Hand-arm Vibration Research Articles

Hand-arm vibration assessment in badminton athletes during three different movements using two rackets

The vibration transferred to the arm of the badminton player through the racket can be associated with disease. This study analyzed the induced hand-arm vibrations (HAV, comparing two rackets with different stiffness, in movements with three handgrips (FH-forehand; FHR-forehand around the head, BH-backhand). The racquet was instrumented with a triaxial piezoelectric accelerometer, and the time of daily exposure to these vibrations was calculated according to ISO 5349 - 1,2, as well as the time required to develop white finger disease with a 10% probability. The main goal of this study is to examine the influence of the racket stiffness on the HAV, and understand the most critical smash movement for the HAV. The results indicate that the HAV vibrations are superior in the less rigid racket, being the daily exposure to these superior to the one defined by the own norms. It is also noted that the movement with the forehand grip is the most critical in what the induced vibrations are concerned. No differences in vibrations between the FH and FHR are observed.

The clinical consequence of using less than four sensory perception examination methods in the Swedish surveillance system for Hand-Arm vibration syndrome.

ObjectivesThe Swedish surveillance system aiming to reveal undetected Hand‐Arm Vibration Syndrome (HAVS) in workers exposed for vibrations is regulated by the provision AFS 2019:3. The goal for the surveillance system is to diagnose HAVS, as well as to find workers at risk for developing HAVS due to other conditions. The national guidelines stipulate examination using at least two out of four hand sensory examination methods (SEM); monofilament (touch), two‐point discrimination (discriminative), tuning fork (vibrotactile), and Rolltemp (thermotactile). The aim of this study was to examine the clinical consequence of using less than four of these SEMs.MethodsWe collected data on SEMs from the medical records of all individuals that went through the specific surveillance medical check‐up in a large occupational health service for 1 year. We then calculated the number of workers found with HAVS when using one, two, or three SEMs, and compared with the result from using all available SEMs.ResultsOut of 677 examined individuals, 199 had positive findings in at least one SEM. The detection rate for these findings was on average 47% when using one SEM, 71% using two SEMs, and 88% using three SEMs (out of 100% detection when all four SEMs were used).ConclusionsIf fewer than four sensory examination methods are used for surveillance of HAVS, many workers with incipient injuries may stay undetected. This may lead to further exposure resulting in aggravation of injury.

HAND-ARM VIBRATION IN DIFFERENT OPERATING CONDITIONS WITH A CHAINSAW

The mechanization of forest harvesting is a trend in Brazil. However, small and medium-sized companies in the forestry sector, even today, opt for semi-mechanized harvesting, using chainsaws for the harvesting and sectioning of trees. Despite technological advances, when operated continuously, chainsaws may cause damage to the operator’s body, acting as a stressor, and vibration excess is responsible for numerous health disorders, among them the Raynaud syndrome. In this sense, this study aimed to determine the vibration levels to which a chainsaw operator is subjected, during the transversal cut (tracing) of the wood, in different forest species and cutting sets. The treatments consisted of three forest species (Eucalyptus grandis, Eucalyptus dunnii and Acacia mearnsii De Wild) and two cutting sets, consisting of square tooth chains of the semi-chisel and chisel types. The vibration assessment was based on the criteria established by the Regulatory Standards NR15, NHO10 and ISO 2631-4. The results of vibration levels were higher than the reference limits established by ISO 2631-4, and, for both cutting sets, the highest vibration levels occurred on the “x” axis. After the data processing, the acceleration values resulting from the normalized exposure to hand-arm vibrations showed significant differences for the “y” and “z” axes. Therefore, it can be inferred that the chainsaw operation is a stressor, potentially capable of causing damage to workers' health.

Design and numerical investigation for reduction of hand-arm vibrations from steering wheel of an agricultural tractor

Steering wheel vibration affects the driver's comfort in an agricultural tractor. In order to increase driver comfort and reduce the hand-arm vibration syndrome (HAVS) effect, it is necessary to reduce the vibrations in agricultural tractors. The tuned mass damper concept is used to reduce vibrations from the tractor's steering wheel. The paper is focused on measuring steering wheel vibration characteristics on the actual tractor, designing a vibration control system and carrying out impact assessment using numerical analysis. The amplitude of vibration at the steering wheel measured by physical measurement on an actual tractor is compared to that determined using MATLAB Simulink. The outcomes of the numerical analysis suggest that the amplitude of vibration can be reduced by using a tuned mass damper (TMD) to achieve the proposed target levels. The effect of hand-arm vibration syndrome can also be decreased, resulting in an increased driver comfort.

Eardrum reflectance in healthy subjects exposed to noise and/or hand-arm vibration

Eardrum reflectance in healthy subjects exposed to noise and/or hand-arm vibration

Technetium-99m hand perfusion scintigraphy (Raynaud's scan) as a method of verification in hand arm vibration syndrome: a review.

