The effect of rest break schedule on acute low back pain development in pain and non-pain developers during seated work

A week-long field study of seated pelvis and lumbar spine kinematics during office work

The study objective was to quantify "natural" seated pelvis and lumbar spine kinematics over multiple days of work at individuals' workstations. Twenty participants completed five days of their usual office work while seated time was characterized from a thigh-worn activity monitor. Seated pelvic tilt and lumbar spine flexion-extension were measured from tri-axial accelerometers. Seated time accounted for approximately 90% of participants' workdays. Sitting was characterized by posterior pelvic tilt and lumbar flexion (43-79% of maximum flexion) with an average of 9 shifts and 13 fidgets every 15 min. No significant differences emerged by sex or between days indicating that a single representative day can capture baseline sitting responses in the field. Average field kinematics tended to agree with the laboratory-collected kinematics, but postural variability was larger in the field. These kinematic values could be useful for designing interventions aimed at reducing spine flexion and increasing spine movement in occupational sitting.

Traditional versus dynamic sitting: Lumbar spine kinematics and pain during computer work and activity guided tasks

Dynamic sitting may mitigate low back pain during prolonged seated work. The current study compared pelvis and lumbar spine kinematics, pain, and work productivity, in traditional and dynamic sitting. Sixteen participants completed three 20-min blocks of computer work and activity guided tasks in a traditional office chair or backless and multiaxial rotating seat pan while kinematics were measured from accelerometers on the low back. Pain ratings were recorded on a visual analogue scale every 10 min. Similar pelvis and lumbar kinematics emerged when performing computer work in traditional and dynamic sitting. Pelvis and lumbar sagittal and frontal plane shifts and fidgets were largest for dynamic sitting in the activity guided tasks. Buttocks pain was higher in dynamic sitting, but low back pain and work productivity were unaffected. Dynamic sitting increased spine movement during activity guided tasks, without negatively impacting lumbar kinematics, low back pain, or productivity during seated computer work.

Mediators and moderators of a walking intervention to prevent neck pain among high-risk office workers: a secondary analysis of a randomized controlled trial

OBJECTIVES

To test hypothesized mediators and moderators of the benefits of an app-provided walking intervention for preventing neck pain in high-risk office workers.

METHODS

Ninety-one office workers at risk for developing neck pain participated in the primary clinical trial. Two hypothesized mediators (the total number of steps taken and the number of days that participants exceed the number of recommended steps) were tested using a smartphone application every month during a 6-month period. Four hypothesized moderators (number of working hours, level of work psychological demands, chair height adjustability, and body mass index) were assessed at baseline. Parallel mediation and moderation analyses were conducted using the Hayes PROCESS macro, model 4 and 1, respectively, with post-hoc Johnson-Neyman techniques.

RESULTS

The number of days that participants exceeded the recommended steps ‒ the specific number was tailored to each participant, but averaged 7735 steps/day ‒ mediated the benefits of the walking intervention for reducing the risk for neck pain at each of six assessment points (B's range -0.63 to -0.89, all p's < 0.05) over 6-month period. None of the hypothesized moderators evidenced statistically significant moderator effects of the walking intervention.

CONCLUSION

Workers should walk at rates greater than recommended levels on as many days as possible, rather than attempt to maximize walking within a limited number of days. Given that the walking program studied appeared to be similarly effective across multiple groups of workers, the findings suggest that regular walking can reduce the risk for developing neck pain among high-risk office workers.

The Effect of an Active Break Intervention on Nonspecific Low Back Pain and Musculoskeletal Discomfort during Prolonged Sitting among Young People-Protocol for a Randomized Controlled Trial

BACKGROUND

The most recent evidence has shown that the pandemic of COVID-19 caused an increasing problem with spinal pain in the population of teenagers and young adults. This may be explained by prolonged sitting times in flexed positions with electronic devices. Positions maintained for a prolonged time cause overloading of soft tissue and discogenic symptoms. This study aims to evaluate the effectiveness of the active break program in reducing musculoskeletal discomfort and LBP (low back pain) among young people.

METHODS

This will be a randomized controlled study. The participants will be recruited from Bachelor's course students of the Physical Education Department aged 18-25 years. The participants will be assigned to an experimental group (with an active break) and a control group. The group with an active break with lumbar and hip extension exercises will be recommended to take a break for every 30 min of sitting. The control group will receive self-care recommendations. The primary outcomes will be pain intensity (Visual Analogue Scale), disability index (Oswestry Disability Index), and perceived musculoskeletal discomfort during prolonged sitting (Borg scale), assessed at baseline and after the intervention, and the Global Perceived Effect, only assessed after the 12-week intervention. The secondary outcome will be a Post-Intervention Questionnaire (a 5-item self-completed questionnaire), only assessed after the 12-week intervention.

