Effect of the 'Crouch, Bind, Set' engagement routine on scrum performance in English Premiership Rugby

The effect of the new scrum engagement sequence introduced at the start of the 2013/2014 season on scrum performance has not been evaluated. This study compared scrum performance indicators pre- (2012/2013 season) and post-law change (2013/2014). Several performance indicators at the scrum were identified in 20 games from each season of the English domestic Premiership. These included the number of penalties, free kicks and resets awarded. A Mann Whitney U test showed a significant increase in the number of scrums per game, from 17.50 to 23.85 (p = 0.003, ES = 0.47). This was contributed to by a 112% increase in the number of reset scrums (p < 0.0005). Of the resets, there was a significant increase in the number of scrums reset due to collapsing, which is of concern for player welfare. However, resets for collapsing accounted for a similar proportion of the total resets pre and post law change at 52% and 53%, respectively, and may be due to the relative novelty of the technique and stringent law enforcement increasing resets. In contrast, there was a decrease in the number of early engagements from 1.65 to 0.40 per match following the law change which is likely beneficial for player welfare

THE EFFECT OF THE BEND ON TECHNIQUE AND PERFORMANCE DURING MAXIMAL SPEED SPRINTING

For 200 and 400 m races half of the race is run around the bend. This study aimed to understand the changes in kinematics that occur during maximal effort bend sprinting. Velocity reduction (5%) on the bend compared to the straight was, for the left step, mainly due to increased (20%) touchdown distance and some angular kinematics changes which led to increased contact time and reduced step frequency. During the right step, performance dropped mainly due to a reduction in step length. It is likely that changes caused by inward lean, to counteract moments caused by centripetal forces, on the bend contributed to detrimental changes in sagittal plane kinematics (e.g. knee flexion at touchdown) normally associated with superior performance in sprinting. Similar to straight sprinting, reduced touchdown distance could hold the key to improve bend performance

BEND SPRINTING AT DIFFERENT RADII OF AN OUTDOOR ATHLETICS TRACK

Athletes in the inners lanes may be at a disadvantage during sprint races that contain a bend portion. This study investigated the effect on performance when sprinting on the different radii of an outdoor track. There was an approximately 2% reduction in mean race velocity from lane 8 (left step: 9.56 m/s, right step: 9.49 m/s) to lane 5 (left step: 9.36 m/s, right step: 9.30 m/s), with only slight further reductions from lane 5 to lane 2 (left step: 9.34 m/s, right step: 9.30 m/s). This was mainly due to reductions in step frequency as radius decreased. The disadvantage of the inner lane compared to the outer lane may be greater than previously suspected. Larger race velocity standard deviations as radius decreased may be indicative of athletes being differently able to accommodate running at tighter radii than others. This may have implications for training and competition

SIMPLIFIED MARKER SETS FOR THE CALCULATION OF CENTRE OF MASS LOCATION DURING BEND SPRINTING

Simplified marker sets for the calculation of whole body centre of mass (CoM) location and associated variables (velocity, touchdown distance and turn of CoM) used in the analysis of bend sprinting performance were examined. CoM related variables were compared between a whole-body (13 segment), lower limb and trunk and lower limb model. Both simplified models showed strong agreement with whole-body CoM (Intraclass correlation: 0.873 - 0.998). The lower limb and trunk model (LLT) was the most accurate representation of whole body calculations, with acceptably low differences in all variables examined. Therefore, the LLT model is recommended for future use

