Sedentariness at work: how much do we really sit?

Workplace interventions for reducing sitting at work

BACKGROUND

Office work has changed considerably over the previous couple of decades and has become sedentary in nature. Physical inactivity at workplaces and particularly increased sitting has been linked to increase in cardiovascular disease, obesity and overall mortality.

OBJECTIVES

To evaluate the effects of workplace interventions to reduce sitting at work compared to no intervention or alternative interventions.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, OSH UPDATE, PsycINFO, Clinical trials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) search portal up to 2 June, 2015. We also screened reference lists of articles and contacted authors to find more studies to include.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), cluster-randomised controlled trials (cRCTs), and quasi-randomised controlled trials of interventions to reduce sitting at work. For changes of workplace arrangements, we also included controlled before-and-after studies (CBAs) with a concurrent control group. The primary outcome was time spent sitting at work per day, either self-reported or objectively measured by means of an accelerometer-inclinometer. We considered energy expenditure, duration and number of sitting episodes lasting 30 minutes or more, work productivity and adverse events as secondary outcomes.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles, abstracts and full-text articles for study eligibility. Two review authors independently extracted data and assessed risk of bias. We contacted authors for additional data where required.

MAIN RESULTS

We included 20 studies, two cross-over RCTs, 11 RCTs, three cRCTs and four CBAs, with a total of 2180 participants from high income nations. The studies evaluated physical workplace changes (nine studies), policy changes (two studies), information and counselling (seven studies) and interventions from multiple categories (two studies). One study had both physical workplace changes and information and counselling components. We did not find any studies that had investigated the effect of periodic breaks or standing or walking meetings. Physical workplace changesA sit-stand desk alone compared to no intervention reduced sitting time at work per workday with between thirty minutes to two hours at short term (up to three months) follow-up (six studies, 218 participants, very low quality evidence). In two studies, sit-stand desks with additional counselling reduced sitting time at work in the same range at short-term follow-up (61 participants, very low quality evidence). One study found a reduction at six months' follow-up of -56 minutes (95% CI -101 to -12, very low quality evidence) compared to no intervention. Also total sitting time at work and outside work decreased with sit-stand desks compared to no intervention (MD -78 minutes, 95% CI -125 to -31, one study) as did the duration of sitting episodes lasting 30 minutes or more (MD -52 minutes, 95% CI -79 to -26, two studies). This is considerably less than the two to four hours recommended by experts. Sit-stand desks did not have a considerable effect on work performance, musculoskeletal symptoms or sick leave. It remains unclear if standing can repair the harms of sitting because there is hardly any extra energy expenditure.The effects of active workstations were inconsistent. Treadmill desks combined with counselling reduced sitting time at work (MD -29 minutes, 95% CI -55 to -2, one study) compared to no intervention at 12 weeks' follow-up. Pedalling workstations combined with information did not reduce inactive sitting at work considerably (MD -12 minutes, 95% CI -24 to 1, one study) compared to information alone at 16 weeks' follow-up. The quality of evidence was low for active workstations. Policy changesTwo studies with 443 participants provided low quality evidence that walking strategies did not have a considerable effect on workplace sitting time at 10 weeks' (MD -16 minutes, 95% CI -54 to 23) or 21 weeks' (MD -17 minutes, 95% CI -58 to 25) follow-up respectively. Information and counsellingCounselling reduced sitting time at work (MD -28 minutes, 95% CI -52 to -5, two studies, low quality evidence) at medium term (three months to 12 months) follow-up. Mindfulness training did not considerably reduce workplace sitting time (MD -2 minutes, 95% CI -22 to 18) at six months' follow-up and at 12 months' follow-up (MD -16 minutes, 95% CI -45 to 12, one study, low quality evidence). There was no considerable increase in work engagement with counselling.There was an inconsistent effect of computer prompting on sitting time at work. One study found no considerable effect on sitting at work (MD -17 minutes, 95% CI -48 to 14, low quality evidence) at 10 days' follow-up, while another study reported a significant reduction in sitting at work (MD -55 minutes, 95% CI -96 to -14, low quality evidence) at 13 weeks' follow-up. Computer prompts to stand reduced sitting at work by 14 minutes more (95% CI 10 to 19, one study) compared to computer prompts to step at six days' follow-up. Computer prompts did not change the number of sitting episodes that last 30 minutes or longer. Interventions from multiple categories Interventions combining multiple categories had an inconsistent effect on sitting time at work, with a reduction in sitting time at 12 weeks' (25 participants, very low quality evidence) and six months' (294 participants, low quality evidence) follow-up in two studies but no considerable effect at 12 months' follow-up in one study (MD -47.98, 95% CI -103 to 7, 294 participants, low quality evidence).

AUTHORS' CONCLUSIONS

At present there is very low to low quality evidence that sit-stand desks may decrease workplace sitting between thirty minutes to two hours per day without having adverse effects at the short or medium term. There is no evidence on the effects in the long term. There were no considerable or inconsistent effects of other interventions such as changing work organisation or information and counselling. There is a need for cluster-randomised trials with a sufficient sample size and long term follow-up to determine the effectiveness of different types of interventions to reduce objectively measured sitting time at work.

Acceptability and feasibility of a low-cost, theory-based and co-produced intervention to reduce workplace sitting time in desk-based university employees

BACKGROUND

Prolonged sedentary time is linked with poor health, independent of physical activity levels. Workplace sitting significantly contributes to sedentary time, but there is limited research evaluating low-cost interventions targeting reductions in workplace sitting. Current evidence supports the use of multi-modal interventions developed using participative approaches. This study aimed to explore the acceptability and feasibility of a low-cost, co-produced, multi-modal intervention to reduce workplace sitting.

METHODS

The intervention was developed with eleven volunteers from a large university department in the UK using participative approaches and "brainstorming" techniques. Main components of the intervention included: emails suggesting ways to "sit less" e.g. walking and standing meetings; free reminder software to install onto computers; social media to increase awareness; workplace champions; management support; and point-of-decision prompts e.g. by lifts encouraging stair use. All staff (n = 317) were invited to take part. Seventeen participated in all aspects of the evaluation, completing pre- and post-intervention sitting logs and questionnaires. The intervention was delivered over four weeks from 7th July to 3rd August 2014. Pre- and post-intervention difference in daily workplace sitting time was presented as a mean ± standard deviation. Questionnaires were used to establish awareness of the intervention and its various elements, and to collect qualitative data regarding intervention acceptability and feasibility.