RESULTS

Our main research outcome-exercise protocols and interventions-will lead to the development of recommendations and protocols for the LBP population. It is important to determine the effect of interventions that are feasible and effective in addressing LBP and perceived musculoskeletal discomfort in young people.

CONCLUSIONS

This is the first study examining the effect of active breaks with proposed lumbar and hip extension exercises on reducing or decreasing LBP in students based on a search of the literature. Exercises and recommendations will be the basis for developing proprietary preventative and therapeutic programs, which will be implemented in selected educational institutions.

Defining the lumbar and trunk-thigh neutral zone from the passive stiffness curve: application to hybrid sit-stand postures and chair design

Minimal data exist on the neutral position for the lumbar spine, trunk, and thighs when adopting a hybrid posture. This study examined sex differences in the neutral zone lumbar stiffness and the lumbar and trunk-thigh angle boundaries of the neutral zone, and determined if the standing lumbar angle fell within the neutral zone. Passive lumbar flexion and extension moment-angle curves were generated for 31 participants (13 M, 18 F), pooled from two datasets, with trunk-thigh angles available for 10 participants. The neutral zone was defined as the low stiffness zone from both the flexion and extension curves. Males demonstrated significantly greater extensor stiffness. Neutral lumbar and trunk-thigh angles ranged on average -22.2 to 0.2° and 124.2 to 159.6° for males and -17.8 to -1.3° and 143.2 to 159.5° for females, respectively. Standing lumbar angles fell outside the neutral zone for 44% of participants. These neutral zone boundaries may inform kinematics for hybrid chair designs.Practitioner summary: Adoption of a neutral spinal posture may be achieved through hybrid chair design, yet minimal data exists on a physiologically defined neutral zone. Using measures of in vivo lumbar stiffness, the lumbar and trunk-thigh angular boundaries of the neutral zone were defined for both males and females.Abbreviations: EMG: electromyography; MVC: maximal voluntary contraction.

Pain experiences among women in midlife with existing health conditions: changes across pre-COVID-19, stay-at-home orders, and initial reopening

OBJECTIVE

To examine the pain experiences of women in midlife with existing health conditions, including changes from prior to the COVID-19 pandemic through the first 6 months of the crisis.

DESIGN

Women ages 40-60 with health conditions (e.g., hypertension; N = 35, MBMI = 32.2 kg/m2) were prompted to complete 5 surveys per day for 5 days at 3 time points: pre-COVID-19, during stay-at-home orders, and at initial reopening.

MAIN OUTCOME MEASURES

Pain occurrence (yes/no), number of locations, and intensity.

RESULTS

Women reported pain at 35% of surveys, particularly after waking and before bed compared to the middle of the day. The occurrence of pain decreased over time, whereas pain intensity decreased between pre-COVID-19 and stay-at-home orders but then remained stable. The number of pain locations decreased between stay-at-home orders and reopening, and pain was more variable during the pandemic than prior to its onset (srs = 0.24-0.32).

CONCLUSION

Women experienced decreased pain frequency and intensity from prior to during the COVID-19 pandemic, though pain was less predictable during (vs. prior to) the pandemic. This information may be useful for informing care in this at-risk group, to prevent the development of chronic pain.

Does sitting on a stability ball increase fall risk during ergonomic reaching tasks?

Although sitting on a stability ball has become an alternative to using an office chair, little is known about the increased potential for a fall on the deformable seat. This study examined differences in stability between sitting on a seat pan of a backless office chair and a stability ball during reaching tasks. Sixteen participants performed forward and lateral reaching tasks on a backless and armless office chair and stability ball while whole-body motion and force data under the seat were recorded. Even with participants placing their feet 16.5 cm wider when seated on the ball, the perceived fall risk was significantly greater. Centre of pressure displacement tended to be smaller under the ball for lateral reach directions, but larger during far anterior reaches. While not statistically significant, the medial-lateral margin of stability was on average 3.4 cm smaller on the ball. Despite attempts to increase stability by widening their stance, stability ball fall risk remained higher.

Effectiveness of workplace exercise interventions in the treatment of musculoskeletal disorders in office workers: a systematic review

OBJECTIVE

To determine the effectiveness of workplace exercise interventions in the treatment of musculoskeletal disorders.

DESIGN

Systematic review of randomised controlled trials (RCTs).

DATA SOURCES

The bibliographical databases PubMed, CINAHL Plus, Cochrane, Scopus, ISI WoS and PeDRO were searched, with studies from 1 January 2010 to 31 December 2020 eligible for inclusion.

