British Journal of Sports Medicine

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British Journal of Sports Medicine
  1. Doosti-Irani A, Nazemipour M, Mansournia MA et al. What are network meta-analyses (NMAs)? A primer with four tips for clinicians who read NMAs and who perform them (methods matter series). Br J Sports Med 2021;55:520–1.

    The complete affiliation for Amin Doosti-Irani is Department of Epidemiology, School of Public Health and research center for Health Sciences, Hamadan University of Medical Sciences, Hamadan, Iran.

  2. In a year of great turmoil and hardship for the vast majority of society, it has also been a time for organisations, professional associations and healthcare bodies to come together, working to bring about positive change and give everybody, regardless of who or where they are, the right to rehabilitation. The Community Rehabilitation Alliance and the Arthritis and Musculoskeletal Alliance ( have made great progress in this area, providing a strong voice to guide the future of population health in the UK. Coming together collaboratively has also allowed these collectives to support the efforts for dealing with the current pandemic and the longer-term post viral rehabilitation needs.

    Underpinning and supporting this agenda for positive change and effective rehabilitation strategies is our research community and current evidence base, with our understanding, interpretation and application of this evidence being absolutely crucial to the centre of everything we do; patients.

  3. Like many areas of medicine, the role of arthroscopy is evolving and its use must be guided by critical analysis of the scientific evidence. Data evaluating arthroscopic knee surgery is complex with heterogenous pathology, patient populations and techniques and, therefore, must be interpreted with care. Attention-grabbing headlines and animations can stimulate discussion, but when key aspects of published science are overlooked, they risk oversimplification. We believe a number of articles published in a recent edition of the British Journal of Sports Medicine (BJSM) represent examples where science may be overshadowed by oversimplification. Thus, we offer additional insights to focus the place of arthroscopy in the management of joint problems.

    Oversimplification can be misleading

    To our interpretation, recent BJSM publications appear to take an emotional stance, indicating that all arthroscopy for conditions that cause joint pain is bad and should be stopped.1 2 Following an...

  4. Type 1 (T1) and type 2 (T2) diabetes mellitus (DM) are significant precursors and comorbidities to cardiovascular disease and prevalence of both types is still rising globally. Currently,~25% of participants (and rising) attending cardiac rehabilitation in Europe, North America and Australia have been reported to have DM (>90% have T2DM). While there is some debate over whether improving glycaemic control in those with heart disease can independently improve future cardiovascular health-related outcomes, for the individual patient whose blood glucose is well controlled, it can aid the exercise programme in being more efficacious. Good glycaemic management not only helps to mitigate the risk of acute glycaemic events during exercising, it also aids in achieving the requisite physiological and psycho-social aims of the exercise component of cardiac rehabilitation (CR). These benefits are strongly associated with effective behaviour change, including increased enjoyment, adherence and self-efficacy. It is known that CR participants with DM have lower uptake and adherence rates compared with those without DM. This expert statement provides CR practitioners with nine recommendations aimed to aid in the participant’s improved blood glucose control before, during and after exercise so as to prevent the risk of glycaemic events that could mitigate their beneficial participation.

  5. Objectives

    To determine if subpopulations of students benefit equally from school-based physical activity interventions in terms of cardiorespiratory fitness and physical activity. To examine if physical activity intensity mediates improvements in cardiorespiratory fitness.


    Pooled analysis of individual participant data from controlled trials that assessed the impact of school-based physical activity interventions on cardiorespiratory fitness and device-measured physical activity.


    Data for 6621 children and adolescents aged 4–18 years from 20 trials were included.

    Main outcome measures

    Peak oxygen consumption (VO2Peak mL/kg/min) and minutes of moderate and vigorous physical activity.


