Effect of Sweating on Insulation of Footwear Kalev Kuklane, Ingvar Holmér, 123-136 Effect of Footwear Insulation on Thermal Responses in the Cold Kalev Kuklane, Qiuqing Geng, Ingvar Holmér, 137-152 Sorbents for Trapping Organic Pollutants From Air Tomasz Ligor, Helena Górecka, Bogusław Buszewski, 153-167 Evaluation of Grip Force Using Electromyograms in Isometric Isotonic Conditions Laurent Claudon, 169-184 Electromyographic Analysis of a Repetitive Hand Gripping Task Thomas Cook, John Rosecrance, Chris Zimmermann, David Gerleman, Paula Ludewig, 185-198 Mathematical Modelling of Muscle Effect on the Kinematics of the Head-Neck Complex in a Frontal Car Collision: A Parameter Study Adam Wittek, Janusz Kajzer, 201-220

Notes:

A Draft of a System of Teaching Occupational Safety and Ergonomics at Universities in Poland Jerzy Słowikowski, 221-236 Risk Assessment in the Working Environment in Estonia p.237 Piia Tint

Book review:

Effect of Sweating on Insulation of Footwear
Kalev Kuklane, Ingvar Holmér

The study aimed to find out the influence of sweating on footwear insulation with a thermal foot model. Simultaneously, the influence of applied weight (35 kg), sock, and steel toe cap were studied. Water to 3 sweat glands was supplied with a pump at the rate of 10 g/hr in total. Four models of boots with steel toe caps were tested. The same models were manufactured also without steel toe. Sweating reduced footwear insulation 19-25% (30-37% in toes). During static conditions, only a minimal amount of sweat evaporated from boots. Weight affected sole insulation: reduction depended on compressibility of sole material. The influence of steel toe varied with insulation. The method of thermal foot model appears to be a practical tool for footwear evaluation.

Effect of Footwear Insulation on Thermal Responses in the Cold
Kalev Kuklane, Qiuqing Geng, Ingvar Holmér

The influence of footwear insulation on foot skin temperature in the cold at low activity was investigated. Simultaneously, the thermal and pain sensations, and the influence of steel toe cap were studied. Eight participants were exposed for 85 min to 3 environmental temperatures
(+3; 12, and 25°C) wearing 5 different boots. Insulation of footwear was determined with a thermal foot model. The study showed the importance of insulation for keeping feet warm. Other factors, such as wetness and vasomotor response, however, modified the thermal response. The most affected parts were toes and heels. Cold and pain sensations were connected with considerably lower temperatures in these local points. No significant differences were observed between boots with and without steel toe cap.

Sorbents for Trapping Organic Pollutants From Air
Tomasz Ligor, Helena Górecka, Bogusław Buszewski

A series of siliceous adsorbents with chemically bonded phases (CBPs) of different polarity were tested as sorbents for trapping air pollutants (petroleum ether) using controlled setup. Moreover, special attention was paid to the potential role of metal impurities as strong adsorption sites. Sorbents were characterized by various physico-chemical methods, such as porosimetry, inductively coupled plasma (ICP) analysis, elemental analysis, derivatography, and gas chromatography. Trapping tubes were utilized for sorption of toxic pollutants from indoor air.

Evaluation of Grip Force Using Electromyograms in Isometric Isotonic Conditions
Laurent Claudon

The purpose of this study was to develop a relationship to evaluate the grip force (forcerel) using the electromyogram (EMGrel) of the flexor digitorum superficialis (FDS) and of the extensor digitorum (ED) according to the flexion-extension wrist angle (qf-e) and to the pronation-supination forearm angle (qp-s). Fifteen participants had to exert 3 levels of grip forces in 4 positions of the wrist combined with 3 positions of the forearm. The relationship is This relationship can be used to estimate grip force for levels of strength lower than 50% of the maximal voluntary contraction.

