Box Handling in the Loading and Unloading of Vans Monique Lortie, Genévieve Baril-Gingras, 3-18 Use of Ergonomics as a Quality Improvement Tool in a Manual Assembly Task Holly S. Wick, Donald S. Bloswick, 19-42 Occupationally Oriented Medical Rehabilitation and Hairdressers' Work Techniques A one-and-a-half-year follow-up Jari P.A. Arokoski, Nina Nevala-Puranen, Rolf Danner, Merja Halonen, Ritva Tikkanen, 43-56 The Effects of Local Cooling on Thermophysiological Response in Participants Wearing Dust-Free Garments Oh Kyung Kwon, Ae Hyun Kwon, Masako Kato, Chio Hayashi, Hiromi Tokura, 57-67 A Device for Preventing Occupational Diseases of Lower Legs Ülo Kristjuhan, Vello Reedik, Toivo Tähemaa, 69-74 Force Velocity Characteristics of Individual Human Skeletal Muscles: TBClat and TBClong Outline of the Method Stefan Kornecki, Adam Siemieński, 75-83

Notes:

Ventilation Flow Organization for Efficient Elimination of Contaminated Air Sture Holmberg, 85-96 Application of the Method of Organizational Congruencies in Substituting Organic Solvents With Vegetable Agents for the Cleaning of an Offset Printing Machine Silvana Salerno, Riccardo Tartaglia, Sauro Garzi, Andrea Biagioni, Giovanni Rulli, Bruno Maggi, Antonio Grieco, 97-106 Classification of the Substances on the Basis of the Acute-Toxic-Class Method (ATC) Jolanta Skowroń, Lidia Zapór, Katarzyna Miranowicz-Dzierżawska, 107115

Book Review p.117

Box Handling in the Loading and Unloading of Vans
Monique Lortie, Genévieve Baril-Gingras

The handling of 2,306 boxes being loaded or unloaded from vans onto or from 4-wheeled trolleys by 31 handlers in a warehouse were characterized. Handling was videotaped and characterized through an analysis grid completed by three trained observers. The following execution parameters were observed: nature of the exertion applied by the upper limbs, plane and direction of the exertion, resulting displacement of the box, grip, use of the lower limbs and the back. Results show that execution parameters used by handlers vary considerably from those usually recommended or studied. For example, symmetric grips were rarely used (4%). The grip was modified during the handling of half the boxes. Significant knee flexion was rarely observed (3% of exertions). Each box was moved by applying an average of 3.5 different exertions. Exertions were mostly applied in a plane parallel to the shoulders; they were rarely executed in a strict sagittal plane (11%). The implication of these observations are discussed.

Use of Ergonomics as a Quality Improvement Tool in a Manual Assembly Task
Holly S. Wick, Donald S. Bloswick

This study attempted to identify a direct relationship between the design characteristics of a manually-assembled product, exposure to work-related ergonomic risk factors, and improvement in product quality. The study considered (a) Accessibility (ease of approach) and Guidance (ease of alignment and positioning) as Design Variables, (b) Shoulder Abduction, Trunk Lateral Flexion, Rate-Normalized Percentage of Maximal Voluntary Contraction (%MVC) of the Wrist Flexors, Wrist Extensors, and Deltoids, and Frequency of Attachment as Ergonomics Variables, and (c) Percentage of Attachment Too Loose, Too Tight, and Misaligned as Quality Variables. Postural data, surface EMG data, and quality data were collected from 10 participants performing four 10-min repetitive manual assembly tasks with plastic threaded nuts, bolts, flat parts, and open-box parts. Unobstructed accessibility of manually-assembled parts was associated with decreased exposure to awkward trunk posture, decreased activity of the wrist flexors and extensors, increased frequency of repetitive motion, and a decrease in the tendency to attach parts too loosely. Accessibility had no effect on misalignment defects as measured. Part guidance decreased the number of parts attached too tightly and aided in increasing the rate of assembly of parts when there was unobstructed access to parts.

Occupationally Oriented Medical Rehabilitation and Hairdressers' Work Techniques A one-and-a-half-year follow-up
Jari P.A. Arokoski, Nina Nevala-Puranen, Rolf Danner, Merja Halonen, Ritva Tikkanen

This study examined changes in work techniques and musculoskeletal symptoms after occupationally oriented medical rehabilitation arranged for 21 hairdressers who were experiencing neck-shoulder or back pain but were still able to work. OWAS (Ovako Working Posture Analysing System) analyses of working postures and questionnaire data were obtained at the beginning of the courses and one and a half years later. The participants worked with their back bent and twisted or their arms at or over shoulder level more seldom (p < .0001) at the end of the follow-up than at the beginning of the rehabilitation. Subjective work-related physical and mental strain had decreased
by 45.4% (p < .001) and 27.1% (p < .05), respectively, and subjective neck and back pain by 40.0% (p < .01) and 45.3% (p < .01), respectively. This study suggests that occupationally oriented medical rehabilitation can have significant and long-lasting effects on the rehabilitee's work techniques and subjective well-being.

