Evaluating the low back biomechanics of three different office workstations: Seated, standing, and perching

The objective of this study was to evaluate how different workstations may influence physical behavior in office work through motion and how that may affect spinal loads and discomfort. Twenty subjects performed a typing task in three different workstations (seated, standing, and perching) for one hour each. Measures of postural transitions, spinal loads, discomfort, and task performance were assessed in order to understand the effects of workstation interaction over time. Results indicated that standing had the most amount of motion (6–8 shifts/min), followed by perching (3–7 shifts/min), and then seating (<1 shift/min). Standing had the highest reports of discomfort and seating the least. However, spinal loads were highest in A/P shear during standing (190N posterior shear, 407N anterior shear) compared to perching (65N posterior shear, 288N anterior shear) and seating (106N posterior shear, 287 anterior shear). These loads are below the risk threshold for shear, but may still elicit a cumulative response. Perching may induce motion through supported mobility in the perching stool, whereas standing motion may be due to postural discomfort. Office workstation designs incorporating supported movement may represent a reasonable trade-off in the costs-benefits between seating and standing.

Source: Le, Peter, & Marras, William S. (2016). Applied Ergonomics, 56(9), 170-178.

Estimation of lumbar spinal loading and trunk muscle forces during asymmetric lifting tasks

Application of whole-body musculoskeletal modelling in OpenSim
Large spinal compressive force combined with axial torsional shear force during asymmetric lifting tasks is highly associated with lower back injury (LBI). The aim of this study was to estimate lumbar spinal loading and muscle forces during symmetric lifting (SL) and asymmetric lifting (AL) tasks using a whole-body musculoskeletal modelling approach. Thirteen healthy males lifted loads of 7 and 12 kg under two lifting conditions (SL and AL). Kinematic data and ground reaction force data were collected and then processed by a whole-body musculoskeletal model. The results show AL produced a significantly higher peak lateral shear force as well as greater peak force of psoas major, quadratus lumborum, multifidus, iliocostalis lumborum pars lumborum, longissimus thoracis pars lumborum and external oblique than SL. The greater lateral shear forces combined with higher muscle force and asymmetrical muscle contractions may have the biomechanical mechanism responsible for the increased risk of LBI during AL.

Source: Kim, Hyun-Kyung, & Zhang, Yanxin. (2016). Ergonomics.

Musculoskeletal Injury Prevention for New Nurses

Nurses continue to sustain musculoskeletal injuries even with increased emphasis on safe patient handling and mobility (SPHM) and organizational cultures of safety to protect health care workers. Analysis of data from 2011-2014 registered nurse graduates explored hospital safety culture, SPHM education/training, and incidence of new-nurse musculoskeletal injury. Results indicated hospitals provided some type of SPHM education and training, but 46% of study participants were not informed or aware of national SPHM standards or guidelines. Merely 13.9% of participants stated a written “no manual lifting policy” had been implemented; only 32.9% indicated staffing was adequate for SPHM tasks; and only 39.4% stated the hospital had all of the equipment needed to perform SPHM safely. Thirty-nine percent of participants had already sustained a musculoskeletal injury with an additional 35% sustaining but not reporting an injury. More actions are needed to ensure a decrease in musculoskeletal injuries for new nurses.

Source: Vendittelli, D., Penprase, Barbara, & Pittiglio, Laura. (2016). Workplace Health & Safety.

Influence of different stool types on muscle activity and lumbar posture among dentists during a simulated dental screening task

Whereas in the past dental stools typically facilitated a 90° hip angle, a number of currently available alternative designs allow for a more extended hip posture. The present study investigated the influence of different stool types on muscle activity and lumbar posture. Twenty five participants completed a simulated dental procedure on a standard stool, a saddle and the Ghopec. The latter stool comprises a seat pan consisting of a horizontal rear part for the pelvis and an inclinable sloping down front part for the upper legs, with a vertically and horizontally adjustable back rest. Lumbar posture was most close to neutral on the Ghopec, whereas sitting on a standard/saddle stool resulted in more flexed/extended postures respectively. Sitting with a 90° angle (standard stool) resulted in higher activation of back muscles while sitting with a 125° angle (saddle and Ghopec) activated abdominal muscles more, although less in the presence of a backrest (Ghopec). To maintain neutral posture during dental screening, the Ghopec is considered the most suitable design for the tasks undertaken.

Source: De Bruyne, Mieke A.A, Van Renterghemb, Benedikt, Baird, Andrew, Palmans, Tanneke, Danneels, Lieven, & Dolphens, Mieke. (2016). Applied Ergonomics, 56(9), 220-226.

