[Discussion on the status quo and problems of health risk management of hand-transmitted vibration in the workplace].

The risk management in workplace is an important measure to effectively prevent and control the harm of hand-transmitted vibration. Based on the relevant developments at home and abroad, this paper expounds the risk of manual vibration operation in workplace by taking contact assessment and hazard assessment as an example. On this basis, the limit management and hierarchical management related to risk management are discussed, and the existing problems are analyzed.

Relation of digital arterial dysfunction to alternative frequency weightings of hand-transmitted vibration.

This study compared the relative performance of alternative frequency weightings of hand-transmitted vibration (HTV) to predict the extent of cold-induced vasoconstriction in the digital arteries of HTV workers. The cold response of digital arteries was related to measures of daily vibration exposure expressed in terms of r.m.s. acceleration magnitude normalised to an 8-h day, frequency weighted according to either the frequency weighting Wh defined in international standard ISO 5349-1:2001 (Ah(8) in ms-2 r.m.s.) or the hand-arm vascular frequency weighting Wp proposed in the ISO Technical Report 18570:2007 (Ap(8) in ms-2 r.m.s.). The measure of daily vibration exposure constructed with the frequency weighting Wp (Ap(8)) was a better predictor of the cold response of the digital arteries in the HTV workers than the metric derived from the conventional ISO frequency weighting Wh (Ah(8)). This finding suggests that a measure of daily vibration exposure constructed with the vascular weighting Wp, which gives more weight to intermediate- and high-frequency vibration (31.5-250 Hz), performed better for the prediction of cold induced digital arterial hyperresponsiveness than that obtained with the frequency weighting Wh recommended in ISO 5349-1 which gives more importance to lower frequency vibration (≤16 Hz).

Vinculin Identified as a Potential Biomarker in Hand-Arm Vibration Syndrome Based on iTRAQ and LC-MS/MS-Based Proteomic Analysis.

Local vibration can induce vascular injuries, one example is the hand-arm vibration syndrome (HAVS) caused by hand-transmitted vibration (HTV). Little is known about the molecular mechanism of HAVS-induced vascular injuries. Herein, the iTRAQ (isobaric tags for relative and absolute quantitation) followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) proteomics approach was applied to conduct the quantitative proteomic analysis of plasma from specimens with HTV exposure or HAVS diagnosis. Overall, 726 proteins were identified in iTRAQ. 37 proteins upregulated and 43 downregulated in HAVS. Moreover, 37 upregulated and 40 downregulated when comparing severe HAVS and mild HAVS. Among them, Vinculin (VCL) was found to be downregulated in the whole process of HAVS. The concentration of vinculin was further verified by ELISA, and the results suggested that the proteomics data was reliable. Bioinformative analyses were used, and those proteins mainly engaged in specific biological processes like binding, focal adhesion, and integrins. The potential of vinculin application in HAVS diagnosis was validated by the receiver operating characteristic curve.

Vascular response to the microcirculation in the fingertip by local vibration with varied amplitude.

Objectives: We investigated the effect of local vibration intensity on the vascular response to the microcirculation of the finger. Materials and methods: We performed hand-transmitted vibration experiments combined with laser Doppler flowmetry (LDF) to measure the blood perfusion signals of fingertips in the vibrated hand and the contralateral middle finger under the same frequency and different amplitude vibration, and to analyze the changes of microcirculatory blood perfusion levels in the fingers, and to investigate the effects of vibration stimulation on the endothelial, neural and myogenic regulatory frequency ranges of fingertips based on wavelet analysis. Furthermore, the transparent silicone films were fabricated and cultured with vascular endothelial cell (EC), which will undergo the local vibration with varied amplitude. And the expression of inflammatory factors was detected in the ECs. Results: Low-frequency vibration leads to a decreased blood flow in fingertip, and the degree of reduction in fingertip blood flow increases as the amplitude gradually increases, and the period required for blood flow to return to normal level after hand-transmitted vibration gradually increases. The decrease in blood flow is more pronounced in the vibrating hand than in the contralateral hand. In addition, nuclear factor-κB (NF-κB) expression increased significantly with the increase of vibration amplitude. Conclusion: High amplitude vibrations caused the inflammatory reaction of ECs which will lead to the altered endothelial regulatory activity. The endothelial regulatory activity is closely related to the blood perfusion in the microcirculation.

