Electromyographic and discomfort analysis of confined-space shipyard welding processes.

This study examined muscle fatigue and discomfort in a confined-space welding operation at a shipyard. Surface electromyography (SEMG) was recorded from seven upper extremity and torso muscles of welders welding in a mock-up of the work environment. Following spectral transform of the SEMG data the percentage of the total signal power in the 10-30 Hz frequency band was compared over time during welding. For the conventional stick electrode welding process (SMAW) several muscles exhibited an increase in the percent of the total signal power in the low-frequency band. Fewer muscles exhibited this fatigue-related spectral density shift with a wire welding process (FCAW) the shipyard has considered adopting. This finding suggests that localized muscle fatigue may be reduced by a change to the wire welding process. Subjectively reported discomfort was generally low for both processes, but confirmed the finding that discomfort in the low back and shoulder regions is experienced in this welding operation.

The application of educational technology to occupational safety and health training.

For years, lectures and films have formed the basis of health and safety training. New communication systems, however, allow trainees such luxuries as receiving instruction from a source that might be hundreds of miles away. Various multimedia systems are described, including CD-ROM, virtual reality, and others that may some day become the mainstays of worker training.