RESULTS

Mean baseline sitting time of 440 min/workday was reported with a mean reduction of 26 ± 54 min/workday post-intervention (n = 17, 95 % CI = -2 to 53). All participants were aware of the intervention as a whole, although there was a range of awareness for individual elements of the intervention. The intervention was generally felt to be both acceptable and feasible. Management support was perceived to be a strength, whilst specific strategies that were encouraged, including walking and standing meetings, received mixed feedback.

CONCLUSIONS

This small-scale pilot provides encouragement for the acceptability and feasibility of low-cost, multi-modal interventions to reduce workplace sitting in UK settings. Evaluation of this intervention provides useful information to support participatory approaches during intervention development and the potential for more sustainable low-cost interventions. Findings may be limited in terms of generalisability as this pilot was carried out within a health-related academic setting.

Sick of sitting

Sitting too much kills. Epidemiological, physiological and molecular data suggest that sedentary lifestyle can explain, in part, how modernity is associated with obesity, more than 30 chronic diseases and conditions and high healthcare costs. Excessive sitting--sitting disease--is not innate to the human condition. People were designed to be bipedal and, before the industrial revolution, people moved substantially more throughout the day than they do presently. It is encouraging that solutions exist to reverse sitting disease. Work environments, schools, communities and cities can be re-imagined and re-invented as walking spaces, and people thereby offered more active, happier, healthier and more productive lives.

Increasing physical activity in office workers--the Inphact Treadmill study; a study protocol for a 13-month randomized controlled trial of treadmill workstations

Background

Sedentary behaviour is an independent risk factor for mortality and morbidity, especially for type 2 diabetes. Since office work is related to long periods that are largely sedentary, it is of major importance to find ways for office workers to engage in light intensity physical activity (LPA). The Inphact Treadmill study aims to investigate the effects of installing treadmill workstations in offices compared to conventional workstations.

Methods/Design

A two-arm, 13-month, randomized controlled trial (RCT) will be conducted. Healthy overweight and obese office workers (n = 80) with mainly sedentary tasks will be recruited from office workplaces in Umeå, Sweden. The intervention group will receive a health consultation and a treadmill desk, which they will use for at least one hour per day for 13 months. The control group will receive the same health consultation, but continue to work at their regular workstations. Physical activity and sedentary time during workdays and non-workdays as well as during working and non-working hours on workdays will be measured objectively using accelerometers (Actigraph and activPAL) at baseline and after 2, 6, 10, and 13 months of follow-up. Food intake will be recorded and metabolic and anthropometric variables, body composition, stress, pain, depression, anxiety, cognitive function, and functional magnetic resonance imaging will be measured at 3–5 time points during the study period. Interviews with participants from the intervention group will be performed at the end of the study.

Discussion

This will be the first long-term RCT on the effects of treadmill workstations on objectively measured physical activity and sedentary time as well as other body functions and structures/morphology during working and non-working hours among office workers. This will provide further insight on the effects of active workstations on our health and could fill in some of the knowledge gaps regarding how we can reduce sedentary time in office environments.

Trial registration

ClinicalTrials.gov Identifier NCT01997970, 2nd Nov 2013.

Interventions to reduce sedentary behavior

PURPOSE

This article reports on the presentations and discussion from the working group on "Influences on Sedentary Behavior and Interventions To Reduce Sedentary Behavior" as part of the Sedentary Behavior: Identifying Research Priorities workshop.

METHODS

Interventions were discussed in the context of targeting sedentary behavior (SB) as a concept distinct from physical activity. It was recommended that interventions targeting SB should consider a life course perspective, a position predicated on the assumption that SB is age and life stage dependent. In addition, targeting environments where individuals have high exposure to SB--such as workplace sitting--could benefit from new technology (e.g., computer-based prompting to stand or move), environmental changes (e.g., active workstations), policies targeting reduced sedentary time (e.g., allowing employees regular desk breaks), or by changing norms surrounding prolonged sitting (e.g., standing meetings).

RESULTS AND CONCLUSIONS

There are limited data about the minimal amount of SB change required to produce meaningful health benefits. In addition to developing relevant scientific and public health definitions of SB, it is important to further delineate the scope of health and quality-of-life outcomes associated with reduced SB across the life course and to clarify what behavioral alternatives to SB can be used to optimize health gains. SB interventions will benefit from having more clarity about the potential physiological and behavioral synergies with current physical activity recommendations, developing multilevel interventions aimed at reducing SB across all life phases and contexts, harnessing relevant and effective strategies to extend the reach of interventions to all sectors of society, as well as applying state-of-the-science adaptive designs and methods to accelerate advances in the science of SB interventions.

Intra-individual and inter-individual variability in daily sitting time and MVPA

OBJECTIVES

Little is known about how much variability exists in free-living sitting time within individuals. The purpose of this study was to examine intra-individual variability of objectively determined daily sitting time and to determine if this variability was related to weekly averages of sitting duration or recommended moderate-vigorous physical activity (MVPA). Also, this study determined the reliability of free-living sitting and MVPA time as it useful for guiding researchers in determining how many days of monitoring are needed.

DESIGN

An activPAL monitor was worn for 7 consecutive days by 68 women (52±8 years).

METHODS

Intra-individual range of daily sitting time was calculated. Generalizability theory analysis determined the reliability of daily sitting and recommended MVPA.

RESULTS

Mean sitting time was 9.0±1.8h/day and the within individual weekly mean range was 4.5±1.7h/day. Similarly, there was a 4.5h/day difference in sitting time between the mean of the lowest sitting (6.7±0.8) and highest sitting (11.3±1.1h/day) quartiles. The intra-individual range in daily sitting did not differ among quartiles of sitting time (i.e., 4.9±1.9, 4.1±1.9, 5.1±1.5, 3.9±1.1h/day for the 1st-4th quartiles) nor among quartiles of MVPA (i.e., 4.2±1.8, 4.7±2.0, 4.6±1.5, 4.4±1.3h/day for the 1st-4th quartiles). A reliability coefficient of 0.80 was achieved with 4 days of objectively measured sitting time and 7 days for MVPA.

CONCLUSIONS

The findings suggest exposure to relatively high levels of sedentary time may occur in people regardless of weekly averages in sitting and regular exercise due to the high day-to-day variation in daily sitting time (4.5h/d range within a week).

