysis.

Abstract: Objective To examine the effects of stepping interventions on fall risk factors and fall incidence in older people. Data source Electronic databases (PubMed, EMBASE, CINAHL, Cochrane, CENTRAL) and reference lists of included articles from inception to March 2015. Study selection Randomised (RCT) or clinical controlled trials (CCT) of volitional and reactive stepping interventions that included older (minimum age 60) people providing data on falls or fall risk factors. Results Meta-analyses of seven RCTs (n=660) showed that the stepping interventions significantly reduced the rate of falls (rate ratio=0.48, 95% CI 0.36 to 0.65, p 2 =0%) and the proportion of fallers (risk ratio=0.51, 95% CI 0.38 to 0.68, p 2 =0%). Subgroup analyses stratified by reactive and volitional stepping interventions revealed a similar efficacy for rate of falls and proportion of fallers. A meta-analysis of two RCTs (n=62) showed that stepping interventions significantly reduced laboratory-induced falls, and meta-analysis findings of up to five RCTs and CCTs (n=36–416) revealed that stepping interventions significantly improved simple and choice stepping reaction time, single leg stance, timed up and go performance (p Conclusions The findings indicate that both reactive and volitional stepping interventions reduce falls among older adults by approximately 50%. This clinically significant reduction may be due to improvements in reaction time, gait, balance and balance recovery but not in strength. Further high-quality studies aimed at maximising the effectiveness and feasibility of stepping interventions are required. Systematic reviews registration number CRD42015017357.

What is the definition of sports-related concussion: a systematic review.

Abstract: Objectives Various definitions for concussion have been proposed, each having its strengths and weaknesses. We reviewed and compared current definitions and identified criteria necessary for an operational definition of sports-related concussion (SRC) in preparation of the 5th Concussion Consensus Conference (Berlin, Germany). We also assessed the role of biomechanical studies in informing an operational definition of SRC. Design This is a systematic literature review. Data sources Data sources include MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature, Cochrane Central Register of Clinical Trials and SPORT Discus (accessed 14 September 2016). Eligibility criteria for selecting studies Eligibility criteria were studies reporting (clinical) criteria for diagnosing SRC and studies containing SRC impact data. Results Out of 1601 articles screened, 36 studies were included (2.2%), 14 reported on criteria for SRC definitions and 22 on biomechanical aspects of concussions. Six different operational definitions focusing on clinical findings and their dynamics were identified. Biomechanical studies were obtained almost exclusively on American football players. Angular and linear head accelerations linked to clinically confirmed concussions demonstrated considerable individual variation. Summary/conclusions SRC is a traumatic brain injury that is defined as a complex pathophysiological process affecting the brain, induced by biomechanical forces with several common features that help define its nature. Limitations identified include that the current criteria for diagnosing SRC are clinically oriented and that there is no gold/standard to assess their diagnostic properties. A future, more valid definition of SRC would better identify concussed players by demonstrating high predictive positive/negative values. Currently, the use of helmet-based systems to study the biomechanics of SRC is limited to few collision sports. New approaches need to be developed to provide objective markers for SRC.

β-alanine supplementation to improve exercise capacity and performance: a systematic review and meta-analysis

Abstract: Objective To conduct a systematic review and meta-analysis of the evidence on the effects of β-alanine supplementation on exercise capacity and performance. Design This study was designed in accordance with PRISMA guidelines. A 3-level mixed effects model was employed to model effect sizes and account for dependencies within data. Data sources 3 databases (PubMed, Google Scholar, Web of Science) were searched using a number of terms (‘β-alanine’ and ‘Beta-alanine’ combined with ‘supplementation’, ‘exercise’, ‘training’, ‘athlete’, ‘performance’ and ‘carnosine’). Eligibility criteria for selecting studies Inclusion/exclusion criteria limited articles to double-blinded, placebo-controlled studies investigating the effects of β-alanine supplementation on an exercise measure. All healthy participant populations were considered, while supplementation protocols were restricted to chronic ingestion. Cross-over designs were excluded due to the long washout period for skeletal muscle carnosine following supplementation. A single outcome measure was extracted for each exercise protocol and converted to effect sizes for meta-analyses. Results 40 individual studies employing 65 different exercise protocols and totalling 70 exercise measures in 1461 participants were included in the analyses. A significant overall effect size of 0.18 (95% CI 0.08 to 0.28) was shown. Meta-regression demonstrated that exercise duration significantly (p=0.004) moderated effect sizes. Subgroup analyses also identified the type of exercise as a significant (p=0.013) moderator of effect sizes within an exercise time frame of 0.5–10 min with greater effect sizes for exercise capacity (0.4998 (95% CI 0.246 to 0.753)) versus performance (0.1078 (95% CI −0.201 to 0.416)). There was no moderating effect of training status (p=0.559), intermittent or continuous exercise (p=0.436) or total amount of β-alanine ingested (p=0.438). Co-supplementation with sodium bicarbonate resulted in the largest effect size when compared with placebo (0.43 (95% CI 0.22 to 0.64)). Summary/conclusions β-alanine had a significant overall effect while subgroup analyses revealed a number of modifying factors. These data allow individuals to make informed decisions as to the likelihood of an ergogenic effect with β-alanine supplementation based on their chosen exercise modality.

