Ergonomic Problems and Improvements in Automobile Assembly Operations

Workers who must perform manual operations with the hands above shoulder level have increased risk of developing painful disorders of the neck and shoulder. This is a special problem in automobile assembly because of the trend toward unit body construction. Parts that operators formerly attached to a frame must now be assembled to the underbody structure.

Using a special conveyor system to tilt the vehicle has been considered as a way to minimize musculoskeletal stress. Experimental trials of chassis assembly operations using a 30 degree tilt are described here. Tilting was not effective in reducing stress of overhead work. The 30 degree angle was insufficient to significantly reduce work height, and tilting frequently obscured, rather than improved, visibility. In order for tilting to be effective, it appears that a full 90 degree rotation is required, and the vehicle needs to be designed to take advantage of body tilting.