ELIGIBILITY CRITERIA

We included RCTs, reported in English or Spanish, with at least an intervention group performing workplace exercises among office workers with musculoskeletal disorders.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers extracted data and assessed the risk of bias. A narrative synthesis was carried out with a tabular method specifying the study characteristics following the SWiM (Synthesis Without Meta-Analysis) guideline for synthesis without meta-analysis. The revised Cochrane Risk of Bias (RoB-2) tool was used to analyse the risk of bias of the included studies.

RESULTS

Seven studies with a total of 967 participants met the inclusion criteria and were included in this review. Due to heterogeneity in different workplace exercise interventions, outcome measures and statistical analyses, it was not possible to conduct a meta-analysis and a narrative synthesis was performed. The interventions were classified into three categories: multiple body regions, neck and shoulder, and lower back. The seven studies concluded that workplace exercise interventions were effective in reducing musculoskeletal disorders and pain compared with other types of interventions or with control groups with no interventions. The RoB-2 tool found a high risk of bias in six of the seven studies.

CONCLUSIONS

The findings of the RCTs on workplace exercise interventions suggest that interventions were effective in treating musculoskeletal disorders among office workers. However, due to the high risk of bias of the included studies, no firm conclusions could be drawn and more high-quality studies are needed.

PROSPERO REGISTRATION NUMBER

CRD42020177462.

The relationship between low back pain and the basic lumbar posture at work: a retrospective cross-sectional study

PURPOSE

This study aimed to analyze the relationship between work-related lumbar posture (sitting, standing, walking, alternating posture) and LBP in workers.

METHODS

This is a retrospective study comprising 529 records of adult workers from a database of a private company. Predominant work-related lumbar posture was classified based on time spent in each posture. A total of 22 personal, occupational, clinical, and psychosocial covariates were evaluated. LBP symptoms in the last 12 months and during the last 7 days were the outcomes of the study. The multivariate analysis model evaluated the independent relationship between the work-related lumbar posture classification and other potential exposure factors with LBP.

RESULTS

The adjusted logistic regression model indicated that predominant walking reduced the likelihood to report LBP during the last 12 months when compared to standing (OR = 0.54; 95% CI 0.30, 0.99; p = 0.048), but there is no association between work-related postures and recent LBP. The adjusted analyses also revealed an association between LBP during the last 12 months and female sex, blue-collar task, frequently feeling tiredness, pain at any other body region previous 12 months, previous LBP, and monotonous work. Recent LBP was associated with female sex, pain at any other body region last 7 days, and previous LBP.

CONCLUSIONS

Standing posture increases the likelihood to report LBP during the last 12 months when compared to walking. LBP over previous year and during the previous 7 days was associated with personal and clinical factors.

The effects of active break and postural shift interventions on recovery from and recurrence of neck and low back pain in office workers: A 3-arm cluster-randomized controlled trial

OBJECTIVES

To investigate the efficacy of active break and postural shift interventions aimed to reduce sitting discomfort on recovery duration and recurrence of neck and low back pain among high-risk office workers.

METHODS

A 3-arm cluster-randomized controlled trial with 12-month follow-up was conducted in 193 healthy but high-risk office workers. Participants in the intervention groups received custom-designed apparatus to facilitate either active breaks or postural shifts to reduce sitting discomfort at work. Participants in a control group received a placebo seat pad. Incidence of neck and low back pain with pain intensity and disability level was recorded monthly. Main outcome measures were recovery time and recurrent rate of neck and low back pain. Analyses were performed using log rank test and Cox proportional hazard models.

RESULTS

Median time to recovery in those receiving active break and postural shift interventions (1 month) was significantly shorter than those in the control group (2 months). Neck and low back pain recurrent rates for the active break, postural shift, and control groups were 21%, 18%, and 44%, respectively. Hazard rate (HR) ratios after adjusting for biopsychosocial factors indicated a protective effect of active break and postural shift interventions for neck and low back pain recurrence (HR_adj 0.22, 95% CI 0.06-0.83 for active breaks and HR_adj 0.35, 95% CI 0.16-0.77 for postural shift).

CONCLUSION

Active break and postural shift interventions shortened recovery time and reduced recurrence of neck and low back pain among high-risk office workers.

Differences in regional and global lumbar angle during slumped sitting and upright sitting among global three subgroups

OBJECTIVE

The purpose of this study was to investigate differences in regional lumbar lordosis (RLL) and global lumbar lordosis (GLL) angle during slumped sitting and upright sitting among three global subgroups.

