Work - Volume 51, issue 3

Article Type: Editorial

DOI: 10.3233/WOR-152020

Citation: Work, vol. 51, no. 3, pp. 389-390, 2015

Authors: Pope-Ford, Regina | Jiang, Zongliang

Article Type: Research Article

Abstract: BACKGROUND: Dental practitioners often suffer musculoskeletal disorders (MSDs) in the upper extremity due to the static, repetitive and precise nature of work. Knowledge regarding muscle activation patterns in that region is essential in understanding the mechanism behind the upper extremity MSDs. However, the literature review has revealed few studies with such a focus. OBJECTIVE: This study aims to examine the inter-relationship of the exertion levels of eleven upper extremity muscles during common dental procedures. This provides insights into the interactive utilization patterns of the targeted muscles and their implications in the development of MSDs. METHODS: …Twelve dentists were recruited. Electromyography (EMG) signals of sampled muscles were collected for 32 trials, i.e. combinations of independent variables (IVs) (and levels): posture (2), precision (2), line of vision (4), and grip type (2). Multivariate statistical methods were used to analyze the effects of IVs on muscle coactivity patterns. RESULTS: MANOVA showed significant main effects and a 2-way interaction between precision and grip type. Most notably, the upper trapezius exhibited consistently higher utilization than other muscles during a seated posture. CONCLUSIONS: Seated postures, preferred by dentists as a way to relieve back stress, may contribute to the development of shoulder or neck MSDs due to elevated upper trapezius exertions. Show more

Keywords: Electromyography, upper trapezius, neck and shoulder pain, myoelectric, musculoskeletal disorders

DOI: 10.3233/WOR-141883

Citation: Work, vol. 51, no. 3, pp. 391-399, 2015

Authors: Serranheira, Florentino | Sousa-Uva, Mafalda | Sousa-Uva, António

Article Type: Research Article

Abstract: BACKGROUND: Hospital work-related musculoskeletal disorders (WRMSDs) symptoms are highly prevalent and nurses are considered the health care professional group more often affected by WRMSDs. OBJECTIVES: Understanding the effects of nursing tasks on WRMSDs symptoms. METHODS: Portuguese nurses answered to a modified Nordic Musculoskeletal symptoms Questionnaire. The increased likelihood of having WRMSDs symptoms was estimated from a daily working task schedule and the probability of suffering from lumbar WRMSDs symptoms intensity was also estimated. RESULTS: Hospital nurses studied (n= 1.396) were mainly females (75.8%), and most of them reported more than 1 …symptom (88%). Low-back pain was the most prevalent complaint (60.9%). Tasks performed more than 10 times a day, such as invasive procedures (OR = 2.142); care of hygiene and patient comfort in bed (OR = 2.484); patient mobilization in bed (OR = 2.022); and patient feeding (OR = 2.186) had an effect on dorsal and lumbar symptoms (p< 0.05). Those tasks involving invasive procedures were just the only ones producing symptoms simultaneously on every studied body part, such as lumbar, dorsal, wrist/hand and ankles/feet areas. CONCLUSIONS: Tasks with a greater effect on low-back pain intensity were patient bed feeding and patient hygiene and care. We found, when analysing simultaneously the effects of every task on the likelihood of having low-back symptoms, that involving invasive procedures were that only ones affecting simultaneously the presence of almost all WRMSDs symptoms studied. Show more

Keywords: Nursing, musculoskeletal symptoms, low-back pain, patient lifting, occupational health

DOI: 10.3233/WOR-141939

Citation: Work, vol. 51, no. 3, pp. 401-409, 2015

Authors: Yu, Shanfa | Lu, Ming-Lun | Gu, Guizhen | Zhou, Wenhui | He, Lihua | Wang, Sheng

Article Type: Research Article

Abstract: OBJECTIVE: To evaluate the combined demand-control-support (DCS) and effort-reward-overcommitment (ERI-OC) stress models in association with sickness absence due to low back symptoms (SA-LBS). METHODS: A total of 2,737 blue-collar workers recruited from 13 companies in the most populous province (Henan) of China were included in the study. Personal and physical job characteristics, psychosocial scales of the stress models, and SA-LBS data in the preceding year were collected by a self-reported questionnaire and analyzed by a multivariable logistic regression model. Tertile exposure levels (low, medium and high) were constructed to discriminate a risk level. Odds ratios (OR) …with 95% confidence intervals (CI) were used as the association with SA-LBS. RESULTS: A large percentage (84.5%) of the Chinese workers did not take sick leave after reporting low back symptoms during the preceding year. High job demand or medium-high reward was associated with SA-LBS. The association of the combined stress models and SA-LBS was not evident. CONCLUSIONS: The ERI-OC model appeared to be more predictive of SA-LBS than the DCS model in the study population. The advantage of using combined stress models for predicting SA-LBS is not evident. Show more