It is important to assess the blood flow of fingers in the verification of hand-arm vibration syndrome. In the Republic of Korea, most assessments of the blood flow in the fingers are performed using a cold provocation test with finger skin color change. However, this test is a non-objective method with a relatively low sensitivity, leading to possible social and legal problems. Thus, we reviewed the characteristics of several tests that assess the blood flow in the fingers. Among these tests, using the radioactive isotope method, Raynaud's scan has a relatively higher sensitivity and specificity than other tests, provides objective results, and is approachable in many hospitals. So we suggest using Raynaud's scan as an alternative test when cold provocation test with finger skin color change is negative in vibration exposed worker.

Muscular Fatigue as an Effect of Muscular Synchronization in Hand-Arm Vibration Exposure

Muscular Fatigue as an Effect of Muscular Synchronization in Hand-Arm Vibration Exposure

Effect of Hand-Arm Vibration on Retina of Road Drilling Machine Laborers Measured by Electroretinography

Effect of Hand-Arm Vibration on Retina of Road Drilling Machine Laborers Measured by Electroretinography

Design and numerical investigation for reduction of hand-arm vibrations from steering wheel of an agricultural tractor

Design and numerical investigation for reduction of hand-arm vibrations from steering wheel of an agricultural tractor

Study of Hand-Arm Vibration Exposure and Its Health Effects in Dentist Employed in Academic Clinics

Study of Hand-Arm Vibration Exposure and Its Health Effects in Dentist Employed in Academic Clinics

A comprehensive diagnostics of neurosensory disorders in hand-arm vibration syndrome (HAVS)

A comprehensive diagnostics of neurosensory disorders in hand-arm vibration syndrome (HAVS)

Palmaris brevis spasm syndrome in manual workers using vibratory tools.

Palmaris brevis spasm syndrome (PBSS) appears to reflect benign muscle hyperactivity, with unprovoked recurrent spasm of the muscle and consequent dimpling of the hypothenar eminence. Two cases are reported, being the first known report of the condition among manual workers or those using vibratory tools. Each was diagnosed during routine health surveillance for hand-arm vibration syndrome. With hand cramps being a frequent report among vibration-exposed workers, this condition should be considered in such cases, although the lack of reports means that the frequency of the condition is unknown. One of the employees described more frequent episodes of spasm during periods of increased manual work. Diagnosis is possible by witnessing the characteristic spasm, or by viewing photographs of it. Functional impairment is not usual, except for the brief duration of an attack. There is no consensus regarding appropriate treatment.

A biomechanical model to predict hand-arm vibration when using different vibration damping gloves

Occupational exposure to the hand-transmitted vibration causes health problems and difficulties in the operators of hand-held power tools. This results in the reduction of manpower and increased costs in terms of compensations remunerated to the affected workers. A principal means to control hand-arm vibration is the use of vibration damping gloves. The primary focus of the current study is to develop biomechanical model of the human bent hand-arm system to predict vibration transmissibility when using different vibration damping gloves. The transmissibility plot was obtained by solving the equations of motion of the biomechanical model considering mass, stiffness and damping coefficient of the gloves. The transmissibility plot obtained from the model indicated that there was no significant reduction in finger vibrations at excitation frequencies less than 100 Hz, even if anti-vibration gloves are used. However, the gloves could appreciably reduce finger vibrations at higher frequencies. The observed response from the model was in agreement with the experimental studies reported in the prior literature suggesting the acceptability of the model for analysing vibration transmissibility characteristics of the human hand-arm system. The model can thus be used to evaluate engineering methods for vibration exposure control during operation of hand-held vibrating tools.

Carpal Tunnel Syndrome and Hand-Arm Vibration: A Swedish National Registry Case-Control Study.

To investigate the increased risk for carpal tunnel syndrome (CTS) in men and women with hand-arm vibration (HAV) exposure. Case-control study of CTS where 4396 cases was obtained from National Outpatient Register between 2005 through 2016. Cases were matched to controls and exposure was estimated using a job exposure matrix. Exposure to HAV increased the risk of CTS with an OR of 1.61 (95% CI 1.46-1.77). The risk was highest in men <30 years of age and among women <30 years no increased risk was observed. The risk increased with a mean year exposure above 2.5 m/s2 to OR 1.84 (95% CI 1.38-2.46). HAV exposure increase the risk of CTS in both genders, with highest risk increase in younger men. This emphasize identification of HAV exposure in patients with CTS.

Partial Experimental Contributions on the Validation of Biomechanical Models of the Human Body Subjected to the Action of Mechanical Vibrations

Abstract This paper focuses on the field of mechanical vibrations experimental analysis in hand arm vibrations (HAVs) for people who by the nature of their job are subject to the mechanical vibrations.