METHODS

A total of 48 young asymptomatic volunteers stood in a comfortable posture, sat upright, and sat in a slumped position for 5 seconds, with inertial measurement units attached to the T10, L3, and S2 vertebrae. According to standing measurement, the participants were categorized into flat-back (GLL < 20∘), normal lordosis (20∘⩽ GLL < 30∘), and hyper-lordosis (30∘⩽ GLL < 40∘) groups.

RESULTS

Both the GLL and RLL in the flat-back group were reduced lumbar lordosis in the upright sitting posture and increased lumbar kyphosis in the slumped sitting postures compared to the other groups (p< 0.05), but the range of motion during the transition from upright sitting to slumped sitting was lower than that of the normal and hyper-lordosis groups (p< 0.05). GLL in standing was a moderate correlation with GLL and RLL during upright sitting (p< 0.05). However, there was a strong correlation between GLL and RLL kinematics during upright and slumped sitting (p< 0.05).

CONCLUSIONS

Flat-back posture is a potential source of low back pain during both upright and slumped sitting compared to the normal and hyper-lordosis groups. Posture measurements in a standing and sitting position conducted to assess lordosis should consider the relationship between GLL and RLL.

Effectiveness of workplace active rest programme on low back pain in office workers: a stepped-wedge cluster randomised controlled trial

OBJECTIVE

This study aimed to investigate the effectiveness of workplace active rest programme (WARP) on chronic low back pain (LBP) among office workers.

DESIGN

A closed cohort, stepped-wedge cluster randomised trial was conducted. The total duration of the study was 16 weeks (4 weeks for each step). Sequence allocation was randomised, but no one was blinded.

SETTING

This study was conducted in three offices in a Japanese electronics company. One office was for the administrative department, the others are for the engineering department.

PARTICIPANTS

We recruited 29 office workers with LBP greater than 3 months. LBP due to specific injury or disease was excluded. The median age was 38 years, and 26 (90%) were male. All participants completed the study.

INTERVENTIONS

In the intervention phase, participants performed WARP comprising frequent stand-up and individualised brief exercise/physical activity during work. Physical therapists held an LBP workshop and developed tailor-made programmes before introducing WARP. We instructed participants to perform WARP at five timings during work. Control phase was set before the intervention and participants stayed as usual.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was pain intensity of LBP assessed using the Brief Pain Inventory. The secondary outcomes were work productivity loss measured using the Work Limitations Questionnaire, LBP disability assessed using the Roland-Morris Disability Questionnaire, psychosocial subscale assessed using the STarT Back Screening Tool and physical activity measured using triaxial accelerometers. These outcomes were collected at baseline and at 4-month follow-up evaluation.

RESULTS

In the intention-to-treat analysis, WARP did not show any significant effects on pain intensity (β, 0.01; 95% CI -0.50 to 0.52) and on the secondary outcomes. The median adherence to WARP was 28.6% (IQR, 16.8-41.1), which was equal to 1.43 times per day. No adverse effect was observed.

CONCLUSIONS

The present study was unable to confirm the effectiveness of active rest in improving LBP. Hence, further study needs to investigate its effectiveness.

TRIAL REGISTRATION NUMBER

UMIN000033210.

Effects of an active break and postural shift intervention on preventing neck and low-back pain among high-risk office workers: a 3-arm cluster-randomized controlled trial

OBJECTIVE

This study evaluated the effects of the promotion of active breaks and postural shifts on new onset of neck and low-back pain during a 6-month follow-up among high-risk office workers.

METHODS

A 3-arm cluster-randomized controlled trial with 6-month follow-up was conducted among healthy but high-risk office workers. Participants were recruited from six organizations in Bangkok, Thailand (N=193) and randomly assigned at cluster level into active break intervention (N=47), postural shift intervention (N=46), and control (N=100) groups. Participants in the intervention groups received a custom-designed apparatus to facilitate designated active breaks and postural shifts during work. Participants in the control group received a placebo seat pad. The primary outcome measure was new onset of neck and low-back pain during 6-month follow-up. Analyses were performed using Cox proportional hazard models.

RESULTS

One-hundred and eighty-six (96%) predominantly female participants were successfully followed up over six months. New onset of neck pain during the 6-month follow-up occurred in 17%, 17%, and 44% of the participants in the active break, postural shift, and control groups, respectively. For new onset of low-back pain, these percentages were 9%, 7%, and 33%, respectively. Hazard rate (HR) ratios after adjusting for biopsychosocial factors indicated a protective effect of the active break and postural shift interventions for neck pain [HRadj 0.45, 95% confidence interval (CI) 0.20-0.98 for active break and HRadj 0.41, 95% CI 0.18-0.94 for postural shift] and low-back pain (HRadj 0.34, 95% CI 0.12-0.98 for active break and HRadj 0.19, 95% CI 0.06-0.66 for postural shift).