A novel rat-tail model for studying human finger vibration health effects.

It has been hypothesized that the biodynamic responses of the human finger tissues to vibration are among the major stimuli that cause vibration health effects. Furthermore, the finger contact pressure can alter these effects. It is difficult to test these hypotheses using human subjects or existing animal models. The objective of this study was to develop a new rat-tail vibration model to investigate the combined effects of vibration and contact pressure and to identify their relationships with the biodynamic responses. Physically, the new exposure system was developed by adding a loading device to an existing rat-tail model. An analytical model of the rat-tail exposure system was proposed and used to formulate the methods for quantifying the biodynamic responses. A series of tests with six tails dissected from rat cadavers were conducted to test and evaluate the new model. The experimental and modeling results demonstrate that the new model behaves as predicted. Unlike the previous model, the vibration strain and stress of the rat tail does not depend primarily on the vibration response of the tail itself but on that of the loading device. This makes it possible to quantify and control the biodynamic responses conveniently and reliably by measuring the loading device response. This study also identified the basic characteristics of the tail biodynamic responses in the exposure system, which can be used to help design the experiments for studying vibration biological effects.

Analysis of the effect of hand-transmitted vibration on hearing loss in male noise-exposed workers / 中国职业医学

Objective To investigate the combined effect of noise and hand-transmitted vibration on hearing loss in male noise-exposed workers. Methods A total of 952 male noise-exposed workers from an automobile manufacturing enterprise were selected as the research subjects using judgment sampling method. Occupational epidemiological surveys, assessments of occupational hazards in workplace, and pure-tone audiometry tests were conducted on the research subjects, and they were divided into low-level noise group, low-level combined group, high-level noise group, and high-level combined group according to whether the noise exposure level exceeded the national standard and whether they were jointly exposed to hand-transmitted vibration. The joint effects of noise and hand-transmitted vibration on hearing loss were analyzed. Results The detection rate of hearing loss in 952 noise-exposed workers was 21.7%. The detection rate of hearing loss of four groups, from high to low, was as follows： high-level combined group, high-level noise group, low-level combined group, and low-level noise group (44.9% vs 32.7% vs 12.9% vs 5.7%, P<0.01). The results of multivariate logistic regression analysis showed that the risk of hearing loss in the low-level noise group, the low-level combined group, the high-level noise group and the high-level combined group increased sequentially after adjusting for the confounding factors such as age, education level, smoking, drinking, listening to music with headphones, frequency of wearing noise-blocking earplugs and body mass index. The risk of hearing loss in the high-level noise group was 8.62 times more than that of the low-level noise group (P<0.01). The risk of hearing loss in the low-level noise combined group was 2.50 times more than that of the low-level noise group (P<0.01). The risks of hearing loss in the high-level combined group were 5.76 and 1.67 times more than that of the low-level combined group and the high-level noise group. Conclusion Combined exposure to noise and hand-transmitted vibration can increase the risk of hearing loss in male noise-exposed workers, and the higher the noise intensity, the greater the synergistic effect. Hand-transmitted vibration is a synergistic risk factor for occupational noise-induced hearing loss.

Effects of various handle shapes and surface profiles on the hand-arm responses and comfort during short-term exposure to handle vibration.