Psychosocial Factors Related to Lateral and Medial Epicondylitis

Results From Pooled Study Analyses
Objective: The goal is to assess the relationships between psychosocial factors and both medial and lateral epicondylitis after adjustment for personal and job physical exposures.
Methods: One thousand eight hundred twenty-four participants were included in pooled analyses. Ten psychosocial factors were assessed.
Results: One hundred twenty-one (6.6%) and 34 (1.9%) participants have lateral and medial epicondylitis, respectively. Nine psychosocial factors assessed had significant trends or associations with lateral epicondylitis, the largest of which was between physical exhaustion after work and lateral epicondylitis with and odds ratio of 7.04 (95% confidence interval?=?2.02 to 24.51). Eight psychosocial factors had significant trends or relationships with medial epicondylitis, with the largest being between mental exhaustion after work with an odds ratio of 6.51 (95% confidence interval?=?1.57 to 27.04).
Conclusions: The breadth and strength of these associations after adjustment for confounding factors demonstrate meaningful relationships that need to be further investigated in prospective analyses.

Source: Thiese, Matthew S.; Hegmann, Kurt T.; Kapellusch, Jay; Merryweather, Andrew; Bao, Stephen; Silverstein, Barbara; Tang, Ruoliang; Garg, Arun. Journal of Occupational & Environmental Medicine: June 2016, Volume 58, Issue 6, p. 588-593.

Reducing Physical Risk Factors in Construction Work Through a Participatory Intervention

Protocol for a Mixed-Methods Process Evaluation
Background: Previous research has shown that reducing physical workload among workers in the construction industry is complicated. In order to address this issue, we developed a process evaluation in a formative mixed-methods design, drawing on existing knowledge of the potential barriers for implementation.
Objective: We present the design of a mixed-methods process evaluation of the organizational, social, and subjective practices that play roles in the intervention study, integrating technical measurements to detect excessive physical exertion measured with electromyography and accelerometers, video documentation of working tasks, and a 3-phased workshop program.
Methods: The evaluation is designed in an adapted process evaluation framework, addressing recruitment, reach, fidelity, satisfaction, intervention delivery, intervention received, and context of the intervention companies. Observational studies, interviews, and questionnaires among 80 construction workers organized in 20 work gangs, as well as health and safety staff, contribute to the creation of knowledge about these phenomena.
Results: At the time of publication, the process of participant recruitment is underway.
Conclusions: Intervention studies are challenging to conduct and evaluate in the construction industry, often because of narrow time frames and ever-changing contexts. The mixed-methods design presents opportunities for obtaining detailed knowledge of the practices intra-acting with the intervention, while offering the opportunity to customize parts of the intervention.

Source: Ajslev J, Brandt M, Møller JL, et al. JMIR Research Protocols, Vol 5, No 2 (2016): Apr-Jun.

A multi-faceted workplace intervention targeting low back pain was effective for physical work demands and maladaptive pain behaviours, but not for work ability and sickness absence

Stepped wedge cluster randomised trial
Aims: The aims of this study were to test whether a multi-faceted intervention effective for low back pain was effective for physical capacity, work demands, maladaptive pain behaviours, work ability and sickness absence due to low back pain. Methods: A stepped wedge cluster randomised, controlled trial with 594 nurses' aides was conducted. The intervention lasted 12 weeks and consisted of physical training (12 sessions), cognitive behavioural training (two sessions) and participatory ergonomics (five sessions). Occupational lifting, fear avoidance, physical exertion, muscle strength, support from management, work ability and sickness absence due to low back pain were measured every 3 months. Before and after the intervention we measured physical capacity, kinesiophobia and need for recovery. Linear mixed models adjusted for baseline values of the outcome were used to estimate the effect. Results: Significant reduction in occupational lifting (–0.35 (95% confidence interval −0.61 to −0.08)), and improvement in two measures of fear avoidance ((–0.75 (95% confidence interval −1.05 to −0.45) and −0.45 (95% confidence interval −0.80 to −0.11)) were found for the intervention group compared to the control. There were no significant effects on physical exertion, muscle strength, support from management, work ability or sickness absence due to low back pain. After the intervention, significant increased physical capacity and improvements in kinesiophobia were found, but no change in need for recovery. Conclusions: The intervention was significantly effective for physical work demands and maladaptive pain behaviours, but not for work ability and sickness absence due to low back pain. To improve work ability or reduce sickness absence due to low back pain more specific interventions should probably be developed.

Source: Rasmussen CD, Holtermann A, Jørgensen MB, et al. Journal of Public Health, 2016.