The Effects of Local Cooling on Thermophysiological Response in Participants Wearing Dust-Free Garments
Oh Kyung Kwon, Ae Hyun Kwon, Masako Kato, Chio Hayashi, Hiromi Tokura

This study was designed to find the effects of two kinds of dust-free garments with (A) and without (B) frozen gel strip (FGS), and half-naked clothing (brassiere and shorts; C) on thermophysiological parameters and on temperature and humidity within clothing. The heart rate, rectal, and skin temperatures as well as sweat rate and clothing microclimate were measured during 140 min in 9 healthy females. Inquiries were also made into the subjective rating of thermal, humidity, and comfort sensations. The main findings in our experiments are as follows: (a) Physiological parameters such as rectal and skin temperatures (chest and forehead), heart rate, and sweat rate were clearly lowest in garb C, intermediate in garb A, and highest in garb B throughout the experiment; (b) Temperature and humidity within clothing were lower in garb A than in garb B; (c) More than half of the 9 participants decreased thermal sensation by wearing garb A. These results suggest that the usage of FGS could improve the heat load in lightly working participants wearing dust-free garments.

A Device for Preventing Occupational Diseases of Lower Legs
Ülo Kristjuhan, Vello Reedik, Toivo Tähemaa

Physiological processes characteristic of the fatigue of legs mainly appear when the worker's activity requires standing. If the processes are intensive and regular, various diseases of legs, such as varicose veins and musculoskeletal disorders of legs and feet, can develop. Therefore, methods of reducing the fatigue of legs are important in occupational health protection. Air jet massage technology was developed and an appropriate massage device was built by the authors. The massage head turning around the lower leg and moving up and down gradually covers the leg's surface. To determine the efficiency of the massage, fatigue processes were studied. These studies showed that jet massage effectively reduces both the subjective and objective fatigue symptoms. The device is convenient for use in industry, services, and at home.

Force Velocity Characteristics of Individual Human Skeletal Muscles: TBClat and TBClong Outline of the Method
Stefan Kornecki, Adam Siemieński

The aim of the work is to outline a procedure of finding force velocity
(F V) characteristics (F = f(V)) of individual skeletal muscles of the human locomotor system. The presentation is based on an example concerning extensors of the elbow joint: the lateral and long heads of triceps brachii (TBClat and TBClong). The experimental part of the procedure involves a natural movement of using the upper extremity to push an external object of variable, adjustable load, engaging both the elbow and shoulder joint. Five men aged 23 took part in the experiment. Their task was to push the handle of aphysical pendulum whose moment of inertia could be adjusted within the range of
58 kg.m2-450 kg.m2, so as to give it maximum angular velocity. During each trial the movement of the trunk, of the upper extremity and of the pendulum was video recorded and the force applied with the hand to the handle of the pendulum was measured. In order to find the F V characteristics a simulation model SHOULDER was used, which is capable of solving the synergy problem for muscles of the arm and the shoulder girdle. It was found that despite considerable dispersion of experimental points the respective regression lines revealed a clear tendency of decreasing muscle force for increased shortening velocity of the monoarticular head (TBClat) and of increasing muscle force for increased lengthening velocity of the biarticular head (TBClong) of the triceps brachii muscle.

Ventilation Flow Organization for Efficient Elimination of Contaminated Air
Sture Holmberg

Displacement ventilation and well-organized ventilation flow structures are emphasized. Perhaps the biggest advantage of displacement ventilation is its increased effectiveness in removing pollutants from a ventilated space and the efficient use of ventilation air. Several questions on how the systems should be designed to achieve optimal efficiency are still unanswered. Small variations in room geometries and air supply arrangements can totally change the conditions. Results from this investigation show the importance of an even distribution of the incoming supply air, numerically calculated age-of-air values and the influence of residual tracer concentrations on measured mean values for the age of air.

Application of the Method of Organizational Congruencies in Substituting Organic Solvents With Vegetable Agents for the Cleaning of an Offset Printing Machine
Silvana Salerno, Riccardo Tartaglia, Sauro Garzi, Andrea Biagioni, Giovanni Rulli, Bruno Maggi, Antonio Grieco

The aim of this research is the application of the Method of Organizational Congruencies before and after the substitution of organic solvents with vegetable agents for the cleaning of an offset printing machine in order to assess the organizational changes. A solvent-free process is the goal of the Subsprint Project (Technology Transfer Program of the European Community). This study shows how human and environmental health is improved by using vegetable agents, though this change may lead to some other organizational constraints such as an increase of the time needed, monotony, andrepetitiveness of the technical actions involved. The authors underline that the knowledge of the impact of the new technology on health helps a better understanding of the resistance to the change and its further amelioration.

Classification of the Substances on the Basis of the Acute-Toxic-Class Method (ATC)
Jolanta Skowroń, Lidia Zapór, Katarzyna Miranowicz-Dzierżawska

The acute-toxic-class method (ATC) is an alternative to the classical LD50 test. Four substances were tested with an ATC testing procedure. The results were compared with LD50 data obtained from the literature. Great importance was attached to the observations of toxic signs following administration. The results of this study have shown that the ATC method allows allocation to toxicity classes in the same manner as on the basis of the classical LD50 tests. The ATC method uses fewer animals and yields the same information on toxic signs. Introducing the ATC method into the quality system allows estimating the acute oral toxicity of chemicals according to the Organisation for Economic Cooperation and Development (OECD; OECD, 1992, 1996).