Placing the back in a weakened posture while repeatedly lifting heavy objects greatly increases the risk of development of MSDs of the back such as strain, sprain, and herniation. Provide a bridge conveyor for sorting tasks such as those where items are moved from one conveyor to another. The bridge, as depicted in Figure 6, will allow employees to move items from the origination conveyor to the destination conveyor without lifting. Transport of items could be accomplished by simply pushing them across the bridge. Hinging the bridge conveyor will allow the unit to be moved out of the way for egress purposes.
Sorters move packages to outgoing sorting conveyors that are located at about floor height.
Employees often lower the packages to the conveyor by bending forward at the waist as can be seen in Figure 4. Performing the task in this manner forces employees to bend at the waist up to or in excess of 80 degrees. Repeatedly bending the torso even if there is no load in the hands is a recognized risk factor for back injuries since the muscles of the back must exert considerable force to support the weight of the upper body while in this posture. Supporting a load in the hands while bending forward, further increases the risk of injury since the load is generally moved away from the body which allows leverage to greatly increase the compressive load placed on the spinal column. Evaluate the flow and reassign designation areas for the outgoing sorting conveyors.