Musculoskeletal Symptoms among Computer-assisted Design (CAD) Operators and Evaluation of a Self-assessment Questionnaire.

A self-administered questionnaire with questions related to the physical workload at video display units (VDUs) was tested for intra- and intermethod reliability among 36 men and 64 women working with research and documentation. The results showed an acceptable test-retest agreement. The answers to three questions were validated by direct measurements: the locations of keyboard and mouse on the table, and the distance between elbow and keyboard heights when working. The self-reported locations of keyboard and mouse showed good agreement with the direct measurements. A revised version of the questionnaire was used at a telecommunication laboratory to study work postures and musculoskeletal symptoms. Among CAD operators with identical work tasks, the women (n = 67) reported a higher prevalence of musculoskeletal symptoms than did the men (n = 475). Calculated prevalence rate ratios (women/men) for musculoskeletal symptoms ranged from 1.4 (low back) to 3.4 (left elbow). The CAD operators with at least 5.6 hours of mouse use/week (median) reported more symptoms in the arms than did the CAD operators with fewer hours' work. Operators with the mouse located outside an "optimal" area on the table reported more symptoms from shoulder joints (upper arms), shoulders (scapular), elbows, and wrists than did operators with the optimal mouse location. Thus, long hours of work with the mouse, as well as working with the mouse non-optimally located on the table, seemed to be risk factors for upper-limb symptoms.

Vibrotactile perception thresholds as determined by two different devices in a working population.

OBJECTIVES: The purpose of this study was to investigate whether two devices for measuring vibrotactile perception thresholds produced similar results on an individual basis and to compare the thresholds in the presence or absence of sensorineural hand symptoms and vibration exposure. METHODS: Vibrotactile perception thresholds were measured with a vibrameter and a tactilometer in 178 men. The tactilometer uses seven discrete frequencies from 8 to 500 Hz, and the vibrameter uses one frequency (100 Hz). Agreement was assessed from the correlations and from a comparison of subjects who had thresholds above the upper quartile of each device as to the presence of sensorineural hand symptoms and occupational vibration exposure. RESULTS: The correlation between the vibrameter and the tactilometer (125 Hz) was 0.59. The agreement between the vibrameter and the tactilometer (63 Hz), when the upper quartile was used as a limit, had a sensitivity of 0.56 and a specificity of 0.85. The sensitivity and specificity for the agreement with symptoms were 0.44 and 0.79, respectively, for the tactilometer and 0.40 and 0.78, respectively, for the vibrameter. The indices combined from the different frequencies of the tactilometer did not improve the agreement. CONCLUSIONS: Some of the discrepancy between the measurement of the vibrameter and tactilometer can be explained by differences in the equipment, the measurement procedures, and the examiner, combined with high inter-and intraindividual variability. Neither of the two devices was superior when the results were compared as to the occurrence of hand symptoms and vibration exposure. As evaluated in this study vibrotactile perception threshold has a restricted value for screening and diagnostic purposes on an individual basis.

Occupational and individual factors related to musculoskeletal symptoms in five body regions among Swedish nursing personnel.

The relationship between individual factors, physical and psychosocial exposure at work, and musculoskeletal symptoms in the neck, shoulders, low back, hands, and knees was studied among female nursing personnel working at a Swedish hospital. The personnel had participated in a course in work technique (patient transfer and handling principles). Prior to the course, the subjects had filled in a questionnaire (n = 688). The aim of this cross-sectional study was to elucidate whether different individual and work factors are related to musculoskeletal symptoms in a specific body region. Due to the cross-sectional design, however, causality cannot be discussed. Univariate analyses and multiple logistic regression analyses were performed and yielded similar results. The latter analyses showed that in the present hospital setting, individual factors together with physical and psychosocial work factors were related to symptoms in the neck, low back, and hands; individual factors and psychosocial work factors were related to symptoms in the shoulders; while only individual factors were related to symptoms in the knees. The results of the present study showed that various individual factors and physical and psychosocial work factors were related to musculoskeletal symptoms in the different body regions. Thus, the identification of risk factors might have far-reaching implications for the way in which effective health programs for prevention should be designed in the hospital setting.