    Interventions modestly improved students’ cardiorespiratory fitness by 0.47 mL/kg/min (95% CI 0.33 to 0.61), but the effects were not distributed equally across subpopulations. Girls and older students benefited less than boys and younger students, respectively. Students with lower levels of initial fitness, and those with higher levels of baseline physical activity benefitted more than those who were initially fitter and less active, respectively. Interventions had a modest positive effect on physical activity with approximately one additional minute per day of both moderate and vigorous physical activity. Changes in vigorous, but not moderate intensity, physical activity explained a small amount (~5%) of the intervention effect on cardiorespiratory fitness.


    Future interventions should include targeted strategies to address the needs of girls and older students. Interventions may also be improved by promoting more vigorous intensity physical activity. Interventions could mitigate declining youth cardiorespiratory fitness, increase physical activity and promote cardiovascular health if they can be delivered equitably and their effects sustained at the population level.

  6. Objective

    To compare the effectiveness of different physical exercise interventions for chronic non-specific neck pain.


    Systematic review and network meta-analysis.

    Data sources

    Electronic databases: AMED, CINAHL, Cochrane Central Register of Controlled Trials, Embase, MEDLINE, Physiotherapy Evidence Database, PsycINFO, Scopus and SPORTDiscus.

    Eligibility criteria

    Randomised controlled trials (RCTs) describing the effects of any physical exercise intervention in adults with chronic non-specific neck pain.


    The search returned 6549 records, 40 studies were included. Two networks of pairwise comparisons were constructed, one for pain intensity (n=38 RCTs, n=3151 participants) and one for disability (n=29 RCTs, n=2336 participants), and direct and indirect evidence was obtained. Compared with no treatment, three exercise interventions were found to be effective for pain and disability: motor control (Hedges’ g, pain –1.32, 95% CI: –1.99 to –0.65; disability –0.87, 95% CI: –1.45 o –0.29), yoga/Pilates/Tai Chi/Qigong (pain –1.25, 95% CI: –1.85 to –0.65; disability –1.16, 95% CI: –1.75 to –0.57) and strengthening (pain –1.21, 95% CI: –1.63 to –0.78; disability –0.75, 95% CI: –1.28 to –0.22). Other interventions, including range of motion (pain –0.98 CI: –2.51 to 0.56), balance (pain –0.38, 95% CI: –2.10 to 1.33) and multimodal (three or more exercises types combined) (pain –0.08, 95% CI: –1.70 to 1.53) exercises showed uncertain or negligible effects. The quality of evidence was very low according to the GRADE (Grading of Recommendations Assessment, Development and Evaluation) criteria.


    There is not one superior type of physical exercise for people with chronic non-specific neck pain. Rather, there is very low quality evidence that motor control, yoga/Pilates/Tai Chi/Qigong and strengthening exercises are equally effective. These findings may assist clinicians to select exercises for people with chronic non-specific neck pain.

    PROSPERO registration number


  7. Objectives

    To examine associations between long-term (11–22 years) adherence to physical activity recommendations and mortality from all causes and from cardiovascular disease.


    Prospective population-based study with repeated assessments of self-reported physical activity (1984–86, 1995–97 and 2006–08) and follow-up until the end of 2013.


    County of Nord-Trøndelag, Norway.


    Men and women aged ≥20 years; 32 811 who participated in 1984–86 and 1995–97; 22 058 in 1984–86 and 2006–08; 31 948 in 1995–97 and 2006–09 and 19 349 in all three examinations (1984–1986, 1995–95 and 2006–08).

    Main outcome measures

    All-cause mortality and cardiovascular disease mortality from the national Cause of Death Registry.


