A pooled analysis has been performed of population groups whose hands have been occupationally exposed to vibration to study exposure evaluation, using epidemiologic data selected from a published meta-analysis. While the analysis cannot confirm the accuracy of the exposure-response relation in ISO 5349-1:2001, it suggests that the relation provides a conservative estimate for the onset of vibration-induced white finger. The analysis also demonstrates that the procedures for calculating vibration exposure in the international standard may need revision. Full article

Cyclists are exposed to hand–arm vibration (HAV) for prolonged periods of time during training sessions and competitions. The vibration can reduce perceived comfort, thus limiting the ability of the cyclist to control the bike in endurance sessions. The study of HAV in cyclists in a controlled environment allows for comparisons between the effects of different postures, materials and technical solutions on perceived discomfort and on the vibration transmitted to specific body segments. This paper describes the experimental setup, the measurement chain and the data processing for the evaluation of bike comfort in the laboratory. The setup is based on single-axis or multiaxial shakers; the time history of the input vibration can be derived from on-field measurements for comparative analyses or can be selected from among classical stimuli for frequency response function evaluation (sine sweep or white noise). Comfort can be quantified via questionnaires; objective measurements can be derived from vibrations measured at different body locations using wearable accelerometers or laser doppler vibrometers. A case study is presented and discussed. Full article

The aim of this research was to study hand-arm vibration (HAV) exposure trends in the workforce in Sweden by using a Job-Exposure matrix (JEM). All individuals employed during 1980 and 2010 with an occupational code were included. The daily eight-hour equivalent HAV exposure values were divided into three exposure categories. During the study period, the proportion of workers exposed above the action value had decreased, as well as the proportion of workers exposed to any HAV. In 2010, 4% of the workforce in Sweden were exposed to HAV above the action value. Full article

The palmar surface (on tool surface) has been defined in ISO 5349-1 as a value of the amount of vibration transmitting to the hand and arm from on-body vibration magnitude. They showed the concept of on-body vibration measurement based on the relationship between the temporary threshold shift (TTS) of the vibrotactile perception threshold (VPT) and the on-body vibration measurement values. However, they did not show that the effectiveness of ISO 5349-1 Annex D for various factors transmitting to the hand was unknown. Therefore, the purpose of this paper is to clarify the new considerations of on-body vibration measurement equipment and to demonstrate the necessity of on-body measurement equipment. Full article

This study found no association between exposure to hand-arm vibrations (HAV) and myocardial infarction. Data was gathered from the Swedish National Cohort on Work and Health and consists of all individuals born in Sweden from 1930 to 1990, with demographic, occupational, and MI data available between 1968 and 2017. All workers in Sweden with an occupational code between 1985 and 2013 were matched to the job-exposure matrix on occupational exposures. The model was adjusted for demographic data and other occupational exposures. The hazard ratio with a 95% confidence interval was 1.01 (0.92–1.11) for those exposed above the daily equivalent HAV level of 5 m/s². Full article

The straightening and forming of metal parts are typical and usual tasks within shipbuilding industries. They may expose boilermakers to high levels of vibration, leading to potential health risks (musculoskeletal disorders and vascular syndromes). This study consisted of helping a company evaluate their hammering machines that were activated by ultrasound, comparing them to conventional impact tools. Vibration measurements were therefore carried out in the field. These were followed by an analysis of the signals according to the regulations and additional assessment tools. Full article

The cold response of the digital arteries in a cohort of vibration-exposed workers was related to measures of daily vibration exposure expressed in terms of r.m.s. acceleration magnitude normalised to an 8-hour day, and frequency was weighted according to either the frequency weighting W_h defined in ISO 5349-1:2001 (A_h(8) in ms⁻² r.m.s) or the hand–arm vascular frequency weighting W_p proposed in the ISO Technical Report 18570:2017 (A_p(8) in ms⁻² r.m.s.). The metric A_p(8), which assigns more weight to intermediate- and high-frequency vibrations (31.5–250 Hz), performed better for the prediction of cold-induced digital arterial hyperresponsiveness in the vibration-exposed workers than the measure A_h(8) derived from the conventional ISO frequency weighting, which gives more importance to lower-frequency vibrations (≤16 Hz). Full article

