On the Evaluation of the Working Posture in Forestry Work (1) - Effects of Working Posture on Work Load

1990

S. 55-64

6 Abb., 6 Tab., 12 Lit. Ang.

Unselbständiges Werk

200034710

Bulletin of the Iwate University Forests 1990 ; (21), S. 55-64

In order to evaluate awkward working posture in forestry work, discomfortable parts of the body, overall discomfort, percentage of increase in the heart rate and percentage of maximal muscular strength were investigated concerning three subjects regarding upright, arms-elevated and trunk-bent posture on condition that the loads acting on the hands were 0 and 8.0 kgf (weight of a chain saw). The results obtained were as follows. (1) The left upper limb was discomfortable at any posture. The low back and lower limbs were also discomofortable at the trunk-bent posture. (2) The overall discomfort of the arms-elevated posture and trunk-bent posture was slightly greater than that of the upright posture at the time of no load. On the other hand, the arms-elevated posture was considerably discomfortable when holding a chain saw. (3) The percentage of increase in the heart rate was largest at arms-elevated posture irrespective of a load acting on the hands. (4) The percentage of maximal muscular strength at the arms-elevated posture when holding a chain saw was more than the allowable value in discontinuous work.In conclusion, the arms-elevated posture was most stressful from the viewpoint of overall discomfort, percentage of increase in the heart rate and percentage of maximal muscular strength. In Part 2, the effects of the angle of inclination of trunk and angle of elevation of upper limbs on the low back load are investigated.