ABSTRACT
The present study aimed to design a sitting stool for fish processing worker to reduce the postural stress during work. The study was conducted on 74 male and female fish processing workers selected randomly. The Musculoskeletal Disorder (MSD) of the subjects was assessed by the modified Nordic Questionnaire method. The body joint angles were measured by a digital goniometer. The results revealed that MSD was highly prevalent in lower back region in both male (78.57%) and female (93.47%) workers. The results of body joint angles suggested a high degree of forward bending during work. Efforts were made to design a sitting stool considering the human factors of the users to reduce the postural problems. The stool was designed by considering 5th and 95th percentile values of different anthropometric dimensions of the male and female workers. Paired comparison tests were employed to determine optimum dimensions of the stool for ensuring the compatibility of the physical characteristics of the stool with human body. From the results of paired comparison test and anthropometric characteristics of the users, physical dimensions of the sitting stool were settled for final designing. From the results, the height of the stool was determined separately for male and female workers. In the suggested design the height of the seat was 25cm for male and 20cm for female where the length and depth of the seat were 40cm and 32cm respectively for both sexes.A mechanical system was incorporated in the design so that the same stool could be used by the male and female workers. Subjective evaluation indicated that most of the subjects (>75%) rated the seat as good or very good. The joint angle study with suggested seat showed improved working posture.
ABSTRACT
In many developed countries, for example, USA, respirator fit testing is required before entering specific work environment to ensure that the respirator worn satisfies a minimum of fit and that the user knows when the respirator fits properly. Unfortunately because we have not fit test regulation in Korea, a lot of workers wearing respirators may be potentially exposed to hazards. This study was conducted to evaluate the fitting performance for respirators and correlation fit factors with facial dimensions of wearers. 110 subjects (70 males, 40 females) were fit tested for three quarter masks, i.e., two domestic-made Mask Z, and Y and one foreign-made Mask T using PortaCount 8020. A facial dimension survey of the same subjects was conducted to develop a facial dimension grids for correlation fit factors with facial dimension parameters. A facial dimension grid was developed on the basis of face length and lip length for quarter masks. The results obtained were as follows: 1. Fit factors of Mask T were much higher than those of Masks Z, and Y. 2. Males were fitted more properly than females. 3. Male in box "f" of grid would be adequately fitted Mask Y and male in box "b", "e", "f", "h" of grid would be sufficiently fitted Mask T. Female in box "h" of grid may have a good fitting performance for both Mask Y, and T. But subjects in all boxes of grid would be inadequately fitted Mask Z.