engleski

The process of the subject lowering and lifting without and with hand load

In this work is firstly described the experiment of observing the subject when from standing posture drops down into a crouch and its backward lifting in the starting position without any hand load. Lowering of the subject lasted about 0.9 seconds, and lifting without weight also about 0.9 seconds. In the other two experiments the subject lifted weight from the floor, first mass of a 10 kg., and in second experiment mass of 20 kg. The pressure in the abdominal press was used as an index of stress in the lumbar spine, which corresponded to the actual body configuration, individual cross section surface of the subject's abdomen and calculated lumbar moment on the level of L4/L5 for the observed temporary load of the subject. Changing in pressure in the abdominal space for unloaded person was ranging from 2.237 kPa to some 12 kPa when weight was not lifted. In next two experiments the intraabdominal pressure immediately rose to almost 20 kPa for the hands mass of 10 kg, and to 26 kPa for the hands mass of 20 kg. From the ergonomic point of view, talking into account repetitive lifting during the working process, abdominal pressure should not exceed the value of 20 kPa, so the lifting mass should not exceed 10 kg.

intraabdominal pressure; index of stress

nije evidentirano