Musculoskeletal health in the workplace.

Musculoskeletal (MSK) problems remain the most frequent reason why individuals are absent from work, including those with work-related musculoskeletal disorders (WRMSDs or MSDs) and those with chronic MSK problems. This paper aims to examine changes in work and the workforce since 2000; how work impacts on chronic MSK conditions and how we can help people with these conditions to stay at work. While our knowledge of the causes of WRMSDs has increased since 2000, there has been limited workplace action in reducing exposure to hazards. A life course approach is needed as individuals of all ages are reporting MSK problems. How people work has also changed and informalisation of work contracts has increased with a perceived concurrent reduction in occupational safety and health (OSH) protection. Retaining people at work with MSK problems requires compliance with relevant safety, health and diversity legislation and a risk management approach. Good and open communication within the workplace and identification of other sources of support is also necessary. Considerations must be made at the individual level (internal motivation), organisational level (a supportive manager) and self-management of symptoms. Simple case examples are provided in the paper of what works in practice as well as a proposed research agenda. Increased awareness at all levels of society of MSK health is essential.

Fire Simulation and Cardiovascular Health in Firefighters.

BACKGROUND: Rates of myocardial infarction in firefighters are increased during fire suppression duties, and are likely to reflect a combination of factors including extreme physical exertion and heat exposure. We assessed the effects of simulated fire suppression on measures of cardiovascular health in healthy firefighters. METHODS: In an open-label randomized crossover study, 19 healthy firefighters (age, 41±7 years; 16 males) performed a standardized training exercise in a fire simulation facility or light duties for 20 minutes. After each exposure, ex vivo thrombus formation, fibrinolysis, platelet activation, and forearm blood flow in response to intra-arterial infusions of endothelial-dependent and -independent vasodilators were measured. RESULTS: After fire simulation training, core temperature increased (1.0±0.1°C) and weight reduced (0.46±0.14 kg, P<0.001 for both). In comparison with control, exposure to fire simulation increased thrombus formation under low-shear (73±14%) and high-shear (66±14%) conditions (P<0.001 for both) and increased platelet-monocyte binding (7±10%, P=0.03). There was a dose-dependent increase in forearm blood flow with all vasodilators (P<0.001), which was attenuated by fire simulation in response to acetylcholine (P=0.01) and sodium nitroprusside (P=0.004). This was associated with a rise in fibrinolytic capacity, asymptomatic myocardial ischemia, and an increase in plasma cardiac troponin I concentrations (1.4 [0.8-2.5] versus 3.0 [1.7-6.4] ng/L, P=0.010). CONCLUSIONS: Exposure to extreme heat and physical exertion during fire suppression activates platelets, increases thrombus formation, impairs vascular function, and promotes myocardial ischemia and injury in healthy firefighters. Our findings provide pathogenic mechanisms to explain the association between fire suppression activity and acute myocardial infarction in firefighters. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01812317.

Feasibility of magnetic resonance imaging (MRI) in obtaining nucleus pulposus (NP) water content with changing postures.

Opportunities to evaluate spinal loading in vivo are limited and a large majority of studies on the mechanical functions of the spine have been in vitro cadaveric studies and/or models based on many assumptions that are difficult to validate. The purpose of this study was to investigate the feasibility of magnetic resonance imaging (MRI) in obtaining nucleus pulposus (NP) water content measurements with changing postures. MRI studies were conducted on 25 healthy males with no history of low back pain (age 20-38). The L1 to S1 intradiscal levels were imaged in supine, sitting and standing postures using an upright 0.6 Tesla magnet, where a set of H2O: D2O7 phantoms were mounted on the back of the subjects. A calibration curve, provided from these phantoms, was applied to the absolute proton density image, yielding a pixel-by-pixel map of the water content of the NP. The NP at all levels showed a highly significant water loss (p<0.001) in sitting and standing postures compared with the supine posture. A trend towards higher levels of water was observed at all levels in the standing posture relative to sitting postures, however statistically significant differences were found only at L4-L5 and L5-S1 levels. This study demonstrates that variations in water content of the NP in different postures are in agreement with those determined from published invasive disc pressure measurements. The result of study demonstrates the feasibility of using MRI to determine the water content of the NP with changing postures and to use these data to evaluate spinal loading in these postures. This measurement method of water content by quantitative MR imaging could become a powerful tool for both clinical and ergonomic applications. The proposed methodology does not require invasive pressure measurement techniques.

