Studying the relationship between low back pain and working postures among those who stand and those who sit most of the working day

Impact of 10-Min Daily Yoga Exercises on Physical and Mental Discomfort of Home-Office Workers During COVID-19

OBJECTIVE

Evaluate the effects of 10 min/day of yoga for 1 month on musculoskeletal discomfort and mood disturbance of home-office workers.

BACKGROUND

The COVID-19 pandemic forced many people to switch to teleworking. The abrupt change from an office setting to an improvised home-office may negatively affect the musculoskeletal and emotional health of workers. By providing mental and physical exercises, yoga may be effective in reducing adverse effects.

METHOD

Fifty-four participants (42 women, 12 men) followed a 1-month yoga program, while 40 participants (26 women, 14 men) continued with their common work routine. The Cornell Musculoskeletal Discomfort Questionnaire was used to evaluate severity, interference with work and frequency of pain, and to obtain a total discomfort score for 25 body areas. Mood disturbance was evaluated with the Profile of Mood States questionnaire. Both groups completed both questionnaires, before and after the experimentation period.

RESULTS

After 1 month, for the yoga group only, significant reductions were observed in the discomfort of eyes, head, neck, upper and lower back, right wrist, and hips/buttocks, as well as reductions in discomfort severity, frequency and interference for the neck, upper and lower back. Total mood disturbance was also significantly reduced for the yoga group only. No favorable changes occurred for the control group.

CONCLUSION

The yoga intervention program appears to reduce musculoskeletal discomfort and mood disturbance of home-office workers.

APPLICATION

Sedentary workers may benefit from 10 min/day of yoga during the workday to attenuate potential physical and emotional discomfort during the current pandemic and beyond.

Comparison of Physiological Effects Induced by Two Compression Stockings and Regular Socks During Prolonged Standing Work

OBJECTIVE

The goal of this study was to evaluate and compare lower-leg muscle fatigue, edema, and discomfort induced by the prolonged standing of security guards wearing regular socks and those wearing 15-20 or 20-30 mmHg compression stockings as intervention.

BACKGROUND

Compression stockings are sometimes used by individuals standing all day at work. However, quantitative evidence showing their potential benefits for lower-leg health issues in healthy individuals during real working conditions is lacking.

METHOD

Forty male security employees participated in the study. All were randomly assigned to the control or one of the two intervention groups (I15-20 or I20-30). Lower-leg muscle twitch force, volume, and discomfort ratings were measured before and after their regular 12-hr standing work shift.

RESULTS

Significant evidence of lower-leg long-lasting muscle fatigue, edema, and discomfort was observed after standing work for guards wearing regular socks. However, no significant changes were found for guards wearing either compression stockings.

CONCLUSION

In healthy individuals, compression stockings seem to attenuate efficiently the tested outcomes in the lower leg resulting from prolonged standing.

APPLICATION

Occupational activities requiring prolonged standing may benefit from 15-20 or 20-30 mmHg compression stockings. As similar benefits were observed for both levels of compression, the lower level may be sufficient.

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.

Comparison of proprioceptive postural control strategies between prolonged standing induced low back pain developers and non-low back pain developers

BACKGROUND

Proprioception deficit has been suggested as a possible mechanism contributing for the impaired postural control in low back pain (LBP) patients. Whether proprioception deficit is a result of or a cause of LBP has not been investigated.

OBJECTIVE

The purpose of this study was to compare proprioceptive postural control strategies between prolonged standing induced low back pain developers (PDs) and non-pain developers (NPDs).

METHOD

Thirty-two healthy subjects performed 1-h prolonged standing and their ratings of perceived LBP have been recorded. Eight quiet standing trials for 60 s performed immediately before and after the prolonged standing. Postural control was challenged by muscle vibration and different postural conditions during quiet standing. Data were recorded using a force platform.

RESULTS

Forty percentage of participants is classified as PD. Before the prolonged standing, relative proprioceptive weighting was greater in the PD compared to NPD group (P = .029). Main effect of postural condition (F_1,24 = 5.21, P = .032) and interaction of time by group (F_1,24 = 8.08, P = .009) were significant for COP displacement in anteroposterior direction. Interaction of postural condition by group (F_1,26 = 7.82, P = .010) and time by group (F_1,26 = 9.71, P = .004) were significant for COP displacement in mediolateral direction. Main effect of postural condition (F_1,26 = 6.31, P = .018) and interaction of postural condition by group (F_1,26 = 7.07, P = .013) were significant for mean velocity in mediolateral direction.

CONCLUSION

The PD group has altered proprioceptive postural control strategies before and after prolonged standing. Proprioception deficit should not be considered to be solely an adaptive response and may be causal for LBP development.

Validation of foot plantar pressure sensor data used to estimate standing, sitting, and moving durations in one working day

BACKGROUND

Maintaining immovable postures for long durations might be a cause of low back pain. However, the relation between low back pain and the maintenance of postures for long durations has been unclear. Therefore, the durations of several postures in one working day should be measured to evaluate the risk of low back pain, although the available measuring methods are limited. To the best of our knowledge, no study has reported the development and investigation of a foot plantar pressure sensor for measurement of standing, sitting, and moving durations in daily work routines. Thus, in this study, we aimed to develop a foot plantar pressure sensor that could withstand long-term loads in the workplace. Furthermore, we aimed to evaluate the estimated results of standing, sitting, and moving durations among factory workers using the developed foot plantar pressure sensor.

METHODS

The developed foot plantar pressure sensor obtained a percentage difference within ±5% to estimate standing, sitting, and moving durations in the laboratory. We measured foot plantar pressures of 20 factory workers to estimate standing, sitting, and moving activity in one working day using data obtained by the foot plantar pressure sensor. The estimated standing, sitting, and moving durations were compared with the human estimation of photo data obtained by a wearable camera.

RESULTS

The agreement rate (Cohen's kappa coefficient) was 0.75 between the evaluation using the foot plantar pressure sensor data and human estimation using a wearable camera. Cohen's kappa coefficient was 0.81 in subjects who sat for ≥30% during daily work and 0.68 in subjects who sat for <30%.

CONCLUSION

Our foot plantar pressure sensor effectively measured the standing, sitting, and moving durations in daily work that requires various movements and assumption of postures.

Psychosocial risk factors for low back pain in US workers: Data from the 2002-2018 quality of work life survey

BACKGROUND

Examining workplace psychosocial risk factors for back pain becomes increasingly important because of the changing nature of work and rising healthcare costs. Some psychosocial risk factors for back pain, such as work and family imbalance, exposure to a hostile work environment, and job insecurity, are understudied for the working population in the United States.

METHODS

Data used in this study came from the Quality of Work Life Survey (QWL), a supplementary module of the General Social Survey conducted in the United States. Data from the 2002, 2006, 2010, 2014, and 2018 QWL surveys were used in these analyses, giving a total sample size of 6661. Five domains of workplace psychosocial risk factors for back pain were examined, including job strain, low social support, work-family imbalance, exposure to a hostile work environment (harassment and discrimination), and job insecurity. The adjusted odds ratio (aOR) of each psychosocial risk factor for back pain with 95% confidence intervals (CI) was estimated using a multivariable logistic regression model after controlling for job physical factors, occupation, and demographic and socioeconomic characteristics.

RESULTS

Significant associations were found between back pain and several psychosocial factors including job strain (aOR 1.19; CI 1.00,1.41), work-family imbalance (aOR,1.42; CI 1.22,1.64), harassment (aOR 1.40; CI 1.15,1.71), and discrimination (aOR 1.20 CI 1.00,1.44).

CONCLUSION

This study contributes to the understanding of the relationship between a variety of workplace psychosocial factors and back pain. Our findings suggest directions in future longitudinal research to examine emerging workplace psychosocial factors for back pain.

Evaluating the biomechanics of an in-between posture to create a multi-posture office environment

BACKGROUND

Prolonged sitting during work is common and has been shown to cause health issues. However, changing working postures has been reported to reduce musculoskeletal issues and impact other health issues; thus, there is a need for an office environment with multiple choices of working postures.

OBJECTIVE

The purpose of this study was to evaluate changes in body position, body loading, and blood perfusion while in a seated, standing, and new office seating position, termed the in-between position.

