A prospective study
OBJECTIVES: The aim of this paper was to investigate if objectively measured daily duration of forward bending of the trunk increases the risk of the development or aggravation of low-back pain (LBP) over one year in a working blue-collar population by examining (i) the incidence rate of LBP among workers reporting no LBP at baseline, and (ii) the aggravation of LBP among workers reporting LBP at baseline. METHODS: Using data from the Danish Physical Activity Cohort with Objective Measurements (DPhacto), the study measured forward bending of the trunk (>60 ) at work (FBW) and during leisure time (FBL), diurnally with accelerometers, and LBP with one-year monthly self-reports among 682 blue-collar workers from 15 workplaces. The development of LBP was investigated with Cox's proportional hazards model (N=200), and the aggravation of LBP was investigated with mixed model for repeated measurements (N=482). RESULTS: Workers with no LBP at baseline had a FBW median of 7.9 minutes/day. Workers with LBP at baseline had a FBW median of 7.3 minutes/day. No significant associations were found between daily duration of forward bending of the trunk and development or aggravation of LBP. Similar results were found in the secondary analyses, in which FBL, different degrees of forward bending (>30 and >90 ), and varying follow-up time since measurement were considered. CONCLUSION: Using objective measurements of forward bending and monthly follow-up of LBP over one year, this study did not confirm the hypothesis of a positive association between daily duration of forward bending and LBP.
Source: Lagersted-Olsen J, Thomsen BL, Holtermann A, et al. Scandinavian Journal of Work Environment & Health, 2016.
A prospective cohort study among the general working population
BACKGROUND: The aim was to determine the prospective association between use of pain medication - due to musculoskeletal pain in the low back, neck/shoulder and hand/wrist - and long-term sickness absence. METHODS: Cox-regression analysis was performed to estimate the prospective association between regular use of pain medication and long-term sickness absence (LTSA; at least 6 consecutive weeks) among 9,544 employees from the general working population (Danish Work Environment Cohort Study 2010) and free from LTSA during 2009-2010. The fully adjusted model was controlled for age, gender, body mass index, smoking, leisure physical activity, job group, physical activity at work, psychosocial work environment, pain intensity, mental health and chronic disease. RESULTS: In 2010, the proportion of regular pain medication users due to musculoskeletal disorders was 20.8%: 13.4% as over-the-counter (i.e. non-prescription) and 7.4% as doctor prescribed. In the fully adjusted model, regular use of over-the-counter [HR 1.44 (95% CI 1.13-1.83)] and doctor prescribed (HR 2.18 (95% CI 1.67-2.86)) pain medication were prospectively associated with LTSA. CONCLUSIONS: Regular use of pain medication due to musculoskeletal pain is prospectively associated with LTSA even when adjusted for pain intensity. This study suggests that use of pain medication can be an important factor to be aware of in the prevention of sickness absence. Thus, regular use of pain medication - and not solely the intensity of pain - can be an early indicator that musculoskeletal pain can lead to serious consequences such as long-term sickness absence. SIGNIFICANCE: Use of medication due to musculoskeletal pain is prospectively associated with long-term sickness absence even when adjusted for pain intensity. Use of pain medication can be a red flag to be aware of in the prevention of sickness absence.
Source: Sundstrup E, Jakobsen MD, Thorsen SV, et al. European Journal of Pain, 2016.
Most previous studies assessing the association between physical workload and development of low-back pain have used self-reports for exposure. Using company records for quantifying exposure, this study shows that consecutive working days and higher workload are associated with acutely increased low-back pain.
Source: Andersen LL, Fallentin N, Ajslev JZN, Jakobsen MD, Sundstrup E. Scand J Work Environ Health, 2016.
This tool is designed to help assess the key risks in manual pushing and pulling operations involving whole-body effort, eg moving loaded trolleys or roll cages, or dragging, hauling, sliding or rolling loads.
It is intended to be used alongside the Manual handling assessment charts (the MAC tool)1 which helps assess lifting and carrying operations, and follows a similar
approach to that tool. It is aimed at those responsible for health and safety in workplaces and will help you to identify high-risk pushing and pulling activities and check the effectiveness of any risk-reduction measures.
Objective: The aim of this study was to explore the longitudinal relationship between sitting time on a working day and vitality, work performance, presenteeism, and sickness absence.
Methods: At the start and end of a five-month intervention program at the workplace, as well as 10 months after the intervention, sitting time and work-related outcomes were measured using a standardized self-administered questionnaire and company records. Generalized linear mixed models were used to estimate the longitudinal relationship between sitting time and work-related outcomes, and possible interaction effects over time.
Results: A significant and sustainable decrease in sitting time on a working day was observed. Sitting less was significantly related to higher vitality scores, but this effect was marginal (b?=?−0.0006, P?=?0.000).
Conclusions: Our finding of significant though marginal associations between sitting time and important work-related outcomes justifies further research.
