Measuring Muscle Visco-Elasticity in Horizontal Bed Rest Model for Better Understanding of Sedentary Life Style
R. Viir, Institute of Exercise Biology and Physiotherapy, University of Tartu, TartuEstonia
RehabCenter, RheumatismFoundationHospital, Heinola, Finland
M. Pääsuke, Institute of Exercise Biology and Physiotherapy, University of Tartu, TartuEstonia
K. Rajaleid, Center for Health Equity Studies, StockholmUniversity/ Karolinska Institutet, Stockholm, Sweden
*Note: The source for this paper is the ISU 12th Annual Symposium – ‘Space Solutions to Earth’s Global Challenges’
The aim of this study was to use the upper trapezius muscle as a representative of the musculoskeletal support system to determine the effect on muscle tension due changing from upright position to a lying position and whether this change could be useful in the prevention of musculoskeletal disorders. Twenty two female subjects participated in this study. Myometric measurements of the upper trapezius muscle on both sides of the body were recorded in a standing, sitting and supine position. Changing from upright positions to a supine position reduced the upper trapezius muscle support function by up to one fifth as characterized with diminishing of muscle tone and stiffness. The change in tone and stiffness of the trapezius muscle is of significance to the well being of sedentary workers. Introducing regular brief breaks of simple unchallenging movements while being in a supine position should enhance recovery from prolonged sitting.
Below is a survey asking SBRN members about their views on the future of the organization, and whether or not the group should formally become a part of the International Society for Physical Activity and Health. Please take 2-5 minutes to complete the survey, as the results will determine the structure and function of the organization in the coming years. Thanks for your time!
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Earlier this year SBRN published an updated definition of the terms “sedentary” and “sedentary behaviour”, which was published in the journals Applied Physiology, Nutrition and Metabolism and Movement & Sport Sciences – Science & Motricité. The definition was originally published in both English (here) and French (here). The definition has now been translated into Spanish and Portuguese by Ana Lúcia André with help from Verónica Varela Mato.
You can find links to the translated definitions below.
The definition can be cited as:
Sedentary Behaviour Research Network. 2012. Standardized use of the terms “sedentary” and “sedentary behaviours”. Appl Physiol Nutr Metab. 37: 540–542.
If you are interested in helping to translate this definition of sedentary behaviour into another language, please contact us through our contact page.
School of Physiotherapy and Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia
Curtin University is the largest university in Western Australia with a strong international focus. The School of Physiotherapy has a reputation for world class applied research and multidisciplinary collaborations. A growing number of research projects have been developed around sedentary behaviour/physical activity, technology and health – for example interventions for children and adolescents, interventions for office workers and large longitudinal epidemiological studies in children/young adults and ‘baby boomers’. These projects are mainly funded by the National Health and Medical Research Council of Australia and involve collaborations with researchers across Australia as well as Europe and North America. The research group is expanding and this creates an exciting opportunity for early career postdocs to join the team and develop as emerging leaders.
We are looking for enthusiastic, competent candidates able to work well with colleagues. Clear, critical thinking, strong conceptual and analytical background, and excellent writing skills are important, along with experience in sedentary behaviour and physical activity measurement. An earned doctorate in a related discipline is required along with strong letters of support from three colleagues/supervisors.
The role will include working with the team on existing projects to capture high quality data, data processing and analyses, and preparing and leading manuscripts and conference presentations. The role will also provide opportunities to develop grant writing and student supervision skills. Postdocs will be mentored by the team and encouraged to develop their own related research interests.
The appointment opportunities are flexible with 1-3 year contracts available. Competitive remuneration commensurate with qualifications will be provided (AUD70,000-80,000pa) along with leave and superannuation entitlements.
Further information is available from: Professor Leon Straker (L.Straker@curtin.edu.au) and Dr Rebecca Abbott (firstname.lastname@example.org; 14thDecember – 21stJanuary 2013 while Leon is on leave)
Click here for further background information on the post-doc positions.
Today SBRN reached 300 members! Thanks to everyone who has joined the network so far, we look forward to many more members in the future!
