One important factor that leads to the development of musculoskeletal disorders (MSD) and cumulative trauma disorders (CTD) among visual display terminal (VDT) users is their work posture. While operating a VDT, a user's body posture is strongly influenced by the task, VDT workstation settings, and layout of computer accessories. This paper presents an analytic and rule-based decision support tool called EQ-DeX (an ergonomics and quantita-tive design expert system) that is developed to provide valid and practical recommenda-tions regarding the adjustment of a VDT workstation and the arrangement of computer accessories. The paper explains the structure and components of EQ-DeX, input data, rules, and adjustment and arrangement algorithms. From input information such as gender, age, body height, task, etc., EQ-DeX uses analytic and rule-based algorithms to estimate quanti-tative settings of a computer table and a chair, as well as locations of computer accessories such as monitor, document holder, keyboard, and mouse. With the input and output screens that are designed using the concept of usability, the interactions between the user and EQ-DeX are convenient. Examples are also presented to demonstrate the recommendations generated by EQ-DeX.

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A survey was conducted to investigate the relationship between job satisfaction and job factors that affect work design in two automotives manufacturing companies in Malaysia. A set of multiple choices questionnaires was developed and data were collected by inter-viewing the employees at the production plant. Hundred and seventy male subjects between the ages of 18 to 40 years with the mean age of 26.8 and SD of 5.3 years and mean work experience of 6.5 and SD of 4.9 years took part in the survey. The survey focused on job factors, i.e. skill variety, task identity, task significance, autonomy and feedback. The results support the previous findings that job factors are significantly correlated to job satis-faction. Furthermore, it also highlights the significant influence of age, work experience and marital status.

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A study was conducted to determine the effects of VDT monitor positions and the use of single vision versus bifocal glasses on somatic elements in the data entry task. Eight male subjects performed data entry using a word processor in eight half-hour sessions with the four different monitor placements, i.e. “eye-level”, “shoulder-level-front”, “shoulder-level-side”, and “sunken-level”, wearing the two types of glasses. A subjective discomfort rating questionnaire covering 12 somatic elements was completed by the subject after each ses-sion. The head inclination and angle of gaze to the monitor were measured with a goniome-ter. The results revealed that the somatic elements which were affected significantly by the placement of the VDT monitor and the type of glasses were discomfort in the neck and back regions and eyestrain, respectively. The neck-back discomfort scores were highest at the “eye-level”, lowest at the “sunken-level”, and intermediate at the “shoulder-level-side” position. The “shoulder-level-front” position was not significantly different in the discom-fort from other three positions. The eyestrain was significantly greater with the bifocal than with the single vision glasses. The lower the monitor was placed, the more forward was the head and gaze inclined. The head was inclined less forward, or even more backward, and the gaze was inclined more forward, with the bifocal than with the single vision glasses. As a conclusion, the VDT operators were advised to avoid the “eye-level” and “shoulder-level-side” positions and to prefer the “sunken-level” and “shoulder-level-front” positions as the first and second best choices, respectively. The preference becomes more critical for the wearers of bifocal glasses that suffer from postural constraints in viewing.

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Since a Japanese-style bow has a very complicated shape and structure, an archer has to apply the "Teno-uchi" maneuver including horizontally twisting torque, or "Nejiri", and sagittally down-pushing torque, or "Uwa-oshi", to the restoring bow in order to hit the tar-get. The purpose of this study was to investigate the biomechanical relationship between the muscular activities of the left forearm and the operation of "Teno-uchi" maneuver. Surface EMG of left forearm muscles and the two kinds of torque acting on the bow around the time of release were recorded in 10 experienced subjects during arrow shooting. The "Biku", an involuntary resignation from release happening in the shooting, was also exam-ined. Close analyses of the results revealed that activation of the extensor carpi ulnaris and extensor digitorum muscles together with inhibition of the flexor carpi ulnaris muscle brought about "Nejiri", while activation of the extensor carpi ulnaris as well as flexor carpi ulnaris muscles and inhibition of the extensor carpi redialis longus and extensor digitorum muscles gave rise to "Uwa-oshi", thus causing activities of trade-off nature in the extensor digitorum and flexor carpi ulnaris muscles for the "Nejiri" and "Uwa-oshi. The trade-off activities were presumably actualized through time-sharing coordination between the mus-cles.

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We examined the effects of a load's mass and position on body sway during standing with a load on the back. Three healthy male subjects participated in this experiment. The sub-jects supported loads of 23kg, 33kg, and 43kg on their backs using a carrier frame. They were asked to stand for 75s on a force platform with their eyes open while being as quiet as possible. Time series data of center-of-pressure (COP) were collected at a sampling rate of 50Hz during the last 60s of the 75s standing period. The COP was measured under three conditions in terms of the load position on the frame: lower (close to the hip), middle, and upper (close to the shoulder). All subjects showed that the lower the position of the load, the more anteriorly the mean COP coordinate was located in the anteroposterior (AP) direction, and the smaller the total distance of the COP trajectories became. Regarding car-rying the heavier loads, each subject showed a specific tendency in the mean AP coordi-nate. The three subjects had different physical characteristics in terms of body height and experience at carrying heavy loads. These results suggest that the examintion of the COP in a static posture can help our understanding of individual information on the posture sup-porting loads and the general positioning of the body.

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This study investigated how socks-wearing habit or habitual barefoot in the cold winter affected skin temperatures of distal lower extremities, the urinary excretion of adrenaline, noradrenaline and cortsisol in young children. In Experiment I for preschool children, the measurements of foot and leg skin temperatures were conducted for 30 min in the class-room controlled at 23±2°c and 50±5%RH, and the excretion of urinary catecholamines and cortisol during nocturnal sleep were analyzed. In Experiment II for elementary school children, nocturnal secretion of urinary catecholamines and cortisol was analyzed. While leg skin temperature tended to be lower in barefoot group than in socks group during Experiment I, foot skin temperature was not significantly different between the two groups. Fall of leg skin temperature during 30 min measurement tended to be smaller in barefoot group than in socks group. Urine volume and urinary excretion of cortisol tended to be greater in barefoot group than in socks group for preschool children. Urinary noradrenaline was significantly greater and cortisol tended to be greater in barefoot group than in socks group for elementary school children. Considering that most of the findings shown above were in the proximity of the established level of statistical significance, it was provisionally concluded that young children with barefoot habituation might show more effective cold adaptation of metabolic type than those without the habituation do, by keeping their skin temperatures higher even in the cold and enhancing the metabolic rate.

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