Models of hand–arm systems (HAS) are purely mechanical. These models do not include the biological active behaviour of the system, even though it has been known since 1997 that there is a tonic vibration reflex. Since then, several authors have investigated this reflex and related it to grip force, posture and some others features of mechanical vibration power absorption. Other scholars proposed models of HAS that do not include the tonic vibration reflex and its consequences. These models, even partial models, are nonetheless effective in describing many aspects of vibration exposure. This is probably due to the complexity of the HAS, so that the confounding factors overwhelm measurements. Full article

Background: to investigate the acute effects of vibration and force level on vibrotactile perception following short-term exposure to hand-arm vibration (HAV). Methods: 12 individuals attended the test, and each of them completed a set of grasping tasks between 10 N and 80 N while being exposed to four intensities of HAV at 125 Hz, ranging from 5.5 to 44.0 m/s² (unweighted), for three minutes. The vibrotactile perception threshold (VPT, at 125 Hz) on the fingertip was assessed before and after the exposure. Results: Vibration caused considerable reductions in VPT, and the higher the HAV amplitude, the more the VPT shifted. There were also noticeable VPT shifts brought on by the force increase, but the force increase from 40 N to 80 N could not make more of a difference at higher vibration levels. Conclusions: Vibrotactile perception was sensitive to the vibration level, and was affected by the applied hand force when the vibration intensity was modest. With high vibration levels, the further sensorineural response to the force is limited after the force reaches a certain level. Full article

Anti-vibration gloves undergo a certification procedure that is described in the EN ISO 10819:2013. This is a laboratory practice that, in this paper, is compared with a standardized field method. Two methods are implemented in the tests: a direct method and an experimental one. The results show that some transmissibility is above the limit suggested by the standard. The difference between the transmissibility measured in the field, using the direct transmissibility as a reference, and the values declared by the manufacturers is very small. In the case of the experimental transmissibility, two out of three gloves amplify vibrations instead of reducing them. Full article

High-frequency shock-type vibration (HFV) with a frequency content mainly above 1250 Hz, e.g., from impact wrenches, is likely to cause a significant amount of vibration injuries and even hand-arm vibration syndrome. The objective of this study was to measure vibration up to 100 kHz with a Laser Doppler Vibrometer (LDV) and investigate the variation of vibration over the machine surface, the vibration propagation into finger tissue, and the vibration reduction on the finger tissue due to a foamed polymer layer. Our results showed that the vibration on the handle varies moderately and that the amplitudes are higher on the machine surface. A large proportion of the vibration is transferred into the finger tissue and thereby subjects the finger tissue to high-vibration amplitudes, but it is effectively reduced by a thin layer of foamed polymer. Full article

Vibration dose assessed by current standards is likely to be poorly suited to protecting workers against vibration white finger (VWF). Therefore, we intended for a two-step approach to better tackle vibration-induced pathophysiological vascular issues. In the first stage, a log₂ linear regression law between the amplitude of vibration acceleration and the wall shear stress (WSS) drop was established. Then, in a second stage, we set up a mechanobiological model for computing the arterial stenosis stemming from the WSS decrease and encountered in patients suffering from VWF. Our findings highlighted a stenosis of about 30% when exposed for 10 years to a 40 m·s⁻² amplitude vibration for 4 h a day. Full article

Pushing and gripping forces may contribute to Hand-Arm Vibration Syndrome but, thus far, have not been taken into account in vibratory dose assessment according to the current standards. To obtain a better understanding of the symptom onset, we developed a finite element model of the hand to replicate its vibratory behaviour in gripping and pushing actions. In a case study, Supersonic Shear Imaging measurements revealed the significant dependence of muscle stiffness and anisotropy on gripping. The use of these measurements in our model showed that muscle activation influences the driving-point mechanical impedance of the hand and local vibration propagation. Full article