The magnitude of hand- (HTV) and wrist- (WTV) transmitted vibration can negatively impact upper limb responses even during short-term exposure. This study aimed to establish the effects of various handle-grip designs on the harmful impacts of vibration, sustained grip exertion, and unnatural posture. The primary focus was to investigate how using a handle grip and how three shapes with two surface profiles affect HTV, WTV, and forearm muscle activities during exposure. The secondary goal was to evaluate the immediate effects on fundamental hand functions, perceived discomfort/comfort, and perceived vibration level after exposure. The final objective was to assess which of the handle designs had the least harmful effects. Fourteen young male adults were recruited and asked to consistently grip a vibrating handle structure for 2 min while the primary parameters were recorded. Pre- and post-task measurements of secondary parameters were recorded on the six design conditions and one control condition (no handle grip). The study found that implementing a regular circular-smooth handle resulted in lower transmitted vibrations, leading to lower upper-limb discomfort, higher grip comfort, and lower perceived vibration. Additionally, shape significantly affected HTV, resulting in grip strength reduction, while surface profile did not influence transmitted vibrations but significantly impacted ring and small finger sensitivity, finger and hand discomfort, and grip comfort. Finally, forearm muscle activities were unaffected, and no significant interaction effects were observed. Circular handles also had the least negative impacts, and elliptic handles had the most negative impacts on the upper extremity because of the level of hand-handle contact stress and hand-grip effort. Meanwhile, the uneven distribution of vibration on the fingers and palm imposed by the rounded spikes on the patterned surface led to decreased finger sensitivity, higher discomfort, and lower grip comfort. Therefore, when machine operation involves moderate grip exertion, pronated forearm posture, and short-term handle vibration exposure, implementing a hard-solid handle with less hand-handle contact area, less grip effort, and even texture is recommended.

Advances on nervous system impairment induced by hand-transmitted vibration / 环境与职业医学

Hand-transmitted vibration is one of the most common physical harmful factors in the workplace，and the hand-arm vibration syndrome caused by it lacks effective treatment, and seriously affects the physical and mental health of the involved workers. As an important target for hand-transmitted vibration, the nervous system has attracted increasing attention from scholars, and much progress has been made in recent years in studying the effects of hand-transmitted vibration on nervous system function. Based on related literature at home and abroad, this paper introduced the hand-transmitted vibration-associated damage in peripheral, autonomic, and central nervous systems, and then explored the associated influence factors, like vibration frequency, environment temperature, and individual factors. The potential directions for further research were also proposed.

Effects of hand-transmitted vibration on fingertip terminal nerve: A meta-analysis / 环境与职业医学

Background Hand-transmitted vibration is one of the most common occupational hazards and is closely related to symptoms of fingertip terminal nerve damage. Objective To analyze the effects of hand-transmitted vibration on the terminal nerve of fingertips. Methods We systematically searched literature about the effects of hand-transmitted vibration on fingertip terminal nerve at home and abroad. The outcome index was the number (rate) of fingertip terminal nerve symptoms reported by the vibration group and the control group, such as finger numbness and finger tingling, and the search period was from database inception to December 2021. The quality of cross-sectional studies was assessed using the criteria recommended by the Agency for Healthcare Research and Quality (AHRQ), and the quality of cohort studies was assessed by the Newcastle-Ottawa Scale (NOS). NoteExpress 3.2 was used for literature management, and Excel 2003 was used for data collection and extraction. RevMan 5.4.1 software was used for statistical analysis, and random effect model was used to calculate the OR value of pooled effects and to draw forest plots. Subgroup analysis was carried out according to the working years with vibration exposure. At the same time, sensitivity analysis was performed after excluding studies with the largest weight and funnel plots were generated to evaluate publication bias. Results A total of 3619 articles were retrieved, and 39 articles were finally included, including 29 Chinese articles and 10 English articles; 36 cross-sectional studies and 3 cohort studies. In total, 8399 subjects were studied, including 5673 cases in the vibration exposure group and 2726 cases in the control group. Random effect model was used to merge the included literature. The results of meta-analysis showed that compared with the control group, hand-transmitted vibration was significantly associated with the self-reported occurrence of finger numbness (OR=8.29, 95%CI: 5.43-12.66), finger tingling (OR=7.50, 95%CI: 4.78-11.77), finger swelling (OR=8.25, 95%CI: 4.06-16.76), finger stiffness (OR=10.71, 95%CI: 3.60-31.87), finger trembling (OR=5.11, 95%CI: 2.60-10.04), hand weakness (OR=11.05, 95%CI: 3.98-30.68), hand sweating (OR=2.70, 95%CI: 1.64-4.43), hand coldness (OR=3.54, 95%CI: 2.42-5.18) (P<0.01). The subgroup analysis showed that the odds ratios of both finger numbness and finger tingling increased in the early and middle stages of vibration exposure (<5 years and 5-10 years of exposure duration）(finger numbness: OR=11.11, 19.07; finger tingling: OR=4.70, 16.55, respectively)(P<0.01), and decreased in the late stage of vibration exposure (10-15 years and ≥15 years of exposure duration) (finger numbness: OR=9.57, 2.30; finger tingling: OR=5.71, 6.00, respectively) (P<0.01). The results of sensitivity analysis showed a stable pooled effect (OR=13.96, 95%CI: 4.85-40.13, Z=4.89, P<0.01). The funnel plot results showed positive publication bias. Conclusion Occupational exposure to hand-transmitted vibration can cause finger numbness, finger tingling, finger swelling, finger stiffness, finger trembling, hand weakness, hand sweating, and hand coldness.