Nonexercise activity thermogenesis in obesity management

Obesity is linked to cardiovascular disease. The global increase in sedentary lifestyle is an important factor contributing to the rising prevalence of the obesity epidemic. Traditionally, counseling has focused on moderate- to vigorous-intensity exercise, with disappointing results. Nonexercise activity thermogenesis (NEAT) is an important component of daily energy expenditure. It represents the common daily activities, such as fidgeting, walking, and standing. These high-effect NEAT movements could result in up to an extra 2000 kcal of expenditure per day beyond the basal metabolic rate, depending on body weight and level of activity. Implementing NEAT during leisure-time and occupational activities could be essential to maintaining a negative energy balance. NEAT can be applied by being upright, ambulating, and redesigning workplace and leisure-time environments to promote NEAT. The benefits of NEAT include not only the extra calories expended but also the reduced occurrence of the metabolic syndrome, cardiovascular events, and all-cause mortality. We believe that to overcome the obesity epidemic and its adverse cardiovascular consequences, NEAT should be part of the current medical recommendations. The content of this review is based on a literature search of PubMed and the Google search engine between January 1, 1960, and October 1, 2014, using the search terms physical activity, obesity, energy expenditure, nonexercise activity thermogenesis, and NEAT.

Workplace interventions for reducing sitting at work

BACKGROUND

The number of people working whilst seated at a desk keeps increasing worldwide. As sitting increases, occupational physical strain declines at the same time. This has contributed to increases in cardiovascular disease, obesity and diabetes. Therefore, reducing and breaking up the time that people spend sitting while at work is important for health.

OBJECTIVES

To evaluate the effects of workplace interventions to reduce sitting at work compared to no intervention or alternative interventions.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, OSH UPDATE, PsycINFO, Clinical trials.gov and the World Health Organization (WHO) search trial portal up to 14 February, 2014. We also searched reference lists of articles and contacted authors.

SELECTION CRITERIA

We included randomised controlled trials (RCT), cluster-randomised controlled trials (cRCTs), and quasi-randomised controlled trials of interventions to reduce sitting at work. For changes of workplace arrangements, we also included controlled before-and-after studies (CBAs) with a concurrent control group. The primary outcome was time spent sitting at work per day, either self-reported or objectively measured by means of an accelerometer coupled with an inclinometer. We considered energy expenditure, duration and number of sitting episodes lasting 30 minutes or more, work productivity and adverse events as secondary outcomes.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles, abstracts and full-text articles for study eligibility. Two review authors independently extracted data and assessed risk of bias. We contacted authors for additional data where required.

MAIN RESULTS

We included eight studies, four RCTs, three CBAs and one cRCT, with a total of 1125 participants. The studies evaluated physical workplace changes (three studies), policy changes (one study) and information and counselling (four studies). No studies investigated the effect of treadmill desks, stepping devices, periodic breaks or standing or walking meetings. All the studies were at high risk of bias. The quality of the evidence was very low to low. Half of the studies were from Australia and the other half from Europe, with none from low- or middle-income countries. Physical workplace changesWe found very low quality evidence that sit-stand desks with or without additional counselling reduced sitting time at work per workday at one week follow-up (MD -143 minutes (95% CI -184 to -102, one study, 31 participants) and at three months' follow-up (MD - 113 minutes, 95% CI -143 to -84, two studies, 61 participants) compared to no intervention. Total sitting time during the whole day decreased also with sit-stand desks compared to no intervention (MD -78 minutes, 95% CI -125 to -30, one study, 31 participants) as did the duration of sitting episodes lasting 30 minutes or more (MD -52 minutes, 95% CI -79 to -26, two studies, 74 participants). Sit-stand desks did not have a considerable effect on work performance and had an inconsistent effect on musculoskeletal symptoms and sick leave. Policy changesWalking strategies had no considerable effect on sitting at work (MD -16 minutes, 95% CI -54 to 23, one study, 179 participants, low quality evidence). Information and counsellingGuideline-based counselling by occupational physicians reduced sitting time at work (MD -28 minutes, 95% CI -54 to -2, one study, 396 participants, low quality evidence). There was no considerable effect on reduction in total sitting time during the whole day.Mindfulness training induced a non-significant reduction in workplace sitting time (MD -2 minutes, 95% CI -22 to 18) at six months' follow-up and at 12 months' follow-up (MD -16 minutes, 95% CI -45 to 12, one study, 257 participants, low quality evidence).There was an inconsistent effect of computer prompting on sitting time at work. One study found no considerable effect on sitting at work (MD -18 minutes, 95% CI -53 to 17, 28 participants, low quality evidence) at 10 days' follow-up, while another study reported a significant reduction in sitting at work (MD -55 minutes, 95% CI -96 to -14, 34 participants, low quality evidence) at 13 weeks' follow-up. Computer prompting software also led to a non-significant increase in energy expenditure at work (MD 278 calories/workday, 95% CI 0 to 556, one study, 34 participants, low quality evidence) at 13 weeks' follow-up.

AUTHORS' CONCLUSIONS

At present there is very low quality evidence that sit-stand desks can reduce sitting time at work, but the effects of policy changes and information and counselling are inconsistent. There is a need for high quality cluster-randomised trials to assess the effects of different types of interventions on objectively measured sitting time. There are many ongoing trials that might change these conclusions in the near future.

Objectively measured and self-reported sedentary time in older Canadians

OBJECTIVE

The aim of this study was to examine objectively measured total and self-reported leisure sedentary time among older Canadians by work status.

METHODS

The analysis was based on 1729 older adults (60-79 years) from the 2007/09 and 2010/11 Canadian Health Measures Survey. Work status, functional limitations, smoking, and perceived health were assessed by self-report and waist circumference (WC) was measured. Total sedentary time (ST) and physical activity (PA) were objectively measured by accelerometer and leisure sedentary activities were assessed by questionnaire.

RESULTS

93.6% of individuals were sedentary for 8 or more hours per day. Measured ST did not differ by work status, while self-reported leisure ST was higher in those not working compared to those working (239 vs. 207 minutes/day, p < 0.05). Correlates of measured ST were fair/poor perceived health (β: 28.76, p < 0.01), smoking (β: 17.12, p < 0.05), high-risk WC (β: 13.14, p < 0.05), and not meeting PA guidelines (β: 35.67, p < 0.001). For self-reported leisure ST, working status (β: 33.80, p < 0.001) and functional limitations (β: 16.31, p < 0.05) were significant correlates.

