scholarly journals Force Production during the Sustained Phase of Rugby Scrums: A Systematic Literature Review

2020 ◽  
Author(s):  
Eric Martin ◽  
George Beckham

Abstract Background: Since World Rugby changed the laws regarding scrums in the 2013-2014 season, the sustained push phase of the scrum has become of greater tactical importance. Therefore, the purpose of this sytematic literature review was to examine the biomechanical demands during the sustained push phase of individual, unit, and full pack scrummaging. Methods: Pubmed, EBSCO (specifically and simultaneously searching Academic Search Premier, CINAHL, and SPORTDiscus), and Google Scholar were searched for any research that presented force production in a live or simulated rugby scrum. Study quality was appraised using the National Institute of Health's Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Recorded scrum forces, positioning of players including joint angles, and testing procedures were extracted and narratively synthesized. Results: Twenty six studies were included in the review. 50% of included studies were rated good, 31% fair, and 19% poor. Major limitations included not reporting any effect size, statistical power, or reliability. Reported group mean values for average sustained forces against a machine generally ranged from 1000-2000 N in individual scrums and 4000-8000 N for full packs of male rugby players older than high school age. Individuals seem to optimize their force generation when their shoulders are set against scrum machine pads at approximately 40% of body height, with feet parallel, and with knee and hip angles around 120°. A 10% difference in pack force seems to be necessary for one pack to drive another back in the scrum, but little data exist to quantify differences in force production between winning and losing packs during live scrums. Data collection within studies was not standardized, making comparisons difficult. There is a lack of data in live scrums, and the current research indicates that machine scrums may not replicate many of the demands of live scrums. There is a lack of data for female rugby players. Conclusions: This review indicates an optimal individual body position for players to strive to achieve during scrummaging, consisting of a low body height (40% of stature) and large extended hip and knee angles (120° each).

2020 ◽  
Author(s):  
Eric Martin ◽  
George Beckham

Abstract Background: Since World Rugby changed the laws regarding scrums in the 2013-2014 season, the sustained push phase of the scrum has increased in tactical importance. Therefore, the purpose of this systematic literature review was to examine the biomechanical demands during the sustained push phase of individual, unit, and full pack scrummaging. Methods: Pubmed, EBSCO (specifically and simultaneously searching Academic Search Premier, CINAHL, and SPORTDiscus), and Google Scholar were searched for any research that presented force production in a live or simulated rugby scrum. Study quality was appraised using the National Institute of Health's Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Recorded scrum forces, positioning of players including joint angles, and testing procedures were extracted and narratively synthesized. Results: Twenty six studies were included in the review. 50% of included studies were rated good, 31% fair, and 19% poor. Major limitations included not reporting any effect size, statistical power, or reliability. Reported group mean values for average sustained forces against a machine generally ranged from 1000-2000 N in individual scrums and 4000-8000 N for full packs of male rugby players older than high school age. Individuals seem to optimize their force generation when their shoulders are set against scrum machine pads at approximately 40% of body height, with feet parallel, and with knee and hip angles around 120°. A 10% difference in pack force seems to be necessary for one pack to drive another back in the scrum, but little data exist to quantify differences in force production between winning and losing packs during live scrums. Data collection within studies was not standardized, making comparisons difficult. There is a lack of data in live scrums, and the current research indicates that machine scrums may not replicate many of the demands of live scrums. There is a lack of data for female rugby players. Conclusions: This review indicates an optimal individual body position for players to strive to achieve during scrummaging, consisting of a low body height (40% of stature) and large extended hip and knee angles (120° each).


2020 ◽  
Author(s):  
Eric Martin ◽  
George Beckham

Abstract Background: Since World Rugby changed the laws regarding scrums in the 2013-2014 season, the sustained push phase of the scrum has become of greater tactical importance. Therefore, the purpose of this sytematic literature review was to examine the biomechanical demands during the sustained push phase of individual, unit, and full pack scrummaging.Methods: Pubmed, EBSCO (specifically and simultaneously searching Academic Search Premier, CINAHL, and SPORTDiscus), and Google Scholar were searched for any research that presented force production in a live or simulated rugby scrum. Study quality was appraised using the National Institute of Health's Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Recorded scrum forces, positioning of players including joint angles, and testing procedures were extracted and narratively synthesized.Results: Twenty six studies were included in the review. 50% of included studies were rated good, 31% fair, and 19% poor. Major limitations included not reporting any effect size, statistical power, or reliability. Reported group mean values for average sustained forces against a machine generally ranged from 1000-2000 N in individual scrums and 4000-8000 N for full packs of male rugby players older than high school age. Individuals seem to optimize their force generation when their shoulders are set against scrum machine pads at approximately 40% of body height, with feet parallel, and with knee and hip angles around 120°. A 10% difference in pack force seems to be necessary for one pack to drive another back in the scrum, but little data exist to quantify differences in force production between winning and losing packs during live scrums. Data collection within studies was not standardized, making comparisons difficult. There is a lack of data in live scrums, and the current research indicates that machine scrums may not replicate many of the demands of live scrums. There is a lack of data for female rugby players.Conclusions: This review indicates an optimal individual body position for players to strive to achieve during scrummaging, consisting of a low body height (40% of stature) and large extended hip and knee angles (120° each).