Effect of exercise training on C reactive protein: a systematic review and meta-analysis of randomised and non-randomised controlled trials

Abstract: Purpose C-reactive protein (CRP) is a marker of chronic systemic inflammation frequently used in cardiovascular disease risk assessment. The purpose of this meta-analysis was to provide a quantitative estimate of the magnitude of change in CRP following participation in physical exercise interventions. Methods All studies included in the meta-analysis were peer reviewed and published in English. Human participants were assigned to a non-exercise comparison group or exercise training group, with the intervention lasting ≥2 weeks. CRP levels were measured at baseline, during and/or after completion of the exercise training programme. Random-effects models were used to aggregate a mean effect size (ES), 95% CIs and potential moderators. Results 83 randomised and non-randomised controlled trials met the inclusion criteria and resulted in 143 effects (n=3769). The mean ES of 0.26 (95% CI 0.18 to 0.34, p Conclusions These results suggest that engaging in exercise training is associated with a decrease in CRP levels regardless of the age or sex of the individual; however, greater improvements in CRP level occur with a decrease in BMI or %Fat.

Effectiveness of conservative interventions including exercise, manual therapy and medical management in adults with shoulder impingement: a systematic review and meta-analysis of RCTs

Abstract: Objective To investigate the effectiveness of conservative interventions for pain, function and range of motion in adults with shoulder impingement. Design Systematic review and meta-analysis of randomised trials. Data sources Medline, CENTRAL, CINAHL, Embase and PEDro were searched from inception to January 2017. Study selection criteria Randomised controlled trials including participants with shoulder impingement and evaluating at least one conservative intervention against sham or other treatments. Results For pain, exercise was superior to non-exercise control interventions (standardised mean difference (SMD) −0.94, 95% CI −1.69 to −0.19). Specific exercises were superior to generic exercises (SMD −0.65, 95% CI −0.99 to −0.32). Corticosteroid injections were superior to no treatment (SMD −0.65, 95% CI −1.04 to −0.26), and ultrasound guided injections were superior to non-guided injections (SMD −0.51, 95% CI −0.89 to −0.13). Nonsteroidal anti-inflammatory drugs (NSAIDS) had a small to moderate SMD of −0.29 (95% CI −0.53 to −0.05) compared with placebo. Manual therapy was superior to placebo (SMD −0.35, 95% CI −0.69 to −0.01). When combined with exercise, manual therapy was superior to exercise alone, but only at the shortest follow-up (SMD −0.32, 95% CI −0.62 to −0.01). Laser was superior to sham laser (SMD −0.88, 95% CI −1.48 to −0.27). Extracorporeal shockwave therapy (ECSWT) was superior to sham (−0.39, 95% CI −0.78 to –0.01) and tape was superior to sham (−0.64, 95% CI −1.16 to −0.12), with small to moderate SMDs. Conclusion Although there was only very low quality evidence, exercise should be considered for patients with shoulder impingement symptoms and tape, ECSWT, laser or manual therapy might be added. NSAIDS and corticosteroids are superior to placebo, but it is unclear how these treatments compare to exercise.