New NIOSH Android App Addresses Ergonomics in Mining

A new mobile app for ergonomic audits in the mining industry is now available from the National Institute for Occupational Safety and Health (NIOSH). The app, ErgoMine, is available for Android devices and provides an ergonomic assessment for three types of operations in the mining industry: bagging, maintenance and repair, and haul truck operations. By asking users a series of questions about work tasks and worksite conditions, ErgoMine produces recommendations for ergonomic improvements in a final summary which details the results of the audit. The app also provides the option for users to email the recommendations to themselves or others for further review.

Source: http://www.cdc.gov/niosh/updates/upd-06-14-16-b.html

Call Center Productivity Over 6 Months Following a Standing Desk Intervention

Background: Many office employees are spending up to 90% of their workday seated, and employers are considering stand-capable desks as a way to increase physical activity throughout the day. When deciding on adoption of stand-capable workstations, a major concern for employers is that the benefits, over time, may not offset the initial cost of implementation.
Methods: This study compared objective measures of productivity over time between a group of stand-capable desk users and a seated control group in a call center. Comparison analysis was completed for continuous six-month secondary data for 167 employees, across two job categories.
Results: Users of stand-capable desks were ∼45% more productive on a daily basis compared to their seated counterparts. Further, productivity of the stand-capable desk users significantly increased over time, from ∼23% in the first month to ∼53% over the next six months. Finally, this productivity increase was similar for employees across both job categories.
Conclusions: These findings suggest important benefits of employing stand-capable desks in the work force to increase productivity. Prospective studies that include employee health status, perceptions of (dis)comfort and preference over time, along with productivity metrics, are needed to test the effectiveness of stand-capable desks on employee health and performance.

Source: Garrett, Gregory, Benden, Mark, Mehta, Ranjana, Pickens, Adam, Peres, Camille, & Zhao, Hongwei. (2016). IIE Transactions on Occupational Ergonomics and Human Factors.

The Effects of Workplace Physical Activity Programs on Musculoskeletal Pain

A Systematic Review and Meta-Analysis
This article reviews the effectiveness of physical activity (PA) interventions at the workplace to reduce musculoskeletal pain among employees and assesses the effect size of these programs using meta-analysis. Four databases (i.e., PubMed, EBSCO, Web of Science, and Cochrane) were searched for research trials, which included comparison groups of employees that assessed PA programs, musculoskeletal pain, and health-related behaviors, published between January 1990 and March 2013. The meta-analysis estimates of standardized mean differences (Hedges' g) present significant evidence of less general pain (g = −.40 with a 95% confidence interval [CI] = [−0.78, −0.02]) and neck and shoulder pain (g = −.37 with a 95% CI = [−0.63, −0.12]) in intervention groups. The few studies of low back pain and arm, elbow, wrist, hand, or finger pain did not present sufficient statistically significant evidence. Consistent evidence demonstrates that workplace PA interventions significantly reduce general musculoskeletal pain and neck and shoulder pain. More studies are needed to determine the effectiveness of work-related PA interventions for arm, elbow, wrist, hand or finger, and low back pain.

Source: Moreira-Silva, Isabel, Teixeira, Pedro M., Santos, Rute, Abreu, Sandra, Moreira, Carlos, & Mota, Jorge. (2016). Workplace Health & Safety, 64 (5), p. 210-222. http://dx.doi.org/10.1177/2165079916629688

Posture and lifting exposures for daycare workers

Daycare employees, specifically caregivers, are a distinct population that may experience increased risk of injury due to the high exposure to bent postures, lifting conditions and high stress associated with their work. The objectives of the study were to collect up to date data on daycare workers and to compare the data between groups working with children of different ages (Infant, Toddler and Preschool). 
The study consisted of two distinct phases: Phase 1 – Questionnaire distribution, Phase 2 – Observation and analysis involving three dimensional postural monitoring and video recording as well as an analysis of the low back forces and moments in lifting.
Results suggested that these employees experience an elevated risk of low back injury caused by their occupational tasks and thus, further research is required to determine appropriate worker accommodations and safe work practices to help mediate these risks for all daycare caregivers.

Source: Labaj, Adam, Diesbourg, Tara, Dumas, Geneviève, Plamondon, André, Mercheri, Hakim, & Larue, Christian. (2016). International Journal of Industrial Ergonomics, 54 (7), p. 83-92.

Take a Stand!