2016 ◽  
Vol 15 (2) ◽  
Author(s):  
Talita Farias Feitosa ◽  
Moelisa Queiroz Dos Santos Dantas ◽  
Cássia Brito Da Silva ◽  
Álvaro Pereira

Aim: To verify, in the scientific production, the degree of reliability of the  Semmens-Weinstein  monofilament  as  a  risk  assessment  tool  for  diabetic  foot. Method:  This  is  an  integrative  literature  review  conducted  from  consultation  of  the electronic  databases  CINAHL,  MEDLINE,  SCOPUS  and  SCIELO.  Results:  Six  articles comprising  five  cross-sectional  studies  and  one  cohort  study  were selected.  The  six articles included in the review were taken from medical journals; no nursing publication was  found  that  met  the  goal.  Conclusion:  The  Semmens-Weinstein  monofilament  is  a reliable tool which has the best performance for assessing the risk for diabetic foot and its applicability is extremely important in consultations.


2020 ◽  
Vol 5 (4) ◽  
pp. 91
Author(s):  
Eric A. Martin ◽  
George K. Beckham

The isometric mid-thigh pull (IMTP) is a multi-joint test of whole-body force production relevant to rugby players. “Rugby AND (mid-thigh pull OR midthigh pull OR mid thigh pull” were searched in PubMed, Sportdiscus, Academic Search Premier, CINAHL Plus with Full Text, and Google Scholar; the final date of search was 24 January 2018. Data extraction from 24 articles included subject characteristics, force data, and IMTP testing procedures. Select ranges of peak forces reported were: Youth: 1162–2374 N; Academy: 1855–3104 N; Professional: 2254–3851 N. Rate of force development (RFD) at 100 and 200 ms ranged from 5521 to 11,892 N and 5403 to 8405 N, respectively, among professional rugby players. Studies’ research design were of moderate quality, but most studies lacked detailed reporting of IMTP procedures. Variability of force characteristics derived from the IMTP within similar populations (e.g., approximately 200% difference in peak force between samples of professional rugby league players) as well as large and unexpected overlaps between dissimilar populations, limit conclusions about force production capabilities relative to playing level, likely due to limitations and lack of standardization of IMTP procedures. Greater uniformity in IMTP testing procedures and reporting is needed. This manuscript provides a guide for reporting needs when presenting results from an IMTP in research.


2019 ◽  
Vol 47 (1) ◽  
pp. 7-29
Author(s):  
Vanessa Machado ◽  
João Botelho ◽  
Paulo Mascarenhas ◽  
José João Mendes ◽  
Ana Delgado

Introduction: The purpose of this study was to seek and summarise the Bolton overall index (OI) and anterior index (AI) regarding normal occlusion and Angle’s malocclusion according to gender, and to assess if these indices support Bolton’s standards as general references. Methods: PubMed, LILACS, Embase, CENTRAL and Google Scholar databases were searched up to June 2019 (CRD42018088438). Non-randomised clinical studies, published in English and assessing Bolton’s OI and/or AI in normal occlusion and Angle’s malocclusion groups, were included. OI and AI means, sample size and SDs were collected. The National Heart, Lung, and Blood Institute’s Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies was used to assess the risk of bias. Pairwise random-effects and multilevel Bayesian network meta-analyses were used to synthesise available data. Results: Fifty-three observational studies were included (11,411 participants; 3746 men, 4430 women; 15 studies lacked gender information). For normal occlusion, pooled estimates for OI and AI means were 91.78% (95% confidence interval [CI] = 91.42–92.14; I2 = 92.87%) and 78.25% (95% CI = 77.87–78.62; I2 = 90.67%), respectively. We could identify in Angle’s Class III patients meaningful OI and AI mean deviations from normal occlusion (0.76, 95% credible interval [CrI] = 0.55–0.98 and 0.61, 95% CrI = 0.35–0.87, respectively), while in Class II patients we found a meaningful mean deviation from normal occlusion only for OI (−0.28, 95% CrI = −0.52–−0.05). Concerning gender impact, male patients presented higher OI (0.30, 95% CI = 0.00–0.59) and AI (0.41, 95% CI = 0.00–0.83) mean values than female patients in Class I. Conclusion: Normal occlusion OI and AI mean values differ from Bolton’s original values. Class II division 2, for OI mean values, and Class III, for both OI and AI, are proportionally larger than normal occlusion patients. Gender had almost no impact on teeth mesiodistal proportion.