Source: Hendriksen, Ingrid J.M.; Bernaards, Claire M.; Steijn, Wouter M.P.; Hildebrandt, Vincent H. Journal of Occupational & Environmental Medicine: August 2016, Volume 58, Issue 8, p. 784-789.
An exploratory analysis
We applied latent class growth analysis was applied in low-back pain patients in an occupational setting to determine different pain trajectories, something that has never been done before. The pain trajectories were used as outcome to evaluate a previously developed prognostic model for the development of chronic low back pain. The prediction model shows (after internal validation) a good predictive performance (AUC: 0.75).
Source: Panken G, Hoekstra T, Verhagen A, van Tulder M, Twisk J, Heymans MW. Scand J Work Environ Health, 2016.
A Repeated Measures Study
Objective: The aim of this study was to determine the impact of a demanding work schedule involving long, cumulative work shifts on response time and balance-related performance outcomes and to evaluate the prevalence of musculoskeletal disorders between day and night shift working nurses.
Methods: A questionnaire was used to identify the prevalence of past (12-month) and current (7-day) musculoskeletal disorders. Nurses worked three 12-hour work shifts in a 4-day period. Reaction time and balance tests were conducted before and after the work period.
Results: The work period induced impairments for reaction time, errors on reaction time tasks, and balance performance, independent of shift type. Musculoskeletal symptom prevalence was high in workers of both work shifts.
Conclusions: Compressed work shifts caused performance-based fatigue in nurses. Reaction time and balance tests may be sensitive fatigue identification markers in nurses.
Source: Thompson, Brennan J.; Stock, Matt S.; Banuelas, Victoria K.; Akalonu, Chibuzo C. Journal of Occupational & Environmental Medicine: July 2016, Volume 58, Issue 7, p. 737-743.
Longitudinal data from the Norwegian HUNT Study
Objectives: To prospectively investigate if the risk of chronic neck/shoulder pain is associated with work stress and job control, and to assess if physical exercise modifies these associations. Material and Methods: The study population comprised 29 496 vocationally active women and men in the Norwegian Nord-Trøndelag Health Study (HUNT Study) without chronic pain at baseline in 1984–1986. Chronic neck/shoulder pain was assessed during a follow-up in 1995–1997. A generalized linear model (Poisson regression) was used to calculate adjusted relative risks (RRs). Results: Work stress was dosedependently associated with the risk of neck/shoulder pain (ptrend < 0.001 in both sexes). The women and men who perceived their work as stressful “almost all the time” had multi-adjusted RRs = 1.27 (95% confidence interval (CI): 1.1–1.47) and 1.71 (95% CI: 1.46–2), respectively, referencing those with no stressful work. Work stress interacted with sex (p < 0.001). Poor job control was not associated with the risk of neck/shoulder pain among the women (RR = 1.04, 95% CI: 0.92–1.19) nor the men (RR = 1.09, 95% CI: 0.95–1.26). Combined analyses showed an inverse dose-dependent association between hours of physical exercise/week and the risk of neck/shoulder pain in the men with no stressful work (ptrend = 0.05) and among the men who perceived their work as “rarely stressful” (ptrend < 0.02). This effect was not statistically significant among the women or among men with more frequent exposure to work stress. Conclusions: Work stress is an independent predictor of chronic neck/shoulder pain and the effect is stronger in men than in women. Physical exercise does not substantially reduce the risk among the persons with frequent exposure to work stress.
Source: Fanavoll R, Nilsen TI, Holtermann A, et al. International Journal of Occupational Medicine and Environmental Health. 2016; 29 (4): 585-95.
Objective: The aim of this study was to identify relationships between work organizational variables (job rotation, overtime work, having a second job, and work pacing) (These work organizational variables and their relationships with biomechanical and psychosocial exposures were studied previously and published in a separate paper.) and health outcome measures [carpal tunnel syndrome (CTS), lateral and medial epicondylitis (LEPI/MEPI)].
Methods: Using a pooled baseline cohort of 1834 subjects, the relationships were studied using logistic regression models.
Results: Varied degrees of associations between the work organizational and outcomes variables were found. Job rotation was significantly associated with being a CTS case [odds ratio (OR)=1.23, 95% confidence interval (95% CI): 1.00 to 1.50]. Overtime work was significantly associated with lower LEPI prevalence (OR=0.48, 95% CI: 0.28 to 0.84). No statistically significant associations were found between having a second job and different work pacing and any of the three health outcome measures.
Conclusions: Work organizational variables were only partially associated with the studied health outcomes.
Source: Bao, Stephen S.; Kapellusch, Jay M.; Merryweather, Andrew S.; Thiese, Matthew S.; Garg, Arun; Hegmann, Kurt T. Silverstein, Barbara A.; Marcum, Jennifer L; Tang, Ruoliang. Journal of Occupational & Environmental Medicine: August 2016, Volume 58, Issue 8, p. 760-764.
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.
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.
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.
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.
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.
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.
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