A simple two-rigid-body model of an electrical grinder was created to calculate the vibration emissions according to the test code EN 60745-2-3. The model assumes that the operator does not affect the vibration emissions. Experiments with and without the operator validated this hypothesis and demonstrated the model’s abilities and limitations. Full article

Some hand-held power tools generate repeated shocks of high amplitudes. The daily vibration exposure $A\left(8\right)$ is rarely evaluated over the whole working day. The vibration total value $a_{hv}$ emitted by a machine and the total daily duration of exposure $T$ are usually estimated from a sample that may not be representative of the whole working task. Thus, the comparison of $A\left(8\right)$ with regulatory limit values is difficult. The daily number of shocks can sometimes be estimated from production features (i.e., the number of manufactured parts). This article presents an $A\left(8\right)$ evaluation method adapted to such situations. It allows for a better evaluation of the risk for non-stationary vibrations. Full article

Hand-arm vibration syndrome (HAVS) is characterized by cold-induced vasospasms of peripheral vasculature, by changes in sensorineural function and by pain. Vibration frequency and amplitude along with pressure applied at the fingertips while gripping a tool may also affect vascular and sensorineural function. Little is known about how these two exposure factors interact to affect the risk of developing HAVS. This study uses a newly developed rat tail model to examine the effects of vibration on vascular and sensorineural function. Exposure to 2N of pressure for 10 consecutive days resulted in an increase in blood flow in the tail, which may have been the result of an increased sensitivity of the arteries to acetylcholine. There was also an increased sensitivity of the small myelinated fibbers to electrical stimulation and of the sensory receptors to a pressure stimulus. Based on these findings, pressure has its own effects on vascular and sensorineural physiology, and these effects can be different from those of vibration. Full article

The use of powered hand tools and equipment that exposes track workers to HAV vibration and other biomechanical hazards in the USA was investigated by a research team, following scientific principles and guidelines including protecting confidentiality of study participants. Musculoskeletal symptoms and neuro-musculoskeletal disorders were linked to workplace physical factors, such as HAV, and were reported in peer-reviewed journals. The methodology and results were subsequently challenged by a team of consultants hired by the Association of American Railroads (AAR), which represents major North American railroad corporations. Such an influence appears to challenge the integrity of occupational health research and impede the conduct of such research. Full article

The use of dental handpieces and ultrasonic instruments expose dental professionals to high-frequency vibration, precise gripping, high pinch force, and repetitive bending movements of wrist during restorative procedures involving cutting dental material, periodontal scaling, and root planning. There is clear evidence of an association between the dentistry profession and work-related musculoskeletal disorders in the neck, upper back and upper extremities; however, the influence of high-frequency vibration on hand and fingers from dental handpieces is not well known. The objectives of the current paper are to present the results of a survey on hand-arm vibration syndrome (HAVS) among members of a professional dental society and to present a literature review on dental handpieces and ultrasonic scalers exposure assessment and occurrence of hand-arm vibration syndrome among dental professionals. There seems to be limited awareness of the occupational risk associated with hand-arm vibration from handpieces and ultrasonic devices. This study highlights the occurrence of vascular and neurological disorders of HAVS among dental professionals, as well as wrist/hand pain, osteoarthritis, diminished hand grip, and carpal tunnel syndrome. The assessment of high-frequency vibration and ultra-vibration from these vibrating tools and vibration-related injuries deserve special attention for future preventive measures. Full article

Impulse tightening tools can generate high-frequency vibrations that are not taken into account in currently applicable standards. In various publications, it has been suggested that those high-frequency vibrations may cause health issues. In the present study, high-frequency vibrations produced by an impulse nutrunner are evaluated and used to assess the potential damping effect provided by a thin layer of soft rubber. Full article