CONCLUSIONS

Older adults accumulate substantial ST regardless of their working status and ST is correlated with indicators of health risk. Older adults are an important target population for interventions to reduce ST.

Occupational Sitting and Physical Activity Among University Employees

The prevalence of overweight and obese in the U.S. has been thoroughly documented. With the advent of inactivity physiology research and the subsequent interest in sedentary behavior, the work environment has come under closer scrutiny as a potential opportunity to reverse inactivity. Therefore, the purpose of this study was to determine the sitting and physical activity (PA) habits among different classifications of university employees. University employees (n=625) completed an online survey based on the Occupational Sitting and Physical Activity Questionnaire (OSPAQ). Participants were instructed to describe time spent sitting, standing, walking, and in heavy physical labor during the last seven days, along with the number of breaks from sitting taken per hour. To establish habitual patterns of PA outside of work, employees recalled their participation in structured PA in the past seven days. Prior to data analysis, employees were categorized as Administration, Faculty, Staff, or Facilities Management. Statistically significant differences were found among employee classifications for min sit/d, p<.001; min stand/d, p<.001; min walk/d, p<.001; and min heavy labor/d, p<.001. No significant differences were found for breaks/h from sitting, p=.259 or participation in structured PA, p=. 33. With the exception of facilities management workers, university employees spent 75% of their workday seated. In conjunction with low levels of leisure time PA, university employees appear to be prime candidates for workplace interventions to reduce physical inactivity.

Get Up, Stand Up

Non-sedentary work configurations, which encourage standing rather than sitting in the course of work, are becoming increasingly prevalent in organizations. In this article, we build and test theory about how non-sedentary arrangements influence interpersonal processes in groups performing knowledge work—tasks that require groups to combine information to develop creative ideas and solve problems. We propose that a non-sedentary workspace increases group arousal, while at the same time decreasing group idea territoriality, both of which result in better information elaboration and, indirectly, better group performance. The results of an experimental study of 54 groups engaged in a creative task provide support for this dual pathway model and underscore the important role of the physical space in which a group works as a contextual input to group processes and outcomes.

Prompts to disrupt sitting time and increase physical activity at work, 2011-2012

Introduction

The objective of this study was to assess change in sitting and physical activity behavior in response to a workplace intervention to disrupt prolonged sitting time.

Methods

Sixty office workers were randomized to either a Stand group (n = 29), which received hourly prompts (computer-based and wrist-worn) to stand up, or a Step group (n = 31), which received the same hourly prompts and an additional prompt to walk 100 steps or more upon standing. An ActivPAL monitor was used to assess sitting and physical activity behavior on the same 3 consecutive workdays during baseline and intervention periods. Mixed-effect models with random intercepts and random slopes for time were performed to assess change between groups and across time.

Results

Both groups significantly reduced duration of average sitting bouts (Stand group, by 16%; Step group, by 19%) and the number of sitting bouts of 60 minutes or more (Step group, by 36%; Stand group, by 54%). The Stand group significantly reduced total sitting time (by 6.6%), duration of the longest sitting bout (by 29%), and number of sitting bouts of 30 minutes or more (by 13%) and increased the number of sit-to-stand transitions (by 15%) and standing time (by 23%). Stepping time significantly increased in the Stand (by 14%) and Step (by 29%) groups, but only the Step group significantly increased (by 35%) the number of steps per workday. Differences in changes from baseline to intervention between groups were not significant for any outcome.

Conclusion

Interventions that focus on disrupting sitting time only in the workplace may result in less sitting. When sitting time disruptions are paired with a physical activity prompt, people may be more likely to increase their workday physical activity, but the effect on sitting time may be attenuated.

Weight Loss Programs May Have Beneficial or Adverse Effects on Fat Mass and Insulin Sensitivity in Overweight and Obese Black Women

Objective

Weight loss interventions have produced little change in insulin sensitivity in black women, but mean data may obscure metabolic benefit to some and adverse effects for others. Accordingly, we analyzed insulin sensitivity relative to fat mass change following a weight loss program.

Design and Methods

Fifty-four black women (BMI range 25.9 to 54.7 kg/m²) completed the 6-month program that included nutrition information and worksite exercise facilities. Fat mass was measured by dual-energy X-ray absorptiometry, and insulin sensitivity index (S_I) was calculated from an insulin-modified intravenous glucose tolerance test using the minimal model.

Results

Baseline S_I (range 0.74 to 7.58 l/mU⁻¹•min⁻¹) was inversely associated with fat mass (r = −0.516, p < 0.001), independent of age. On average, subjects lost fat mass (baseline 40.8 ± 12.4 to 39.4 ± 12.6 kg [mean ± SD], P < 0.01), but 17 women (32 %) actually gained fat mass. S_I for the group was unchanged (baseline 3.3 ± 1.7 to 3.2 ± 1.6, P = 0.67). However, the tertile with greatest fat mass loss (−3.6 kg, range −10.7 to −1.7 kg) improved insulin sensitivity (S_I +0.3 ± 1.2), whereas the tertile with net fat mass gain (+0.9 kg, range −0.1 to +3.8 kg) had reduced insulin sensitivity (S_I −0.7 ± 1.3) from baseline values (P < 0.05 by ANOVA).

Conclusions

Black women in a weight loss program who lose fat mass may have improved insulin sensitivity, but fat mass gain with diminished sensitivity is common. Additional support for participants who fail to achieve fat mass loss early in an intervention may be required for success.

Tucker S, Leonhard C. Acceptability and effects of a seated active workstation during sedentary work

Purpose

– The purpose of this paper is to test the user acceptability (Phase 1) and effects (Phase 2) of completing sedentary work while using a seated active workstation.

Design/methodology/approach

– In Phase 1, 45 sedentary employees completed an acceptability questionnaire immediately after performing sedentary work tasks (typing, mousing) while using the seated active workstation for 30 minutes. In Phase 2, the paper tested the differential effects of completing sedentary work tasks at two different workstations (sedentary workstation vs seated active workstation) on physiological (energy expenditure, muscle activity, heart rate, blood pressure), cognitive (learning, memory, attention) and work performance (typing and mousing ability) outcomes among 18 sedentary employees.

Findings

– In Phase 1, 96 percent of participants reported they would use the seated active workstation “daily” if provided access in their office. In Phase 2, working while using the seated active workstation increased energy expenditure (p<0.001; d=3.49), heart rate (p<0.001; d=1.26), systolic blood pressure (p=0.02; d=0.79), and muscle activation of the biceps femoris (p<0.001; d=1.36) and vastus lateralis (p<0.001; d=1.88) over the sedentary workstation. No between-group differences were observed for any measures of cognitive function. Mouse point and click time was slower while using the seated active workstation (p=0.02).

