Industrial health
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Comparative Study
An electromyographic study of two different types of ballpoint pens--investigation of a one hour writing operation.
Recently there has been an increasing incidence of occupational cervicobrachial disorders (OCD) and writer's cramp in office workers using ballpoint pens in writing operations. For the sake of workers who use ballpoint pens, it is essential to prevent such health hazards. It has been observed that a strong gripping pressure on the ballpoint pen significantly contributes to the development of these conditions. ⋯ The EMG of the flexor pollicis brevis was measured and recorded every second, while subjective pain scores were recorded every five minutes for the thumb, forefinger, middle finger, thenar, forearm extensor (forearm) and shoulder. The EMG of the flexor pollicis brevis and the pain scores for the thumb, forefinger, middle finger, forearm and shoulder were significantly lower for the new pen than for the conventional pen. These results suggest that after an hour of continuous writing, the new pen reduces the muscle load on the upper limb, and therefore mitigates fatigue in this area.