Keywords: Demand-control-support, efforts-reward-overcommittment, stress, low back symptoms, sickness absence

DOI: 10.3233/WOR-141881

Citation: Work, vol. 51, no. 3, pp. 411-421, 2015

Authors: Khalaf, Tamer | Karwowski, Waldemar | Sapkota, Nabin

Article Type: Research Article

Abstract: BACKGROUND: Human responses at work may exhibit nonlinear properties where small changes in the initial task conditions can lead to large changes in system behavior. Therefore, it is important to study such nonlinearity to gain a better understanding of human performance under a variety of physical, perceptual, and cognitive tasks conditions. OBJECTIVE: The main objective of this study was to investigate whether the human trunk kinematics data during a manual lifting task exhibits nonlinear behavior in terms of determinist chaos. METHODS: Data related to kinematics of the trunk with respect to the pelvis were …collected using Industrial Lumbar Motion Monitor (ILMM), and analyzed applying the nonlinear dynamical systems methodology. Nonlinear dynamics quantifiers of Lyapunov exponents and Kaplan-Yorke dimensions were calculated and analyzed under different task conditions. RESULTS: The study showed that human trunk kinematics during manual lifting exhibits chaotic behavior in terms of trunk sagittal angular displacement, velocity and acceleration. CONCLUSIONS: The findings support the importance of accounting for nonlinear dynamical properties of biomechanical responses to lifting tasks. Show more

Keywords: Manual lifting, low back, trunk kinematics, deterministic chaos

DOI: 10.3233/WOR-141880

Citation: Work, vol. 51, no. 3, pp. 423-437, 2015

Authors: Azevedo, Rui | Mourão, Paulo | Abade, Eduardo | Carvalho, Alberto

Article Type: Research Article

Abstract: BACKGROUND: Lifting objects without knowing its weight may result in postural imbalances and be a risk factor for falls. OBJECTIVE: The aim of this study was to examine the influence of the load knowledge in postural balance when lifting different weight loads. METHODS: Thirteen male subjects (23.8 ± 3.1 years; 73.5 ± 7.8 kg; 179.1 ± 7.5 cm; foot length, 25.7 ± 1.2 cm) participated in the study. The effect of the weight overestimation on the postural stability was measured by the Index of Proximity to Stability Boundary (IPSB) and through the anterior-posterior and …medio-lateral lengths displacements of the Center of Pressure (CoP). RESULTS: The results showed an increase in the IPSB when the 5 kg lifting task was performed with load knowledge. Moreover, the length of the antero-posterior and medio-lateral CoP displacement was reduced in the 5 kg lift with knowledge. CONCLUSIONS: Results showed that the lack of the loads' knowledge may lead to balance loss. Thus, when the preparation processes are not adequate, picking up similar objects with different loads may increase the risk of fall, mainly when a light weight is suddenly lifted up after a heavy one. Show more

Keywords: Postural stability, center of pressure, occupational safety

DOI: 10.3233/WOR-152009

Citation: Work, vol. 51, no. 3, pp. 439-444, 2015

Authors: Rodrigues, Nelson J.O. | Oliveira, Ricardo F. | Teixeira, Senhorinha F.C.F. | Miguel, Alberto Sérgio | Teixeira, José Carlos | Baptista, João S.

Article Type: Research Article

Abstract: BACKGROUND: Studies concerning indoor thermal conditions are very important in defining the satisfactory comfort range in health care facilities. OBJECTIVE: This study focuses on the evaluation of the thermal comfort sensation felt by surgeons and nurses, in an orthopaedic surgical room of a Portuguese hospital. METHODS: Two cases are assessed, with and without the presence of a person. Computational fluid dynamic (CFD) tools were applied for evaluating the predicted mean vote (PMV) index locally. RESULTS: Using average ventilation values to calculate the PMV index does not provide a correct and enough descriptive …evaluation of the surgical room thermal environment. As studied for both cases, surgeons feel the environment slightly hotter than nurses. The nurses feel a slightly cold sensation under the air supply diffuser and their neutral comfort zone is located in the air stagnation zones close to the walls, while the surgeons feel the opposite. It was observed that the presence of a person in the room leads to an increase of the PMV index for surgeons and nurses. That goes in line with the empirical knowledge that more persons in a room lead to an increased heat sensation. CONCLUSIONS: The clothing used by both classes, as well as the ventilation conditions, should be revised accordingly to the amount of persons in the room and the type of activity performed. Show more

Keywords: Numerical study, hospital personnel, surgeon, nurse

DOI: 10.3233/WOR-141882

Citation: Work, vol. 51, no. 3, pp. 445-456, 2015

Authors: Oliveira, A. Virgílio M. | Gaspar, Adélio R. | Raimundo, António M. | Quintela, Divo A.