CONCLUSION

Interventions to increase either active breaks or postural shifts reduced new onset of neck and low-back pain among high-risk office workers.

Correlation between Individual Characteristics and Rest Break with Work-related Fatigue on Telecommunication Network Service Workers

Introduction: Work-related fatigue on workers are usually caused by some factors such as individual characteristics (age, work period, nutritional status) and rest break. This research aims to analyze the correlation between individual characteristics and rest break with work-related fatigue on telecommunication network service workers. Method: This research used an observational analytic and a cross-sectional approach. The population and sample in this research were all 32 workers at I-OAN unit in a telecommunication network service company. The independent variables in this study were age, work period, nutritional status, and rest break, while the dependent variable was work-related fatigue. Data were obtained throughquestionnaires about individual characteristics (age, work period, nutritional status) and rest break filled by workers. The data were also obtained through the Industrial Fatique Research Committee (IFRC) questionnaires filled by workers. All of the data in this study were analyzed with the Spearman correlation test (α = 0.05). Results: The majority of I-OAN unit workers are in the age range of 25-29 years (46.9%), have 3-4 years of work period (56.2%), and have normal nutritional status (40.6%). For the rest break variable, there are16 workers (50%) who have <30 minutes rest break and also 16 workers (50%) who have ≥ 30 minutes rest break. Conclusion: There is a correlation between individual characteristics and rest break with work-related fatigue on telecommunication network service workers.Keywords: individual characteristics, rest break, work-related fatigue

Work-related musculoskeletal disorders and associated factors among bank workers in Addis Ababa, Ethiopia: a cross-sectional study

Background

Work-related musculoskeletal disorders (WMSDs) are dramatically increased in the world due to the advancement of technology and competitiveness of markets. There were limited studies carried out regarding WMSDs among bank workers in Africa particularly in Ethiopia. Therefore, the aim of this study was to assess the magnitude of work-related musculoskeletal disorders and associated factors among bank workers in Addis Ababa, Ethiopia.

Methods

Institution-based cross-sectional study design was employed in the study. Multi-stage sampling techniques were used to select 838 bank workers from 62 banks in Addis Ababa. Self-administered standard Nordic questionnaires were used as well. Multivariable binary logistic regression analyses were employed to identify factors associated with WMSDs. Moreover adjusted odds ratio (AOR), 95% confidence interval (CI) and p value < 0.05 was used to show the strength of association between explanatory variables and dependent variable.

Results

Out of 838 total numbers of participants, 755 bank workers returned their questionnaires responding with a rate of 90%. Of these, 77.6% (N = 586) suffered WMSDs with a 95% CI [75–81%]. Based on the final multivariate logistic regression analysis being female [AOR = 2.98, 95% CI 1.91–4.65], sitting back in a twisted position [AOR = 3.59, 95% CI 2.13–6.08], sitting back bent [AOR = 4.06, 95% CI 2.48–6.66], work on fixed position [AOR = 1.78, 95% CI 1.17–2.71], no work time break [AOR = 3.33, 95% CI 1.44–7.71], type of chairs [AOR = 2.62, 95% CI 1.19–5.75] and job stress [AOR = 2.33, 95% CI 1.19–4.54] were factors significantly associated with WMSDs.

Conclusion

From the study’s findings, the magnitude of work-related musculoskeletal disorders among bank workers was high. Being female, awkward posture, no work time break, fixed position, type of chairs, and job stress are the factors significantly associated with WMSDs. So bank workers should use proper types of chairs, practice proper work posture, increase healthy working conditions, and create awareness programs on how to maintain beneficial health conditions which may lead to increased leisure time.

It is Time to Have Rest: How do Break Types Affect Muscular Activity and Perceived Discomfort During Prolonged Sitting Work

Background

Prolonged sitting at work can lead to adverse health outcomes. The health risk of office workers is an increasing concern for the society and industry, with prolonged sitting work becoming more prevalent.

Objective

This study aimed to explore the variation in muscle activities during prolonged sitting work and found out when and how to take a break to mitigate the risk of muscle symptoms.

Methods

A preliminary survey was conducted to find out the prevalence of muscle discomfort in sedentary work. Firstly, a 2-h sedentary computer work was designed based on the preliminary study to investigate the variation in muscle activities. Twenty-four participants took part in the electromyography (EMG) measurement study. The EMG variations in the trapezius muscle and latissimus dorsi were investigated. Then the intervention time was determined based on the EMG measurement study. Secondly, 48 participants were divided into six groups to compare the effectiveness of every break type (passive break, active break of changing their posture, and stand and stretch their body with 5 or 10 mins). Finally, data consisting of EMG amplitudes and spectra and subjective assessment of discomfort were analyzed.