Percussive tools can generate high-frequency vibrations that are not taken into account in currently applicable standards. In various publications, it has been suggested that those high-frequency vibrations may cause health issues. In the present study, high-frequency vibrations produced by a chipping hammer are evaluated and used to assess the potential damping effect provided by a thin layer of soft rubber. Full article

To protect workers, it is necessary to characterize the noise and vibration emissions value of nailers. Standardized characterization methods exist but require three trained human operators, which leads to a dispersion in the results and a difficult implementation. An automatic test stand (ATS) was developed to characterize those values without the participation of human operators. It is proposed here that we compare the results obtained by the two methods. Preliminary results suggest that further refinement of the ATS is needed to better mimic the biodynamics of the human hand–arm and that a larger number of operators would be required for validation. Full article

The objective of this simulation was to determine the number of measured data sets that will provide an acceptable estimate of the upper quartile hand-arm vibration value for real use of a power tool. Monte Carlo simulations were performed based on the analysis of data sets from the HSE’s hand-arm vibration database. The simulation used random uniform distribution to generate simulated machine data sets. The simulations showed that for practical measurements, a sample size of between 20 and 30 measurements is likely to achieve a reliable estimate of the upper quartile value. Full article

In an epidemiological case-control study, exposure-response relationship between hand-arm vibration exposure and the risk of musculoskeletal disorders (MSDs) of the upper extremities were examined among 209 male cases and 614 controls in the German construction, mining, metal, and wood-working industries. To quantify individual vibration exposures, a database of industrial hygiene measurements of over 700 power tools was established. In addition, individual work histories were collected in detail. The dose-response relationships between hand-arm vibration exposure and the risk of MSDs were quantified based on multivariable logistic regression analysis. After adjusting for relevant confounders, statistically significant dose-response relationships between cumulative hand-arm vibration exposure doses and MSDs of the upper extremities could be established. Full article

High-frequency shock-type vibrations (HFVs) from, e.g., impact wrenches with a frequency content mainly above 1250 Hz have long been suspected to cause a significant number of vibration injuries, HAVS. These vibrations are unregulated in the current standard for risk estimation, ISO 5349-1; thereby, the risk of injury is suspected to be underestimated. The objective of this study was to investigate the effects on finger tissue subjected to HFVs similar to those from impact wrenches by using a 2D finite element model of a fingertip. The model was validated through experiments. Using the input acceleration from the experiments, the model predicted high pressure variation and particular negative pressures at levels close to 0.1 MPa (1 Bar) or more, which are levels where cavitation in liquid can occur, with a detrimental effect on biological systems. Full article

The objective of this study was to develop a new rat-tail vibration model for studying finger vibration health effects. Unlike the previous rat-tail models, the vibration strain and stress of the rat tail can be conveniently and reliably quantified and controlled in a biological experiment. This makes it possible to identify and understand the quantitative relationships between these biodynamic responses and vibration health effects. Full article

Vibration injuries cause significant costs for society, great personal suffering, and often the relocation of personnel within a company. The project “Zero Vibration Injuries” is a Swedish initiative with the objective of taking a holistic approach to the problem, involving all stakeholders. The project’s vision is “Zero Vibration Injuries”. This is achieved by addressing the source of the problem by reducing the vibration levels in hand-held machines and applying the solutions in industry to the benefit of the users. Full article

The clinical evaluation of patients with neurosensory injury is based on quantitative sensory testing. Such tests require the patient’s cooperation, which may sometimes hinder a correct diagnosis. Objective findings, e.g., with biomarkers, would therefore be valuable. We evaluated serum biomarkers of vascular and neural injury in 92 patients with vibration injuries and in 64 referents. Thrombomodulin (TM), a biomarker for endothelial damage, was elevated in HAVS patients with Raynaud’s phenomenon (RP) compared to those without, as it also was in comparison to the referents. In the patients without RP, those with increased cold sensitivity showed somewhat higher—but not significantly different—values of TM (p = 0.4) than those without increased cold sensitivity, indicating an endothelial dysfunction or injury. Full article