Omega-3 fatty acids for depression in adults

BACKGROUND: Major depressive disorder (MDD) is highly debilitating, difficult to treat, has a high rate of recurrence, and negatively impacts the individual and society as a whole. One emerging potential treatment for MDD is n-3 polyunsaturated fatty acids (n-3PUFAs), also known as omega-3 oils, naturally found in fatty fish, some other seafood, and some nuts and seeds. Various lines of evidence suggest a role for n-3PUFAs in MDD, but the evidence is far from conclusive. Reviews and meta-analyses clearly demonstrate heterogeneity between studies. Investigations of heterogeneity suggest differential effects of n-3PUFAs, depending on severity of depressive symptoms, where no effects of n-3PUFAs are found in studies of individuals with mild depressive symptomology, but possible benefit may be suggested in studies of individuals with more severe depressive symptomology.OBJECTIVES: To assess the effects of n-3 polyunsaturated fatty acids (also known as omega-3 fatty acids) versus a comparator (e.g. placebo, anti-depressant treatment, standard care, no treatment, wait-list control) for major depressive disorder (MDD) in adults. SEARCH METHODS: We searched the Cochrane Depression, Anxiety and Neurosis Review Group's Specialised Registers (CCDANCTR) and International Trial Registries over all years to May 2015. We searched the database CINAHL over all years of records to September 2013.SELECTION CRITERIA: We included studies in the review if they: were a randomised controlled trial; provided n-3PUFAs as an intervention; used a comparator; measured depressive symptomology as an outcome; and were conducted in adults with MDD. Primary outcomes were depressive symptomology (continuous data collected using a validated rating scale) and adverse events. Secondary outcomes were depressive symptomology (dichotomous data on remission and response), quality of life, and failure to complete studies.DATA COLLECTION AND ANALYSIS: We used standard methodological procedures as expected by Cochrane.MAIN RESULTS: We found 26 relevant studies: 25 studies involving a total of 1438 participants investigated the impact of n-3PUFA supplementation compared to placebo, and one study involving 40 participants investigated the impact of n-3PUFA supplementation compared to antidepressant treatment.For the placebo comparison, n-3PUFA supplementation results in a small to modest benefit for depressive symptomology, compared to placebo: standardised mean difference (SMD) -0.32 (95% confidence interval (CI) -0.12 to -0.52; 25 studies, 1373 participants, very low quality evidence), but this effect is unlikely to be clinically meaningful (an SMD of 0.32 represents a difference between groups in scores on the HDRS (17-item) of approximately 2.2 points (95% CI 0.8 to 3.6)). The confidence intervals include both a possible clinically important effect and a possible negligible effect, and there is considerable heterogeneity between the studies. Although the numbers of individuals experiencing adverse events were similar in intervention and placebo groups (odds ratio (OR) 1.24, 95% CI 0.95 to 1.62; 19 studies, 1207 participants; very low-quality evidence), the confidence intervals include a significant increase in adverse events with n-3PUFAs as well as a small possible decrease. Rates of remission and response, quality of life, and rates of failure to complete studies were also similar between groups, but confidence intervals are again wide.The evidence on which these results are based is very limited. All studies contributing to our analyses were of direct relevance to our research question, but we rated the quality of the evidence for all outcomes as low to very low. The number of studies and number of participants contributing to all analyses were low, and the majority of studies were small and judged to be at high risk of bias on several measures. Our analyses were also likely to be highly influenced by three large trials. Although we judge these trials to be at low risk of bias, they contribute 26.9% to 82% of data. Our effect size estimates are also imprecise. Funnel plot asymmetry and sensitivity analyses (using fixed-effect models, and only studies judged to be at low risk of selection bias, performance bias or attrition bias) also suggest a likely bias towards a positive finding for n-3PUFAs. There was substantial heterogeneity in analyses of our primary outcome of depressive symptomology. This heterogeneity was not explained by the presence or absence of comorbidities or by the presence or absence of adjunctive therapy.Only one study was available for the antidepressant comparison, involving 40 participants. This study found no differences between treatment with n-3PUFAs and treatment with antidepressants in depressive symptomology (mean difference (MD) -0.70 (95% CI -5.88 to 4.48)), rates of response to treatment or failure to complete. Adverse events were not reported in a manner suitable for analysis, and rates of depression remission and quality of life were not reported.AUTHORS' CONCLUSIONS: At present, we do not have sufficient high quality evidence to determine the effects of n-3PUFAs as a treatment for MDD. Our primary analyses suggest a small-to-modest, non-clinically beneficial effect of n-3PUFAs on depressive symptomology compared to placebo; however the estimate is imprecise, and we judged the quality of the evidence on which this result is based to be low/very low. Sensitivity analyses, funnel plot inspection and comparison of our results with those of large well-conducted trials also suggest that this effect estimate is likely to be biased towards a positive finding for n-3PUFAs, and that the true effect is likely to be smaller. Our data, however, also suggest similar rates of adverse events and numbers failing to complete trials in n-3PUFA and placebo groups, but again our estimates are very imprecise. The one study that directly compares n-3PUFAs and antidepressants in our review finds comparable benefit. More evidence, and more complete evidence, are required, particularly regarding both the potential positive and negative effects of n-3PUFAs for MDD.</p