Research limitations/implications

– These findings suggest this seated active workstation to be acceptable by users and effective for offsetting occupational sedentary time without compromising cognitive function and/or work performance.

Originality/value

– The present study is the first to test the potential of this seated active workstation in any capacity.

Treadmill workstations: the effects of walking while working on physical activity and work performance

We conducted a 12-month-long experiment in a financial services company to study how the availability of treadmill workstations affects employees' physical activity and work performance. We enlisted sedentary volunteers, half of whom received treadmill workstations during the first two months of the study and the rest in the seventh month of the study. Participants could operate the treadmills at speeds of 0-2 mph and could use a standard chair-desk arrangement at will. (a) Weekly online performance surveys were administered to participants and their supervisors, as well as to all other sedentary employees and their supervisors. Using within-person statistical analyses, we find that overall work performance, quality and quantity of performance, and interactions with coworkers improved as a result of adoption of treadmill workstations. (b) Participants were outfitted with accelerometers at the start of the study. We find that daily total physical activity increased as a result of the adoption of treadmill workstations.

Randomized trial of nutrition education added to internet-based information and exercise at the work place for weight loss in a racially diverse population of overweight women

OBJECTIVE

Obesity in the United States is highly prevalent, approaching 60% for black women. We investigated whether nutrition education sessions at the work place added to internet-based wellness information and exercise resources would facilitate weight and fat mass loss in a racially diverse population of overweight female employees.

METHODS

A total of 199 (average body mass index 33.9±6.3 kg m(-2)) nondiabetic women (57% black) at our institution were randomized to a 6-month program of either internet-based wellness information (WI) combined with dietitian-led nutrition education group sessions (GS) weekly for 3 months and then monthly with shift in emphasis to weight loss maintenance (n=99) or to WI alone (n=100). All were given access to exercise rooms convenient to their work site. Fat mass was measured by dual-energy X-ray absorptiometry.

RESULTS

WI+GS subjects lost more weight than WI subjects at 3 months (-2.2±2.8 vs -1.0±3.0 kg, P>0.001). Weight (-2.7±3.9 vs -2.0±3.9 kg) and fat mass (-2.2±3.1 vs -1.7±3.7 kg) loss at 6 months was significant for WI+GS and WI groups (both P<0.001), but without significant difference between groups (both P>0.10); 27% of the WI+GS group achieved 5% loss of initial weight as did 18% of the WI group (P=0.180). Blacks and whites similarly completed the study (67 vs 74%, P=0.303), lost weight (-1.8±3.4 vs -3.3±5.2 kg, P=0.255) and fat mass (-1.6±2.7 vs -2.5±4.3 kg, P=0.532), and achieved 5% loss of initial weight (21 vs 32%, P=0.189), irrespective of group assignment.

CONCLUSION

Overweight women provided with internet-based wellness information and exercise resources at the work site lost weight and fat mass, with similar achievement by black and white women. Additional weight loss benefit of nutrition education sessions, apparent at 3 months, was lost by 6 months and may require special emphasis on subjects who fail to achieve weight loss goals to show continued value.

Multicomponent intervention to reduce daily sedentary time: a randomised controlled trial

OBJECTIVES

To test the efficacy of a multicomponent technology intervention for reducing daily sedentary time and improving cardiometabolic disease risk among sedentary, overweight university employees.

DESIGN

Blinded, randomised controlled trial.

SETTING

A large south-eastern university in the USA.

PARTICIPANTS

49 middle-aged, primarily female, sedentary and overweight adults working in sedentary jobs enrolled in the study. A total of 40 participants completed the study.

INTERVENTIONS

Participants were randomised to either: (1) an intervention group (N=23; 47.6+9.9 years; 94.1% female; 33.2+4.5 kg/m(2)); (2) or wait-list control group (N=17; 42.6+8.9 years; 86.9% female; 31.7+4.9 kg/m(2)). The intervention group received a theory-based, internet-delivered programme, a portable pedal machine at work and a pedometer for 12 weeks. The wait-list control group maintained their behaviours for 12 weeks.

OUTCOME MEASURES

Primary (sedentary and physical activity behaviour measured objectively through StepWatch) and secondary (heart rate, blood pressure, height, weight, waist circumference, per cent body fat, cardiorespiratory fitness, fasting lipids) outcomes were measured at baseline and postintervention (12 weeks). Exploratory outcomes including intervention compliance and process evaluation measures were also assessed postintervention.

RESULTS

Compared to controls, the intervention group reduced daily sedentary time (mean change (95%CI): -58.7 min/day (-118.4 to 0.99; p<0.01)) after adjusting for baseline values and monitor wear time. Intervention participants logged on to the website 71.3% of all intervention days, used the pedal machine 37.7% of all working intervention days and pedalled an average of 31.1 min/day.

CONCLUSIONS

These findings suggest that the intervention was engaging and resulted in reductions in daily sedentary time among full-time sedentary employees. These findings hold public health significance due to the growing number of sedentary jobs and the potential of these technologies in large-scale worksite programmes.

TRIAL REGISTRATION

ClinicalTrials.gov #NCT01371084.

Sit-stand desks in call centres: associations of use and ergonomics awareness with sedentary behavior

OBJECTIVE

To investigate whether or not use of sit-stand desks and awareness of the importance of postural variation and breaks are associated with the pattern of sedentary behavior in office workers.

METHOD

The data came from a cross-sectional observation study of Swedish call centre workers. Inclinometers recorded 'seated' or 'standing/walking' episodes of 131 operators over a full work shift. Differences in sedentary behavior based on desk type and awareness of the importance of posture variation and breaks were assessed by non-parametric analyses.

RESULTS

90 (68.7%) operators worked at a sit-stand desk. Working at a sit-stand desk, as opposed to a sit desk, was associated with less time seated (78.5 vs 83.8%, p = 0.010), and less time taken to accumulate 5 min of standing/walking (36.2 vs 46.3 min, p = 0.022), but no significant difference to sitting episode length or the number of switches between sitting and standing/walking per hour. Ergonomics awareness was not associated with any sedentary pattern variable among those using a sit-stand desk.

CONCLUSION

Use of sit-stand desks was associated with better sedentary behavior in call centre workers, however ergonomics awareness did not enhance the effect.