Reality about migration of the nucleus pulposus within the intervertebral disc with changing postures.

BACKGROUND: Previous studies reported that, in non-degenerate discs, the nucleus pulposus migrates posteriorly during flexion and anteriorly during extension within the intervertebral disc. However, in these studies the differences between anterior and posterior distances have been regarded as an indicator of nucleus pulposus migration. This study investigated the reality of migration of the nucleus pulposus within the intervertebral disc with changing postures. METHOD: Magnetic resonance images were obtained of the lumbar spines of 25 asymptomatic volunteers in sitting, standing and supine postures. The anterior and posterior height of the intervertebral disc, the anterior -posterior length of the intervertebral disc and nucleus pulposus, and the positions of the anterior and posterior margins of the nucleus were measured from mid-line sagittal images. FINDINGS: Changing postures altered the anterior and posterior height of the disc and three types of morphological changes, including changes in the anterior -posterior lengths of the intervertebral disc and nucleus pulposus, together with the position of the nucleus in the disc were found. The length of the intervertebral disc and nucleus pulposus changed under the variations in spinal loading caused by posture. INTERPRETATION: The results of this study indicated that the apparent nucleus pulposus migration within intervertebral disc is actually deformation of the nucleus pulposus length which depends on posture and the magnitude of the load. In other words, adopting different postures deforms the nucleus pulposus and therefore, changes the position of the nucleus pulposus but there is no apparent nucleus pulposus migration within the intervertebral disc.

Working Conditions in Carpet Weaving Workshops and Muscu-loskeletal Complaints among Workers in Tabriz - Iran.

BACKGROUND: Carpet weaving operations usualy involve poor working conditions that can lead to the development of musculoskeletal disorders (MSDs). This study investigated MSDs among car¬pet weavers in relation to working conditions from workers' view in Tabriz City, Northwest Iran. METHODS: This cross-sectional and descriptive study was conducted in city of Tabriz, Iran. Data were col¬lected using interviews and questionnaires. The study population consisted of 200 randomly selected healthy weavers from twenty five active carpet weaving workshops. RESULTS: The results showed a high prevalence of musculoskeletal problems among the study population. The most commonly affected body areas were neck, lower back, ankles/feet, hands/wrists, upper back, shoulders and knees, respectively. More than half of the weavers were not satisfied with the thermal con¬dition, noise level and cleanliness of the air in the workshops. The result indicated a significant relation¬ship between upper back symptoms and daily working time and between lower back symptoms and the numbers of rows of knots woven in a day. Weavers' satisfaction with hand tools shape and thermal condi¬tion of the workshops were associated with lower back symptoms, whereas satisfaction with weaving looms were associated with upper back complaints. CONCLUSION: The poor working condition of hand-woven carpet workshops such as environmental con¬ditions and work station design and tools should be the subject of ergonomics interventions.

Protecting respiratory health: what should be the constituents of an effective RPE programme?

Although personal respiratory protection is widely recognized as having a lower priority than reduction of any risk at source, respiratory protective equipment (RPE) is a major part of risk management for many employers. We have identified the key elements of what constitutes an effective risk control programme involving RPE, through a 3-fold approach involving (i) a review of the published scientific literature, (ii) exploring the issue through >40 years of research publications from the Institute of Occupational Medicine (IOM) (in which the ergonomics of personal protection equipment has been a significant thread), and (iii) a series of interviews and discussions with IOM and Health and Safety Executive staff with experience in the testing, prescription, or use of RPE. We have used the findings to formulate a series of recommendations for the constituents of an effective RPE programme. The role of management is paramount in recognizing the need for and providing appropriate RPE, which is both technically and ergonomically effective. Only then does any focus on the role of the employee, in wearing the RPE correctly at the appropriate times, becomes viable.