Vibration attenuation and dexterity of different types of protective gloves / 环境与职业医学

Background Wearing anti-vibration gloves is a simple and effective way to prevent hand-arm vibration disease. The requirements for vibration damping gloves are varied by types of operations exposed to vibration. Objective To study the vibration attenuation and dexterity of different types of protective gloves, and to provide reference for scientific wearing of vibration damping gloves for people working with vibration exposure. Methods Nine kinds of common protective gloves (A and B were dipping gloves; C, D, and E were rubber gloves; F and G were textile and fabric gloves; H was cotton gloves; I was leather gloves) used by workers exposed to vibration in 28 factories in Guangdong Province were selected as research objects by typical case sampling method, and the basic parameters of included protective gloves were investigated and measured. According to ISO 10819:2013, a glove vibration transmissibility (GVT) test system was used to detect the vibration transmissibility values and analyze vibration attenuation characteristics of the subjects wearing different protective gloves. The dexterity was tested by Minnesota Manual Dexterity Test. Pearson test was used to analyze the correlations among glove thickness, vibration transmissibility, dexterity score, and grip strength score. Results For rubber gloves (C, D, and E), the associated average adjusted vibration transmissibility at middle and low frequencies \begin{document}$ {\overline T _{\text{M}}} $\end{document} and average adjusted vibration transmissibility at high frequency \begin{document}$ {\overline T _{\text{H}}} $\end{document} were lower than those of other gloves (0.89-0.91 and 0.59-0.80 respectively), the vibration transmissibility values of 50-200 Hz frequency band was 0.81-0.97, and the vibration transmissibility values of 315-1250 Hz frequency band decreased with the increase of frequency (the minimum value was 0.13). For other types of gloves (A, B, F, G, H, and I), the \begin{document}$ {\overline T _{\text{M}}} $\end{document} and \begin{document}$ {\overline T _{\text{H}}} $\end{document} were 0.95-0.98 and 1.03-1.11 respectively, the vibration transmissibility values of 50-200 Hz frequency band was 0.96-1.02, and the vibration transmissibility values of 400-1250 Hz frequency band increased (the maximum value was 1.29). The \begin{document}$ {\overline T _{\text{M}}} $\end{document}, \begin{document}$ {\overline T _{\text{H}}} $\end{document}, and vibration transmissibility values of 40-1250 Hz frequency band of rubber gloves with double-layer protective materials (C, D, and E) were significantly lower than those of gloves with single-layer protective materials. But the \begin{document}$ {\overline T _{\text{M}}} $\end{document} and \begin{document}$ {\overline T _{\text{H}}} $\end{document} of gloves of other types with double-layer materials (F, H, and I) were still greater than 0.9 and 1.0 respectively. Compared with single-layer protective materials, the gloves of other types with double-layer materials showed no significant changes in the vibration transmissibility values of 25-200 frequency band (0.91-1.06), and an increase in the vibration transmissibility values of 250-630 Hz frequency band (the maximum value was 1.22). The dexterity scores and grip strength scores of dipping gloves (A and B) were the lowest. Rubber gloves C had the highest dexterity score and grip strength score. The thickness of protective gloves was negatively correlated with the vibration transmissibility values, and positively correlated with the dexterity score and the grip strength score (P < 0.05). The vibration transmissibility value was negatively correlated with the dexterity score and the grip strength score (P < 0.05). Conclusion Among the 9 kinds of gloves, cotton gloves and leather gloves have no damping effect. Rubber gloves have certain vibration reduction effect, and the vibration reduction effect on high frequency band is better than that on low frequency band. The thicker the damping material is, the better the damping effect is, but the less the dexterity is. Appropriate damping gloves should be selected according to actual vibration operations.

