This type of highly repetitive motion increases the risk of development of chronic MSDs of the shoulder such as tendonitis and bursitis. Provide employees who load the truck with a stable platform to stand on when stacking packages to elevated locations. Unloading and sorting employees perform highly repetitive lifting tasks in awkward postures. Lifting frequencies observed during the inspection measured approximately 14 lifts per minute for unloaders and approximately 10 lifts per minute for sorters. Lifting at these frequencies reduces the weight that can be lifted safely.
Employees use asymmetric lifting techniques and twist the torso while lifting packages.
Continuing to lift at the observed rates and with the observed techniques greatly increase the risk of development of MSDs of the low back and shoulders. Completely modify the sorting areas so packages do not need to be lifted from one conveyor to another. A design similar to that shown in Figure 8 would allow 3 employees to move and sort to at least 4 different areas without ever lifting a package. Packages could come to the station on a central, supply conveyor, where the first employee would pre-sort parcels in one of two directions. After a package has been sorted to one side or the other, a subsequent sort could be performed and the package could be pushed down the appropriate chute.