The energy expenditure of sedentary behavior: a whole room calorimeter study

It has recently been recommended that sedentary behavior be defined as sitting or reclining activities expending less than 1.5 metabolic equivalents (METs), which is distinct from the traditional viewpoint based on insufficient moderate-vigorous activity or formal exercise. This study was designed to determine the energy expenditure associated with common sedentary behaviors. Twenty-five African American adults (BMI 27.8±5.5) participated in the metabolic chamber study. Participants entered the metabolic chamber in the morning and their basal metabolic rate was estimated. They were fed breakfast and then engaged in four different sedentary behaviors sequentially, lasting 30 minutes each. The activities included reclining, watching TV, reading, and typing on a computer. In the afternoon, the participants were fed lunch and then the activities were repeated. The results show that the energy expenditure values between the morning and afternoon sessions were not significantly different (p = .232). The mean energy expenditure of postprandial reclining (0.97 METs) was slightly, but significantly, lower than postprandial watching TV (p = .021) and typing (p<.001). There were no differences in energy cost (1.03–1.06 METs) between the seated (i.e., reading, typing, watching TV) sedentary activities. The energy expenditure of several common sedentary behaviors was approximately 1.0 METs in the postprandial state. The results support the conclusion that the average energy cost of common sedentary behaviors is narrowly banded around 1.0 METs in the postprandial state.

Treadmill desks: A 1-year prospective trial

OBJECTIVE

Sedentariness is associated with weight gain and obesity. A treadmill desk is the combination of a standing desk and a treadmill that allow employees to work while walking at low speed.

DESIGN AND METHODS

The hypothesis was that a 1-year intervention with treadmill desks is associated with an increase in employee daily physical activity (summation of all activity per minute) and a decrease in daily sedentary time (zero activity). Employees (n = 36; 25 women, 11 men) with sedentary jobs (87 ± 27 kg, BMI 29 ± 7 kg/m(2) , n = 10 Lean BMI < 25 kg/m(2) , n = 15 Overweight 25 < BMI < 30 kg/m(2) , n = 11 Obese BMI > 30 kg/m(2) ) volunteered to have their traditional desk replaced with a treadmill desk to promote physical activity for 1 year.

RESULTS

Daily physical activity (using accelerometers), work performance, body composition, and blood variables were measured at Baseline and 6 and 12 months after the treadmill desk intervention. Subjects who used the treadmill desk increased daily physical activity from baseline 3,353 ± 1,802 activity units (AU)/day to, at 6 months, 4,460 ± 2,376 AU/day (P < 0.001), and at 12 months, 4,205 ± 2,238 AU/day (P < 0.001). Access to the treadmill desks was associated with significant decreases in daily sedentary time (zero activity) from at baseline 1,020 ± 75 min/day to, at 6 months, 929 ± 84 min/day (P < 0.001), and at 12 months, 978 ± 95 min/day (P < 0.001). For the whole group, weight loss averaged 1.4 ± 3.3 kg (P < 0.05). Weight loss for obese subjects was 2.3 ± 3.5 kg (P < 0.03). Access to the treadmill desks was associated with increased daily physical activity compared to traditional chair-based desks; their deployment was not associated with altered performance. For the 36 participants, fat mass did not change significantly, however, those who lost weight (n = 22) lost 3.4 ± 5.4 kg (P < 0.001) of fat mass. Weight loss was greatest in people with obesity.

CONCLUSIONS

Access to treadmill desks may improve the health of office workers without affecting work performance.

Does prolonged seated deskwork alter the lumbar flexion relaxation phenomenon?

Sustained maximum lumbar spine flexion can increase the angle at which the low back flexion relaxation phenomenon (FRP) is observed. This adaptation has been hypothesized to have implications for the control of lumbar spine stability and increase the potential for low back injury. The objective of this study was to investigate if similar changes in the FRP would occur from sub-maximal spine flexion induced by an extended continuous duration of seated office deskwork. Twenty-three participants (12 male and 11 female) performed three bouts of full forward spine flexion interspersed with two 1-h periods of seated deskwork. Lumbar spine angular kinematics and electromyographic activity from the lumbar erector spinae were obtained throughout all trials. The angles at which myoelectric silence occurred (FRP onset) were documented. Lumbar flexion at FRP onset increased by 1.3±1.5° after 1-h of sitting (p<0.05) with no further increase after 2-h. However, when the angle at the FRP onset was normalized to the total range of flexion, there was no difference in the FRP onset. These results suggest that the seated posture may induce residual deformation in the viscoelastic passive tissues of the low back; this could increase the challenge of controlling spine motion and reduce the load-bearing capacity of the lumbar spine system during activities performed following extended bouts of sitting.

Prolonged sedentary time and physical activity in workplace and non-work contexts: a cross-sectional study of office, customer service and call centre employees

BACKGROUND

To examine sedentary time, prolonged sedentary bouts and physical activity in Australian employees from different workplace settings, within work and non-work contexts.

METHODS

A convenience sample of 193 employees working in offices (131), call centres (36) and customer service (26) was recruited. Actigraph GT1M accelerometers were used to derive percentages of time spent sedentary (<100 counts per minute; cpm), in prolonged sedentary bouts (≥20 minutes or ≥30 minutes), light-intensity activity (100-1951 cpm) and moderate-to-vigorous physical activity (MVPA; ≥1952 cpm). Using mixed models adjusted for confounders, these were compared for: work days versus non-work days; work hours versus non-work hours (work days only); and, across workplace settings.

RESULTS

Working hours were mostly spent sedentary (77.0%, 95%CI: 76.3, 77.6), with approximately half of this time accumulated in prolonged bouts of 20 minutes or more. There were significant (p<0.05) differences in all outcomes between workdays and non-work days, and, on workdays, between work- versus non-work hours. Results consistently showed "work" was more sedentary and had less light-intensity activity, than "non-work". The period immediately after work appeared important for MVPA. There were significant (p<0.05) differences in all sedentary and activity outcomes occurring during work hours across the workplace settings. Call-centre workers were generally the most sedentary and least physically active at work; customer service workers were typically the least sedentary and the most active at work.

CONCLUSION

The workplace is a key setting for prolonged sedentary time, especially for some occupational groups, and the potential health risk burden attached requires investigation. Future workplace regulations and health promotion initiatives for sedentary occupations to reduce prolonged sitting time should be considered.