Vibration injury in the hand–arm system from hand-held machines is one of the most common occupational health injuries. Machines emitting high-frequency shock vibrations, e.g., impact wrenches have since long been identified as a special risk factor. In legislative and standard texts, the terms shock, impact, peak and transient vibration are frequently used to underline the special risks associated with these kinds of vibrations. Despite this fact, in the literature there is not a mathematically stringent definition of either shock vibration or how the amplitude of the shock is defined. In this study, we suggest algorithms for definition and quantification of these terms and apply them to machine vibrations of various kinds. Full article

This systematic review covering publications in the Medline and Embase databases for the period 1946 to 2020 revealed a higher prevalence of Dupuytren’s disease among men exposed to vibration compared to men not exposed to vibration. The risk assessment, also considering the risk of bias, corresponded to a roughly doubled risk of Dupuytren’s disease when working with vibrating machines. The supplementary meta-analysis confirmed a more than doubled risk. A possible exposure–response relation was supported by the result from the meta-analysis, which showed a doubled risk for high exposure relative to low exposure. Full article

This systematic review on radiographic hand osteoarthritis (HOA) covering publications in the databases Medline and Embase for the period 1947 to April 2021, with a final selection of 10 studies, revealed a high prevalence of hand osteoarthritis among both vibration-exposed men and non-exposed. The results show a non-significant, unadjusted risk-increase of about 50% for X-ray-diagnosed hand osteoarthritis for those who work with vibrating machinery compared to referents. The risk estimate does not provide reliable support that working with exposure from vibrating machines increases the risk of radiographic changes in the hands. Full article

To control vibration-induced white finger among workers performing the fine grinding of golf club heads, in this study, the influence of different factors on vibration acceleration were verified by adjusting the eccentric mass of different dynamic balance wheels, adjusting the angle of driving wheels and passive wheels, increasing the number of rubber cushions, and using new and old sand belts. This study determined that the eccentric mass of the dynamic balance wheel, the number of rubber pads, and the newness of the sand belt are significant factors affecting the vibration of workers. The vibration hazard posed to workers can be reduced by correcting the dynamic balance of the front wheel, increasing the amount of rubber pads, and replacing the type of sand belt with a newer one. Full article

Workers in the rock face stabilisation sector are exposed to high levels of vibration from pneumatic rock drills, which can lead to vibration injuries. The work situation is also ergonomically challenging since the work often is performed on steep cliffs with heavy equipment and a substantial degree of dust exposure. To reduce exposure to vibrations, the equipment has been redesigned, including the machine’s handle, feeding hoist and the implementation of a reciprocating mass generating a counter force to reduce the vibrations. As a side project, a dust removal device was also developed. It was shown that vibration and dust exposure can be substantially reduced. Full article

Workers can be exposed daily to foot-transmitted vibration (FTV) from standing on mobile equipment or vibrating platforms and surfaces. This results in a consistent risk of developing neurological, vascular, and musculoskeletal problems. To date, there are no international standards describing procedures with which to evaluate the health risks deriving from long-term exposure to FTV. To study the applicability of hand–arm vibration (HAV) standards to the foot, the biomechanical responses of the hand and foot in terms of the frequency response function upon varying contact conditions were compared. Results evidenced similarities between the responses of the wrist and ankle, with differences in resonance for the fingers and toes. The study confirms that HAV standards are more suitable than whole-body vibration standards for evaluating higher frequency exposure to FTV. Full article

Physiological health effects (vibration perception thresholds and infrared skin temperature) of single-impact exposures and vibration exposures have been evaluated. In this experiment, a total of 52 healthy male participants were randomly exposed to single shocks of different frequencies (1 s⁻¹, 4 s⁻¹, and 20 s⁻¹) and to random signal vibration exposures (4 × 5 min exposure duration). We observed frequency-dependent and eventually dose-dependent physiological effects. No exposure parameter systematically correlated to any of the examined physiological outcomes. This could hint at different pathways for physiological effects. Full article