Author(s):  
Rogério de Siqueira Peters ◽  
Maria do Socorro Luna Cruz ◽  
Claudio Hernández-Mosqueira ◽  
Cristian Martinez-Salazar ◽  
Fernando Policarpo Barbosa

To verify the influence of the resting heart rate (RHR) measurement on different positions in the calculation of VO2max intensities in young individuals of both sexes. Methods: A cross-sectional study with a correlational design with a sample of 22 men and 11 women, aged 27.8 ± 6.5 years and 29.0 ± 8.6 years, respectively, healthy, active and sedentary, who performed the stress test on a treadmill until fatigue. For the treatment of the data, a repeated measures ANOVA was carried out with Bonferroni’s post hoc test. Results: The comparison of the mean values of baseline heart rate (Bhr) between the groups of women and men showed significant differences (t = 2.329; gl 31; p = 0.027). However, no significant differences were noted for lying (t = 0.057; gl 31; p = 0.95), sitting (t = 0.196 gl 31; p = 0.85) or standing (t = −0.290; gl 31; p = 0.77). But in the analysis of the intensities of the RHR in different positions, the calculations with baseline and lying HR were significantly different (p < 0.05). Conclusion: The determination of aerobic training intensities by RHR method must observe the heart rate measurement at rest in the sitting and/or standing positions minutes before the training session.


Author(s):  
Vanessa Machado ◽  
João Botelho ◽  
Paulo Mascarenhas ◽  
José João Mendes ◽  
Ana Delgado

Introduction: The purposes of this study were to seek for overall ratio (OR) and anterior ratio (AR) patients data in normal occlusion and Angle&rsquo;s malocclusion studies, and to assess if such results support Bolton&rsquo;s standards as general references.&nbsp;Methods: Pubmed, Medline, CENTRAL and Scholar databases were searched up to February 2018 (CRD42018088438). Gray literature was explored through OpenGray. Non-randomized clinical studies, published in English and assessing Bolton&rsquo;s OR and AR in normal occlusion and Angle&rsquo;s malocclusion groups (Class I, Class II, Class II division 1, Class 2 division 2, Class III) patients were included. OR and AR means and standard deviations (SD) were collected. Potential covariates (study design, publication year, country where the study was conducted, number of cases, gender, mesiodistal measurement method, and calibration method) were also extracted. The National Health Heart Lung, and Blood Institute&rsquo;s Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies was used to assess each included studies quality. Pairwise Random-Effects and Multilevel Bayesian Network Meta-Analyses were used to synthesize available data.&nbsp;Results: Fifty-two observational studies were included (8872 participants; male/females 2674/3272; 16 studies lacked gender information). For normal occlusion, global pooled estimates for OR and AR means were 91.74% (95% CI: 91.37-92.10) and 78.24% (95% CI: 77.85-78.63), respectively. We could identify on Angle&rsquo;s Class III patients meaningful OR and AR mean deviations from normal occlusion (0.89, 95% credible interval [CrI], 0.66-1.12, and 0.66, 95% CrI, 0.38-0.94, respectively), while on Class I patients we found a meaningful mean deviation from normal occlusion only for OR (0.25, 95% CrI, 0.03-0.47). Concerning gender impact, male patients presented higher OR (0.30, 95% CI 0.00-0.59) and AR (0.41, 95% CI 0.00-0.83) mean values than females in Class I.&nbsp;Conclusions: The results show that global pooled OR and AR mean values for normal occlusion patients are slightly above Bolton&rsquo;s original values. Class I, for OR mean values, and Class III, for both OR and AR, are proportionally larger than normal occlusion patients. Gender had almost no impact on teeth mesiodistal proportion.


Neurology ◽  
2020 ◽  
Vol 95 (4) ◽  
pp. e402-e412 ◽  
Author(s):  
Kathryn Y. Manning ◽  
Jeffrey S. Brooks ◽  
James P. Dickey ◽  
Alexandra Harriss ◽  
Lisa Fischer ◽  
...  

