Effects of different block designs on low back and shoulders biomechanical loads and postural stability during crab pot handling

In commercial Dungeness crab fishing vessels, the block pulls crab pots for harvesting and typically positions them to the side of vessels, rather than the sorting tables on board. Consequently, fishermen must reach outside the vessel to grab the pots, posing increased risk of musculoskeletal and fall-related injuries. To investigate the effects of block design on these risks, 25 participants in a repeated-measures laboratory study handled a pot under two block conditions: away-from-table (conventional setting) and above-table (intervention). Low back and shoulder muscle activities, angles, moments, perceived exertion, and postural stability were measured. The results showed reduced L5/S1 and shoulder moments and angles; decreased muscle activities in the low back, shoulders, and upper extremities; and lower perceived exertion ratings and postural sway measures with the intervention. These findings indicate that positioning the pot closer to fishermen onboard could reduce the injury and fall risk associated with crab pot handling.