Electromyographic Analysis of a Repetitive Hand Gripping Task
Thomas Cook, John Rosecrance, Chris Zimmermann, David Gerleman, Paula Ludewig

Electromyography (EMG) has been proposed as a method for determining muscle effort in repetitive upper limb tasks, which are often related to cumulative trauma disorders. EMG activity of the finger flexor musculature was investigated during a repetitive hand gripping task having 5 different cycle durations (2 to 6 s), various percentage of work time (and rest) within the work cycle (20% to 80%), and 3 different grip force levels. Thirty healthy adult participants each performed 27 randomly ordered 30-s repetitive hand gripping trials as well as 3 isometric contractions, which were used to normalize data from the hand gripping trials. There was a significant decrease in mean EMG as the duration of the work-rest cycle time increased. At each force level, EMG increased as the percentage of work time within the work-rest cycle increased, but to a greater extent at the highest force level. The results of this study suggest that overall muscle effort, and perhaps muscle fatigue, can be reduced most effectively by modifying the force requirements of the repetitive task. Other variables, such as the percentage of work time with in a cycle and overall work cycle time have less effect on the EMG activity level. The results of this study have implications for developing strategies to reduce muscle fatigue during repetitive hand gripping tasks in an effort to reduce the effects of cumulative trauma disorders.

Mathematical Modelling of Muscle Effect on the Kinematics of the Head-Neck Complex in a Frontal Car Collision: A Parameter Study
Adam Wittek, Janusz Kajzer

A two-dimensional multibody model of the head-neck complex with muscle elements was developed to estimate the influence of muscles on the kinematics of the head-neck complex in a frontal car collision. With this model the authors evaluated how strongly the calculated influence of muscles depends on 3 important factors: (a) impact severity, (b) reflex time, and (c) parameters that determine characteristics of different components of the muscle model. When muscles were triggered at the beginning of impact, the maximum angle of the head flexion was decreased by the muscles by 40% in a frontal collision with an acceleration of 15 g. The influence of muscles was significant for reflex times lower than 60 (80) ms. The calculated influence of muscles was not sensitive to most parameters of the muscle model.

A Draft of a System of Teaching Occupational Safety and Ergonomics at Universities in Poland
Jerzy Słowikowski

The aim of the study was to develop a set of curricula for teaching Occupational Safety and Ergonomics at colleges and universities of various types, aimed at equipping students with knowledge and skills and at shaping active attitudes towards the practical application of the acquired knowledge in their future working lives. On the basis of the analysis of the curricula at Polish and foreign colleges and universities, a set (canon) of educational contents constituting a common practice in the academic teaching of Occupational Safety and Ergonomics was established. Then, a convenient for teaching this subject classification of university specialisations in Poland was introduced. This led to identifying and defining a taxonomic unit called here an educational profile. Next, curriculum minima for the developed profiles were defined objectively. To achieve this aim, the set of educational contents was ranked by university teachers and specialists in occupational safety and ergonomics. Each part of the educational contents (subject) was ranked on a 10-point scale in relation to each educational profile. The results of this ranking led to formulating sets of educational contents for each educational profile. On this basis, a repertoire of curricula (6 curricula, in 2 hour-by-hour versions each) was prepared, with methodological guidelines for lecturers. The results of the study were presented in the form of a manual for academic authorities.

Risk Assessment in the Working Environment in Estonia
Piia Tint

The first step to chart hazards in the working environment in Estonia (labour force: 0.65 million) was taken by the National Board of Health Protection in the beginning of 1996. The existing chemical, physical, and biological agents in the working environment were investigated with the help of local health inspectors in all counties. An identification of hazards and workers at risk was carried out. The results of the analysis showed that 16% of Estonian industrial workers are exposed to different hazards: 20,000 persons are exposed to noise, 11,000 are working in the conditions of vibration, 10,000 are affected by unsatisfactory microclimate, 6,000 complain about long-lasting work in a compulsory posture, the overexertion of eyes is suffered by 5,500 persons, and physical overload by 3,500 workers. In the group of chemical hazards the greatest numbers of workers are exposed to organic dust (6,500) and welding aerosols (5,400), followed by petroleum products (2,700), and oil-shale dust (4,300). The measurements of working conditions showed that an average of 30.3% of the results are above the standards. Proposals for the improvement of the situation in occupational safety and health are presented.