METHODS

Ground reaction forces, joint angles, pelvic tilt, openness angle (angle between the pelvis plane and thorax), and blood perfusion were evaluated for three positions. A motion capture system with markers was used to capture the position of anatomical landmarks. A six-axis force plate was used to collect the ground reaction forces, and a laser doppler perfusion monitor was used to obtain the blood perfusion.

RESULTS

Data showed that the in-between position articulated the hips, which provided a hip and lumbar position closer to a standing posture than a seated posture. The average vertical ground reaction force in the in-between position was larger than the seated position but significantly smaller than during standing (p < 0.0001). There were no significant differences in anterior/posterior ground reaction forces between the seated and the in-between positions (p = 0.4934). Lastly, blood perfusion increased during the dynamic transitions between positions indicating changes in blood flow.

CONCLUSION

The in-between position provides benefits of both standing (larger pelvic tilt and increased lumbar lordosis) and sitting (reduction in ground reaction forces).

The biomechanical benefits of active sitting

This cross-sectional study examined the biomechanical effects of two active chairs (AC1: had the feature to pedal and slide forward on the seat pan; AC2: a multiaxial motion seat pan) compared to a traditional office chair and standing workstation. Twenty-four healthy participants worked at each of the workstations for 60-min. The following equipment was used: Motion Capture, Electromyography, Ratings of Perceived Discomfort Questionnaire, and Exit Survey. The active protocol had positive effects on the body, including increased neuromuscular activity in the gastrocnemius, increased overall movement, and a more open trunk-thigh angle. Greater discomfort in the buttocks due to the lack of seat pan contour was reported for the AC1 which identified a need for a design modification. While standing, participants' shoulders were less flexed than when sitting in any of the three seats, however, greater discomfort was reported in the lower legs after 1 h of computer work. Practitioner summary: A comparison of four different workstations was conducted to further understand the use of active workstations. Active sitting was found to have positive effects on the body, such as allowing sitters to increase movement while sitting without the high activation of muscular activity. Standing can also provide a positive break from sitting.

A Conceptual Model for the Impact of Occupational Standing on Enterprise Outcomes Using an Inductive Content Analysis of California Lawsuits

OCCUPATIONAL APPLICATIONSIn this paper, we provide a framework for practitioners when (re)designing tasks that historically have required standing in the workplace. While the goal is not to remove standing from all jobs, practitioners must work with management to align health and safety outcomes related to standing at work with the enterprise's main outcomes. Practitioners should also be made aware that in many of these jobs, standing has been required because, in the enterprise's judgment, it improves performance and customer service. Understanding common beliefs about customer interactions and job performance in the workplace will be vital to implementing changes that have previously been difficult to navigate.

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.

Anti-fatigue mats can reduce low back discomfort in transient pain developers

Complaints of musculoskeletal pain are common among employees who stand for prolonged periods. This study sought to determine if an anti-fatigue mat (AFM) could uniquely affect low back pain (LBP), low back posture, and foot-floor interface responses in individuals prone to developing LBP (termed pain developers (PDs)) during prolonged standing experiments compared to those who do not develop LBP under the same exposures (termed non pain developers (NPDs)). Sixteen volunteers (8 PDs and 8 NPDs) were recruited based on their pain-development tendencies, which were established in previous standing experiments. They visited the laboratory on two separate days for 60 min of light manual work while standing on either a rigid floor or AFM. All participants were asymptomatic at the beginning of each experimental session. The amount of LBP experienced during the standing exposure, measured via a visual analogue scale, was reduced (p = 0.03) in the PD group when on the AFM (3.6 ± 6 mm) compared to the rigid floor (6.8 ± 7 mm). LBP levels remained low and unchanged (p = 0.5) between the AFM (2.4 ± 5 mm) and rigid floor (1.6 ± 2 mm) conditions for the NPD group. Neither postural nor foot-floor interface measures correlated with this unique reduction of LBP for the PD group when standing on the AFM. The AFM did, however, increase centre of pressure excursion (NPD 55% increase; PD 35% increase) and tended to increase the number of body weight shifts (NPD 116% increase; PD 54% increase) in both the PD and NPD groups. These findings suggest that AFMs may selectively benefit individuals prone to developing standing-induced back pain by facilitating subtle movements at the foot-floor interface.

Association between sedentary behavior and low back pain; A systematic review and meta-analysis

Background: Sedentariness is a substantial risk for many chronic diseases. We aimed to investigate the correlation of sedentary behavior and its indicators with low back pain (LBP) among adults and children.

Methods: Original articles published up to April 28, 2020, using PubMed, Embase, Web of Science and Scopus were evaluated. Odds ratio (OR, 95% CI) was considered the overall effect size for desired associations.

Results: We reviewed 49 English articles with analytical observational study design, of which, 27 studies with cross sectional/survey design were retained in the meta-analysis. Among adults, sedentary lifestyle was a considerable risk factor for LBP (OR=1.24, 1.02-1.5); prolonged sitting time (OR=1.42, 1.09-1.85) and driving time (OR=2.03, 1.22-3.36) were the significant risk factors. Sedentary behavior was associated with LBP in office workers (OR=1.23). Moreover, excess weight (OR=1.35, 1.14-1.59) and smoking (OR=1.28, 1.03-1.60) were associated with LBP. Among children, sedentary lifestyle was a remarkable risk factor for LBP (OR=1.41, 1.24- 1.60); prolonged TV watching (OR=1.23, 1.08-1.41) and computer/mobile using and console playing time (OR=1.63, 1.36-1.95) were significant risk factors for LBP. Consumption of coffee, however, has yield conflicting results to be considered as a risk factor. Moreover, the researches on the correlation between sedentariness and high-intensity LBP are scarce and inconclusive.

Conclusion: Sedentary behavior, whether in work or leisure time, associates with a moderate increase in the risk of LBP in adults, children and adolescents.

Physical work conditions and disparities in later life functioning: Potential pathways

Research in the US on the social determinants of reduced physical functioning at older ages has typically not considered physical work conditions as contributors to disparities. We briefly describe a model of occupational stratification and segregation, review and synthesize the occupational health literature, and outline the physiological pathways through which physical work exposures may be tied to long-term declines in physical functioning. The literature suggests that posture, force, vibration, and repetition are the primary occupational risk factors implicated in the development of musculoskeletal disorders, through either acute injuries or longer-term wear and tear. Personal risk factors and environmental and structural work characteristics can modify this association. In the long-term, these musculoskeletal disorders can become chronic and ultimately lead to functional limitations and disabilities that interfere with one's quality of life and ability to remain independent. We then use data on occupational characteristics from the Occupational Information Network (O*NET) linked to the 2019 American Community Survey (ACS) to examine disparities among sociodemographic groups in exposure to these risk factors. Occupations with high levels of these physical demands are not limited to those traditionally thought of as manual or blue-collar jobs and include many positions in the service sector. We document a steep education gradient with less educated workers experiencing far greater physical demands at work than more educated workers. There are pronounced racial and ethnic differences in these exposures with Hispanic, Black, and Native American workers experiencing higher risks than White and Asian workers. Occupations with high exposures to these physical risk factors provide lower compensation and are less likely to provide employer-sponsored health insurance, making it more difficult for workers to address injuries or conditions that arise from their jobs. In sum, we argue that physical work exposures are likely an important pathway through which disparities in physical functioning arise.

Evaluation of Back Pain and Lead Apron Use Among Staff at a District General Hospital

Objectives

To evaluate the prevalence of back pain among staff who regularly use lead aprons, correlating this to their use, and improve the knowledge and understanding of lead apron use among staff.

Methods

A questionnaire study was undertaken from November 2018 to February 2019 on staff in departments using lead aprons on a routine basis (n = 59) defined as the study group (SG), and staff who did not wear lead aprons (n = 62) defined as the control group (CG). Additionally, a separate questionnaire (n = 43) was distributed to lead apron users regarding education and knowledge, following which an education session was set up and the staff was re-evaluated.

Results

The prevalence of back pain was higher in the SG; 63% (SG) versus 32% (CG). The proportion of staff that felt lead aprons (SG) or work (CG) was the cause of this back pain was also higher in the SG than the CG: 83% versus 37%. A significant proportion of staff was unaware of the lead equivalence, material, and types of lead aprons available, after education this improved; 92% of staff now think more carefully when choosing a lead apron.

