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.
Lowe
B D
BD
US Department of Health and Human Services, National Institute for Occupational Safety and Health, Cincinnati, OH 45226-1998, USA. blowe@cdc.gov
Wurzelbacher
S J
SJ
Shulman
S A
SA
Hudock
S D
SD
D000328:Adult; D001416:Back Pain; D004576:Electromyography; D016552:Ergometry; D006801:Humans; D008297:Male; D015233:Models, Statistical; D018763:Muscle Fatigue; D019547:Neck Pain; D009784:Occupational Diseases / Q000517:prevention & control*; D010146:Pain / Q000517:prevention & control*; D012767:Ships; D012782:Shoulder; D014896:Welding