Article Type: Research Article

Abstract: BACKGROUND: The assessment of heat stress in the ceramic industry is a matter of great concern for safety and health of workers. For this purpose working conditions in the last two decades are analysed. OBJECTIVE: To study occupational hot thermal environments in the Portuguese ceramic activity sector in 8 industrial units and 21 workplaces. METHODS: In order to characterise the level of heat exposure, the method proposed by ISO 7243 (1989) based on the Wet-Bulb Globe Temperature (WBGT) index was adopted. RESULTS: Two field surveys, one carried out in 1994 and the …other in 2012 are considered. The WBGT mean values varied between 23.7 and 37.8°C in the 1994 survey while in 2012 those values ranged from 21.5 to 30.5°C. In the 1994 evaluations 5 out of 8 (62.5%) of the workplaces present heat stress conditions whereas in the 2012 assessments the corresponding value is 46.2% (6 out of 13 workplaces). CONCLUSIONS: Despite two decades between the two surveys, the results highlight that the overall thermal conditions of the workplaces in the ceramic sector are still quite similar, suggesting that the working conditions have not changed enough, a conclusion that asks for further analysis and improvements. Show more

Keywords: Health and safety, heat stress, WBGT index, industrial units, ceramics

DOI: 10.3233/WOR-141938

Citation: Work, vol. 51, no. 3, pp. 457-470, 2015

Authors: Joines, Sharon | James, Tamara | Liu, Siwen | Wang, Wenjiao | Dunn, Rebecca | Cohen, Shane

Article Type: Research Article

Abstract: BACKGROUND: Lighting is a part of every work task in the office environment, yet it is often overlooked. Research links direct and indirect glare to increased risk of visual discomfort among office workers with symptoms ranging from dry eyes to blurry vision or headaches. Researchers have been primarily concerned with those characteristics of task lighting that cause glare including luminance level, position (line of sight), and control. It is unknown what the benefits of adjustable task lights are and whether or not their use has an effect on musculoskeletal comfort or posture. No comprehensive field evaluations of this …type were found among peer-reviewed, indexed journals. OBJECTIVE: The purpose of this study was to assess the ergonomic and calculated utility power consumption benefits of adjustable LED task lighting in an office environment using a control/intervention experiment design. METHODS: One hundred participants were originally recruited and randomly assigned to intervention and control groups. Self-reported data was collected on level of eye fatigue, perception of job content, intervention usability, and musculoskeletal discomfort. Data was also collected on workspace level of illumination and posture during standardized tasks (assessed using RULA). RESULTS: Comparing baseline data to follow-up data for the intervention group, the use of the adjustable, LED task lights provided statistically significant, positive impacts on users' rating of discomfort, eye fatigue, perception of job content, and posture between baseline and the short-term follow up. CONCLUSIONS: Significant benefits to musculoskeletal comfort, posture, and visual comfort were documented when participants used the adjustable task lights. Participants' assessments of the light's usability, usefulness and desirability were positive. There were no negative results found with adjustable task light use. Show more

Keywords: Musculoskeletal, vision, usability, posture, discomfort

DOI: 10.3233/WOR-141879

Citation: Work, vol. 51, no. 3, pp. 471-481, 2015

Authors: Boustras, Georgios | Hadjimanolis, Athanasios

Article Type: Research Article

Abstract: BACKGROUND: Ergonomics in Cyprus is a rather neglected area of safety. The size of the country, the lack of scientific expertise, the nature of the economy and the nature of the majority of the enterprises make it a case, different from the average. OBJECTIVE: The aims of the survey were to examine the views and perceptions of employees and owners/managers on safety issues of micro-firms in Cyprus, to collect information on accidents and other aspects of safety performance in micro-firms and to cross-check the above data with data collected from safety inspectors for the above firms. …METHODS: The authors with the collaboration of the Department of Labour Inspection of the Republic of Cyprus collected information from a relatively large number of micro companies in a National survey. Information from employees, employers and labour inspectors was drawn. RESULTS: Particular emphasis is paid on the exploration of the relationship of the non-use of personal protection equipment with a number of factors. Results show the resistance of employees to the use of PPE (Personal Protective Equipment) and GPM (General Protective Measures). CONCLUSIONS: The results of the survey are in line with the relevant literature. Micro firms illustrate several interesting findings that are discussed in detail in the paper. Show more

Keywords: Use of PPE, use of GPM, ergonomic factors

DOI: 10.3233/WOR-152008

Citation: Work, vol. 51, no. 3, pp. 483-493, 2015