Results

In the EMG experiment, results from the joint analysis of the spectral and amplitude method showed muscle fatigue after about 40 mins of sedentary work. In the intervention experiment, the results showed that standing and stretching for 5 mins was the most effective break type, and this type of break could keep the muscles' state at a recovery level for about 30−45 mins.

Conclusions

This study offers the possibility of being applied to office workers and provides preliminary data support and theoretical exploration for a follow-up early muscle fatigue detection system.

The Effects of Workplace Rest Breaks on Health Problems Related to Long Working Hours and Shift Work among Male Apartment Janitors in Korea

Background

Rest breaks at work are reported to reduce fatigue and job stress. Apartment janitors in Korea who perform night shift work and work long hours can be exposed to various health problems (HPs). However, few studies have evaluated relationships between their rest breaks and HPs. This study was conducted to examine the relationships between long working hours, shift work, and insufficient rest breaks and HPs among Korean apartment janitors.

Methods

Data on 1,212 selected male apartment janitors were obtained from the 3rd and 4th Korean Working Conditions Surveys. Demographic and occupational characteristics were collected using self-reported questionnaires. Rest breaks at work were classified as "sufficient" or "insufficient." Long working hours were considered as working more than 60 hours per week. Zero-inflated negative binomial (ZINB) regression was performed to investigate the effects of shift work and long working hours on HPs and the effects of rest breaks on relationships between HPs and long working hours and shift work.

Results

Among those with insufficient rest breaks at work, significant associations were found between long working hours and the risk of HPs [odds ratio (OR) = 1.489; 95% confidence interval (CI) = 1.038-2.136] and work-related HPs (WRHPs) [OR 1.621; 95% CI = 1.156-2.272], and between shift work and HPs [OR = 1.603; 95% CI = 1.084-2.372]. These relationships became nonsignificant when sufficient rest breaks were provided.

Conclusion

It is important to provide breaks at work to reduce HPs because of long working hours and shift work among aged workers such as apartment janitors.

Methods in Experimental Work Break Research: A Scoping Review

The number of studies on work breaks and the importance of this subject is growing rapidly, with research showing that work breaks increase employees’ wellbeing and performance and workplace safety. However, comparing the results of work break research is difficult since the study designs and methods are heterogeneous and there is no standard theoretical model for work breaks. Based on a systematic literature search, this scoping review included a total of 93 studies on experimental work break research conducted over the last 30 years. This scoping review provides a first structured evaluation regarding the underlying theoretical framework, the variables investigated, and the measurement methods applied. Studies using a combination of measurement methods from the categories “self-report measures,” “performance measures,” and “physiological measures” are most common and to be preferred in work break research. This overview supplies important information for ergonomics researchers allowing them to design work break studies with a more structured and stronger theory-based approach. A standard theoretical model for work breaks is needed in order to further increase the comparability of studies in the field of experimental work break research in the future.

Work-break schedules for preventing musculoskeletal symptoms and disorders in healthy workers

BACKGROUND

Work-related musculoskeletal disorders are a group of musculoskeletal disorders that comprise one of the most common disorders related to occupational sick leave worldwide. Musculoskeletal disorders accounted for 21% to 28% of work absenteeism days in 2017/2018 in the Netherlands, Germany and the UK. There are several interventions that may be effective in tackling the high prevalence of work-related musculoskeletal disorders among workers, such as physical, cognitive and organisational interventions. In this review, we will focus on work breaks as a measure of primary prevention, which are a type of organisational intervention.

OBJECTIVES

To compare the effectiveness of different work-break schedules for preventing work-related musculoskeletal symptoms and disorders in healthy workers, when compared to conventional or alternate work-break schedules.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, CINAHL, PsycINFO, SCOPUS, Web of Science, ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform, to April/May 2019. In addition, we searched references of the included studies and of relevant literature reviews.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of work-break interventions for preventing work-related musculoskeletal symptoms and disorders among workers. The studies were eligible for inclusion when intervening on work-break frequency, duration and/or type, compared to conventional or an alternate work-break intervention. We included only those studies in which the investigated population included healthy, adult workers, who were free of musculoskeletal complaints during study enrolment, without restrictions to sex or occupation. The primary outcomes were newly diagnosed musculoskeletal disorders, self-reported musculoskeletal pain, discomfort or fatigue, and productivity or work performance. We considered workload changes as secondary outcomes.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles, abstracts and full texts for study eligibility, extracted data and assessed risk of bias. We contacted authors for additional study data where required. We performed meta-analyses, where possible, and we assessed the overall quality of the evidence for each outcome of each comparison using the five GRADE considerations.