Vibration Disease: Exposure Level and Duration-Dependent Characteristics and Features of the Clinical Picture Following Local and Combined Local and Whole Body Vibration

Introduction: Vibration disease is induced by a long-term occupational exposure to vibration above the maximum permissible level and is manifested by damage to the peripheral vascular and nervous systems and disorders of the musculoskeletal system. Objective: To study the exposure level and duration dependency and features of the clinical picture of vibration disease in workers exposed to local and combined local and whole body vibration. Materials and methods: The study included 136 male workers. Cohort I consisted of 60 patients (mean age: 49.5 ± 7.4 years) with vibration disease related to the local vibration exposure; cohort II included 76 patients (mean age: 55.7 ± 4.8 years) with vibration disease induced by the combined exposure to hand-arm and whole body vibration. Results: The examined subjects worked in harmful working conditions of classes 3.1–3.4. Measured vibration exceeded maximum permissible values at most workplaces. Levels of local vibration did not differ significantly between the cohorts and amounted to 115.0 and 118.0 dB; the level of whole body vibration in cohort II was 116.0 dB. Shorter work experience and younger age at the time of diagnosing the occupational disease were registered in people exposed to local vibration only compared to those with a combined exposure. The angiodystonic syndrome was twice as frequent in cohort I, while cohort II had a larger proportion of patients with concomitant diseases (low back pain, periarthrosis, etc.). Conclusion: Our findings indicate the necessity to reduce occupational exposures to vibration and take appropriate therapeutic and preventive measures in order to maintain health and work ability of employees.

Impedance controlled human–robot collaborative tooling for edge chamfering and polishing applications

Surface finishing, as the final stage in the manufacturing pipeline, is a key process in determining the quality and life span of a product. Such a task is characterized by low contact forces and minimal material removal from the object surface. Despite the advancements in machine learning and artificial intelligence, human workforce is still irreplaceable in performing such tasks due to superior dexterity and adaptability, but this is often prone to risks such as hand-arm vibration syndrome due to hand-held tools. Therefore, we propose a collaborative approach to assist the human in carrying out such tasks with the help of two case studies: Human–Robot-Collaborative edge chamfering and polishing tasks, based on an impedance controlled collaborative curve tracing technique. We propose a collaborative framework, where the robot assists an operator to guide the end-effector/tool along a pre-defined parametric curve. The algorithm is demonstrated in two scenarios. In the first case, we address a collaborative chamfering task whereas the second case focuses on a polishing application (for straight edges). For these kinds of tasks, the curve to be traced assumes the shape of a straight line along the edge. We make use of the compliant feature of a cobot, which allows the user to physically guide the robot in the task space, to generate a mathematical model for the tool path. From the end-user perspective, this is more intuitive than the classical programming-based path planning approaches. In the process of machining, to enhance the path tracking accuracy and to ensure constant tool-surface contact, we implement guidance virtual fixtures through impedance control. As a result, the machining error is reduced.

Hand–Arm Vibration Syndrome: A Guide for Occupational Health Practitioners

Hand–Arm Vibration Syndrome: A Guide for Occupational Health Practitioners

Evaluation of the Sport Intervention Effect on the Grip Strength of Workers Exposed to Hand-arm Vibration

Evaluation of the Sport Intervention Effect on the Grip Strength of Workers Exposed to Hand-arm Vibration

Design of a robust active fuzzy parallel distributed compensation anti-vibration controller for a hand-glove system.

Undesirable vibrations resulting from the use of vibrating hand-held tools decrease the tool performance and user productivity. In addition, prolonged exposure to the vibration can cause ergonomic injuries known as the hand-arm vibration syndrome (HVAS). Therefore, it is very important to design a vibration suppression mechanism that can isolate or suppress the vibration transmission to the users’ hands to protect them from HAVS. While viscoelastic materials in anti-vibration gloves are used as the passive control approach, an active vibration control has shown to be more effective but requires the use of sensors, actuators and controllers. In this paper, the design of a controller for an anti-vibration glove is presented. The aim is to keep the level of vibrations transferred from the tool to the hands within a healthy zone. The paper also describes the formulation of the hand-glove system’s mathematical model and the design of a fuzzy parallel distributed compensation (PDC) controller that can cater for different hand masses. The performances of the proposed controller are evaluated through simulations and the results are benchmarked with two other active vibration control techniques-proportional integral derivative (PID) controller and active force controller (AFC). The simulation results show a superior performance of the proposed controller over the benchmark controllers. The designed PDC controller is able to suppress the vibration transferred to the user’s hand 93% and 85% better than the PID controller and the AFC, respectively.