The authors evaluated the short-term neuromuscular effects on the assessment of mechanical hand—arm systems induced by vibrating tools to investigate the relationship between the force exerted and the vibration exposure. The motor task consisted of holding the instrumented handle with the dominant hand at predetermined grip force values. Five subjects took part in the tests. The tests were developed in the absence of vibration and in the presence of vibration at 5 m/s², 7.5 m/s² and 10 m/s². The push and pull force values were calculated in the tests on the five subjects. Full article

This study encompasses two implementations of evaluation of the daily exposure to hand-arm vibration of employees. The first one focuses on maintenance technicians and operating agents in wastewater treatment plants and as network technicians on the water distribution network. The second one focuses on technicians in the after-sales service of a company supplying a wide range of percussive and vibrating portable tools for professionals and the general public. In both cases, we established a precise inventory of the tools used by the employees, and computed the duration of use per day of each tool. We used the INRS tools N43 “Calculette Vibrations Mains Bras” and N59 “OSEV—Vibrations transmises aux membres supérieurs” to determine the daily exposure A(8). These results were explained to the employees, with practical advice for prevention, collectively during meetings and individually during sensitization workshops. Full article

When working in different directions, factors such as awkward postures can lead to different physical stresses, which can have an influence on the effects of hand–arm vibrations. In this regard, the individual forces can have an influence on the hand–arm-vibration (HAV). In this context, a force plate can be used to determine the feed force. In the case of different working directions, the measured values determined in this way can lead to misinterpretations if the force direction is not considered correctly. Within the scope of the study, screwdriving activities were carried out using an impact wrench in different working directions by 5 test subjects. In addition to the HAV, the feed force, body posture and muscle activity were recorded and evaluated. The results showed that there was a significantly different load for similar HAV. Full article

Overhead work and awkward hand–arm posture can impact muscle load. Additional workloads such as hand–arm vibration exposure while carrying or holding a power tool can contribute to adverse health effects. This study investigated the posture and muscle activity of 11 subjects while using an impact wrench in three working directions: upwards, forwards, and downwards. Although the vibration exposure did not show notable differences in the magnitude (4.6 ± 0.2 m/s²), postural behaviour and muscle activity showed higher workloads for working upwards and downwards compared to forwards. The results of muscle activity, and the self-reported exposure level, highlight the necessity of considering posture while exposed to vibration exposure. Full article

In order to analyse the exposure-response relationship between hand–arm-vibration exposure and the risk of musculoskeletal disorders (MSDs) of upper extremities in an epidemiological case-control study, a database was established to provide technical characteristics such as vibration exposure data and its frequency component measured at workplaces. This hand-arm vibration database consists of over 730 technical tools and devices, whereas 422 devices were used for exposure assessment in the epidemiological case-control study. The devices used were divided into a total of 13 device groups: hammers, grinding machines, compactors, screwdrivers and saws were the most frequently used devices. Full article

The objectives of the Workshop are addressed using epidemiologic data from population groups in occupations involving exposure to hand-transmitted vibration and/or shocks. Pooled analyses demonstrate the limitations of the exposure–response relation in ISO 5349-1:2001, and that A(8) is inappropriate for calculating the daily exposure to shocks as well as to continuous vibration. Alternative frequency weightings and metrics for daily exposure are explored. Full article

Shock vibrations from handheld tools have long since been suspected to cause an increased risk of hand-arm vibration syndrome. This paper gives an introduction to its physical origin and transformation of the hand. Also, the pathophysiological effects on biological systems from shock vibration are shown through in vitro models on fibroblasts and red blood cells. Finally, the results from an in vivo rat tail model are described. The results show that high-amplitude shocks with a high-frequency content have a detrimental effect on biological systems, and thereby presumably also have a negative effect on human hand tissue. This indicates the need for a risk estimation for vibration injuries that includes the frequency range of shock vibrations and can quantify their peak amplitudes. Full article