Sedentary behaviour, physical activity and dietary patterns are independently associated with the metabolic syndrome

AIM

This study assessed the independent relationships of daily sitting time, levels of work and leisure-time physical activity (PA), and dietary patterns of patients with the metabolic syndrome (MetS).

METHODS

This population-based, cross-sectional study included 3090 French subjects aged 35-64 years. Daily time spent sitting and PA levels were assessed by an interview-administered questionnaire, while dietary patterns were identified using the factorial method of principal component analysis. Independent associations of lifestyle behaviours with the MetS were assessed by multivariable logistic-regression models adjusted for age, centre, educational level, smoking status, total calorie intake, heart rate and menopausal status.

RESULTS

The multivariable-adjusted ORs [95% CI] for MetS in the fourth quartile of sitting time and leisure-time PA were 1.65 [1.11-2.44] (P for trend < 0.01) and 0.58 [0.40-0.84] (P for trend < 0.001), respectively, for men, and 2.35 [1.41-3.92] (P for trend < 0.01) and 0.52 [0.33-0.82] (P for trend < 0.01), respectively, for women. Work PA was not favourably related to the MetS, particularly in women. An 'energy-dense' dietary pattern was independently associated with higher ORs for the MetS in both genders. However, accounting for body mass index (BMI) weakened the associations, which otherwise remained significant for leisure-time PA and the energy-dense dietary pattern in men, suggesting that BMI may be a potential mediator of these relationships.

CONCLUSION

This study demonstrated a dose-response association between sitting time, an energy-dense dietary pattern and the MetS, together with a graded inverse association between leisure-time PA and the MetS. In addition to the usual advice for PA and healthy eating, limiting the amount of time spent sitting should also be promoted through public-health initiatives.

Variation between seated and standing/walking postures among male and female call centre operators

Background

The dose and time-pattern of sitting has been suggested in public health research to be an important determinant of risk for developing a number of diseases, including cardiovascular disorders and diabetes. The aim of the present study was to assess the time-pattern of seated and standing/walking postures amongst male and female call centre operators, on the basis of whole-shift posture recordings, analysed and described by a number of novel variables describing posture variation.

Methods

Seated vs. standing/walking was recorded using dichotomous inclinometers throughout an entire work shift for 43 male and 97 female call centre operators at 16 call centres. Data were analysed using an extensive set of variables describing occurrence of and switches between seated and standing/walking, posture similarity across the day, and compliance with standard recommendations for computer work.

Results

The majority of the operators, both male and female, spent more than 80% of the shift in a seated posture with an average of 10.4 switches/hour between seated and standing/walking or vice versa. Females spent, on average, 11% of the day in periods of sustained sitting longer than 1 hour; males 4.6% (p = 0.013). Only 38% and 11% of the operators complied with standard recommendations of getting an uninterrupted break from seated posture of at least 5 or 10 minutes, respectively, within each hour of work. Two thirds of all investigated variables showed coefficients of variation between subjects above 0.5. Since work tasks and contractual break schedules were observed to be essentially similar across operators and across days, this indicates that sedentary behaviours differed substantially between individuals.

Conclusions

The extensive occurrence of uninterrupted seated work indicates that efforts should be made at call centres - and probably in other settings in the office sector - to introduce more physical variation in terms of standing/walking periods during the work day. We suggest the metrics used in this study for quantifying variation in sedentary behaviour to be of interest even for other dichotomous exposures relevant to occupational and public health, for instance physical activity/inactivity.

Scalable office-based health care

The goal of health care is to provide high-quality care at an affordable cost for its patients. However, the population it serves has changed dramatically since the popularization of hospital-based health care. With available new technology, alternative health care delivery methods can be designed and tested. This study examines scalable office-based health care for small business, where health care is delivered to the office floor. This delivery was tested in 18 individuals at a small business in Minneapolis, Minnesota. The goal was to deliver modular health care and mitigate conditions such as diabetes, hyperlipidaemia, obesity, sedentariness and metabolic disease. The modular health care system was welcomed by employees - 70% of those eligible enrolled. The findings showed that the modular health care deliverable was feasible and effective. The data demonstrated significant improvements in weight loss, fat loss and blood variables for at risk participants. This study leaves room for improvement and further innovation. Expansion to include offerings such as physicals, diabetes management, smoking cessation and prenatal treatment would improve its utility. Future studies could include testing the adaptability of delivery method, as it should adapt to reach rural and under-served populations.

The mechanical effect of anterior pelvic tilt taping on slump sitting by seated workers

The objectives of this study were to determine whether there is a change in the pelvic inclination after about 30 min of slump sitting by seated workers, and if so, to determine whether these changes can be prevented by the application of anterior pelvic tilt taping (APTT). The subjects who consented to participate in the experiment were randomly allocated to two groups: no-APTT group and APTT group. The no-APTT group performed slump sitting for 30 min, and the both pelvic inclinations were remeasured. In the APTT group, the both pelvic inclinations were measured immediately after the application of the APTT, and then again after 30 min of slump sitting. The both pelvic inclinations in the no-APTT group were significantly decreased (p<0.05) after they returned to the upright standing posture. The both pelvic inclinations in the APTT group were significantly increased immediately after the APTT (p<0.05), and this increase was maintained when returning to the upright standing posture after 30 min of slump sitting (p>0.05). We suggest that APTT can be applied as an auxiliary treatment method for preventing changes in pelvic inclination and musculoskeletal problems of low back area by awkward sitting posture in the seated worker.

Globalization and modernization: an obesogenic combination

Animal research has well established that a link exists between variations in corticosteroids and the proneness to excess body fat accumulation. Accordingly, it is known that adrenalectomy is an efficient approach to counteract weight gain in most animal models of obesity. In humans, the association between variations in corticosteroids, its stress-related environmental effects and the predisposition to obesity is more difficult to demonstrate. In this paper, we propose that this relationship is accentuated by globalization and modernization which favour a labour context imposing additional stress and changes in life habits promoting a positive energy balance. Our main hypothesis is that the increase in knowledge-based work, and the decrease of quality and duration of sleep both induce an increase in cortisolaemia and glycaemia instability, which results in an increase in food intake, a reduction in energy expenditure and body fat gain. The authors of this paper believe that, from a socioeconomic perspective, globalization leads every nation of the world in conflict with itself and may consequently represent a real problem. On one hand, there are preoccupations related to productivity and money making. On the other hand, people have to adopt a daily lifestyle leading to hyperphagia and decreased energy expenditure in order to maintain their economic competitiveness.

