- Applied Research
- Case Studies
Order Picking Medical Supplies
Medical supplies were stored in a warehouse that used a traditional racking system. A large percentage of these were packaged in 50-pound containers and stored in slots. Employees would move a “walkie” pallet jack down the rack aisles, picking customer orders. The rate of low-back injuries sustained by employees doing this job was unacceptably high, but the facility had no budget to change its racking system, and it could not dictate how suppliers packaged their case goods.
The only option for improvement was to look at case pick methods. Employees experienced at this job provided several opinions regarding how they believed case-picking could be made safer, but there was no data to show that one particular method was substantially better than another.
The Lumbar Motion Monitor (LMM) was used to determine how employees’ trunk motions, and the job’s injury risk, was impacted by the position of the pallet jack during order picking and, subsequently, how this influenced movement. Three locations were selected, based on work practices:
- The “standard” method, in which the pallet jack was positioned directly in front of, and as close as possible to, the slot where the item to be picked was stored;
- The first alternative pallet jack position, which was close to the rack but moved forward from the slot where cases were being picked; and
- The second alternative position, which was in front of the rack where the picking occurred but spaced further out from the slot compared to the standard method.
Outcome and Impact
The results calculated by the LMM and its low-back injury risk model were very telling.
- As expected, the standard pick method produced a low back injury risk value of 65%. (Risk is considered to be high if above 60%). This was due not only to the weight of the cases being handled but by the extreme amount of forward bending required when cases were lifted from or to low pallet layers. This work method also resulted in moderate trunk twisting speeds and high side-bending speeds.
- Alternative pick method 1 was only slightly improved, as it produced a risk value of 61% (still considered to be high risk for injury). Although this work method reduced side-bending trunk speeds, it actually increased trunk twisting speeds.
- Alternative pick method 2 considerably improved the risk score, lowering it to 50% (considered to be moderate risk for injury). This work practice drastically reduced back side-bending speed when cases were handled.
The analysis provided the company with objective information that was used to train employees on how to position their walkies that would lower the injury risk associated with this physically demanding activity.