Peripheral circulation and peripheral nerve injury in workers exposed to vibration at two different frequencies / 环境与职业医学

Background Hand-arm vibration disease is harmful to human body, but there are no effective diagnosis and treatment so far, and current occupational exposure limits underestimate the health damage caused by high-frequency vibration exposure. Objective To evaluate and compare the damage to workers' peripheral circulation and peripheral nerve caused by different frequencies of vibration operation. Methods Drilling workers (n=187) from a mining company in Shandong Province and golf club head grinding workers (n=228) from a sports equipment factory in Guangdong Province were selected as study subjects. Hand symptoms were investigated. SV106 vibration meter was used to measure the target operation-associated vibration frequency spectrum. The 8 h energy-equivalent frequency weighted acceleration, cumulative vibration exposure level (CVEL), and the working age related to causing white finger in 10% of an exposed group were calculated. Result The study subjects were all male. More grinding workers reported hand symptoms than the drilling workers, e.g. peripheral circulation injury (52.6% vs 19.3%), peripheral nerve injury (71.5% vs 23.0%), hand stiffness (64.0% vs 7.0%), and deformed fingers (69.7% vs 4.3%) (all P<0.001). The main vibration frequencies of grinding operation (500-800 Hz) were much higher than those of drilling operation (125~160 Hz). CVEL and working age of vibration exposure showed a linear rising relationship with the cumulative prevalence rate of peripheral circulation and peripheral never injury, the fitting lines all showed good fitting effects (R2=0.812-0.988), and the slope of the fitting line of the grinding workers was larger than that of the drilling workers. The working age of vibration exposure associated with 10% cumulative prevalence of white finger was shorter in the grinding workers than in the drilling workers (6.81 years vs 10.27 years). According to the ISO prediction formula, the working age of vibration exposure was associated with 10% white finger prevalence shorter in the drilling workers than in the grinding workers (3.12 years vs 8.23 years). Conclusion Both the vibration exposure level and the prevalence of hand symptoms are high in two groups of workers with different vibration frequencies, and vibration exposure at a higher frequency tends to have severer damage to workers' hands.

Hand-transmitted vibration and occupational health / 环境与职业医学

The hand-arm vibration disease due to widespread hand-transmitted vibration operations is difficult to cure and seriously affects the health and quality of life of patients. Focusing on the prevention and control of hand-transmitted vibration and its occupational hazards, advances in occupational health relevant to hand-transmitted vibration were reviewed from the aspects of occupational hazard status, health impact, exposure monitoring, prevention and control of hand-transmitted vibration, as well as health surveillance, diagnosis, and treatment of hand-arm vibration disease. In addition, further suggestions on prevention and control of occupational hazards related with hand-transmitted vibration were prospected.

Effects of hand-transmitted vibration on upper limbs of workers: A meta-analysis / 环境与职业医学

