OBJECTIVES 31 railway workers and 32 lumberjacks were examined to compare the dose-response relation between the exposure to two types of hand-arm vibration and the sensory disturbances in peripheral nerves as evaluated by the vibration perception thresholds (VPTs). METHODS Clinical examinations were carried out that included measurements of the VPTs, and electroneuromyography (ENMG), and an ...

Abstract: In this paper, we present the use of the laser tracker to aid the alignment of a Swing Arm Profilometer (SAP) and measure the length of the swinging arm, thus calibrating the operating radius of the SAP. The measurement uncertainty analysis is given. A laser tracker is used to align the SAP to ensure the path of the probe head passes through the rotary axis of the rotary table. By bui...

Absorbed power characteristics of seated human subjects under fore-aft (x-axis) and lateral (y-axis) vibration are investigated through measurements of dynamic interactions at the two driving-points formed by the body and the seat pan, and upper body and the backrest. The experiments involved: (i) three back support conditions (no back support, and back supported against a vertical and an incli...

The efficiency and positional accuracy of a lightweight flexible manipulator are limited by its flexural vibrations, which last after a gross motion is completed. The vibration delays subsequent operations. In the proposed work, the vibration is suppressed by inertial force of a small arm in addition to the joint actuators and passive damping treatment. The proposed approach is: 1) Dynamic mode...

Nacrtak Despite technological advancements in machinery for timber harvesting, chainsaws are fre­ quently used in forest operations. In Austria 85% of the wood volume harvested (15 million m3) are cut by chainsaws. The two most frequently documented ergonomic threats during motor manual felling include exposure to noise and vibration. This paper presents the results of exposure to hand-arm vibr...

Underground tunnel face bolting and pipe umbrella reinforcement are one of the most challenging tasks in construction whether industrial or not, and infrastructures such as roads or pipelines. It is one of the first sectors of economic activity in the world. Through a variety of soil and rock, a cyclic Conventional Tunneling Method (CTM) remains the best one for projects with highly variable gr...

The Japan Society for Occupational Health (JSOH) recommends the Occupational Exposure Limits (OELs) as reference values for preventing adverse health effects on workers caused by occupational exposure to chemical substances, continuous or intermittent noise, impulsive or impact noise, heat stress, cold stress, whole-body vibration, hand-arm vibration and time-varying electric, magnetic and elec...

A new frequency weighting method to assess hand-arm vibration exposure is proposed in this paper. The influence of frequency components was first estimated using the method of multivariate analysis, then a simple form of the weighting curve was introduced. Compared with the frequency weighting in the current ISO 5349-1 (2001), the proposed weighting can better explain the relationship between r...