Fishermen-developed “banger bar” helps reduce risk of injury on crab boats, study finds

Newswise —

An Oregon State University investigation discovered that using a metal bar to hit crab pots during the harvest can aid Dungeness crab fishers in avoiding job-related injuries, despite the fact that they are at a heightened risk of injury.

The research aimed to evaluate the effectiveness of the "banger bar," a tool designed by fishermen, in enhancing worker safety on crab boats. The metal bar is placed on the crab-sorting table and assists fishermen in emptying the crab pots retrieved from the ocean floor. However, there is currently no established industry norm regarding the installation or configuration of the bar by crabbers.

As it was not practical to take accurate measurements on the deck of a commercial crab boat, the researchers replicated the deck environment in Oregon State University's Occupational Ergonomics and Biomechanics Laboratory to capture the fishermen's movements, muscle exertion, and risk of injury.

According to Jay Kim, an associate professor who heads the lab at the College of Public Health and Human Sciences at OSU, the act of lifting and emptying crab pots is a repetitive motion that exposes fishermen to the risk of injury. The more force they apply, the more pressure they place on their bodies, exacerbating the risk of strain.

“This was our very first attempt to quantify those injuries in this fishery using biomechanical measures,” Kim said.

The National Oceanic and Atmospheric Administration reports that Dungeness crab is among the most valuable commercial fisheries on the West Coast, generating roughly 26% of total annual fishing revenue. In Oregon, the state Department of Fish and Wildlife revealed that the 2019-20 season yielded $72.7 million.

Laurel Kincl, an associate professor of environmental and occupational health and co-author of the study, stated that the Fishermen Led Injury Prevention Program played a role in the conception of the OSU research. The program serves as a platform for OSU researchers to collaborate with fishermen to enhance safety measures within the industry.

According to Kincl, providing scientific evidence about safety interventions aids deckhands, captains, owners, and fabricators in gauging the potential benefits and risks. Through surveys and community outreach, the researchers discovered that the installation of a banger bar on a vessel was a matter of personal preference. However, those fishermen who used the bar reported that it was effective in preventing injuries.

To conduct the study, the research team affixed electrodes and reflective markers to the participants' bodies and utilized 3D motion-capture cameras and force plates in the laboratory to capture data on muscle movement, force, and torque. They evaluated five different banger bar configurations, which mimicked the variability observed on commercial crabbing vessels, including no bar, a flat bar at three distinct heights, and a triangular bar.

During the study, the participants were required to tilt the crab pot and strike it against the banger bar or the table's surface, repeating the task three times for each of the five conditions with breaks in between. The researchers analyzed the muscle activity data to determine which banger bar position necessitated the least amount of effort.

The study discovered that the highest setting for the flat bar and the triangular bar were the most beneficial for the participants' bodies, as they resulted in less strain on the shoulders and lower back, particularly the trapezius, deltoid, and erector spinae muscles, in comparison to not using a bar or using a low bar. The biceps and triceps also exhibited less strain when the bar height was higher.

Although the participants in the study were not commercial fishermen, the researchers enlisted the assistance of two Dungeness crab fishermen and a fabricator to verify the accuracy of the study setup and pot-handling techniques before data collection.

Kiana Kia, the lead author of the study and a postdoctoral researcher in Kim's lab, stated that even though the crab pot used in the study was empty and lighter than usual, they still observed considerably high muscle activity and joint moment. According to Kia, this suggests that the actual activity in the field could be even more challenging. The task of lifting and dumping crab pots is physically demanding and could increase the risk of injury in the low back and shoulders.

Additionally, the task of lifting and dumping crab pots is also asymmetrical, which means it places more strain on one side of the body than the other. As a result, Kia recommended that fishermen rotate tasks regularly to reduce the risk of injury. However, Kincl pointed out that switching sides on the crab sorting table requires additional training on other tasks on the vessel.

The research team is currently conducting another study that focuses on how the height of the sorting table impacts fishermen's bodies. They also plan to investigate the "block," which is the crane mechanism used to pull crab pots up from the water, and how to minimize the risk of injury when pulling in the crab-pot line. These studies are part of a broader effort to improve safety for commercial fishermen and reduce the risk of on-the-job injuries in the industry.