Background Hand arm vibration disease (HAVD) is one of the legal occupational diseases in China, and its pathogenesis is not clear. Operators exposed to electric vibration tools for a long time have an increased risk of HAVD. Objective To conduct a systematic evaluation of the effects of vibration operations on workers' upper limb nerves, blood vessels, and muscles. Methods Relevant studies on the effects of hand-transmitted vibration on HAVD were searched and collected from the China Knowledge Infrastructure, Wanfang, and PubMed databases, and the literature was published from January 1974 to April 2021. The quality of cohort and case-control studies was assessed by the Newcastle-Ottawa Scale (NOS), and the quality of cross-sectional studies was by the evaluation criteria recommended by the Agency for Healthcare Quality and Research (AHRQ). Statistical analyses of outcome indicators (OR) in the included literature were performed using RevMan 5.4.1 software, effect sizes in the literature on vibration-induced white finger and neurosensory impairment were combined using a random-effect model, those that included carpal tunnel syndrome were combined using a fixed-effect model, and subgroup and publication bias analyses were also performed. To explore sources of study heterogeneity, meta-regression was performed using Stata 16.0 software, and sensitivity analyses were performed on the included literature. Results A total of 716 papers were retrieved from the databases, and 18 articles were retrieved by manual searching. A total of 34 papers were included after excluding those not meeting the criteria. Of the papers, 11004, 7270, and 1722 subjects related to vibration-induced white finger, neurosensory impairment, and carpal tunnel syndrome, respectively. The results of meta-analysis showed that compared with the control group, the combined ORs of hand-transmitted vibration exposure were 4.25 (95%CI: 2.72−6.65) for vibration-induced white finger, 4.03 (95%CI: 2.46−6.61) for neurosensory impairment, and 2.44 (95%CI: 1.61−3.71) for carpal tunnel syndrome. Heterogeneity was identified in the original studies related to vibration-induced white finger (I2=81%, P < 0.001) and neurosensory impairment (I2=90%, P < 0.001), except carpal tunnel syndrome (I2=23%, P < 0.001). The results of sensitivity analysis showed that the combined effect sizes (ORs) were stable and reliable. The results of meta-regression showed that the factors contributing to high heterogeneity of combined vibration-induced white finger and neurosensory impairment were time of publication (t=−2.10, P=0.049) and working age (t=−2.40, P=0.032), respectively. Conclusion Hand-transmitted vibration is a risk factor for vibration-induced white finger, neurosensory impairment, and carpal tunnel syndrome in operators.

A Review of Hand-Arm Vibration Studies Conducted by US NIOSH since 2000.

Studies on hand-transmitted vibration exposure, biodynamic responses, and biological effects were conducted by researchers at the Health Effects Laboratory Division (HELD) of the National Institute for Occupational Safety and Health (NIOSH) during the last 20 years. These studies are systematically reviewed in this report, along with the identification of areas where additional research is needed. The majority of the studies cover the following aspects: (i) the methods and techniques for measuring hand-transmitted vibration exposure; (ii) vibration biodynamics of the hand-arm system and the quantification of vibration exposure; (iii) biological effects of hand-transmitted vibration exposure; (iv) measurements of vibration-induced health effects; (iv) quantification of influencing biomechanical effects; and (v) intervention methods and technologies for controlling hand-transmitted vibration exposure. The major findings of the studies are summarized and discussed.

Hand-Arm Vibration Exposure in Rock Drill Workers: A Comparison between Measurements with Hand-Attached and Tool-Attached Accelerometers.

OBJECTIVES: To assess the hazard of tool vibrations, we need valid exposure measurements. The use of hand-attached accelerometers (vibration sensors) to measure hand-arm vibrations (HAVs) has become a popular approach. However, according to International Standard ISO 5349-2, the preferred attachment of accelerometers is at the tool handle. We compared measures of HAV between hand- and tool-attached accelerometers in rock drilling. METHODS: We measured HAV in five rock drillers using jackleg drills in normal working operations with simultaneous measures of both hand-attached and tool-attached accelerometers. Five to seven measurement cycles of 15 s were executed on each worker, resulting in a total of 29 measurement cycles. To identify possible differences in working technique, we recorded videos of tool handle handgrips during drilling. RESULTS: There was a significant difference (9.5 m s-2; P ≤ 0.05) in vibration magnitudes measured by the tool-attached accelerometers compared with the hand-attached accelerometers. The hand-attached accelerometer showed a lower vibration magnitude for all workers (range of difference: 2.3-14.6). The variation between the two accelerometer attachments was larger between workers than within workers (ICC = 0.68). CONCLUSIONS: For measurements of HAV from jackleg drills, the use of hand-attached accelerometers may cause a lower recorded vibration level compared with tool-attached accelerometers. This difference is likely to vary depending on how workers grip the tool handle, and a misclassification of exposure will occur if workers grip the tool handle in a way that makes the accelerometer lose contact with the vibrating surface. Individual differences in how workers grip the tool handles should be considered when assessing HAV.

