Workers use highly repetitive movements while doing this task. They also overreach forward and sideways and use forceful movements to grasp the bottles. This combination of movements creates stress on the neck, shoulders, wrists and arms. Prolonged standing on a hard floor adds stress to the legs and back.
How can we reduce the risk factors for RMI?
The three main tasks in this recycling department represent three significantly different types of work that expose workers to different health hazards.
- "The throw on" operation, with excessive lifting and extreme body motion, creates the risk for back injury.
- The "bottom saw" operation is a classic example of a workplace with a high risk for injuries of the wrists, arms, neck and shoulders.
- "Housekeeping," although physically demanding, does not create any particular hazard for repetitive motion injuries for fit and well-conditioned individuals.
These different tasks require different approaches. Workers should continue to rotate to other tasks.
"Throw On"
| The "throw on" is a high risk operation for back injuries as well as to the wrists, neck and shoulders. Workers are exposed to heavy lifting, repetitive and forceful movements, and awkward body positions. Manual lifting cannot be fully eliminated; however, it is possible to reduce the effort of lifts from above shoulder and floor level by adjusting the height of the pallet to be always between waist and shoulder level (Figure 12). | 
Figure 12 |
A lifting table for the pallet would reduce bending and overreaching (Figure 12). To reduce twisting and carrying distance, it would be desirable to place the pallets closer to the conveyor.
The suggested improvements will reduce the effort required to lift boxes. It is still important to keep the weight of the loads below the level suggested by the NIOSH Guide for Manual Lifting.
"Bottom Saw"
Workers involved in the "bottom saw" operation are exposed to awkward body positions. Forceful and repetitive movements are also used when throwing the boxes for disposal.
To reduce awkward postures, it is necessary to elevate the worker so that he can grasp the boxes at the waist height (Figure 13). To ease the effort for throwing the boxes for disposal, it is necessary to lower the height of the conveyor belt transporting the boxes (Figure 13). Workers should have a foot rail so they can shift the weight of their bodies.
They should also have a chair or a sit/stand stool (Figure 14) to reduce the stress on the body from standing. To benefit fully from a sit/stand stool, workers should have a firm foot support.
Figure 13 | 
Figure 14 |
"On Caser"
Workers involved in the "on caser" operation are exposed to repetitive movements and awkward body positions such as working with elevated arms and bending and twisting.
To reduce the repetitive pattern of the work, it is essential to rotate workers to other tasks.
- To reduce bending, it is necessary to place the pallet on a lifting table (Figure 15).
- To reduce twisting while piling boxes on the pallet, place the pallet beside the worker (Figure 16).
- To reduce stress on the legs and back due to prolonged standing, use anti-fatigue matting.
Figure 15 | 
Figure 16 |
"Rejects"
Workers involved in the "rejects" operation are exposed to repetitive movements and awkward body positions.
| To reduce awkward body positions such as overreaching, it is necessary to install a funneling device on the conveyor. This device directs the bottles to the half of the conveyor closest to the worker (Figure 17). | 
Figure 17 |
This funneling device reduces the capacity of the area that collects bottles. In this case, the bottles have to be removed more often. The fact that there are fewer bottles on the conveyor at a time may encourage the worker to use a slower pace of work. To reduce stress on the legs and back due to standing on a hard floor, use anti-fatigue matting.
General Recommendation
Workers in the bottle recycling department should continue to do different tasks to change body positions and use different parts of the body. However, all the tasks, except housekeeping, are very similar in nature, and do not give workers muscle relief.
As a general strategy, the workload should be evenly distributed among the four workers. This can be accomplished by rotating workers to other tasks. The rotation could be organized so that each worker spends 15 minutes every hour doing housekeeping activities. This task is not particularly hazardous for repetitive motion injuries. It allows workers to impose their own pace of work. It also allows workers to use different groups of muscles.
Acknowledgment
The Canadian Centre for Occupational Health and Safety in cooperation with the Government of Newfoundland and Labrador, Department of Employment and Labour Relations, Occupational Health and Safety Branch would like to acknowledge the participation of the Labatt Breweries of Newfoundland (A Division of Labatt Brewing Co. Ltd.) who so freely gave their time and resources to assist us in the development of this case study.
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