MAIN RESULTS

We included six studies (373 workers), four parallel RCTs, one cross-over RCT, and one combined parallel plus cross-over RCT. At least 295 of the employees were female and at least 39 male; for the remaining 39 employees, the sex was not specified in the study trial. The studies investigated different work-break frequencies (five studies) and different work-break types (two studies). None of the studies investigated different work-break durations. We judged all studies to have a high risk of bias. The quality of the evidence for the primary outcomes of self-reported musculoskeletal pain, discomfort and fatigue was low; the quality of the evidence for the primary outcomes of productivity and work performance was very low. The studies were executed in Europe or Northern America, with none from low- to middle-income countries. One study could not be included in the data analyses, because no detailed results have been reported.Changes in the frequency of work breaksThere is low-quality evidence that additional work breaks may not have a considerable effect on musculoskeletal pain, discomfort or fatigue, when compared with no additional work breaks (standardised mean difference (SMD) -0.08; 95% CI -0.35 to 0.18; three studies; 225 participants). Additional breaks may not have a positive effect on productivity or work performance, when compared with no additional work breaks (SMD -0.07; 95% CI -0.33 to 0.19; three studies; 225 participants; very low-quality evidence).We found low-quality evidence that additional work breaks may not have a considerable effect on participant-reported musculoskeletal pain, discomfort or fatigue (MD 1.80 on a 100-mm VAS scale; 95% CI -41.07 to 64.37; one study; 15 participants), when compared to work breaks as needed (i.e. microbreaks taken at own discretion). There is very low-quality evidence that additional work breaks may have a positive effect on productivity or work performance, when compared to work breaks as needed (MD 542.5 number of words typed per 3-hour recording session; 95% CI 177.22 to 907.78; one study; 15 participants).Additional higher frequency work breaks may not have a considerable effect on participant-reported musculoskeletal pain, discomfort or fatigue (MD 11.65 on a 100-mm VAS scale; 95% CI -41.07 to 64.37; one study; 10 participants; low-quality evidence), when compared to additional lower frequency work breaks. We found very low-quality evidence that additional higher frequency work breaks may not have a considerable effect on productivity or work performance (MD -83.00 number of words typed per 3-hour recording session; 95% CI -305.27 to 139.27; one study; 10 participants), when compared to additional lower frequency work breaks.Changes in the duration of work breaksNo trials were identified that assessed the effect of different durations of work breaks.Changes in the type of work breakWe found low-quality evidence that active breaks may not have a considerable positive effect on participant-reported musculoskeletal pain, discomfort and fatigue (MD -0.17 on a 1-7 NRS scale; 95% CI -0.71 to 0.37; one study; 153 participants), when compared to passive work breaks.Relaxation work breaks may not have a considerable effect on participant-reported musculoskeletal pain, discomfort or fatigue, when compared to physical work breaks (MD 0.20 on a 1-7 NRS scale; 95% CI -0.43 to 0.82; one study; 97 participants; low-quality evidence).

AUTHORS' CONCLUSIONS

We found low-quality evidence that different work-break frequencies may have no effect on participant-reported musculoskeletal pain, discomfort and fatigue. For productivity and work performance, evidence was of very low-quality that different work-break frequencies may have a positive effect. For different types of break, there may be no effect on participant-reported musculoskeletal pain, discomfort and fatigue according to low-quality evidence. Further high-quality studies are needed to determine the effectiveness of frequency, duration and type of work-break interventions among workers, if possible, with much higher sample sizes than the studies included in the current review. Furthermore, work-break interventions should be reconsidered, taking into account worker populations other than office workers, and taking into account the possibility of combining work-break intervention with other interventions such as ergonomic training or counselling, which may may possibly have an effect on musculoskeletal outcomes and work performance.