Discussion

Back pain is prevalent among staff using lead aprons and a lack of education regarding their use is evident. This could result in time off work and lead to unsafe practices around ionizing radiation. Education improved the knowledge and understanding of lead apron use. This could lead to increased comfort and less strain on the back, potentially lowering the prevalence of back pain.

Gait Characteristics and Fatigue Profiles When Standing on Surfaces with Different Hardness: Gait Analysis and Machine Learning Algorithms

Simple Summary

The purpose of this study was to explore if an anti-fatigue soft mat could improve the gait performance after standing for long periods and to examine if a machine-learning algorithm could evaluate fatigue state objectively. Compared with standing directly on the hard ground, using an anti-fatigue mat could reduce the negative effect of standing for a long time (4 h). The machine-learning algorithm demonstrated moderate accuracy in measuring fatigue. The accuracy of gait parameters used to consider a non-fatigued state following the use of an anti-fatigue mat was higher than that of the fatigue state. The results may indicate that it is beneficial to use anti-fatigue mats when standing for long periods, and it is feasible to use gait parameters and machine-learning algorithms to detect fatigue.

Abstract

Background: Longtime standing may cause fatigue and discomfort in the lower extremities, leading to an increased risk of falls and related musculoskeletal diseases. Therefore, preventive interventions and fatigue detection are crucial. This study aims to explore whether anti-fatigue mats can improve gait parameters following long periods of standing and try to use machine learning algorithms to identify the fatigue states of standing workers objectively. Methods: Eighteen healthy young subjects were recruited to stand on anti-fatigue mats and hard ground to work 4 h, including 10 min rest. The portable gait analyzer collected walking speed, stride length, gait frequency, single support time/double support time, swing work, and leg fall intensity. A Paired sample t-test was used to compare the difference of gait parameters without standing intervention and standing on two different hardness planes for 4 h. An independent sample t-test was used to analyze the difference between males and females. The K-nearest neighbor (KNN) classification algorithm was performed, the subject’s gait characteristics were divided into non-fatigued and fatigue groups. The gait parameters selection and the error rate of fatigue detection were analyzed. Results: When gender differences were not considered, the intensity of leg falling after standing on the hard ground for 4 h was significantly lower than prior to the intervention (p < 0.05). When considering the gender, the stride length and leg falling strength of female subjects standing on the ground for 4 h were significantly lower than those before the intervention (p < 0.05), and the leg falling strength after standing on the mat for 4 h was significantly lower than that recorded before the standing intervention (p < 0.05). The leg falling strength of male subjects standing on the ground for 4 h was significantly lower than before the intervention (p < 0.05). After standing on the ground for 4 h, female subjects’ walking speed and stride length were significantly lower than those of male subjects (p < 0.05). In addition, the accuracy of testing gait parameters to predict fatigue was medium (75%). After standing on the mat was divided into fatigue, the correct rate was 38.9%, and when it was divided into the non-intervention state, the correct rate was 44.4%. Conclusion: The results show that the discomfort and fatigue caused by standing for 4 h could lead to the gait parameters variation, especially in females. The use of anti-fatigue mats may improve the negative influence caused by standing for a long period. The results of the KNN classification algorithm showed that gait parameters could be identified after fatigue, and the use of an anti-fatigue mat could improve the negative effect of standing for a long time. The accuracy of the prediction results in this study was moderate. For future studies, researchers need to optimize the algorithm and include more factors to improve the prediction accuracy.

Determining the interactions between postural variability structure and discomfort development using nonlinear analysis techniques during prolonged standing work

PURPOSE

Nonlinear analysis techniques provide a powerful approach to explore dynamics of posture-related time-varying signals. The aim of this study was to investigate the fundamental interactions between postural variability structure and discomfort development during prolonged standing.

METHODS

Twenty participants, with equal distribution for gender and standing work experience (SWE), completed a simulated long-term standing test. Low back and legs discomfort, center of pressure, lumbar curvature, and EMG activity of trunk and leg muscles were monitored. Nonlinear measures including largest lyapunov exponent, multi-scale entropy, and detrended fluctuation analysis were applied to characterize the variability structure (i.e., complexity) in each signal. The size (i.e., amount) of variability was also computed using traditional linear metrics.

RESULTS

With progress of low back and legs discomfort over standing periods, significant lower levels were perceived by the participants having SWE. The amount of variability in all signals (except external oblique EMG activity) were significantly increased with the time progress for all participants. The structure of variability in most signals demonstrated a lower complexity (more regularity) with fractal properties that deviated from 1/f noise. The SWE group showed a higher complexity levels.

CONCLUSIONS

Overall, the findings verified variations in structure and amount of the postural variability. However, nonlinear analysis identified postural strategies according to the perceived discomfort in a different way. These results provide supports for future application of nonlinear tools in evaluating standing tasks and related ergonomics interventions as it allows further insight into how discomfort development impact the structure of postural changes.

The effects of prolonged sitting, standing, and an alternating sit-stand pattern on trunk mechanical stiffness, trunk muscle activation and low back discomfort

Sit-stand desks continue to be a popular intervention for office work. While previous studies have reported changes in subjective measures, there is limited understanding of how sit-stand work differs from prolonged sitting or standing work, from a biomechanical standpoint. The objective of this study was to investigate the effects of prolonged sitting, prolonged standing, and a sit-stand paradigm on changes in trunk stiffness, low back discomfort, and trunk muscle activation. Twelve healthy participants performed 2 h of computer-based tasks in each protocol, on three different days. The sit-stand protocol was associated with a significant increase in trunk stiffness and a decrease in muscle activation of lumbar multifidus and longissimus thoracis pars thoracis, compared to both prolonged sitting and standing. Both sitting and standing were associated with increased low back discomfort. These findings may be worth exploring in more detail, for why alternating sit-stand patterns may help alleviate low back pain. Practitioner summary: We explored changes in objective and subjective measures related to low back discomfort following prolonged sitting, standing, and alternating sit-stand patterns. Alternating sit-stand pattern was associated with increased trunk stiffness and decreased back muscle activity. Hence, sit-stand desks may have benefits in terms of preventing/mitigating low back pain. Abbreviations: DOF: degree of freedom; EMG: electromyogram; ILL: iliocostalis lumborum pars lumborum; LTL: longissimus thoracis pars lumborum; LTT: longissimus thoracis pars thoracis; LBP: low back pain; LM: lumbar multifidus; MVEs: maximum isometric voluntary exertions; RANOVA: repeated-measure analysis of variance; RMS: root mean square.

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.

Health Disparities Among Workers With Standing Position and Limited Restroom Access: A Cosmetics Saleswomen Study in South Korea

Korean cosmetics sales workers in department stores face harmful working environments, including limited restroom access, working long hours in a standing position, and customer violence. This study investigated health disparities between cosmetics saleswomen and the general population of working women in South Korea. We assessed the prevalence of health indicators, including physician-diagnosed disease, using a cross-sectional survey of 860 Korean cosmetics saleswomen in September 2018. Health indicators of cosmetics saleswomen were compared to those of general working women from the nationally representative datasets (e.g., National Health Insurance Service-National Sample Cohort). We estimated age-standardized prevalence ratios (SPRs) for health outcomes, including physical, mental, and health-related behavioral conditions. Cosmetics saleswomen were more likely to be diagnosed or treated for physical and mental conditions (e.g., cystitis SPR: 4.03, 95% confidence interval [CI]: 3.48-4.65; plantar fasciitis SPR: 23.48, 95% CI: 18.12-29.93; varicose vein SPR: 38.41, 95% CI: 32.18-45.49; and depression SPR: 11.18, 95% CI: 8.53-14.40) compared to general working women. Prevalence of smoking and hazardous alcohol consumption was also higher among cosmetics saleswomen than those of general women workers. Given our findings, further research is needed to identify work-related risk factors that could deteriorate cosmetic sales workers' health in South Korea.

Negative Impacts of Prolonged Standing at Work on Musculoskeletal Symptoms and Physical Fatigue: The Fifth Korean Working Conditions Survey

PURPOSE

We aimed to investigate variations in the risk of low back pain (LBP), lower extremity muscle pain, and whole body fatigue according to differences in prolonged standing work hours in relation to risk factor exposure and rest frequency.

