Work - Volume Pre-press, issue Pre-press

Authors: Fräulin, L. | Holzgreve, F. | Hänel, J. | Filmann, N. | Schmidt, H. | Bader, A. | Frei, M. | Groneberg, D. A. | van Mark, A. | Ohlendorf, D.

Article Type: Research Article

Abstract: BACKGROUND: It is unclear whether and under which conditions stretch training programs lead to gains in flexibility when applied in work health promotion for office workers in order to reduce musculoskeletal disorders (MSD). OBJECTIVE: The aim of this study was to analyze whether the stretch training “five-Business” leads to gains in range of motion (ROM). Furthermore, the influence of baseline flexibility and socio-demographic factors (sex, age, weight, height and body mass index (BMI)) on trainability was assessed. METHODS: 161 office workers (n  = 45 female; n  = 116 male) without major MSD were recruited. Over three months, a …standardized static stretch training (“five-Business”) was executed on a device, supervised twice per week for 10 min. ROM was assessed using a digital inclinometer (shoulder, hip and trunk extension) and a tape measure (fingertip-to-floor and lateral inclination). RESULTS: ROM gains (p ≤0.001) were present in all tests, except for the hip extension. ROM changes correlated moderately (0.24–0.62) with the baseline flexibility (p ≤0.001). Subjects with limited flexibility reached the largest gains (1.41–25.33%). Regarding the socio-demographic factors only one low correlation occurred (weight - retroflexion; –0.177). CONCLUSION: The “five-Business” stretch training effectively increases ROM in office workers, especially when baseline flexibility is limited. Show more

Keywords: Musculoskeletal disorders, desk worker, occupational medicine

DOI: 10.3233/WOR-203273

Citation: Work, vol. Pre-press, no. Pre-press, pp. 1-12, 2020

Authors: Brkić, Aleksandar | Veljković, Zorica | Spasojevic Brkić, Vesna | Essdai, Ahmed | Pavićević, Snežana

Article Type: Research Article

Abstract: BACKGROUND: Previous research has shown that the collection and analysis of crane operators’ anthropometric characteristics is very important for operators’ comfort, health and working ability and also from the aspect of performance, productivity and safety. OBJECTIVE: The first aim of this survey is to collect up-to-date anthropometric data of crane operators in Serbia and to collect those data for the first time in Libya. The second aim of this survey is to compare the collected data. The third aim is to model the interior space necessary to accommodate operators in the cabins they operate in Serbia and Libya. …METHODS: Standing height, sitting height, lower leg length, upper leg length, shoulder width, hip breadth, arm length, foot length and weight data were collected of 83 Serbian and 50 Libyan crane operators. Descriptive statistics, correlation analysis and tests for differences between variables were conducted to examine differences between Serbian and Libyan crane operators and enable further modeling. The modeling of the cabin interior was done using both univariate and multivariate operators’ models from both samples. RESULTS: There are only four common correlations between variables for both samples. The only measurement without statistical differences is shoulder width. Serbian crane operators have statistically higher values of almost all measurements in comparison to Libyans. The minimal cabin interior space dimensions are 1207×1080×1884 mm for Serbian operators and 1106×1040×1790 mm for Libyan operators when using univariate approach, while multivariate approach provides more precise and comfortable accommodation within 1327×1123×1926 mm for Serbian operators and 1203×1090×1830 mm for Libyan operators. Accordingly, our survey shows that percentile models include less than the intended population proportion in the design problem with few dimensions and depends on correlations among them. CONCLUSIONS: A number of problems are solved through modeling the crane operator workspace and it has been shown that cabins with different dimensions have to be offered to Serbian and Libyan markets. Show more

Keywords: Serbian and Libyan crane operators, weight, anthropometric measurements, statistical analysis, interior space dimensions

DOI: 10.3233/WOR-203241

Citation: Work, vol. Pre-press, no. Pre-press, pp. 1-16, 2020

Authors: Coelho, Denis A. | Lourenço, Miguel L.

