Association between Whole-Body Vibration exposure and musculoskeletal disorders among dumper operators: A case-control study in Indian iron ore mines

BACKGROUND: Dumper operators in mines worldwide are subjected to Musculoskeletal Disorders (MSDs) due to whole-body vibration exposure. This study evaluated the working-life-Whole-Body Vibration (WBV)-exposure and their association with various MSDs among dumper operators in mines which remains poorly addressed. METHODS: This case-control study in Indian iron ore mines was conducted to compare randomly selected 65 dumper operators and 65 office workers. Data were collected through face-to-face interviews using the Nordic Musculoskeletal Questionnaire (NMQ) and were analysed using logistic regression models. RESULTS: The study revealed that majority of the dumper operators were exposed to WBV exceeding the ISO-2631 limits. Compared with controls, the dumper operators had a much higher risk of upper back pain (age-overweight-adjusted odds ratio ORao = 5.37, 95%CI = 1.78–16.20), lower back pain (ORao = 2.72, 95%CI = 1.25–5.94), knee and leg pain (ORao = 3.68, 95%CI = 1.22–11.11), and having 2+ MSDs (ORao = 5.05, 95%CI = 1.88–13.51, vs. no MSDs). Working-life-WBV-exposure was higher among dumper operators having upper back pain (mean (SD) = 7.1 (1.91) vs. 5.7 (1.91), p < 0.01) and lower back pain (mean (SD) = 6.63 (2.10) vs. 5.55 (1.71), p < 0.01) compared to those without these MSDs. Older age was associated with higher risk of MSD pains. CONCLUSION: Dumper operators have excess MSDs due to high working-life-WBV-exposure. Their MSDs and working-life-WBV-exposure should be regularly evaluated and reduced.

The Effects of Altering the Center of Pressure in Standing Subjects Exposed to Foot-Transmitted Vibration on an Optimized Lumped-Parameter Model of the Foot

Many workers are exposed to foot-transmitted vibration, which can lead to the development of vibration-induced white foot: a debilitating condition with neurological, vascular and osteoarticular symptoms. To design effective prevention mechanisms (i.e., boots and insoles) for isolating workers from vibration exposure, continued model development of the foot’s biodynamic response in different positions is necessary. This study uses a previously developed model of the foot–ankle system (FAS) to investigates how altering the center of pressure (COP) location can change the biodynamic response of the FAS to standing vibration exposure. Formerly published experimental responses for apparent mass and transmissibility at five anatomical locations in three COP positions were used to optimize the model. Differences occurred with the Kelvin–Voigt elements used to represent the soft tissues of the foot sole: at the heel, the distal head of the metatarsals and distal phalanges. The stiffness increased wherever the COP was concentrated (i.e., forward over the toes or backward over the heel). The variability of the model parameters was always greatest when the COP was concentrated in the heel. This suggests future FAS models need to more clearly address how the soft tissue of the plantar fat pad is modelled.

Analyzing the Vibration Exposure to the Safety and Health at Workplace: A Case in the Urea Granulation Unit of the Fertilizer Factory

This study aims to evaluate the vibration exposure experienced by workers in the Urea Granulation Screen Unit (UGSU) at the fertilizer factory in Aceh, Indonesia. This study involved 30 labors in charge as operators, mechanical maintenance officers, electrical maintenance officers, instrument maintenance officers, and inspectors. The measurement of vibration was carried out using a Triaxial Accelerometer with Integral Magnet and shows that the vibration exposure on the factory floor of the urea granulation screen unit occurs vertically with a minimum value of 0.298 m/s2 and a maximum of 1.630 m/s2. According to ISO 2631-1:1997, the maximum vibration values that occur are categorized as a likely health risk zone and result in uncomfortable reactions to the workers. Furthermore, this study analyzes the effect of vibrations on musculoskeletal problems using a Nordic Body Map (NBM) questionnaire. It reveals that the average score of musculoskeletal complaints is 71.6, which defines a high degree of pain. The results of the NBM questionnaire also showed that the vulnerable part of the body which experienced musculoskeletal complaints is the knee. The result of vibration exposure on this body part shows the highest value of 3.437 m/s2. To minimize occupational diseases and accidents, it is necessary to manage a working system that takes into account legal standards, ideal working time, and working shifts in the work area.

The Consequences of Mechanical Vibration Exposure on the Lower Back of Bus Drivers: A Systematic Review

Professional drivers are exposed to whole-body vibration while driving, which contributes to an increased risk of developing physical problems, such as pain in the lower back. This article aims to review the effects of vibration exposure on bus drivers. Searches were performed on the PubMed, Embase, Web of Science, and Scopus databases. Only full articles of observational and experimental studies that investigated the effects of vibration on bus drivers with consequences in the lumbar region published in English were included. Data on driver demographics, study design, objectives, bus model, seat model, length of exposure to vibration, and outcomes were extracted. Two studies were classified as evidence level III-2 and three studies as level III-3. The methodological quality of the publications presented one with a moderate and four with a serious risk of bias. In all the publications, pain in the lumbar spine was reported. In conclusion, the results of this systematic review suggest that bus drivers are exposed to mechanical vibration in their work routine, and this might be considered a risk factor for the development of pain in the lumbar spine, bearing in mind that the exposure is for long periods.

The Effect of the Operation Time, Orientation of Passenger and Body Mass Index on Passengers’ Whole-Body Vibration on Urban Rail

Urban rail is a widely used public transportation; the vibration from frequent rides may impact passengers. The rail vehicle’s vibrations can cause human fatigue and result in severe musculoskeletal problems to the passenger. This paper aims to identify the effects of passenger orientation, operation time and body mass index on passengers’ whole-body vibration on an urban rail in Malaysia. Real-time monitoring of the whole-body vibration was conducted using 23 full factorial designs of the experiment, which was analysed statistically using Minitab Software. The overall result of this study is that the passengers in a seated position had greater exposure to whole-body vibration, which is 0.3686 ms-2 than standing passengers, 0.2965 ms-2. Also, passengers tend to be exposed to greater vibration during an off-peak time of 0.4063 ms-2, than a peak time of 0.3706 ms-2. Lastly, overweight passengers were exposed to greater vibration, of 0.4063 ms-2, than passengers within the ideal weight range of 0.4000 ms-2. This study has statistically proven that all the factors were significantly influenced the vibration exposure to the passenger. The most significant factor towards the vibration exposure is the “Body Mass Index (BMI)”, in which the p-value is less than 0.001. This study concludes that the whole-body vibration of a passenger is affected by the orientation of the passenger, operation time and body mass index of passengers on urban rail service.

Effect of the Shoe Sole on the Vibration Transmitted from the Supporting Surface to the Feet

Vibration transmitted through the foot can lead to vibration white feet, resulting in blanching of the toes and the disruption of blood circulation. Controlled studies identifying industrial boot characteristics effective at attenuating vibration exposure are lacking. This work focused on the evaluation of vibration transmissibility of boot midsole materials and insoles across the range 10–200 Hz at different foot locations. Questionnaires were used to evaluate the comfort of each material. The materials were less effective at attenuating vibration transmitted to the toe region of the foot than the heel. Between 10 and 20 Hz, all midsole materials reduced the average vibration transmitted to the foot. The average transmissibility at the toes above 100 Hz was larger than 1, evidencing that none of the tested material protects the worker from vibration-related risks. There was a poor correlation between the vibration transmissibility and the subjective evaluation of comfort. Future research is needed to identify materials effective for protecting both the toe and the heel regions of the foot. Specific standards for shoe testing are required as well.