MATERIALS AND METHODS

From the fifth Korean Working Conditions Survey data collected in 2017, data for 32970 full-time workers who worked for more than 1 year at their present job were analyzed. We classified the workers according to exposure to fatigue or painful postures, carrying heavy objects, performance of repetitive movements that burden the musculoskeletal system, and how often they took a break. Relationships between time spent in a standing posture at work and risks of LBP, lower extremity muscle pain, and whole body fatigue were analyzed by multivariate logistic regression.

RESULTS

Of the full-time workers in the survey, 48.7% worked in a standing position for more than half of their total working hours. A higher odds ratio (OR) value for lower extremity muscle pain was observed in female not exposed to carrying heavy objects [OR: 3.551, 95% confidence interval (CI): 3.038-4.150] and not exposed to performing repetitive movements (OR: 3.555, 95% CI: 2.761-4.557).

CONCLUSION

Changes in work methodologies are needed to lower the number of hours spent in a prolonged standing posture at work, including being able to rest when workers want to do so, to reduce pain and fatigue.

Is a Modified Package of Exercise Training Useful on Low Back Pain in Nursing?

The article's abstract is not available.  

Ergonomics training coupled with new Sit-Stand workstation implementation influences usage

Currently, there is no guidance on the training programme approach that should be provided to new sit-stand workstation users to optimally integrate workstation usage patterns into their working day. The objective of this research study was to determine if a training programme could influence long-term usage of sit-stand workstations. Thirty-five employees from the University of Waterloo volunteered to participate in this longitudinal study. Two different types of training programmes were delivered: (1) an example from industry and (2) based on current literature. There was an influence of training programme on the frequency of sit to stand transitions made each day. Those who received the additional training programme also reported sitting less, standing more and used their sit-stand workstations more consistently day-to-day than those who did not. Practitioner Summary: A longitudinal study was conducted to assess the impact of training programmes on sit-stand workstation usage. A training programme based on current literature resulted in more consistent sit-stand usage than an industry example.

Australian emergency nurses' lumbar movement during a shift: An observational study

BACKGROUND

Emergency nurses are at higher risk than the average worker of experiencing lumbar pain. This is the first study to undertake real time monitoring to quantify lumbar movements of nurses working in the emergency department (ED).

METHODS

Emergency nurses at a single Australian ED were recruited for a prospective observational case study. Participants worked in four discrete clinical areas of the ED; In-charge, triage, resuscitation, and cubicles. Data collected included participant demographics, lumbar pain pre- and post-shift, and real-time recording of lumbar movements.

RESULTS

Sixty-two nurses participated. There were statistically significant differences in time spent standing (p = 0.005), sitting (p ≤ 0.001) and in locomotion (moving) (p ≤ 0.001) when compared by clinical role. Triage nurses spent over half their shift sitting, had the most sustained (> 30 s) flexions (60+ degrees) and had a median of 4 periods of uninterrupted sitting (10-30 mins) per shift.

CONCLUSIONS

Differences in movement demands were identified based on various clinical roles in the ED. Triage was associated with greater periods of uninterrupted sitting and with greater degrees of sustained flexion, both of which are predictors for back pain. This study provides foundation evidence that triage may not be the most appropriate location for staff returning from back injury.

The impact of a progressive sit-stand rotation exposure duration on low back posture, muscle activation, and pain development

This study evaluated early and frequent seated breaks from standing work to reduce low back pain (LBP) in known pain developers (PD). Twenty-four participants, classified as either PD or non-PD during a separate 2-hour standing session, performed 124 minutes of standing work with seated breaks at a 3:1 stand-sit ratio with increasing durations from 3:1 minute to 48:16 minutes. Back pain and spine posture measures showed no differences between PD and non-PD. Females had greater left glutaeus medius activation (8.4%MVC) than males (4.5%MVC) and greater glutaeus medius co-contraction. This protocol was successful at reducing LBP in PD to the level of non-PD, with mean pain scores (13 mm) only slightly exceeding the clinical LBP threshold of 10 mm. Early and frequent breaks within the first hour of standing work appear to be an effective solution to reduce the LBP that often occurs at the beginning of standing work. Practicioner Summary: Sit-stand workstations may be an effective solution to reduce static occupational low back postures. This experimental study demonstrated that early and frequent seated breaks from standing work may be an effective solution to reduce tissue aggravation that often occurs within the first 45 minutes of a standing work exposure. Abbreviations: LBP: low back pain; PD: pain developer; NPD: non-pain developer; VAS: visual analog scale; EMG: electromyography; LES: lumbar erector spinae; TES: thoracic erector spinae; GMD: glutaeus medius; IOB: internal oblique; MVC: maximum voluntary contraction; CCI: co-activation coefficient; FDA: functional data analysis.

Effect of standing desk use on cognitive performance and physical workload while engaged with high cognitive demand tasks

It is clear that the cognitive resources invested in standing are greater than in sitting, but six of eight previous studies suggested that there is no difference in cognitive performance. This study investigated the effects of sitting and standing workstations on the physical workload and cognitive performance under variable cognitive demand conditions. Fifteen participants visited two times for testing sitting and standing workstations, and were asked to play two difficulty levels of Tetris game for 40 min while kinematic variables, CoP regularity, CoP SD, and cognitive performances were captured every 5 min. Results revealed a more neural posture in standing than in sitting, but using the standing workstation degraded attention and executive function. The CoP SD was 7 times greater in standing, but the CoP regularity was 1/4 in sitting, denoting greater attentional investment while engaged at the standing workstation.

Improving IR Ergonomics Using a Flexible C-Arm System

PURPOSE

To evaluate the impact of a versatile flexible ceiling-mounted C-arm on active table and gantry repositioning during interventions and its effect on operator discomfort, system usability, and patient safety compared with a traditional ceiling-mounted system.

MATERIALS AND METHODS

There were 100 IR procedures studied: 50 in a traditional IR system (standard group) and 50 with a novel multiaxis ceiling-mounted system (test group). FlexArm was capable of multiple gantry rotation points allowing increased access to the patient in addition to 236 cm of lateral x-ray detector travel. For each procedure, both the table and the gantry repositioning were measured. Patient safety, patient/equipment repositioning effort, and physical discomfort were evaluated through an operator survey.

RESULTS

Table repositioning was reduced from 42 to 16 instances per procedure (P < .001) in the test group compared with the standard group. The operators perceived less table and gantry repositioning effort (P < .0001) and decreased risks of equipment collisions, displacement of vascular access, and dislodgment of tubes/lines with the test group (P < .0001). Operator discomfort was reduced for all body areas in the test group over the standard group (P < .0001).

CONCLUSIONS

The FlexArm system geometry enhances operator ergonomics, as there was a decrease need to move the table, leading to a perceived decrease in patient risk and decrease operator physical discomfort when compared to a traditional imaging system.

Brain activity during a working memory task in different postures: an EEG study

While working is more comfortable in a supine position and healthier in a standing, most people work in a sitting. However, it is unclear whether there are differences in brain activity efficiency in different postures. Here, we, therefore, compared changes in brain activity across three different postures to determine the optimal posture for performing working memory tasks. Their effect on brain activity was examined using EEG signals together with the information of accuracy and reaction times during 2-back task in 24 subjects. Substantial differences in brain waves were observed at sitting and standing positions compared to the supine, especially in delta waves and frontal lobe, where is known to improve the modulation of brain activity efficiently. Brain efficiency was higher during standing and sitting than in a supine. These findings show that postural changes may affect the efficiency of brain activity during working memory tasks. Practitioner summary: Differences in brain efficiency between different postures during working memory tasks have not been explored. This study suggests that efficiency in several brain areas is higher during sitting and standing than in a supine position. This finding has important implications regarding workplace environments. Furthermore, this result would be useful to improve accomplishment and reduce negative effects of work posture. Abbreviations: EEG: electroencephalogram; PSQI: Pittsburgh sleep quality index; KSS: Karolinska sleepiness scale; FFT: fast fourier transform; ROI: region of interest; ANS: autonomic nervous system; Fp: prefrontal; AF: anterior frontal; frontal; Fz: midline frontal; temporal; central; Cz: midline central; P: parietal; Pz: midline parietal; O: occipital; Oz: midline occipital.