The pattern of habitual sedentary behavior is different in advanced Parkinson's disease

Physical behavior changes in Parkinson's disease (PD), however, objective evidence of this is lacking. This study explored methods to objectively quantify sedentary behavior (SB) in advanced PD with the aim of identifying changes that could impact on the burden of disease. We compared the SB of 17 PD (UPDRS III 29.1 ± 5.5; disease duration 12.5 ± 6.4; H&Y (3 & 4) and 17 aged and gender matched healthy subjects. SB was measured objectively over a 7 day period using the activPAL accelerometer. SB was defined as sitting or lying and described in terms of the volume and pattern of SB. Comparison between PD and controls showed that whilst there was no difference in the volume of sedentary time (P = 0.15), there was a significant difference in distribution (P < 0.01) and pattern of accumulation of sedentary time (P < 0.01). Bouts of SB in people with PD tend to last longer than that of controls, whilst the total time spent inactive is the same for the two groups. These results suggest that PD leads to a change in the pattern of SB but not the volume. This may be interpreted as a strategy to conserve energy to maximize function. Studying the pattern of SB appears promising and has the potential to help us to understand the impact of PD and the consequences of changes in SB on the burden of disease.

Non-exercise physical activity in agricultural and urban people

With evidence that urbanisation is associated with obesity, diabetes, hypertension and cardiovascular disease, this article compares daily physical activity between rural and urban dwellers. Specifically, it examines habitual daily activity levels, non-exercise activity thermogenesis (NEAT) and energy expenditure in agricultural and urban Jamaicans and urban North Americans. Ambulation was 60 per cent greater in rural Jamaicans than in the urban dwellers (4675 ± 2261 versus 2940 ± 1120 ambulation-attributed arbitrary units (AU)/day; P = 0.001). Levels of ambulation in lean urban Jamaicans were similar to those in lean urban North Americans, whereas obese urban dwellers walked less than their lean urban counterparts (2198 ± 516 versus 2793 ± 774 AU/day; P = 0.01). The data with respect to daily sitting mirrored the walking data; obese Americans sat for almost four hours more each day than rural Jamaicans (562 ± 78 versus 336 ± 68 minutes/day; P < 0.001). Urbanisation is associated with low levels of daily activity and NEAT.

Spontaneous activity, economy of activity, and resistance to diet-induced obesity in rats bred for high intrinsic aerobic capacity

Though obesity is common, some people remain resistant to weight gain even in an obesogenic environment. The propensity to remain lean may be partly associated with high endurance capacity along with high spontaneous physical activity and the energy expenditure of activity, called non-exercise activity thermogenesis (NEAT). Previous studies have shown that high-capacity running rats (HCR) are lean compared to low-capacity runners (LCR), which are susceptible to cardiovascular disease and metabolic syndrome. Here, we examine the effect of diet on spontaneous activity and NEAT, as well as potential mechanisms underlying these traits, in rats selectively bred for high or low intrinsic aerobic endurance capacity. Compared to LCR, HCR were resistant to the sizeable increases in body mass and fat mass induced by a high-fat diet; HCR also had lower levels of circulating leptin. HCR were consistently more active than LCR, and had lower fuel economy of activity, regardless of diet. Nonetheless, both HCR and LCR showed a similar decrease in daily activity levels after high-fat feeding, as well as decreases in hypothalamic orexin-A content. The HCR were more sensitive to the NEAT-activating effects of intra-paraventricular orexin-A compared to LCR, especially after high-fat feeding. Lastly, levels of cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C) in the skeletal muscle of HCR were consistently higher than LCR, and the high-fat diet decreased skeletal muscle PEPCK-C in both groups of rats. Differences in muscle PEPCK were not secondary to the differing amount of activity. This suggests the possibility that intrinsic differences in physical activity levels may originate at the level of the skeletal muscle, which could alter brain responsiveness to neuropeptides and other factors that regulate spontaneous daily activity and NEAT.

Integrated electronic platforms for weight loss

What can be done to build effective weight loss solutions for the 1.5 billion people with obesity? It is self-evident that no one good solution exists for people who are overweight or obese, otherwise it would have been applied across the people who need it worldwide. There is, therefore, an urgent need for approaches that will afford weight loss; what is more, such approaches need to be scalable. For that reason, it is attractive to consider electronic platforms as an avenue for scalable weight loss solutions. Such platforms often do not require substantial investments but rather the integration of pre-existing off-the-shelf components. In this article we explore the concepts and design challenges for electronic platforms that precipitate weight loss.

Causal assessment of occupational sitting and low back pain: results of a systematic review

BACKGROUND CONTEXT

Low back pain (LBP) is a common and disabling musculoskeletal disorder that often occurs in a working-age population. Determining the precise causation of LBP remains difficult. Any attempt to implicate a specific occupational activity in the genesis of LBP requires a methodologically rigorous approach.

PURPOSE

To conduct a systematic review of the scientific literature focused on evaluating the causal relationship between occupational sitting and LBP.

STUDY DESIGN

Systematic review of the literature using Medline, EMBASE, CINAHL, Cochrane Library, Occupational Safety and Health database, grey literature, hand-searching occupational health journals, reference lists of included studies, and content experts. Evaluation of study quality using a modified version of the Newcastle-Ottawa Scale. Summary levels of evidence supporting Bradford-Hill criteria for different categories of sitting and types of LBP.

SAMPLES

Studies reporting an association between occupational sitting and LBP.

OUTCOME MEASURES

Numerical association between different levels of exposure to occupational sitting and the presence or severity of LBP.

METHODS

A systematic review was performed to identify, evaluate, and summarize the literature related to establishing a causal relationship, according to Bradford-Hill criteria, between occupational sitting and LBP.

RESULTS

This search yielded 2,766 citations. Twenty-four studies met the inclusion/exclusion criteria and five were high-quality studies, including two case-controls and three prospective cohorts. Strong, consistent evidence was found for no association between occupational sitting and LBP. A moderate level of evidence was found for the absence of any dose-response trend. Risk estimates evaluating temporality were not statistically significant. Biological plausibility was not discussed in these studies. No evidence was available to assess the experiment criterion.

CONCLUSIONS

This review failed to uncover high-quality studies to support any of the Bradford-Hill criteria to establish causality between occupational sitting and LBP. Strong and consistent evidence did not support criteria for association, temporality, and dose response. Based on these results, it is unlikely that occupational sitting is independently causative of LBP in the populations of workers studied.