ObjectiveTo longitudinally assess brain microstructure and function in female varsity athletes participating in contact and noncontact sports.MethodsConcussion-free female rugby players (n = 73) were compared to age-matched (ages 18–23) female swimmers and rowers (n = 31) during the in- and off-season. Diffusion and resting-state fMRI (rs-fMRI) measures were the primary outcomes. The Sports Concussion Assessment Tool and head impact accelerometers were used to monitor symptoms and impacts, respectively.ResultsWe found cross-sectional (contact vs noncontact) and longitudinal (in- vs off-season) changes in white matter diffusion measures and rs-fMRI network connectivity in concussion-free contact athletes relative to noncontact athletes. In particular, mean, axial, and radial diffusivities were increased with decreased fractional anisotropy in multiple white matter tracts of contact athletes accompanied with default mode and visual network hyperconnectivity (p < 0.001). Longitudinal diffusion changes in the brainstem between the in- and off-season were observed for concussion-free contact athletes only, with progressive changes observed in a subset of athletes over multiple seasons. Axial diffusivity was significantly lower in the genu and splenium of the corpus callosum in those contact athletes with a history of concussion.ConclusionsTogether, these findings demonstrate longitudinal changes in the microstructure and function of the brain in otherwise healthy, asymptomatic athletes participating in contact sport. Further research to understand the long-term brain health and biological implications of these changes is required, in particular to what extent these changes reflect compensatory, reparative, or degenerative processes.


2020 ◽  
Vol 90 (5-6) ◽  
pp. 535-552 ◽  
Author(s):  
Mahdieh Abbasalizad Farhangi ◽  
Mahdi Vajdi

Abstract. Backgrounds: Central obesity, as a pivotal component of metabolic syndrome is associated with numerous co-morbidities. Dietary factors influence central obesity by increased inflammatory status. However, recent studies didn’t evaluate the association between central obesity and dietary inflammation index (DII®) that give score to dietary factors according to their inflammatory potential. In the current systematic review and meta-analysis, we summarized the studies that investigated the association between DII® with central obesity indices in the general populations. Methods: In a systematic search from PubMed, SCOPUS, Web of Sciences and Cochrane electronic databases, we collected relevant studies written in English and published until 30 October 2019. The population of included studies were apparently healthy subjects or individuals with obesity or obesity-related diseases. Observational studies that evaluated the association between DII® and indices of central obesity including WC or WHR were included. Results: Totally thirty-two studies were included; thirty studies were cross-sectional and two were cohort studies with 103071 participants. Meta-analysis of observational studies showed that higher DII® scores were associated with 1.81 cm increase in WC (Pooled weighted mean difference (WMD) = 1.813; CI: 0.785–2.841; p = 0.001). Also, a non-significant increase in the odds of having higher WC (OR = 1.162; CI: 0.95–1.43; p = 0.154) in the highest DII category was also observed. In subgroup analysis, the continent, dietary assessment tool and gender were the heterogeneity sources. Conclusion: The findings proposed that adherence to diets with high DII® scores was associated with increased WC. Further studies with interventional designs are necessary to elucidate the causality inference between DII® and central obesity indices.


2018 ◽  
Vol 8 (6) ◽  
pp. 138-144
Author(s):  
Thien Nguyen Duc ◽  
Tai Tran Tan

Background: Periodontal disease is a prominent and important issue of public health, especially in pregnant women. The objective of this study is to describe the clinical characteristics; learn knowledge, attitudes, practice oral hygiene and assess the need for treatment of periodontal disease in pregnant women. Subjects and Methods: A cross-sectional study of 210 pregnant women who visited the Department of Obstetrics and Gynecology at the Hue University of Medicine and Pharmacy Hospital. Clinical examination and interview questions on knowledge, attitudes and practice of oral care for all subjects. Results: The incidence of gingivitis was 100%, with mild gingivitis of 4,3% and moderate gingivitis of 95.7%. There was a difference in incidence rates of gingivitis in the gestational period (p<0.001). The incidence of periodontitis is 17.6% and there is no difference in gestational age (p>0.05). The mean values of GI and BOP indices differed by gestation period (p<0.05) and PD, OHI-S, PlI have statistically significant relationship with gestation period (p>0.05). The incidence of periodontal disease is 80.5%; The percentage of pregnant women who abstain from brushing their teeth after birth is 61.4%. Prevalence of brushing once a day: 7.1%; Twice a day: 70.5% and 3 times daily: 22.4%; The mean values of GI, PD, BOP, OHI-S and PlI were inversely proportional to the number of brushing (p<0.001). The rate of dental hygiene is just 3.3%; The rate of oral hygiene, dental plaque and plaque removal was 94,3%; The proportion of subjects required for intensive treatment is 2.4%. Conclusion: Periodontal disease, especially for pregnant women, is high. It is necessary to educate the knowledge, attitudes and practice of proper oral hygiene and to better meet the demand for periodontal disease treatment for pregnant women. Key words: Periodontal disease, pregnant women, knowledge, attitude, practice for oral hygiene, treatment needs


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