Vibration-Sensing Electronic Yarns for the Monitoring of Hand Transmitted Vibrations.

Overexposure to hand transmitted vibrations (HTVs) from prolonged use of vibrating power tools can result in severe injuries. By monitoring the exposure of a worker to HTVs, overexposure, and injury, can be mitigated. An ideal HTV-monitoring system would measure vibration were it enters the body, which for many power tools will be the palm and fingers, however this is difficult to achieve using conventional transducers as they will affect the comfort of the user and subsequently alter the way that the tool is held. By embedding a transducer within the core of a textile yarn, that can be used to produce a glove, vibration can be monitored close to where it enters the body without compromising the comfort of the user. This work presents a vibration-sensing electronic yarn that was created by embedding a commercially available accelerometer within the structure of a yarn. These yarns were subsequently used to produce a vibration-sensing glove. The purpose of this study is to characterize the response of the embedded accelerometer over a range of relevant frequencies and vibration amplitudes at each stage of the electronic yarn's manufacture to understand how the yarn structure influences the sensors response. The vibration-sensing electronic yarn was subsequently incorporated into a fabric sample and characterized. Finally, four vibration-sensing electronic yarns were used to produce a vibration-sensing glove that is capable of monitoring vibration at the palm and index finger.

The hand-arm vibration syndrome associated with the grinding of handheld workpieces in a subtropical environment.

OBJECTIVES: To study the characteristics and the factors influencing the occurrence of the Hand-Arm Vibration Syndrome (HAVS) for a population grinding handheld workpieces in a subtropical environment. METHODS: A total of 803 workers grinding handheld workpieces formed the exposure group and 464 workers not exposed to hand-transmitted vibration (HTV) were recruited as the non-exposed group within the same factory in a subtropical climate area. The basic personal information and clinical symptoms reported were collected by trained physicians using a questionnaire and representative measurements were made of the HTV exposure levels and dose. RESULTS: The average HTV exposure dose A(8) was measured as 5.3 ± 2.0 m/s2. The proportion of grinders reporting finger blanching was 15.4% while it was 27.5% for finger numbness. Among the non-exposed group, that proportion was 0% and 6.3% respectively. There was a positive association between the vibration exposure duration and the occurrence of finger blanching, finger numbness and finger coldness. Riding a motorcycle to work was also identified as a factor that could contribute to a higher prevalence of finger blanching among the exposed workers, the OR value was found to be 1.75 (1.12, 2.75). CONCLUSIONS: Workers exposed to vibration in a subtropical area can also present evidence of finger blanching in addition to neurological symptoms. The reported rate of HAVS was positively associated with the exposure duration. And the levels of the duration of exposure relative to symptoms of vibration white finger in a subtropical temperate environment exposed to a high-frequency vibration might be deemphasized by the current ISO weighting. Motorcycle transportation to work was identified as a factor that could influence the development of the HAVS among the exposed population of grinders.

Application of finger systolic blood pressure in the diagnosis of vibration-induced vascular injury / 中国职业医学

OBJECTIVE: To evaluate the application value of finger systolic blood pressure(FSBP) in the diagnosis of vibration-induced vascular injury. METHODS: Thirty patients with vibration-induced vascular injury [vibration-induced white finger(VWF)] were selected as the case group by a non-randomized concurrent controlled trial, and 30 hand-transmitted vibration workers without VWF were selected as the control group. The FSBP test was performed on the tested hands of all subjects, and the FSBP index of each Finger(F_( i)) was measured. RESULTS: The F_i of the index finger, middle finger, ring finger and tail finger of the tested hand in the case group were lower than that in the control group(all P<0.01). In the case group, the F_i of index finger was lower than ring finger and tail finger(all P<0.01). The abnormal rates of F_i on the index, middle and ring fingers in the case group were higher than those in the control group(86.7% vs 10.0%, 76.7% vs 13.3%, 43.3% vs 10.0%, all P<0.01). The area under the receiver operator characteristic curve of the measured F_i of the index finger, middle finger, ring finger and tail finger were 0.884, 0.843, 0.764 and 0.687 respectively. The diagnostic cut off value of the F_i of index finger was 80.2%. The sensitivity and specificity were 86.7% and 90.0%, respectively. CONCLUSION: FSBP test has a good application value in the diagnosis of vibration-induced vascular injuries. It is suggested that the F_i of index finger be the first choice as the diagnostic index, and the abnormal value can be set at 80.0%.