Effect of hurdling step strategy on the kinematics of the hurdle clearance technique

Athletes use either an eight-step or a seven-step strategy to reach the first hurdle in the 110 m hurdles event. This study investigates the effect of step strategy on the hurdle clearance technique and spatio-temporal parameters of the four steps prior to hurdle clearance. Two-dimensional video data were collected in the sagittal plane from 12 male sprinters, grouped as seven-step (n = 6) or eight-step (n = 6) strategists. The take-off distance was 0.20 m further from the hurdle and the touchdown was 0.42 m closer to the hurdle for seven-step athletes. Additionally, seven-step athletes reduced the length of the final step before hurdle take-off by 0.14 m compared with the previous step, whereas the eight-step athletes extended their final step by 0.17 m. There was negligible difference between the mean horizontal velocities of the two groups throughout the hurdle clearance (0.02 m/s) or the approach time to the first hurdle from the block clearance (0.01 s). This presents an important first insight into the effect of the step strategy on the first hurdle kinematics. Our findings identify the take-off and touchdown distance parameters of the hurdle clearance technique, and approach step characteristics for a successful seven- or eight-step approach strategy to be employed

Effect of hurdling step strategy on the kinematics of the block start.

Athletes use either a seven-step or eight-step strategy to reach the first hurdle in the 110 m hurdle event. This study investigated the effect of step strategy on the start position, the block exit and the first four approach steps. Two-dimensional video data were collected in the sagittal plane from 12 male sprinters, grouped as seven-step (n = 6) or eight-step (n = 6) strategists. Mean block spacing was 0.08 m further apart, block contact time 0.06s longer, first step 0.25 m longer and first ground contact 0.03s longer for seven-step athletes compared with eight-step athletes. There was also a greater vertical displacement of the centre of mass (CoM) (0.04 m) for the seven-step athletes compared with the eight-step athletes. Additionally, the front hip mean angular acceleration was 197°/s2 slower for the seven-step athletes than the eight-step athletes. There was limited difference between groups for mean horizontal velocity at the moment of block exit (0.14 m/s). These technical alterations provide an important first insight into start kinematics. The findings of this study identify the position in the starting blocks, and the key parameters which pertain to the initial phases for a successful seven-step approach strategy to be employed

The effect of the bend on technique and performance during maximal effort sprinting

This study investigated changes in performance and technique that occur during maximal effort bend sprinting compared to straight-line sprinting under typical outdoor track conditions. Utilising a repeated measures design, three-dimensional video analysis was conducted on seven male sprinters in both conditions (bend radius: 37.72 m). Mean race velocity decreased from 9.86 m/s to 9.39 m/s for the left step (p = 0.008) and from 9.80 m/s to 9.33 m/s for the right step (p = 0.004) on the bend compared to the straight, a 4.7% decrease for both steps. This was due mainly to a 0.11 Hz (p = 0.022) decrease in step frequency for the left step and a 0.10 m (p = 0.005) reduction in race step length for the right step. The left hip was 4.0° (p = 0.049) more adducted at touchdown on the bend than the straight. Furthermore, the bend elicited significant differences between left and right steps in a number of variables including ground contact time, touchdown distance and hip flexion/extension and abduction/adduction angles. The results indicate that the roles of the left and right steps may be functionally different during bend sprinting. This specificity should be considered when designing training programmes

School-based interventions to prevent anxiety, depression and conduct disorders in children and young people:a systematic review, network meta-analysis and economic evaluation