Article Type: Research Article

Abstract: BACKGROUND: Static muscular activity of muscles activated in the use of the conventional PC mouse is believed to represent a higher risk for the musculoskeletal health of the user than dynamic muscular activity. OBJECTIVE: This paper presents a compounded muscular activity dynamics indicator (akin to percent relative range), enabling comparison between computer handheld pointing devices. METHODS: This muscular dynamism approach considers baseline muscular activity (APL, ECR, ECU and ED) relative to the Maximum Voluntary Contraction as well as the dynamics of muscular activation. The latter is computed as the ratio of the difference between APDF90 and …APDF10 divided by APDF50 (APDF-Amplitude Probability Distribution Function for the 90th, 50th and 10th percentiles). The paper demonstrates the approach with results of comparative evaluation of a horizontal, a slanted and a vertical PC mouse, through surface EMG monitoring of 20 participants performing standardized graphical task with the devices. RESULTS: Hand size impacts muscular activity dynamics in these four muscles, which supersedes differences in device geometry, across the range of devices tested. CONCLUSION: Smaller devices relative to hand size foster more dynamic muscular activity. Show more

Keywords: Graphical tasks, static contractions, hand size, conventional mouse, percent relative range, APL, ECR, ECU, ED, APDF, MVC, S-EMG, dynamic muscular activity

DOI: 10.3233/WOR-203242

Citation: Work, vol. Pre-press, no. Pre-press, pp. 1-13, 2020

Authors: Lee, Roger | James, Carole | Edwards, Suzi | Snodgrass, Suzanne J.

Article Type: Research Article

Abstract: BACKGROUND: Non-neutral postures during computerised device use coupled with increased usage may increase the risk of neck pain. Greater knowledge of postures that individuals with neck pain adopt during computerised device use is warranted. OBJECTIVE: To evaluate neck and upper limb posture while using a tablet, laptop and desktop computer (sitting and standing) in individuals with chronic neck pain. METHODS: Differences in three-dimensional kinematic variables were assessed during four conditions: tablet, laptop, desktop computer (sitting and standing) in 22 individuals with chronic neck pain >3 months. Differences between kinematic variables were determined using one-way repeated measures …ANOVA with Bonferroni post-hoc tests. RESULTS: Compared to the desktop (sitting), tablet and laptop use resulted in increased neck flexion (mean difference tablet – 14.42°, 95% CI – 19.88, – 8.96, P  <  0.001; laptop –7.19°, –12.08, –2.31, P  = .020); upper trunk flexion (tablet –14.89°, –20.22, –9.56, P  <  0.001; laptop –5.56, –10.02, –1.09, P  = .009) and tablet bilateral shoulder elevation (left 11.01 mm, 2.01, 20.04, P  <  .016; right 13.08 mm, 3.09, 23.11, P  <  .006). CONCLUSIONS: Tablet and laptop use resulted in greater neck flexion, bilateral shoulder elevation and upper trunk flexion compared to a standard desktop computer, suggesting individuals with chronic neck pain should be mindful of their posture when using these smaller devices. Future research should explore how differences in posture may influence neck pain. Show more

Keywords: Biomechanics, ergonomics, biomechanical, spine, shoulder

DOI: 10.3233/WOR-203245

Citation: Work, vol. Pre-press, no. Pre-press, pp. 1-15, 2020

Authors: Bagheri Hosseinabadi, Majid | Khanjani, Narges | Norouzi, Pirasteh | Reza Mirbadie, Seyed | Fazli, Mozhgan | Mirzaii, Mehdi

Article Type: Research Article

Abstract: BACKGROUND: Occupational exposure to extremely low frequency electromagnetic fields (ELF-EMFs) may have harmful effects on biologic systems and has raised many concerns in the last decades. OBJECTIVE: The aim of this study was to determine the effects of exposure to extremely low frequency electric and magnetic fields on lipid peroxidation and antioxidant enzyme activities. METHODS: This study was conducted on 115 power plant workers as the exposed group and 145 office workers as the non-exposed group. The levels of Malondialdehyde (MDA), Superoxide Dismutase (SOD), Catalase (Cat), and Total Antioxidant Capacity (TAC) were measured in the serum …of all subjects. Exposure to ELF-EMFs was measured based on spot measurements and the IEEE Std C95.3.1 standard. RESULTS: The levels of MDA, SOD, and Cat in the exposed group were significantly higher than in the non-exposed group. However, the level of TAC was not significantly different between the exposed (2.45±1.02) and non-exposed (2.21±1.07) groups. The levels of MDA and SOD were higher among workers with higher exposure to electric fields than workers with low exposure. All oxidative stress indicators increased with increased exposure to magnetic fields, except TAC. CONCLUSIONS: The antioxidant system imbalance among power plant workers may be related to long term occupational exposure to electromagnetic fields. Show more

Keywords: Catalase, malondialdehyde, power plant workers, superoxide dismutase, total antioxidant capacity

DOI: 10.3233/WOR-203244

Citation: Work, vol. Pre-press, no. Pre-press, pp. 1-8, 2020