Are blue-collar workers more physically active than white-collar at work?

This study evaluates the physical activity level at work and leisure time of white-collar and two groups of blue-collar workers from the latex glove industry and the association of physical activity level and musculoskeletal complains and work ability. The workers' sociodemographic and behavioral health characteristics, work ability index, musculoskeletal complains, total step count and caloric expenditure for three consecutive days, were assessed. The blue-collar workers that move most from the workstation (longD) were more physically active at work compared to white-collar and blue-collar that moved close the workstation (shortD). But in leisure-time the result is reversed, white-collar and blue-collar groups were significantly more active. There was no association between physical activity level and musculoskeletal pain intensity and work ability. All the groups of workers exhibited satisfactory physical activity levels, but only blue-collar (longD) were more physically active (10,000 steps per day).

Pain symptoms are reported earlier than quantitative measures of low back pain during prolonged standing

BACKGROUND

Along with quantitative measures, pain symptoms may help inform early interventions to prevent prolonged standing induced low back pain (LBP); however, the relationship between quantitative and qualitative measures has not been assessed.

OBJECTIVE

Determine the relationship between qualitative and quantitative measures of pain development during prolonged standing induced LBP development.

METHODS

Thirty-five participants performed two-hours of standing. A visual analog scale (VAS) and the Short-Form McGill Pain Questionnaire were used to assess the participant's LBP every 7.5-minutes. Participants were classified as a pain developer (PD) based on VAS scores or three consecutive pain symptom reports.

RESULTS

Pain symptom reports occurred 31.3 (±24.8) minutes earlier than the VAS reports. Eight participants (44%) were non-PDs with the VAS and PDs with the symptom method (p = 0.0047).

CONCLUSIONS

A subset of participants who were not categorized as LBP developers during prolonged standing using the VAS method still report LBP symptoms. The inclusion of pain symptom reporting could provide additional information for practitioners when identifying individuals who would benefit from early interventions for standing induced LBP.

Low back pain development differentially influences centre of pressure regularity following prolonged standing

Occupations requiring prolonged periods of static standing are associated with the development of low back pain (LBP). Certain individuals are susceptible to LBP development during prolonged standing (pain developers, PDs) while others are not (non-pain developers, NPDs). Linear centre of pressure (COP) measures suggest that standing balance control is negatively influenced following prolonged standing, and that PDs and NPDs may be differentially affected. The objective of this study was to determine if nonlinear standing balance control, quantified on COP, using sample entropy, is altered after 2-h of standing. Thirty two participants stood for 2-h. Separate 2-min standing trials, performed with eyes open and eyes closed, were collected before and after the 2-h standing protocol. Sample entropy, median power frequency and RMS amplitude of the COP time-series, was calculated from the 2-min standing trials for all participants. For comparison, participants were classified, post hoc, as PDs or NPDs according to visual analog scale pain scores. Sample entropy decreased after 2-h of standing for both PDs and NPDs, however, the decrease for NPDs was only 21% of the decrease observed in PDs. This study demonstrated that nonlinear control of upright standing changes after 2- hours of standing, resulting in an increase in COP regularity post 2- hours of standing for both PDs and NPDs. PDs displayed a greater change in COP regularity, which is supported by the theory that increased COP regularity occurs with pain/pathology.

Development and evaluation of RAMP II - a practitioner's tool for assessing musculoskeletal disorder risk factors in industrial manual handling

RAMP II is an observation-based tool developed for assessing a wide range of musculoskeletal disorder risk factors related to industrial manual handling. RAMP II, which is part of the RAMP tool, is based on research studies and expert judgments. The assessment relies mainly on direct or video observations of the work being assessed, but additionally on measured push/pull forces and weights of handled objects, and on perceived workload and discomfort. Over 80 practitioners participated in the development of the tool. According to the evaluations, 73% of the assessment items evaluated had acceptable reliability, and the majority of the potential end-users reported that RAMP II is usable for assessing risks and as a decision base. It is concluded that this study provides support that RAMP II is usable for risk assessment of musculoskeletal disorder risk factors in industrial manual handling. Practitioner summary: RAMP II is an observation-based assessment tool for screening and assessing major musculoskeletal exposures in industrial manual handling jobs. Over 80 practitioners participated in the development of the tool. This study provides support that RAMP II is usable for risk assessment of musculoskeletal disorder risk factors in industrial manual handling. Abbreviations: CTS: carpal tunnel syndrome; HARM: the Hand Arm Risk Assessment method; IMP: intramuscular pressure; κ_w: linearly weighted kappa; LBD: lower back disorders; LBP: lower back pain; MAWL: maximum acceptable weight of lift; MHO: manual handling operations; MSD: musculoskeletal disorder; MNSD: neck-shoulder disorder; NSP: neck-shoulder pain; OCRA: the Occupational Repetitive Action methods; OHS: occupational health and safety; PABAK: prevalence and bias adjusted kappa; p₀: proportion of agreement; RAMP: Risk Assessment and Management tool for manual handling Proactively; ROM: range of motion; RPL: risk and priority level; RSI: the Revised Strain Index; RULA: the Rapid Upper Limb Assessment; SWEA: Swedish Work Environment Authority; UEMSDs: upper-extremity work-related musculoskeletal disorders; WMSD: work-related musculoskeletal disorder; WRMSD: work-related musculoskeletal disorder; workday_8h: eight hours workday.

Workplace interventions for increasing standing or walking for decreasing musculoskeletal symptoms in sedentary workers

BACKGROUND

The prevalence of musculoskeletal symptoms among sedentary workers is high. Interventions that promote occupational standing or walking have been found to reduce occupational sedentary time, but it is unclear whether these interventions ameliorate musculoskeletal symptoms in sedentary workers.

OBJECTIVES

To investigate the effectiveness of workplace interventions to increase standing or walking for decreasing musculoskeletal symptoms in sedentary workers.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, OSH UPDATE, PEDro, ClinicalTrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) search portal up to January 2019. We also screened reference lists of primary studies and contacted experts to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), cluster-randomised controlled trials (cluster-RCTs), quasi RCTs, and controlled before-and-after (CBA) studies of interventions to reduce or break up workplace sitting by encouraging standing or walking in the workplace among workers with musculoskeletal symptoms. The primary outcome was self-reported intensity or presence of musculoskeletal symptoms by body region and the impact of musculoskeletal symptoms such as pain-related disability. We considered work performance and productivity, sickness absenteeism, and adverse events such as venous disorders or perinatal complications as secondary outcomes.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles, abstracts, and full-text articles for study eligibility. These review authors independently extracted data and assessed risk of bias. We contacted study authors to request additional data when required. We used GRADE considerations to assess the quality of evidence provided by studies that contributed to the meta-analyses.