Medium-term effects of a two-desk sit/stand workstation on cognitive performance and workload for healthy people performing sedentary work: a secondary analysis of a randomised controlled trial

Implementing sit/stand workstations in sedentary work environments is a common way to reduce sedentary time, but their medium-term effect on cognitive performance is unclear. To address this circumstance, eighteen office workers participated in a two-arm, randomised controlled cross-over trial (ClinicalTrials.gov Identifier: NCT02825303), either working at a traditional (sit) or an interventional (sit/stand) workplace for 23 weeks. Cognitive performance (working speed, reaction time, concentration performance, accuracy), workload and relevant covariates (salivary cortisol level, heart rate, physical activity, sitting time) were measured pre- and post-intervention under laboratory conditions. MANOVA and RMANOVA results did not show differences in performance parameters and workload, respectively, between sit/stand and traditional workplace users. Differences in text editing accuracy and cortisol levels for sit/stand workstation users indicate potential connectivity to cognitive parameters which should be further examined with large-scale studies. Practitioner summary: Medium-term effects of working at sit/stand workstations on cognitive performance and workload are unexplored. This randomised controlled trial suggests that cognitive performance and workload are unaffected for sit/stand workstation users after 23 weeks of use. However, accuracy appeared to improve and physiological stress appeared to be altered. Abbreviations: BMI: body mass index; IPAQ: International physical activity questionnaire; MET: metabolic equivalent of task; MANOVA: multivariate ANOVA; NASA TLX: NASA task load index; RMANOVA: repeated measures ANOVA.

The impact of work rest scheduling for prolonged standing activity

Prolonged standing can cause discomfort on the body of the workers and can lead to injury and occupational disease. One of the ergonomic intervention is through improving the work-rest scheduling. The purpose of this study are to identify the fatigue level from the perception of the worker and to investigate the impact of the work-rest scheduling to the standing workers for 12 h working time with a different gender. This study involved two methods which are self-assessment of the worker and direct measurement by using electromyography (EMG). For self-assessment, 80 workers have been interviewed using questionnaire in order to identify the fatigue level. For direct measurement, EMG was attached to the 15 selected workers at their respective leg and lower back to analyse the muscle efforts. In terms of perception, the results show the discomfort and fatigue level at the lower body region in the following order as foot ankle, lower back and leg. There is a significant difference between gender on discomfort pain for foot ankle and leg. The results show short frequent break by 10 min can reduce the fatigue at the leg and infrequent long break is preferable in order to reduce the fatigue at the lower back. In conclusion, it was found that prolonged standing affect the muscle fatigue and discomfort especially lower extremities such as foot ankle, lower back and leg. Besides that, different type of work rest scheduling and gender have significant result towards the muscle fatigue development.

The effects of breaks on low back pain, discomfort, and work productivity in office workers: A systematic review of randomized and non-randomized controlled trials

The purpose of this study was to evaluate the effectiveness of breaks on low back pain, discomfort, and work productivity in office workers. Publications were systematically searched in several databases from 1980 to December 2016. Relevant randomized and non-randomized controlled trials were retrieved and assessed for methodological quality by two independent reviewers. Quality of evidence was assessed and rated according to GRADE guidelines. Eight randomized controlled trials and three non-randomized controlled trials were included in this review, of which 10 were rated as high-quality studies. The break programs were highly heterogeneous with work duration ranging from 5 min to 2 h and break duration ranging from 20 s to 30 min. The results showed low-quality evidence for the conflicting effect of breaks on pain and low-quality evidence for the positive effect of breaks on discomfort. When stratified by type of breaks, moderate-quality evidence was found for the positive effect of active breaks with postural change for pain and discomfort. Moderate-quality evidence indicated that the use of breaks had no detrimental effect on work productivity. More high-quality studies are needed before recommendations can be given. Within a number of methodological limitations that are present in the published studies, active breaks with postural change may be effective in reducing pain in workers with acute low back pain and to prevent discomfort in healthy subjects.

Seat Pressure Distribution Characteristics During 1 Hour Sitting in Office Workers With and Without Chronic Low Back Pain

Background

Low back pain (LBP) is a major problem for office workers. Individuals adopting poor postures during prolonged sitting have a considerably increased risk of experiencing LBP. This study aimed to investigate seat pressure distribution characteristics, i.e., average pressure, peak pressure ratio, frequency of postural shift, and body perceived discomfort (BPD), during 1 hour of sitting among office workers with and without chronic LBP.

Methods

Forty-six participants (chronic LBP = 23, control = 23) typed a standardized text passage at a computer work station for an hour. A seat pressure mat device was used to collect the seat pressure distribution data. Body discomfort was assessed using the Body Perceived Discomfort scale.

Results

Office workers with chronic LBP sat significantly more asymmetrically than their healthy counterparts. During 1-hour sitting, all workers appeared to assume slumped sitting postures after 20 minutes of sitting. Healthy workers had significantly more frequent postural shifts than chronic LBP workers during prolonged sitting.

Conclusion

Different sitting characteristics between healthy and chronic LBP participants during 1 hour of sitting were found, including symmetry of sitting posture and frequency of postural shift. Further research should examine the roles of these sitting characteristics on the development of LBP.