    Compared with the reference category comprising individuals who adhered to the physical activity recommendations (≥150 min of moderate intensity or ≥60 min of vigorous intensity physical activity per week) over time, individuals who remained inactive (reporting no or very little physical activity) from 1984–86 to 1995–97 had HRs (95% CI) of 1.56 (1.40 to 1.73) for all-cause mortality and 1.94 (1.62 to 2.32) for cardiovascular disease mortality. Individuals who were inactive in 1984–86 and then adhered to recommendations in 2006–08 had HRs of 1.07 (0.85 to 1.35) for all-cause mortality and 1.31 (0.87 to 1.98) for cardiovascular disease mortality. In a subsample of individuals who participated at all three time points, those who were inactive or physically active below the recommended level across three decades (1984–86, 1995–97 and 2006–2008) had an HR of 1.57 (1.22 to 2.03) for all-cause mortality and 1.72 (1.08 to 2.73) for cardiovascular disease mortality.


    Individuals who remained, or became, physically inactive had substantially greater risk of all-cause and cardiovascular disease mortality compared with those who met the physical activity recommendations throughout the lifespan.

  8. Background

    Cardiorespiratory fitness (CRF) is an important marker of current and future health status. The primary aim of our study was to evaluate the impact of a time-efficient school-based intervention on older adolescents’ CRF.


    Two-arm cluster randomised controlled trial conducted in two cohorts (February 2018 to February 2019 and February 2019 to February 2020) in New South Wales, Australia. Participants (N=670, 44.6% women, 16.0±0.43 years) from 20 secondary schools: 10 schools (337 participants) were randomised to the Burn 2 Learn (B2L) intervention and 10 schools (333 participants) to the control. Teachers in schools allocated to the B2L intervention were provided with training, resources, and support to facilitate the delivery of high-intensity interval training (HIIT) activity breaks during curriculum time. Teachers and students in the control group continued their usual practice. The primary outcome was CRF (20 m multi-stage fitness test). Secondary outcomes were muscular fitness, physical activity, hair cortisol concentrations, mental health and cognitive function. Outcomes were assessed at baseline, 6 months (primary end-point) and 12 months. Effects were estimated using mixed models accounting for clustering.


    We observed a group-by-time effect for CRF (difference=4.1 laps, 95% CI 1.8 to 6.4) at the primary end-point (6 months), but not at 12 months. At 6 months, group-by-time effects were found for muscular fitness, steps during school hours and cortisol.


    Implementing HIIT during curricular time improved adolescents’ CRF and several secondary outcomes. Our findings suggest B2L is unlikely to be an effective approach unless teachers embed sessions within the school day.

    Trial registration number

    Australian New Zealand Clinical Trials Registry (ACTRN12618000293268).

  9. Physical activity is an encompassing term for all human movement, in homes, schools, organisations and communities. Physical activity benefits individuals and societies, contributing to many of the United Nations Sustainable Development Goals, as outlined in International Society for Physical Activity and Health (ISPAH)’s Bangkok Declaration.1 The health benefits of physical activity are established and multifaceted and include reduced risk of a wide range of non-communicable diseases as well as improved mental health, sleep and cognitive function.2

    Globally, around one in four adults and four in five adolescents are insufficiently active,3 4 and inequities in participation exist by geography, sex and socioeconomic status. In response, two targets have been endorsed by the World Health Assembly, for a global reduction in physical inactivity by 10% by 2025 and 15% by 2030.5 In order to achieve these targets, advocacy and delivery efforts...

  10. Sports and exercise medicine clinicians often refer for diagnostic imaging to help direct clinical management. The use of musculoskeletal MRI has risen rapidly in recent decades, yet the clinical benefit of MRI is uncertain.1 Imaging is useful for the differential diagnosis of many health conditions, including possible red flags, however, there are growing concerns of potential harm from MRIs caused by clinicians misinterpreting results triggering unnecessary interventions escalating patient fear/distress.2 Evidence-based reporting and clinically relevant interpretation of MRIs is critical.

    Recognising the clinical significance of MRI findings is often a challenge given the substantial discordance that exists between structural pathology and symptoms. Emerging evidence indicates a high prevalence of so-called abnormal findings on MRI in individuals without symptoms. A collation of systematic reviews (and cohort studies when no review available) highlights that typical features of deterioration, such as cartilage lesions, hip and shoulder labral tears...