MAIN RESULTS

We found ten studies including three RCTs, five cluster RCTs, and two CBA studies with a total of 955 participants, all from high-income countries. Interventions targeted changes to the physical work environment such as provision of sit-stand or treadmill workstations (four studies), an activity tracker (two studies) for use in individual approaches, and multi-component interventions (five studies). We did not find any studies that specifically targeted only the organisational level components. Two studies assessed pain-related disability. Physical work environment There was no significant difference in the intensity of low back symptoms (standardised mean difference (SMD) -0.35, 95% confidence interval (CI) -0.80 to 0.10; 2 RCTs; low-quality evidence) nor in the intensity of upper back symptoms (SMD -0.48, 95% CI -.096 to 0.00; 2 RCTs; low-quality evidence) in the short term (less than six months) for interventions using sit-stand workstations compared to no intervention. No studies examined discomfort outcomes at medium (six to less than 12 months) or long term (12 months and more). No significant reduction in pain-related disability was noted when a sit-stand workstation was used compared to when no intervention was provided in the medium term (mean difference (MD) -0.4, 95% CI -2.70 to 1.90; 1 RCT; low-quality evidence). Individual approach There was no significant difference in the intensity or presence of low back symptoms (SMD -0.05, 95% CI -0.87 to 0.77; 2 RCTs; low-quality evidence), upper back symptoms (SMD -0.04, 95% CI -0.92 to 0.84; 2 RCTs; low-quality evidence), neck symptoms (SMD -0.05, 95% CI -0.68 to 0.78; 2 RCTs; low-quality evidence), shoulder symptoms (SMD -0.14, 95% CI -0.63 to 0.90; 2 RCTs; low-quality evidence), or elbow/wrist and hand symptoms (SMD -0.30, 95% CI -0.63 to 0.90; 2 RCTs; low-quality evidence) for interventions involving an activity tracker compared to an alternative intervention or no intervention in the short term. No studies provided outcomes at medium term, and only one study examined outcomes at long term. Organisational level No studies evaluated the effects of interventions solely targeted at the organisational level. Multi-component approach There was no significant difference in the proportion of participants reporting low back symptoms (risk ratio (RR) 0.93, 95% CI 0.69 to 1.27; 3 RCTs; low-quality evidence), neck symptoms (RR 1.00, 95% CI 0.76 to 1.32; 3 RCTs; low-quality evidence), shoulder symptoms (RR 0.83, 95% CI 0.12 to 5.80; 2 RCTs; very low-quality evidence), and upper back symptoms (RR 0.88, 95% CI 0.76 to 1.32; 3 RCTs; low-quality evidence) for interventions using a multi-component approach compared to no intervention in the short term. Only one RCT examined outcomes at medium term and found no significant difference in low back symptoms (MD -0.40, 95% CI -1.95 to 1.15; 1 RCT; low-quality evidence), upper back symptoms (MD -0.70, 95% CI -2.12 to 0.72; low-quality evidence), and leg symptoms (MD -0.80, 95% CI -2.49 to 0.89; low-quality evidence). There was no significant difference in the proportion of participants reporting low back symptoms (RR 0.89, 95% CI 0.57 to 1.40; 2 RCTs; low-quality evidence), neck symptoms (RR 0.67, 95% CI 0.41 to 1.08; two RCTs; low-quality evidence), and upper back symptoms (RR 0.52, 95% CI 0.08 to 3.29; 2 RCTs; low-quality evidence) for interventions using a multi-component approach compared to no intervention in the long term. There was a statistically significant reduction in pain-related disability following a multi-component intervention compared to no intervention in the medium term (MD -8.80, 95% CI -17.46 to -0.14; 1 RCT; low-quality evidence).

AUTHORS' CONCLUSIONS

Currently available limited evidence does not show that interventions to increase standing or walking in the workplace reduced musculoskeletal symptoms among sedentary workers at short-, medium-, or long-term follow up. The quality of evidence is low or very low, largely due to study design and small sample sizes. Although the results of this review are not statistically significant, some interventions targeting the physical work environment are suggestive of an intervention effect. Therefore, in the future, larger cluster-RCTs recruiting participants with baseline musculoskeletal symptoms and long-term outcomes are needed to determine whether interventions to increase standing or walking can reduce musculoskeletal symptoms among sedentary workers and can be sustained over time.

Are hybrid sit-stand postures a good compromise between sitting and standing?

Potential alternatives for conventional sitting and standing postures are hybrid sit-stand postures (i.e. perching). The purposes of this study were (i) to identify where lumbopelvic and pelvic angles deviate from sitting and standing and (ii) to use these breakpoints to define three distinct postural phases: sitting, perching, and standing, in order to examine differences in muscle activations and ground reaction forces between phases. Twenty-four participants completed 19 1-min static trials, from sitting (90°) to standing (180°), sequentially in 5°trunk-thigh angle increments. The perching phase was determined to be 145-175° for males and 160-175° for females. For both sexes, knee extensor activity was lower in standing compared to perching or sitting (p < .01). Anterior-posterior forces were the highest in perching (p < .001), requiring ∼15% of body-weight. Chair designs aimed at reducing the lower limb demands within 115-170° trunk-thigh angle may improve the feasibility of sustaining the perched posture. Practitioner summary: Individuals who develop low back pain in sitting or standing may benefit from hybrid sit-stand postures (perching), yet kinematic and kinetic changes associated with these postures have not been investigated. Perching can improve lumbar posture at a cost of increased lower limb demands, suggesting potential avenues for chair design improvement. Abbreviations: A/P: anterior-posterior; M/L: medial-lateral; LBP: low back pain; EMG: electromyography; TES: thoracic erector spinae; LES: lumbar erector spinae; VMO: vastus medialis obliquus; MVC: maximum voluntary contraction; ASIS: anterior superior iliac spine; PSIS: posterior superior iliac spine; BW: body weight; RMSE: root mean square error; SD: standard deviation; ROM: range of motion.

Predictors of pain intensity and Oswestry Disability Index in prolonged standing service workers with nonspecific chronic low back pain subclassified as active extension pattern

BACKGROUND

Because patients with nonspecific chronic low back pain (NSCLBP) are heterogeneous, subgrouping patients with NSCLBP might clarify the research findings. NSCLBP in the direction of extension movement, namely active extension pattern (AEP), is common during prolonged standing.

OBJECTIVE

Predictors of pain intensity and dysfunction were determined in prolonged standing service workers (PSSWs) with NSCLBP subclassified as AEP in the motor impairment subgroup.

METHODS

Variables were measured using questionnaires including a visual analog scale (VAS), the Oswestry Disability Index (ODI), Borg Rating of Perceived Exertion (RPE) Scale, and Korean Occupational Stress Scale (KOSS). Postural assessment was performed by measuring pelvic anterior tilting angle (PATA). The smart KEMA measurement system was used to evaluate hip flexion, hip extension (HE), and knee flexion range of motion (ROM), as well as hip extensor strength, hip abductor strength (HArS), hip external rotator strength (HERrS), hip internal rotator strength, knee extensor strength, and knee flexor strength, and lumbopelvic stability (LS) in 78 PSSWs with NSCLBP subclassified as AEP.

RESULTS

In prediction models, HArS, LS, PATA, KOSS and HE ROM accounted for 40.1% of the variance in the VAS (p < 0.05); predictors of dysfunction included the HERrS and age, which accounted for 11.9% of the variance in the ODI (p < 0.05) in multiple regression models when using a stepwise selection procedure.

CONCLUSIONS

The present results indicate that HArS and HERrS, LS, PATA, KOSS, HE ROM and age should be considered for evaluating and predicting NSCLBP subclassified as AEP in PSSWs, and when designing interventions.

Walking breaks can reduce prolonged standing induced low back pain

Standing is commonly recommended to reduce sedentary behavior in the workplace; however, constrained prolonged standing has also been linked to musculoskeletal symptoms, such as low back pain (LBP). Light physical activity breaks, such as walking, may change lumbar spine posture enough to reduce LBP during standing. This study assessed the effectiveness of inserting 5-minute walking breaks every 25 min for reducing prolonged standing-induced LBP development. Nineteen participants completed two bouts of standing lasting 2 h - one with a 5-minute walking break every 25 min and one with no breaks. Pain measures were completed throughout the trial to categorize participants as pain developers (PDs) or non-pain developers (non-PDs). Lumbar region kinematics angle and range of motion were measured continuously. In standing, 58% (11/19) of participants were PDs, compared to just 26% when walking breaks were inserted. Seventy-three percent (8/11) were categorized as non-PDs with walking breaks. Median lumbar flexion increased during walking compared to standing. Lumbar region range of motion in the coronal and transverse planes also increased during walking. The intermittent lumbar flexion may help decrease LBP during prolonged standing. These results demonstrate that walking breaks may help promote lumbar movement and reduce prolonged standing-induced LBP.

Physiotherapist perceptions of optimal sitting and standing posture

BACKGROUND

Assessment of, and advice about, spinal posture is common when people with spinal pain present to physiotherapists. Most descriptions regarding optimal spinal posture have been qualitative in nature.

OBJECTIVES

To determine the beliefs of physiotherapists regarding optimal sitting and standing posture.

DESIGN

Online survey.

METHOD

544 Greek physiotherapists selected an optimal sitting (choice of seven) and standing (choice of five) posture, while providing justification for their choice.

RESULTS

Education regarding optimal sitting and standing posture was considered "considerably" or "very" important by 93.9% of participants. Three different sitting postures, and two different standing postures, were selected as the optimal posture by 97.5% and 98.2% of physiotherapists respectively. While this reflects a lack of complete consensus on optimal posture, the most commonly selected postures were all some variation of upright lordotic sitting, in contrast slouched spinal curves (sitting) or forward head posture (sitting and standing) almost never being selected as optimal. Interestingly, participants used similar arguments (e.g. natural curves, muscle activation) to justify their selection regardless of the spinal configuration of each selected posture.

