いちごの選果作業姿勢の人間工学的改善による局所疲労の軽減について

抄録

Many of the Japanese farmers engaging in strawberry cultivation in green houses complaint of low back pain, shoulder stiffness and others. These complaints are considered to be caused partly by the bowing postures when picking strawberries and partly by the traditional sitting _postures on tatami mats or floor of a living room when sorting and packing strawberries.
In the present study, an ergonomic improvement of the traditional work postures was intended by adopting a sitting work posture on a seat. Based on the data of an experimental study, we advised the farmers to adopt the sitting posture on a seat. Later on, a fact-finding survey was performed on them. The exchange of the traditional work postures for the sitting posture on a seat proved to decrease localized fatigue and to increase work efficiency. From the results of the survey and ergonomic considerations, the sitting work posture on a seat under the following ergonomic conditions was concluded to be valid:
1) A seat adjustable in height with a backrest and casters is recommended. The height should be adjusted to [(body height) ×1/4-1] cm above the floor.
2) A strawberry container (size: 40cm×60cm×10cm in the present study) is put on the table that consists of only a top board and legs. The container should have the inclination of 15°.
3) The height of the container brim of a farmer's side should be adjusted to [(body height) ×7/17-2] cm above the floor.
4) The horizontal distance between the container and the iliospinale anterius of the farmer's body should be about 20cm.
5) The seat and table should be used in a workshop with enough illumination, moderate temperature and flat floor.