Amulti-component intervention aimed at reducing sitting time among office workers - A cluster randomized trial
BACKGROUND: Prolonged sitting time has been associated with adverse health outcomes. Interventions at work may contribute to reduced sitting. The objective was to test if a multicomponent work-based intervention can reduce sitting time and the number of prolonged sitting periods (> 30 min), increase the number of sit-to-stand transitions and decrease waist circumference and body fat percentage among office workers. Primary outcomes were: change in sitting time, prolonged sitting periods and sit-to-stand transitions at follow-up 1 month later. METHODS: At four workplaces, 19 offices (317 workers in total) were cluster randomized for intervention or control. The intervention included the appointment of local ambassadors, management support, environmental changes, a lecture and a workshop. Sitting time was measured using an ActiGraph GT3X+ fixed on the thigh. Data were processed using Acti4 software providing data on time spent sitting, standing and doing other activities. Control participants were instructed to behave as usual. Follow-up measurements were obtained after 1 and 3 months. RESULTS: At 1 and 3 months, total sitting time was 71 (P< 0.001) and 48 min (P< 0.001) lower per 8-h workday in the intervention group compared with the control group. At 1 month, the number of prolonged sitting periods was lower (-0.79/8-h workday,P< 0.001) and sit-to-stand transitions were higher (+14%/sitting hour,P= 0.001) in the intervention compared with the control group. After 3 months, trends persisted. The body fat percentage was lower by 0.61 percentage points (P= 0.011) in the intervention group compared with the control group after 3 months. CONCLUSIONS: The multicomponent workplace-based intervention was effective in reducing sitting time, prolonged sitting periods and body fat percentage, and in increasing the number of sit-to-stand transitions.

Source: Danquah IH, Kloster S, Holtermann A, et al. Int J Epidemiol, 2016.

Carpal tunnel syndrome and manual work

The OCTOPUS cohort, results of a ten-year longitudinal study
This large longitudinal cohort study provides a prospective validation of the ACGIH TLV® method for the assessment of biomechanical exposures at work. It confirmed that “forceful hand exertions” more than “any exertion” significantly increase the risk of CTS. This study suggests that the current limits (AL and TLV) might not be sufficiently protective for some workers.

Source: Violante FS, Farioli A, Graziosi F, Marinelli F, Curti S, Armstrong TJ, Mattioli S, Bonfiglioli R. Scand J Work Environ Health, 2016.  

Tarification à l’expérience, incidence des troubles musculo-squelettiques et arrêts de travail

L'assurance des risques professionnels des travailleurs salariés du Régime général est financée par les entreprises sur la base de cotisations modulées selon leur sinistralité passée. En théorie, ce mode de tarification devrait contribuer à inciter les employeurs à développer des démarches de prévention des risques professionnels et à minimiser ainsi le coût des mauvaises conditions de travail. À partir d'une expérience naturelle observée en région Nord – Pas-de-Calais – Picardie en 2007, cette étude mesure l'influence d'une augmentation de la contribution des entreprises au coût des troubles musculo-squelettiques (TMS) sur l'incidence de ces maladies et les arrêts de travail associés. Cette étude s'appuie sur les données administratives de tarification des risques professionnels. La méthode repose sur une estimation en différence de différences. Les résultats indiquent que l'augmentation de la contribution des entreprises au coût des TMS a eu pour effet de limiter l'incidence de ces maladies. Cela s'est traduit par une baisse significative du nombre de jours d'arrêts de travail liés à ces pathologies.

Source: http://www.irdes.fr/recherche/questions-d-economie-de-la-sante/215-tarification-a-l-experience-incidence-des-troubles-musculo-squelettiques-et-arrets-de-travail.pdf

Effects of participatory ergonomic intervention on the development of upper extremity musculoskeletal disorders and disability in office employees using a computer

Objective: To evaluate the participatory ergonomic method on the development of upper extremity musculoskeletal disorders and disability in office employees. Methods: This study is a randomized controlled intervention study. It comprised 116 office workers using computers. Those in the intervention group were taught office ergonomics and the risk assessment method. Cox proportional hazards model and generalized estimating equations (GEEs) were used. Results: In the 10-month postintervention follow-up, the possibility of developing symptoms was 50.9%. According to multivariate analysis results, the possibility of developing symptoms on the right side of the neck and in the right wrist and hand was significantly less in the intervention group than in the control group (p < 0.05). Neck disability/symptom scores over time were significantly lower in the intervention group compared with the control group (p < 0.05). Conclusion: The participatory ergonomic intervention decreases the possibility of musculoskeletal complaints and disability/symptom level in office workers.

Source: Baydur, Hakan, Ergör, Alp, Demiral, Yücef, & Akalin, Elif. (2016). Journal of Occupational Health.

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