CONCLUSIONS

These results reinforce previous data suggesting that upright lordotic sitting postures are considered optimal, despite a lack of strong evidence that any specific posture is linked to better health outcomes. While postural re-education may play a role in the management of spinal pain for some patients, awareness of such widespread and stereotypical beliefs regarding optimal posture may be useful in clinical assessment and management.

Sitting versus standing makes a difference in musculoskeletal discomfort and postural load for surgeons performing vaginal surgery

INTRODUCTION AND HYPOTHESIS

We compared musculoskeletal discomfort and postural load among surgeons in sitting and standing positions during vaginal surgery.

MATERIALS AND METHODS

Assessment of discomfort and posture of the primary surgeons in both positions was performed at two institutions. The primary outcome was an increase in body discomfort score after surgery as determined from subjective responses using validated tools. The secondary outcome was the percentage of time spent in awkward body postures measured objectively and stratified into awkward postures for neck, trunk, and bilateral shoulder angles. Variables were compared between sitting and standing positions using Fisher's exact test for primary outcomes and Wilcoxon rank-sum test for secondary outcomes.

RESULTS

Data were collected for 24 surgeries from four surgeons in sitting position and nine surgeries from nine surgeons in standing position. The standing surgeons reported a significant increase in discomfort postoperatively for bilateral wrists, thighs, and lower legs compared with the sitting surgeons. The median percentage of time spent in awkward postures was significantly lower for the trunk in the standing versus sitting position (median 0.3% vs 58.8%, p < 0.001) but was significantly higher for both shoulders in the standing versus the sitting position (right shoulder: median 17.8% vs 0.3%, p = 0.003; left shoulder: median 7.4% vs 0.2%, p = 0.003).

CONCLUSION

Surgeons reported more discomfort in when performing vaginal surgery while standing. The postural load was worse for trunk but favorable for bilateral shoulders when seated. Such differences may impact a surgeon's decision to perform vaginal surgery seated rather than standing.

The effects of introducing electric adjustable height desks in an office setting on workplace physical activity levels: A randomised control field trial

BACKGROUND

Electric adjustable height desks (EAHD) have been promoted as an opportunity for desk based workers to stand at work but there is limited evidence that they have an effect on light physical activity.

OBJECTIVE

The main objective was to determine if there would be a change in light physical activity with the introduction of EAHD. The secondary objective was to assess if there was an associated change in leisure time activity.

METHODS

Activity levels were measured by step counts, self-reported activity levels and pre- and post-trial recall levels. Statistical analysis of the data was performed with the software R. Generalised linear models were fitted to the data. A Poisson regression was used for count data. Statistical hypotheses were deemed significant if their p values were less than 0.05.

RESULTS

There was a significant (p < 0.001) effect on step counts associated with allocation of EAHD and a significant (p < 0.001) increase in self-reported activity for the Intervention (EAHD) group. Having an EAHD was associated with increased activity during leisure (p = 0.039).

CONCLUSIONS

Activity levels, especially light physical activity, were significantly increased with the allocation of an electric adjustable height desk. This pilot study showed that the environmental change of introduction of electric adjustable height desks into an office workplace can increase physical activity and reduce sitting durations. There is limited evidence that the increase in work activity has a positive impact on leisure time activity.

Sewing shirts with injured fingers and tears: exploring the experience of female garment workers health problems in Bangladesh

Background

The ready-made garment industry in Bangladesh not only contributes to the nation’s economic development, but has created income opportunities for women, benefiting their whole family. However, these benefits come at considerable cost to the women. This research examines how the work environment and gendered family role in this conservative society affect the health of the female industrial workers.

Methods

A qualitative study employed in-depth interviews (n-20) and focus group discussions with female garment workers (n-4) in two cities of Dhaka district. Further, key informant interviews (n = 4) with factory doctors, along with eight workplace observations were conducted to explore the lived experience of female workers’ health issues. Interview transcripts were coded in Atlas-ti, 5.2. The data were analysed using thematic analysis approach. The themes are illustrated with case narratives.

Results

The female workers reported that their work has led to back and joint pain, continuous headache, eye pain and difficulty in breathing associated with inhaling fabric dust. Inadequate lighting, constantly sitting in one position without back rest and continuous noise from hundreds of machines makes them feel permanently tired. Further, the female workers reported that working in the factory and meeting the expectations of the families at home has doubled their workload. The doctors indicated that the physical work environment, their low job status and the nature of the job affect the health of female workers.

Conclusion

This study found that female workers in the ready-made garment industry face a high risk of health problems. Both government and non-government organizations need to be better involved in designing interventions targeting these women, to protect them from such health risks. In addition, recognition by the whole society of the important role the women play in the economy is needed, so that support by both family and society can be improved.

Electronic supplementary material

The online version of this article (10.1186/s12914-019-0188-4) contains supplementary material, which is available to authorized users.

Standing working posture and musculoskeletal pain among Citrus sinensis workers in a low-income country

Background. Work-related musculoskeletal pain (WRMP) among Citrus sinensis farm workers has barely been studied. Yet most work tasks in such farms are manually performed using awkward standing postures that can contribute to WRMP. Aim. This study assessed the standing working posture in relation to WRMP among C. sinensis workers. Methods. Ninety-two workers engaged in manual tasks participated in this cross-sectional study. Postures at the upper limbs were analysed using the rapid upper limb assessment (RULA) method. Data were analysed using SPSS version 20. Results. Analyses generally showed statistically significant associations (p < 0.05) between a body part RULA score and WRMP at the concerned body part. The upper arm score was >1 in 77.2% of the workers and caused upper arm pain in 66.3%; the association between the upper score and upper pain was statistically significant (χ ²= 20.57; p < 0.05). Similarly, significant associations were found between: (a) wrist score and wrist pain; (b) neck score and neck pain; (c) trunk score and back pain. Conclusions. C. sinensis workers use unsafe postures which contribute to WRMP at the upper arm, trunk, neck and wrists. Ergonomics measures are required to improve their working posture.

The association between occupational standing and sedentary leisure time over consecutive workdays among blue-collar workers in manual jobs

PURPOSE

Blue-collar workers spend much leisure time sedentary, which is associated with numerous health impairments. The extensive sedentary leisure time among blue-collar workers could be caused by fatigue from physically demanding work, like stationary standing. Occupational stationary standing is prevalent in many blue-collar jobs and has been shown to induce fatigue. The objective of this study was to investigate the association between occupational standing and sedentary leisure time over several workdays among blue-collar workers.

METHODS

This study used data from 925 workers from Danish workplaces within cleaning, transportation, manufacturing, construction, road maintenance, garbage disposal, and health service. Eligible workers wore accelerometers for 2-5 consecutive workdays. A linear regression was used to investigate the association between percent of work time spent standing and leisure time spent sedentary. A multilevel growth model was used to assess the association between standing during work and sedentary leisure time over consecutive workdays.

RESULTS

We found no association between percent of work hours spent standing and percent of leisure time spent sedentary (coef. = 0.01, p = 0.84). The results showed an increase in the workers' sedentary leisure time over a week (coef. = 0.70, p < 0.01). However, this increase was not associated with consecutive workdays exposed to occupational standing (coef. = 0.02, p = 0.42).

CONCLUSION

In this study, we found no support of a positive association between occupational standing and sedentary leisure time. This lack of association could be attributable to a low variation in sedentary leisure time or the chosen definition and measurement of occupational standing.

Association between objectively measured static standing and low back pain - a cross-sectional study among blue-collar workers

This study aims to investigate the cross-sectional association between objectively measured total time and temporal patterns of static standing (short bouts: 0-5 min; moderate bouts: >5-10 min; and long bouts: >10 min) during work and leisure and low back pain (LBP) among 698 blue-collar workers. Workers reported LBP on a 0-10 scale. The association between time spent on static standing and LBP was tested with linear regression. A positive association with LBP intensity was found for long bouts of static standing (β = 0.27) during total day (work + leisure), and total static standing time at leisure (β = 0.12). No significant associations were found for static standing during work and LBP intensity. These findings indicate that particularly long bouts of static standing over the entire day contribute to LBP in blue-collar workers. Practitioner Summary: The association between LBP and static standing time was investigated. This study indicates that prolonged time standing during total day and standing during leisure are positively associated with LBP among blue-collar workers. Therefore, practitioners should consider long periods of standing as a potential risk factor for LBP.

