Abstract
Some experiments were carried out in order to investigate the most suitable position for lifting and placing small object on the shelf by hand. The physiological response during this task were examined synthetically by breath analysis, electromyography and electrocargiography. The work lifting and placing the object (weight of 2kg or 0.1kg) on the shelf were tasked for 6 adult females.
The height of shelf was changed as follow:
1) The height of finger tip minus 20cm when arm was upright. 2) Eye height. 3) Acrominal height. 4) Elbow height when arm was downward. 5) Wrist height when arm was downward. 6) Knee ankle height The distance between subject and shelf were selected in 3 ways (that is (a) 0cm (b) 21±4cm, (c) 42±8cm).
The following result were obtained;
(1) The number of pulse frequency is minimum when the subjects performed the task in the region of elbow height, while it increased at higher or lower position than elbow height.
(2) The respiration rate and RMR shown a same tendency as the palse rate.
(3) In the region of elbow height, the task can be performed with relatively little effort in muscle activity than other height.
(4) The above mentioned results were shown synthetically in Fig. (10). When the distance between shelf and subject is 21±4cm, the optimum range of the height for this task is wider with compared to the other distance.
