frontal cranking
Photo: Washington State Department of Labor and Industries

Researchers share cranking techniques for reducing truck driver shoulder injuries

January 8, 2019

Olympia, WA — Strategic positioning during cranking of landing gears can help prevent truck drivers from injuring their shoulders when raising or lowering trailers, results of a recent study by the Washington State Department of Labor & Industries and North Carolina State University suggest.

Researchers observed 12 male drivers during cranking operations, with a focus on 16 muscles that affect shoulder movement. They then measured both the truckers’ scapular range of motion and shoulder muscle activity during cranking.

The researchers determined that when raising a trailer, standing parallel to it while cranking – known as sagittal cranking – is safer for truckers because it uses more full-body strength and lessens the workload on the shoulder. This full-body strength is needed because raising a trailer involves more resistance.

When lowering a trailer, which involves less resistance, drivers are safer facing the trailer and cranking the handle perpendicularly – or frontally – to the crank rotation. This method mainly involves shoulder rotations. With frontal cranking, researchers said the truckers experienced more rubbing and grinding of the ligaments, causing increased wear and tear and leading to injury.

More than 70,000 work-related shoulder injuries were recorded in 2016, according to the Bureau of Labor Statistics.

The study was published online Oct. 3 in the journal Applied Ergonomics.