Analysis of influencing factors of fingertip thermotactile perception threshold in healthy young adults / 中国职业医学

OBJECTIVE: To analyze the stability of test results of fingertip thermotactile perception threshold(TPT) among healthy individuals and the influencing factors of the TPT test. METHODS: Fifty healthy young volunteers aged 20-25 were selected as the study subjects using the convenience sampling method. The HVLab thermal aesthesiometer was used to perform the fingertip TPT test under the standard condition. Right index, middle, ring, little, left index and little fingers were tested. According to the method of random number table, we selected 25 subjects to receive second test after the interval of two weeks. RESULTS: Intraclass correlation coefficient(ICC) for cold threshold of right little finger was bigger than 0.75, suggesting the test-retest reliability was excellent. The ICC for hot threshold of six test fingers, cold threshold of right and left index fingers, right middle and left little finges was in the range of 0.60-0.74, indicating the test-retest reliability was good. However, the ICC for cold threshold of right ring finger was less than 0.40, and the test-retest reliability was poor. The hot threshold of right middle, ring and little fingers, and the cold threshold of left little finger of males were higher than those of females(all P<0.05). The cold threshold of right index and little fingers were lower than those of left hand in males(all P<0.05). The cold threshold of right middle and ring fingers were lower than that of the right index finger in females(all P<0.05). The cold threshold of right little finger was lower than those of right index, middle and ring fingers in females(all P<0.05). CONCLUSION: The stability of the fingertip TPT result is good in healthy young adults aged 20-25. The fingertip TPT test could be used for occupational health surveillance of workers exposed to hand-transmitted vibration. We should take into account the influence of gender, the right or left hand and different fingers when developing TPT reference values.

Analysis of the vibration reduction effect of three common protective gloves / 中国职业医学

OBJECTIVE: To test and analyze the vibration transmissivity of three common kinds of protective gloves, and to determine their actual protecting effect. METHODS: Three kinds of protective gloves were selected as test materials, and five healthy volunteers were selected as subjects using typical sampling methods. According to the ISO 10819:2013 Mechanical Vibration and Shock--Hand-arm Vibration--Measurement and Evaluation of the Vibration Transmissibility of Gloves at the Palm of the Hand(hereinafter referred to as ISO 10819:2013), investigation and measurement of basic parameters of protective gloves. The gloved vibration transmission(GVT) test system was used to test the vibration transmission of different protective gloves worn by the subjects, and the spectrum analysis of vibration reduction characteristics was carried out. RESULTS: The thickness of damping material of all the three kinds of protective gloves met the standard requirements. The mean value for the corrected frequency-weighted glove vibration transmissibility values at 25.0-200.0 Hz were 0.91, 0.75 and 0.94, and 1.05, 0.85 and 1.10 at 200.0-1 250.0 Hz, for the protective gloves A, B and C, respectively. The results of anti-vibration characteristic spectrum analysis show that there has no vibration reduction effect at the frequency of 25.0-200.0 Hz when wearing these three kinds of gloves. Wearing gloves A and B on part of the 200.0-1 250.0 Hz frequency vibration has an amplifying effect. Wearing glove C has a partial vibration reduction effect at the 200.0-1 250.0 Hz frequency, and the vibration reduction efficiency is the highest at the frequency of 1 250.0 Hz.CONCLUSION: According to the ISO 10819:2013 standard, the mean value of GVT measured when wearing the three kinds of protective gloves does not meet the relevant requirements, and the anti-vibration effect is poor. These gloves cannot be defined as anti-vibration gloves.