Diabetologia: Sedentary time in adults and the association with diabetes, cardiovascular disease and death: systematic review and meta-analysis
Aims/hypothesisSedentary (sitting) behaviours are ubiquitous in modern society. We conducted a systematic review and meta-analysis to examine the association of sedentary time with diabetes, cardiovascular disease and cardiovascular and all-cause mortality.MethodsMedline, Embase and the Cochrane Library databases were searched for terms related to sedentary time and health outcomes. Cross-sectional and prospective studies were included. RR/HR and 95% CIs were extracted by two independent reviewers. Data were adjusted for baseline event rate and pooled using a random-effects model. Bayesian predictive effects and intervals were calculated to indicate the variance in outcomes that would be expected if new studies were conducted in the future.ResultsEighteen studies (16 prospective, two cross-sectional) were included, with 794,577 participants. Fifteen of these studies were moderate to high quality. The greatest sedentary time compared with the lowest was associated with a 112% increase in the RR of diabetes (RR 2.12; 95% credible interval [CrI] 1.61, 2.78), a 147% increase in the RR of cardiovascular events (RR 2.47; 95% CI 1.44, 4.24), a 90% increase in the risk of cardiovascular mortality (HR 1.90; 95% CrI 1.36, 2.66) and a 49% increase in the risk of all-cause mortality (HR 1.49; 95% CrI 1.14, 2.03). The predictive effects and intervals were only significant for diabetes.Conclusions/interpretationSedentary time is associated with an increased risk of diabetes, cardiovascular disease and cardiovascular and all-cause mortality; the strength of the association is most consistent for diabetes.
New Paper: Impact of “noncaloric” activity-related factors on the predisposition to obesity in children
The research related to childhood obesity generally emphasizes the impact of unhealthy eating and sedentary behavior as the main determinants of the predisposition to the positive energy balance that underlies excess body fat accumulation. Recent investigations have, however, demonstrated that “noncaloric” activity-related factors can induce a significant imbalance between spontaneous energy intake and energy expenditure. This is the case for short sleep duration that favors hormonal changes that increase hunger and energy intake. This agrees with our research experience demonstrating that short sleeping predicts the risk of obesity in children to a greater extent than sedentary behavior. Recent research by our team has also showed that demanding mental work promotes a substantial increase in energy intake without altering energy expenditure. In addition, our preliminary data suggest that the regular practice of school-related cognitive efforts is predictive of an increase in abdominal fat accumulation. As discussed in this paper, individual variations in brain oxygenation and its related cerebral aerobic fitness might play a role in the relationship between mental work, energy intake, and the risk of excess body weight.
The full paper is available for free here.
Earlier this year SBRN published a new definition of sedentary behaviour in in French and English in the journals Applied Physiology, Nutrition and Metabolism, Movement & Sport Sciences – Science & Motricité and the African Journal for Physical, Health Education, Recreation and Dance.
Although the APNM and AJPHERD versions have been online for a month or so, due to differences in publishing schedules the Movement & Sport Sciences issue was published online this past week. It can be found here.
Here is the definition of sedentary behaviour, as proposed by the SBRN membership:
We suggest that journals formally define sedentary behaviour as any waking behaviour characterized by an energy expenditure ≤1.5 METs while in a sitting or reclining posture. In contrast, we suggest that authors use the term “inactive” to describe those who are performing insufficient amounts of MVPA (i.e., not meeting specified physical activity guidelines).
Nous suggérons que les revues définissent de façon formelle le comportement sédentaire comme une situation d’éveil caractérisée par une dépense énergétique ≤1,5 METs en position assise ou allongée.En revanche, nous suggérons que les auteurs utilisent le terme « inactif » pour décrire les individus ayant un niveau insuffisant d’activité physique d’intensité modérée à intense (MVPA), c’est-à-dire, n’atteignant pas le seuil d’activité physique recommandé.
The definition can be cited as:
From BMJ Open:
Objectives To determine the impact of sitting and television viewing on life expectancy in the USA.
Design Prevalence-based cause-deleted life table analysis.
Setting Summary RRs of all-cause mortality associated with sitting and television viewing were obtained from a meta-analysis of available prospective cohort studies. Prevalences of sitting and television viewing were obtained from the US National Health and Nutrition Examination Survey.
Primary outcome measure Life expectancy at birth.
Results The estimated gains in life expectancy in the US population were 2.00 years for reducing excessive sitting to <3 h/day and a gain of 1.38 years from reducing excessive television viewing to <2 h/day. The lower and upper limits from a sensitivity analysis that involved simultaneously varying the estimates of RR (using the upper and lower bounds of the 95% CI) and the prevalence of television viewing (±20%) were 1.39 and 2.69 years for sitting and 0.48 and 2.51 years for television viewing, respectively.
Conclusion Reducing sedentary behaviours such as sitting and television viewing may have the potential to increase life expectancy in the USA.
The full article is available for free here.
As with previous meetups at ICDAM and ISBNPA, SBRN recently hosted an informal meetup at the American College of Sports Medicine Annual Scientific Meeting in San Francisco, USA. The lunch was organized by Ernesto Ramirez, and was attended by 14 researchers from Europe, North America, and Oceania.
The conference also featured numerous well-received presentations by SBRN members. One such presentation by Bethany Howard of the Baker IDI is shown below.
If you are heading to a conference and would like to organize a meetup for other sedentary behaviour researchers under the SBRN banner, please go right ahead! Feel free to send a note to the list serve organizing the event, and you’re good to go. We love to highlight the events here on the website, so please try to get a picture if you can.