ABSTRACT
When Mitsuo Nagamachi started working with the Aging of Society Policy, by then the Labor Ministry Employment Security Bureau from the 52nd year of the Showa era (1972), he had been mentoring Toyota Motor and Nissan Motor on aged-persons employment strategy. During his lecture on the Aging of Society Policy to 70 shop floor industrial engineering (IE) staff at the Nissan Motor Zama plant, as an example, he gave advice about improvement of the final fitting line. At the time, the fitting line was only for workers under 40 years of age. If many aged workers entered the workforce, there would be a higher possibility that an aged worker would be assigned to the fitting line, requiring them to do assembly work in unusual and awkward positions. The discovery of physically difficult work in the workplace is the duty of ergonomists.1,2
He felt that he could use the results of experiments related to energy consumption of the working posture relative metabolic rate (RMR), which he had been conducting in Hiroshima University’s ergonomics lab under a research grant from the Labor Ministry.3,4 He had thoroughly looked into what kind of working postures there were at all production lines at Nissan Motor, and compiled them into 10 kinds of typical postures in the automotive industry. Then he asked his students to assume and hold those postures, and he conducted a job aptitude test-“bean picking”—for 3 minutes. During the test, the students were made to carry a Douglas bag on their backs while an electromyogram was taken of their erector muscles. It was very heavy labor for the students, but as Nagamachi elaborated later, this study resulted in very valuable data.