The athlete monitoring cycle: a practical guide to interpreting and applying training monitoring data

Abstract: Given the relationships among athlete workloads, injury1 and performance,2 athlete monitoring has become critical in the high-performance sporting environment. Sports medicine and science staff have a suite of monitoring tools available to track how much ‘work’ an athlete has performed, the response to that ‘work’ and whether the athlete is in a relative state of fitness or fatigue. The volume of literature, coupled with clever marketing around the ‘best approaches’ to optimising athlete performance, has resulted in practitioners having more choices than ever before. Furthermore, the range of different practices used in sport and the lack of agreement between parties emphasise the importance of having a clear rationale for athlete monitoring. The aim of this paper is to provide a practical guide to strategic planning, analysing, interpreting and applying athlete monitoring data in the sporting environment irrespective of data management software. When deciding on the athlete monitoring tools to use with your athletes, the first question one should ask is “What do I want to achieve through athlete monitoring?” Quite commonly, the answer is to maximise the positive effects (eg, fitness, readiness and performance) and minimise the negative effects (eg, excessive fatigue, injury and illness) of training. Once practitioners know the reasons for athlete monitoring, appropriate tools can be chosen in order to answer the athlete monitoring question. For example, if practitioners wish to maximise ‘fitness’ and minimise ‘fatigue’, then appropriate monitoring tools to measure these outcomes are necessary. Measurement of fitness improvements for a Premier League football player (eg, a Yo-Yo test) …

International normative 20 m shuttle run values from 1 142 026 children and youth representing 50 countries

Abstract: Objective To develop sex-specific and age-specific international norms for the 20 m shuttle run test (20mSRT) in children and youth (aged 9–17 years), and to estimate the prevalence meeting the FITNESSGRAM criterion-referenced standards for healthy cardiorespiratory endurance (CRE). Methods A systematic review was undertaken to identify papers explicitly reporting descriptive 20mSRT (with 1 min stages) data on children and youth since 1981. Data were included on apparently healthy (free from known disease/injury) 9–17 years old. Following standardisation to a common metric and for protocol differences, pseudo data were generated using Monte Carlo simulation, with population-weighted sex-specific and age-specific normative centiles generated using the Lambda Mu and Sigma (LMS) method. Sex-related and age-related differences were expressed as per cent and standardised differences in means. The prevalence with healthy CRE was estimated using the sex-specific and age-specific FITNESSGRAM criterion-referenced standards for . Results Norms were displayed as tabulated centiles and as smoothed centile curves for the 20mSRT using 4 common metrics (speed at the last completed stage, completed stages/minutes, laps and relative ). The final data set included 1 142 026 children and youth from 50 countries, extracted from 177 studies. Boys consistently outperformed girls at each age group (mean difference±95% CI: 0.86±0.28 km/h or 0.79±0.20 standardised units), with the magnitude of age-related increase larger for boys than for girls. A higher proportion of boys (mean±95% CI: 67±14%) had healthy CRE than girls (mean±95% CI: 54±17%), with the prevalence of healthy CRE decreasing systematically with age. Conclusions This study provides the most comprehensive and up-to-date set of international sex-specific and age-specific 20mSRT norms for children and youth, which have utility for health and fitness screening, profiling, monitoring and surveillance.

Preventing overuse shoulder injuries among throwing athletes: a cluster-randomised controlled trial in 660 elite handball players

Abstract: Background Shoulder problems are highly prevalent among elite handball players. Reduced glenohumeral rotation, external rotation weakness and scapula dyskinesis have been identified as risk factors. Aim Evaluate the effect of an exercise programme designed to reduce the prevalence of shoulder problems in elite handball. Methods 45 elite handball teams (22 female teams, 23 male teams, 660 players) were cluster randomised (22 teams, 331 players in the intervention group, 23 teams, 329 players in the control group) and followed for 1 competitive season (7 months). The Oslo Sports Trauma Research Center (OSTRC) Shoulder Injury Prevention Programme, an exercise programme to increase glenohumeral internal rotation, external rotation strength and scapular muscle strength, as well as improve kinetic chain and thoracic mobility, was delivered by coaches and captains 3 times per week as a part of the handball warm-up. The main outcome measures, prevalence of shoulder problems and substantial shoulder problems, were measured monthly. Results The average prevalence of shoulder problems during the season was 17% (95% CI 16% to 19%) in the intervention group and 23% (95% CI 21% to 26%) in the control group (mean difference 6%). The average prevalence of substantial shoulder problems was 5% (95% CI 4% to 6%) in the intervention group and 8% (95% CI 7% to 9%) in the control group (mean difference 3%). Using generalised estimating equation models, a 28% lower risk of shoulder problems (OR 0.72, 95% CI 0.52 to 0.98, p=0.038) and 22% lower risk of substantial shoulder problems (OR 0.78, 95% CI 0.53 to 1.16, p=0.23) were observed in the intervention group compared with the control group. Conclusions The OSTRC Shoulder Injury Prevention Programme reduced the prevalence of shoulder problems in elite handball and should be included as a part of the warm-up. Trial registration number ISRCTN96217107.