Background: Schools in the UK increasingly have to respond to anxiety, depression and conduct disorder as key causes of morbidity in children and young people. Objective: The objective was to assess the comparative effectiveness of educational setting-based interventions for the prevention of anxiety, depression and conduct disorder in children and young people. Design: This study comprised a systematic review, a network meta-analysis and an economic evaluation. Data sources: The databases MEDLINE, EMBASE™ (Elsevier, Amsterdam, the Netherlands), PsycInfo® (American Psychological Association, Washington, DC, USA) and Cochrane Central Register of Controlled Trials (CENTRAL) were searched to 4 April 2018, and the NHS Economic Evaluation Database (NHS EED) was searched on 22 May 2019 for economic evaluations. No language or date filters were applied. Main outcomes: The main outcomes were post-intervention self-reported anxiety, depression or conduct disorder symptoms. Review methods: Randomised/quasi-randomised trials of universal or targeted interventions for the prevention of anxiety, depression or conduct disorder in children and young people aged 4–18 years were included. Screening was conducted independently by two reviewers. Data extraction was conducted by one reviewer and checked by a second. Intervention- and component-level network meta-analyses were conducted in OpenBUGS. A review of the economic literature and a cost–consequence analysis were conducted. Results: A total of 142 studies were included in the review, and 109 contributed to the network meta-analysis. Of the 109 studies, 57 were rated as having an unclear risk of bias for random sequence generation and allocation concealment. Heterogeneity was moderate. In universal secondary school settings, mindfulness/relaxation interventions [standardised mean difference (SMD) –0.65, 95% credible interval (CrI) –1.14 to –0.19] and cognitive–behavioural interventions (SMD –0.15, 95% CrI –0.34 to 0.04) may be effective for anxiety. Cognitive–behavioural interventions incorporating a psychoeducation component may be effective (SMD –0.30, 95% CrI –0.59 to –0.01) at preventing anxiety immediately post intervention. There was evidence that exercise was effective in preventing anxiety in targeted secondary school settings (SMD –0.47, 95% CrI –0.86 to –0.09). There was weak evidence that cognitive–behavioural interventions may prevent anxiety in universal (SMD –0.07, 95% CrI –0.23 to 0.05) and targeted (SMD –0.38, 95% CrI –0.84 to 0.07) primary school settings. There was weak evidence that cognitive–behavioural (SMD –0.04, 95% CrI –0.16 to 0.07) and cognitive–behavioural + interpersonal therapy (SMD –0.18, 95% CrI –0.46 to 0.08) may be effective in preventing depression in universal secondary school settings. Third-wave (SMD –0.35, 95% CrI –0.70 to 0.00) and cognitive–behavioural interventions (SMD –0.11, 95% CrI –0.28 to 0.05) incorporating a psychoeducation component may be effective at preventing depression immediately post intervention. There was no evidence of intervention effectiveness in targeted secondary, targeted primary or universal primary school settings post intervention. The results for university settings were unreliable because of inconsistency in the network meta-analysis. A narrative summary was reported for five conduct disorder prevention studies, all in primary school settings. None reported the primary outcome at the primary post-intervention time point. The economic evidence review reported heterogeneous findings from six studies. Taking the perspective of a single school budget and based on cognitive–behavioural therapy intervention costs in universal secondary school settings, the cost–consequence analysis estimated an intervention cost of £43 per student. Limitations: The emphasis on disorder-specific prevention excluded broader mental health interventions and restricted the number of eligible conduct disorder prevention studies. Restricting the study to interventions delivered in the educational setting may have limited the number of eligible university-level interventions. Conclusions: There was weak evidence of the effectiveness of school-based, disorder-specific prevention interventions, although effects were modest and the evidence not robust. Cognitive–behavioural therapy-based interventions may be more effective if they include a psychoeducation component. Future work: Future trials for prevention of anxiety and depression should evaluate cognitive–behavioural interventions with and without a psychoeducation component, and include mindfulness/relaxation or exercise comparators, with sufficient follow-up. Cost implications must be adequately measured. Study registration: This study is registered as PROSPERO CRD42016048184. Funding: This project was funded by the National Institute for Health Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 9, No. 8. See the NIHR Journals Library website for further project information