Neck-shoulder loading in wordprocessor use. Effect of learning, gymnastics and armsupports.

The loading of wordprocessor workers was followed over a four month period of a re-education course with the aid of electromyography of the trapezius and frontalis muscles in order to study the effect of learning. Working with the word processor increased the electrical activities in both muscles. The increase did not diminish with the learning of the work. On the contrary the electrical activity increased significantly in the frontalis muscle. Intervening gymnastics during work decreased the electrical activities. The screen (on/off) did not affect the activity. Most effective in lowering the myoelectrical activity in both muscles were the armsupports. A significant positive linear correlation was observed in the electrical activities of the trapezius and frontalis muscles both at rest and during wordprocessor work.