Effects of footrest heights on muscle fatigue, kinematics, and kinetics during prolonged standing work

BACKGROUND

Among the tools for relieving lower back pain, footrests are commonly recommended. Few studies have investigated the effects of footrest and the proper application of footrest height.

OBJECTIVE

The purpose of this study was to compare the effects of the normalized footrest height on muscle fatigue, kinematics, kinetics, and pain intensity.

METHODS

In total, 13 males who had a history of non-specific lower back pain during prolonged standing were recruited. The experimental conditions were 2-hour prolonged standing with no footrest and with footrests of 5%, 10%, and 15% of body height. Muscle fatigue was investigated through measurements of the median frequency ratio and the muscle activity ratio (post/pre) in lumbar erector spinae. The lumbo-pelvic angles, and the external moment in the lumbar region were investigated. A visual analog scale was used to investigate the intensity of the pain.

RESULTS

The footrests at 10% and 15% of the body height caused a lower change in the median frequency ratio and the muscle activity ratio than the other conditions. The footrest at 10% of the body height placed the lowest external moment on the lumbar region among all the conditions. The pain intensity was significantly lower in with footrest conditions than with no footrest condition.

CONCLUSIONS

The results suggests that a footrest height of 10% of the body height can be recommended as a normalized height for prolonged standing work in subjects with a history of non-specific lower back pain during prolonged standing.

The effect of cushioning materials on musculoskeletal discomfort and fatigue during prolonged standing at work: A systematic review

This systematic review updates the current state of evidence on the effectiveness of softer flooring and cushioned shoe insoles on reducing musculoskeletal discomfort amongst workers who are required to stand for prolonged periods to work and the impact of factors such as age and gender on the outcomes. A systematic search identified 10 unique studies that met the eligibility criteria. The heterogeneity of study designs impacted on the strength of evidence. A moderate level of evidence was found in support of using cushioned materials in reducing discomfort/fatigue among standing workers. A limited level of evidence exists in favour of using insoles over anti-fatigue mats. Insufficient information exists for the impact of gender or age. Larger, good quality prospective intervention trials based in real workplaces that consider the impact of psychosocial and organisational factors on musculoskeletal discomfort whilst standing at work are required to inform industry recommendations.

The effect of task type and perceived demands on postural movements during standing work

This study investigated how task demands affect postural behaviour during standing. Twenty-four participants completed three different 12-min tasks: (1) a cognitive task that involved answering questions based on a written passage; (2) a light manual assembly task; and (3) standing quietly with no secondary task. The manual task was associated with the lowest amount of postural movement and a more static pose than the other two conditions. Specifically, postural variability of the lumbar (F = 5.8; p = 0.01) and thoracic (F = 4.2; p = 0.03) spine, and fidgets and shifts of the spine (F = 3.2; p = 0.048), were lowest in the manual task. Additionally, individuals perceiving tasks to be more demanding-regardless of task type-tended to move less (p = 0.049) than those perceiving lower demands. These findings provide important initial evidence that the type and perceived demands of standing work tasks can affect postural movement.

Reducing sedentary behaviour to decrease chronic low back pain: the stand back randomised trial

OBJECTIVE

The Stand Back study evaluated the feasibility and effects of a multicomponent intervention targeting reduced prolonged sitting and pain self-management in desk workers with chronic low back pain (LBP).

METHODS

This randomised controlled trial recruited 27 individuals with chronic LBP, Oswestry Disability Index (ODI) >10% and desk jobs (sitting ≥20 hours/week). Participants were randomised within strata of ODI (>10%-<20%, ≥20%) to receive bimonthly behavioural counselling (in-person and telephone), a sit-stand desk attachment, a wrist-worn activity-prompting device and cognitive behavioural therapy for LBP self-management or control. Self-reported work sitting time, visual analogue scales (VAS) for LBP and the ODI were assessed by monthly, online questionnaires and compared across intervention groups using linear mixed models.

RESULTS

Baseline mean (SD) age was 52 (11) years, 78% were women, and ODI was 24.1 (10.5)%. Across the 6-month follow-up in models adjusted for baseline value, work sitting time was 1.5 hour/day (P<0.001) lower comparing intervention to controls. Also across follow-up, ODI was on average 8 points lower in intervention versus control (P=0.001). At 6 months, the relative decrease in ODI from baseline was 50% in intervention and 14% in control (P=0.042). LBP from VAS was not significantly reduced in intervention versus control, though small-to-moderate effect sizes favouring the intervention were observed (Cohen's d ranged from 0.22 to 0.42).

CONCLUSION

An intervention coupling behavioural counselling targeting reduced sedentary behaviour and pain self-management is a translatable treatment strategy that shows promise for treating chronic LBP in desk-bound employees.

TRIAL REGISTRATION NUMBER

NCT0224687; Pre-results.

Hip Abductor Fatigability and Recovery Are Related to the Development of Low Back Pain During Prolonged Standing

A prolonged standing exposure can identify asymptomatic adults who have a higher risk of developing clinical low back pain later in life. Hip abductor cocontraction differences can predict low back pain development during standing exposures. This study’s purpose was to determine if hip abductor strength, fatigability, and recovery during prolonged standing were related to standing-induced low back pain. Forty young, asymptomatic adults (50% female) performed two 2-hour standing sessions; a fatiguing hip abductor exercise was performed prior to 1 of the 2 standing sessions. Hip abductor strength and surface electromyography of gluteus medius and tensor fascia latae were measured. Self-reported low back pain differentiated low back pain developing (PD) and nonpain developing (NPD) groups. The PD group hip abductors fatigued before the NPD group, with similar perceived effort and force losses. Mean power frequency decreases with fatigue were similar between pain groups for all muscles measured after the fatiguing exercise. Unlike NPDs, PDs did not recover force losses after 120 minutes of standing. Hip abductor fatigability may be related to the development of low back pain in this population.

Use of a footrest to reduce low back discomfort development due to prolonged standing

Prolonged standing is common in many occupations and has been associated with low back discomfort (LBD). No recent studies have investigated a footrest as an intervention to reduce LBD associated with prolonged standing. This study investigated the effect of a footrest on LBD and sought to determine if LBD changes were accompanied by changes in muscle fatigue and low back end-range posture and movement. Twenty participants stood for two 2-h trials, one with and one without a footrest. LBD, lumbar erector spinae electromyography, upper lumbar (UL) and lower lumbar (LL) angles were measured. A significant increase in LBD occurred in both conditions but the footrest did not significantly decrease LBD. The only significant finding between conditions was that UL lordosis became more similar to usual standing over time with footrest use. These findings suggest that footrest use may not reduce LBD development and that development of LBD with prolonged standing is unlikely to be due to muscle fatigue or end-range posture mechanisms.

Evaluating biomechanics of user-selected sitting and standing computer workstation

A standing computer workstation has now become a popular modern work place intervention to reduce sedentary behavior at work. However, user's interaction related to a standing computer workstation and its differences with a sitting workstation need to be understood to assist in developing recommendations for use and set up. The study compared the differences in upper extremity posture and muscle activity between user-selected sitting and standing workstation setups. Twenty participants (10 females, 10 males) volunteered for the study. 3-D posture, surface electromyography, and user-reported discomfort were measured while completing simulated tasks with each participant's self-selected workstation setups. Sitting computer workstation associated with more non-neutral shoulder postures and greater shoulder muscle activity, while standing computer workstation induced greater wrist adduction angle and greater extensor carpi radialis muscle activity. Sitting computer workstation also associated with greater shoulder abduction postural variation (90th-10th percentile) while standing computer workstation associated with greater variation for should rotation and wrist extension. Users reported similar overall discomfort levels within the first 10 min of work but had more than twice as much discomfort while standing than sitting after 45 min; with most discomfort reported in the low back for standing and shoulder for sitting. These different measures provide understanding in users' different interactions with sitting and standing and by alternating between the two configurations in short bouts may be a way of changing the loading pattern on the upper extremity.